What are the main advantages of using automated RTM (Resin Transfer Molding) over traditional prepreg manufacturing for aircraft seat structures?

Improving one-piece aerostructures by automating preforming
Israel Aerospace Industries (IAI, Tel Aviv, Israel) has produced crashworthy seat structures for aircraft since 1978. Its turnkey service includes design, certification and manufacturing. IAI has developed a reputation for producing lightweight seating through the use of composites, and developed efficient production via RTM but now augments both with automation.
“The idea was to implement ‘one-shot’ technology, manufacturing a part in a single, automated process,” explains IAI development program manager Hary Rosenfeld. IAI already had acquired expertise in resin transfer molding (RTM) during development of the 2.8m-long, one-piece composite rudder it now produces for the Gulfstream G250 business jet (see “RTM showcase: One-Piece Rudder”). “We know how to design parts for RTM,” says Rosenfeld, “but now we wanted to automate the preforming as well.”
For a test case, IAI selected an in-process composite helicopter cockpit seat. “We chose a helicopter seat because we already had this part designed in prepreg, so we could compare the weight and cost for parts made with prepreg and autoclave cure vs. the consolidated design using automated RTM.” The resulting seat reduces cost by 30% vs. its prepreg predecessor while maintaining critical strength and crash performance, and shaving weight by 7%.
Part and process design
Rosenfeld points out there is a strong relationship between the design of the automated production line and that of the part. “The part geometry was challenging with regard to creating the prepreg layup,” he explains. “When you try to fold the prepreg material into a corner, it wants to wrinkle. So, you have to cut darts. But these reduce the strength of the part and you have to then compensate for this.” RTM offered improvements by moving away from prepreg layup, but there were new considerations. Forming was still required, but using dry fabrics instead of prepregs improved drapeability, reducing the need for manipulations such as darts. The process was also amenable to automation, but Rosenfeld notes, “we had to keep in mind what a robot can do.”
A key aspect of composite aerostructures design is certification. “We must certify the part and the production line,” says Rosenfeld. “Most parts are certified together with the airplane they fly on.

“Both temperature and pressure are increased in the mold, reaching 180°C and a pressure of 6 bar during a 2-hour molding cycle.” The mold is cooled to 50°C, opened and the finished part is removed. The cycle time, including injection and mold cleaning, takes about 7 hours.
That automated preforming and RTM have succeeded in cutting seat cost vs. autoclaved prepreg is, perhaps, an obvious outcome, but the source of the 7% weight reduction? That was not so obvious. According to Rosenfeld, “This is due to very accurate plies. We optimized the part design for RTM, so there is not as much overlap in ply location and less material wasted. You also don’t have to factor in manual layup errors, so this reduces extra material as well.” He explains that the manual layup process has inaccuracies almost every time, but the robot is very predictable and less prone to errors.
Part of what makes the robot so accurate is CAC’s “intelligent automation.” “We integrate a camera into the robotic arm,” says Thimon, “so that vision inspection is completed while preforming operations are ongoing. When you unroll material, it will check fiber orientation. It will also inspect during pick-and-place layup for fine positioning of the ply onto the tool/preform and for other defects in this part of the process, such as missing plies and incorrect fiber orientation.” IAI has worked with CAC to validate the inspection results. “It compares the visual images taken by the camera with the computer design file and shows any deviation,” says Rosenfeld. “CAC has developed a very good algorithm for this, and we have verified how well it works.”
Although cycle time has already been reduced to one completed RTM seat per 8.5-hr shift, he believes this robotic inspection can eventually further reduce manual inspection times for even faster production. This automated RTM process also produces net-shaped parts with a high-quality finish on both sides, so the only post-molding operation is drilling a few holes. “We will also keep looking at newer resins that cure more quickly, like in automotive,” notes Rosenfeld.
The fabrication and installation of 700+ composite panels has a backstory of detailed design and careful quality assurance.
The old art behind this industry’s first fiber reinforcement is explained,with insights into new fiber science and future developments.

Short description of the technology
RTM (resin transfer molding) – molding technology via impregnating preforms (blanks made of fibers) with resin under pressure. The RTM process is suitable for medium and big series production. The method consists of impregnating dry fibers (first cut and placed into the mold) with thermoset resin under pressure. RTM parts have accurate surface and high mechanical properties. This technology allows us to produce highly loaded parts with strict tolerances (for example, airplane engine parts).
Advantages and restrictions of the technology
RTM technology requires the use of two-sided molds (punch and matrix). The high cost of mold production, together with a medium-level production rate, makes this technology expensive for part production. Nevertheless, this method is widely used in some industries because of its advantages:
– The ability to produce complex, integrated parts with inserts, with sandwich structure (foam core) helps to shorten assembly time;
– High accuracy (low tolerances) and almost no post-molding processing;
– The ability to produce parts with a high thickness and complex shape, which is usually impossible with other methods;
– The high mechanical properties and wear-resistance (lifetime) of produced parts, and low-porous surface;
– Easily painted surface (up to Class A);
– The quality is reproducible in big series manufacturing.
Depending on the customer’s needs, several types of reinforcing materials can be used: various fabrics and mats made of glass, carbon, organic or basalt fibers. Polyester or epoxy resins with low viscosity are usually used as a matrix material.
RTM parts have smooth, accurate surfaces on all sides. This method offers wide design possibilities with a properly designed mold and careful preform preparation. The produced parts can have a complex profile, with different types of bosses, waves, different thickness and so on. The possibilities and restrictions of part design with RTM technology are described in detail in the table below.
Table. Design of RTM parts
|Thickness accuracy, mm|
|Minimum inside radius, mm|
|Minimum thickness, mm|
|Maximum thickness, mm|
We produce polymer composite parts with high requirements for strength and accuracy using the RTM method.
For example, for certain clients we have made prototypes and set up mass production of glass fiber-reinforced exterior bus parts made by RTM.

This process is generally performed at both elevated pressure and elevated temperature. The use of elevated pressure facilitates a high fibre volume fraction and low void content for maximum structural efficiency.
Resin transfer moulding (RTM)
A process using a two-sided mould set that forms both surfaces of the panel. The lower side is a rigid mould. The upper side can be a rigid or flexible mould. Flexible moulds can be made from composite materials, silicone or extruded polymer films such as nylon. The two sides fit together to produce a mold cavity. The distinguishing feature of resin transfer moulding is that the reinforcement materials are placed into this cavity and the mould set is closed prior to the introduction of matrix material. Resin transfer moulding includes numerous varieties which differ in the mechanics of how the resin is introduced to the reinforcement in the mould cavity.
Other types of moulding include press moulding, transfer moulding, pultrusion moulding, filament winding, casting, centrifugal casting and continuous casting. There are also forming capabilities including CNC filament winding, vacuum infusion, wet lay-up, compression moulding, and thermoplastic moulding.
Low-temperature-cure epoxy tooling prepregs, such as HX50 and HX70 from Amber Composites or LTM series from Advanced Composite Group, have now become benchmark products in aerospace, automotive, marine, industrial and motorsport applications. With their reliability long-proven, steady improvement has resulted in materials that are easy to handle and apply, provide Class-A surface finish, and offer surprising longevity of tool life. Some systems now enable 200°C end use temperatures, and recent advancements in materials have enabled composite tools to be compatible with an ever wider variety of processing methods.
Illsey points to the example of F1 car builders and America's Cup boat builders.
“F1 teams need a large number of small, complicated parts. Yacht builders may need a single 30 m long part. Both require extremely precise dimensions. You can find both using a similar HX tooling system with great results.”
Today's high-performance contemporary yacht moulds are frequently made using tooling prepreg, as are the moulds in military and unmanned aerospace applications. Even in the commercial aerospace industry, after a long development cycle, composites are now widely used. Entire wing sections on the new Airbus A350, for instance, will be made from carbon fibre, and a considerable proportion of the tooling will utilise composite prepreg.

The question was, ‘What type of equipment and process steps were needed between cutting and RTM?’ “We looked at the cutting system and what type of communication would be required,” explains Marc-Ruddy Thimon, director of sales for CAC. “The next steps would include automated layup, using a pick-and-place robot and application of plies onto a preforming tool, followed by debulking/compaction where heat and vacuum are applied.”
In the solution developed by IAI and TME, a cutting table and single robot are synchronized via a central control unit. Rosenfeld explains: “The robot picks up plies in a predefined sequence per the design: Two glass fabric plies (face-up and face-down) and two carbon fabric plies (face-up and face-down), which achieve a symmetric laminate.” The synchronized system changes the rolls of fabric automatically as needed to keep the production line running. The system is set to cut a number of “boards,” which contain cuts (pieces) from the same roll, according to the specific layup stage. The number of cuts within a “board” varies between four and 30, depending on the layup configuration as defined per each layup stage. The cuts are nested to achieve maximum material usage and minimize waste. The fabric is also coated with thermoplastic powder to aid preform consolidation.
The robot then places the cut plies onto the heated mold to achieve a 3D shape. However, there is an important bit of innovation here: “We have developed specialized end-effectors that operate like hands,” explains Thimon, “allowing 2D materials to be folded and formed into complex-shaped areas like corners.” As part of the preform building process, periodic vacuum debulks are performed with a reusable membrane. Debulk of prepregs with the same membrane was an established step in the prepreg seat process. IAI found that it also worked well to consolidate the thermoplastic-coated fabrics into a high-quality preform.
The single work cell robot, with end effector now changed to trimming head, is then used to trim the preform to achieve a net-shape part. The trimmed preform is manually transferred to the bottom mold in the RTM press. “We apply vacuum and begin resin injection, using the Isojet injection machine,” says Rosenfeld.

However, this part was developed independent of a specific aircraft program, but instead as a retrofit that can be applied to many different types of helicopters.” Certification mandated testing of materials and finished parts. It was completed by the Civil Aviation Authority of Israel (CAAI) and recognized by the Federal Aviation Admin. (FAA, Washington, DC, US) through a reciprocal agreement.
Thus, design began. “We defined design allowables for the two different laminates we used,” says Rosenfeld. A satin weave glass fiber fabric and a satin weave carbon fiber fabric from Hexcel (Stamford, CT, US) were selected, along with Prism EP2400 epoxy resin from Solvay Composite Materials (Alpharetta, GA, US), which meets aircraft/rotorcraft flame, smoke and toxicity (FST) requirements. “The epoxy resin is cured at 180°C to meet strength requirements,” he notes, adding, “There are resins that can cure at lower temperatures, such as 130°C, but these have a longer cycle time.”
After materials were characterized, the work of detailing the automated manufacturing process began.
A key partner in IAI’s development of this new process was composites automation specialist Techni-Modul Engineering (TME, Coudes, France). IAI had been working with RTM equipment supplier Isojet (Corbas, France), which then recommended TME as a toolmaker for RTM. Isojet and TME are part of Composite Alliance Corp. (CAC, Dallas, TX, US), which provides composites manufacturing solutions ranging from single tooling and equipment to automated work cells and complete turnkey systems (see ”Automated preforming: Intelligent automation in pick-and-place systems”). “We completed the RTM tool development and were very satisfied,” Rosenfeld continues. “When we were ready to develop the preforming automation, we decided to keep working with TME. They helped us to define the design and requirements for the production line and suggested automation possibilities.”
Automated cutting tables were well integrated into the IAI production flow and cutter operations had been optimized by implementing Plataine Technologies’ (Waltham, MA, US and Tel Aviv, Israel) Total Production Optimization (TPO) software (see ”Optimizing composite aerostructures production”).

The operation requires separate manufacturing facilities, and the "B" stage material must be stored at low temperature and in sealed containers to avoid contact with moisture. The resins must be conditioned to a specific state of polymerization, and the process must be stopped to retain the "tack" condition over an extended period of time.
In the wet resin impregnation process, woven cloth or fiber is impregnated with a liquid resin that is catalyzed to process or cure in a short continuous period of time. In this process, the resin is impregnated by squeegee of ply by ply of a layup at the site of component fabrication. The impregnated material may be handled at room temperature or elevated temperature for a certain period during which the resin gels, followed by final curing either at room temperature or elevated temperature in the same tool or mold.
A wet resin impregnation process referred to as resin transfer molding (RTM) is a process to saturate the fabric with resin using two-sided tooling that is usually metal to withstand extreme pressures needed to force the resin through the fabric. The tool may be heated in order to lower the viscosity of the resin, and large presses are utilized to hold the mold together. Heat is supplied with hot oil or heating elements placed in the mold. Because of the great hydraulic pressure that is generated as the resin is pushed into the fabric to saturate the fabric, the mold will try to expand outwardly and open the internal clearances when the resin is injected into the mold. If the mold is fabricated correctly, the resin will form a wave front and move across the fabric uniformly. However, if the machining clearances vary even a few hundred thousands of an inch, the fabric will be squeezed more in one area than another and the resin will move in the path of least resistance. The areas that are compressed too much will eventually form air pockets as the resin surrounds these areas and air voids form.
Current RTM technology suffers from the unpredictability of the formation of the resin wave. Typically, aerospace grade parts using the RTM process are made with the same number of plies of fabric throughout the part. Placement of the fiber plies in the mold and machining of the mold must match precisely. If the number of fabric plies varies, the placement of ply changes must precisely match thickness changes in the mold itself. This task is difficult in a production environment.

Process Development for the Sequential Preforming of Semi-Finished Products
Climate change and its consequences are pushing societies worldwide to adopt a more energy- and resource-efficient lifestyle. Global warming can only be curbed in the long term if the emission of greenhouse gases is greatly reduced over the next years. Since the energy consumption of vehicles directly determines the amount of pollutants that are emitted, the strategic relevance of lightweight construction in the automobile industry will increase in the future.
Fiber-reinforced polymers are being used with greater frequency in addition to established lightweight construction materials. These polymers have great potential due to their density-specific material properties. High-performance composites with a high fiber volume are of especial interest because of their excellent mechanical properties. In particular anisotropic layer constructions, oriented according to the load path, enable the production of high-strength structural components suitable for lightweight applications. Automated, robust and quality-assured manufacturing technologies are needed in the future in order to successfully introduce this material system to large-scale automotive production.
The Technology Cluster Composites (TC2) focused, among other things, on the industrialization of RTM process chains for the manufacture of structural components for automotive lightweight construction. An outstanding feature of TC2 was an integrated approach to technological challenges that was not based on individual problems but focused on connections and interactions within continuous process chains.
The cost structure of the RTM process chain is a strong argument for the implementation of automated preforming. The automatization of handling operations as well as the reshaping process (draping) within the preforming procedure can drastically reduce production cycle times, which leads to a significant reduction in overall RTM production costs. At the same time, the reproducibility of component quality increases as the degree of automation becomes greater which, in turn, results in a noticeable decrease in the rate of production waste.
Fundamental draping and fixation strategies for preform manufacturing were developed and validated within the framework of TC2 by the participating group partners Fraunhofer ICT, the Institute of Aircraft Design of the University of Stuttgart (IFB), the Institute of Textile Technology and Process Engineering Denkendorf, the Institute of Production Science (wbk) and the Institute of Vehicle Systems Technology of the Karlsruhe Institute of Technology. The sequential reshaping of entire layer constructions using a multiple-stamp mold has proven to be the best method for the automated manufacture of components with complex geometries. In this method, the layer constructions are locally prestressed.

"Applying the chopped material robotically right to the shape not only cuts the amount of scrap, but it's cheaper scrap." Since the preform is built right on the tool, the process eliminates the step required to transfer the finished preform from a manufacturing station to the part mold, so there is no risk of damage and no extra space is required to store preforms or preform tools.
RIMFIRE + ZIP RTM
In production, RIMFIRE can be used with most available closed molding options, including standard resin transfer molding (RTM) and various methods of vacuum-assisted resin transfer molding (VARTM) and vacuum-assisted resin infusion molding (VARIM). Sea Ray currently uses ZIP RTM (zero injection pressure resin transfer molding) process, licensed from Plastech Thermoset Tectonics (Gunnislake, Plymouth, U.K.) and Plastech's North American partner JHM Technologies (Fenton, Mich.). ZIP RTM motivates resin flow with both vacuum and injection pressure, slightly favoring the vacuum, which results in less stress on the mold. This permits the use of less costly semi-rigid tooling. A multi-station inline system, ZIP RTM processes several lower molds simultaneously, but requires only two upper mold halves per line, keeping mold manufacturing costs to a minimum. (photos show construction of Sea Ray's 20-ft/6m 205 sport boat hull.)
Before production starts, technicians apply Chemlease (Chem-Trend, Howell, Mich.) or equivalent semipermanent release agents to upper and lower molds. Gel coat is applied to the lower mold and allowed to cure. Meanwhile, the specified fiberglass gun roving is loaded onto pallets behind the robot. Four rovings of continuous glass, typically 112- or 113-yield, are threaded through the end effector.
In a pre-loading station ahead of the RIMFIRE preforming cell, multiaxial glass fabric is laid into tight radii in the lower mold, if called for in the FEA, to prevent bridging of the preform spray over the angle. The mold is then latched onto a computer-controlled indexing device that rides on a floor-mounted rail, and is moved into the preform cell.
An operator starts the previously downloaded software program.

The binder mixing tube conveys the commingled powders through the back of the robot and into the end effector. Chopped 25.4-mm and 50.8-mm (1-inch and 2-inch) fibers and binder are deposited in a random pattern at a pre-programmed rate, as determined by the FEA analysis. This may be done in a single pass, or in multiple passes, as needed to achieve an even surface on a laminate thickness of 6.35-mm/0.25-inch or more. Conditions that influence the number of passes include part geometries, draft design and the amount of glass specified for deposit.
When the preform is complete, the mold progresses to a third station, where engineered fiberglass fabrics are hand placed to reinforce the preform. A combination of chopped strand mat and 0°/90° stitched fabric is laid into the bottom of the hull and around the chine, where the outer edge of the hull bottom joins the hull side. Multiaxial stitched or woven materials are added to other areas that will be exposed to high loads. Next, the preform overspray is trimmed off the flange of the lower mold.
The lower mold then moves to the mold closure station, where a convex upper tool, mounted in a wheeled trolley, is automatically moved into position over the lower mold by a manipulator arm on a fixed gantry. The edges of the upper and lower molds are joined and sealed, and the tooling set then moves into the resin injection station.
The ZIP RTM method feeds resin around the perimeter of the joined molds while a vacuum is pulled through a center vent in the upper mold. Resin flow is controlled by a mechanical vacuum molding pressure control (VMPC) sensor, also mounted in the upper mold. The VMPC reacts to internal pressure changes. In the event the pressure becomes positive, the VMPC sends a signal to interrupt the resin flow until the vacuum re-establishes negative pressure within the tool, and then restarts resin flow automatically.
Moved to the curing station, both the upper and lower molds are heated electrically, and the part is allowed to cure at 32°C to 38°C (90°F to 100°F) for about one hour.
In the next station, a second manipulator arm removes the upper tool, which then is returned to the closure station to be mated with the next lower mold tool.

The epoxy is a new formulation designed to fill the fabric when heated and compressed under a vacuum bag without requiring an autoclave.
Vacuum bags are also getting bigger to mold large parts like wind blades without seams. Airtech International Inc., Huntington Beach, Calif., introduced Big Blue L-100, a 12-meter-wide, five-layer vacuum bag with adhesive. A 10.5-meter-wide film will soon be offered by Aerovac in the U.K., sister company of Richmond Aircraft Products.
New RTM consumables
Several companies introduced new transport media for resin transfer molding to use between the peel ply and vacuum bag. PGI Industrial (formerly Polymer Group Inc.) introduced Flowmat, a polyester nonwoven with canals that help resin infuse faster. It is distributed in the U.S. by Nida-Core.
Henkel’s new Hysol EA 9895 is a thin polyester wet peel ply, which reportedly needs 30% less peel force than conventional peel plies.

The new Boeing 787 Dreamliner is composed of over 50% composites and some very large production tools are made of composite tooling prepreg.
More recently, companies are also able to consider developing very low cost composite tooling through the development of prepreg that can be processed without the need for autoclave pressure and without increasing resin volume. These are commonly known as out of autoclave (OOA) products. This technique is helpful when making large parts and when the integrity of the pattern/master cannot withstand the pressure of an autoclave.
Benefits of composite tooling
Compared with traditional metal tooling, composite tooling can provide a lower cost of production and easier handling and storage. For performance parts requiring accurate dimensions, composite tooling offers a CTE closer to the part CTE, helping the part maintain dimensional integrity during cure.
Compared with a few years ago, composite tooling is more widely available, more user-friendly, and more efficient to process. Prepreg is now available with excellent drapeability enabling accurate reproduction of small radii corners, a wide range of tackiness, a wide range of curing temperatures, and a wide range of dimensions.
“A great example application was the recent development of the ALMA telescopes to be placed in Chile”, says Illsley. “The telescope is comprised of a set of segments, each of which have to be identical and precise. In order to meet these exacting accuracy requirements, they used our HX50 tooling prepreg. And, to address the outlife challenges faced when working with such a large tool, we supplied the tooling prepreg in pre-cut squares.”
Another reason composite tooling is gaining popularity is the availability of a proven package solution. Customers can buy a complete set of materials including tooling paste or blocks, adhesive, release agent, primer, sealer, tooling prepreg and component prepreg — all from a single source and all proven to work together seamlessly. Axson Technologies is a full-service supplier that has seen rapid growth from its complete solution packages.
Amber tooling prepreg
Multipreg HX42: An epoxy resin system that can be pre-impregnated into high performance fibres such as carbon, and glass. It is an exceptional and very well-proven system in aerospace applications that exhibits a high end-use temperature and extended outlife.

Epoxy resins have not yet been run, but Lammers anticipates no difficulties, with the right glass and sizing.
Altair Engineering (Troy, Mich.) or equivalent finite element analysis (FEA) software is used to determine the laminate materials and architecture that best suit the requirements of the entire boat structure. The property values of the materials to be used are factored into that analysis. The preform design is built into a computer-aided design (CAD) file. Once the design file is ready, the robot's deposition rate is set by preprogramming the process software, which calibrates the yield of the roving, the speed of the robot arm/end effector and the servo motor speed on the chopper gun.
While the part tooling is being made, robot programming is done offline using software such as that provided by Delmia Corp. (Auburn Hills, Mich.). When the mold tooling is ready, the software can be downloaded into the robot controller for immediate start of production. "Programming offline saves cost in overtime that might otherwise need to be expended to generate programs after regular working hours, so as not to interrupt production," says Lammers.
Since RIMFIRE production began, early in 2003, Sea Ray's three plants in Tennessee have built more than 5,000 hulls for its 18-ft to 24-ft (5.5m to 7.3m) sport boats. Cost savings have been enormous. To hand assemble a hull preform using dry mat and fabric would take three technicians 45 minutes, or 2.25 worker hours. Using RIMFIRE for a hull of the same size, says Lammers, one part-time operator and one robot can build a preform in about 20 minutes. Two robots can cut the time to 10 to 15 minutes. Use of gun roving reduces material cost by about 50 percent, compared to mat and fabric. Typically, chopped fibers and binder are sprayed directly onto the cured gel coat, with no veil or barrier coat in between. According to Sea Ray, the process has no negative effect on the Class A finish of the gel coat, a standard polyester system from one of several suppliers.
"Furthermore, layup of rolled goods usually results in a lot of scrap material that gets trimmed away," Lammers adds.

An additional disadvantage of a wet resin process is that personnel may come in direct contact with the resin, which is undesirable. Additionally, it is difficult to create uniform resin content free of voids and bubbles. Wet resin content fabricated products are usually of higher resin content than similar prepreg fabricated products in order to ensure freedom of void within the laminant, and thus such articles are heavier than articles made from prepreg materials.
An additional form of wet resin process utilizes vacuum to draw the resin through the fabric. Resin and catalyst systems are mixed in a container, and then introduced from the container to a dry cloth fiber reinforced layer placed in a tool. A vacuum bag is placed over the dry cloth layup with an inlet tube from the resin container to an edge of the layup under the vacuum bag. The vacuum bag outlet to the vacuum source is at the center of the assembly. When a vacuum is pulled, the bag pulls against the layup, and when the resin is released, the resin passes through the tube from the resin container and impregnates the fiber reinforcement or cloth from the edge thereof. Thereafter, resin flow proceeds toward the vacuum outlet at the center of the fiber reinforcement. When the resin reaches the vacuum outlet, the article is impregnated, and the resin inlet is sealed to stop any additional resin flow. The cure cycle is completed with continued vacuum pressure and heat.
Vacuum techniques are deficient due to pressure limitations of the vacuum as well as limitations in the size of the article to be fabricated. Vacuum techniques do not satisfactorily impregnate close weave fiber reinforcement, such as carbon fiber panels, entirely along the length and width thereof, to useful large size. Vacuum techniques further have difficulty achieving low air voids.
A need has thus arisen for an improved method for manufacturing fiber reinforced composite articles in order to produce aerospace quality composite parts having high fiber volume and low air void content.
A need has arisen for a process to create composite parts having ply areas with different reinforcement. A process is needed to enable the fabrication of a part in which areas needing reinforcement can be fabricated with extra plies of fabric, to specifically address load paths in the articles, while complementing the capability of composite construction to reinforce areas of stress, or use less material where the strength of thicker layers is not required.

Integrated assemblies are the Holy Grail for design
engineers because they lighten structures, reduce assembly costs, and increase
In the new approach being used by Boeing with help from NASA, dry carbon fiber structures are stitched together and then placed in a heated tool. A vacuum is pulled and epoxy resin is infused into the structure.
"The composites technology used in the (787) Dreamliner is 25 to 30 years old," says Andy Harber, senior project manager, design engineering for Boeing. "In the new approach, there is no lay-up and no autoclaves."
The Dreamliner represented a dramatic increase in aircraft composites'
use, with about half of the structure made with carbon-reinforced plastic
(CFRP). As reported by Design
News in an award-winning series, the concept
required development of autoclaves larger than those ever previously used.
Otherwise, the technology was similar to composites technology long-used in making fiberglass composites. Hand lay-up is an open mold process in which successive plies of reinforcing material, usually fiberglass or resin-impregnated reinforcements are applied to a mandril. Curing is accelerated in an autoclave.
Deliveries of the Dreamliner are running more than three years late because of a variety of problems, including issues with fasteners and attachment points in the composite structure.
No decision has been made at Boeing about potential use of the new assembly technology for commercial aircraft. But Harber says Boeing expects to use the technology in a next-generation blended wing body aircraft designed for reduced noise and pollution.
The process received its first field test as
replacement landing gear doors in C-17s used as transport
aircraft in Afghanistan. "On Sept. 17, 2009, we delivered to NATO eight landing
gear doors featuring resin-infused, stitched composites," says Harber.
The original doors were made with traditional materials and had taken a beating in the rough landing environment in the battle zone. Tools for the C-17 doors were developed by Process Fab Inc.
The first licensee for the Boeing-developed technology is General Dynamics Armament and Technical Products, which was awarded a $17 million contract by Boeing for the production of composite components and spares for the C-17 Globemaster III aircraft. Production and program management is being done at General Dynamics' advanced materials facility in Marion, VA.

Description of the Related Art
Reinforced thermoplastic and thermoset materials have wide application in, for example, the aerospace, automotive, industrial/chemical, and sporting goods industries. Thermosetting resins are impregnated into the reinforcing material before curing, while the resinous materials are low in viscosity. Thermoset composites suffer from several disadvantages. Low molding pressures are used to prepare these composites to avoid damage to the fibers. These low pressures, however, make it difficult to suppress the formation of bubbles within the composite which can result in voids or defects in the matrix coating. Thus, most processing problems with thermoset composites are concerned with removing entrained air or volatiles so that a void-free matrix is produced. Thermoset composites made by the prepreg method require lengthy cure times with alternating pressures to control the flow of the resin as it thickens to prevent bubbles in the matrix. While current fabrication of large structures utilize robotic placement of the thermoset composite material to increase production rate, its overall production rate for the component is limited by the lengthy cure in the autoclave process step and related operations to prepare the material for that process step. Some high volume processes, such as resin infusion avoid the prepreg step but still require special equipment and materials along with constant monitoring of the process over the length of the cure time (e.g. U.S. Pat. Nos. 4,132,755, and 5,721,034). Although thermoset resins have enjoyed success as in lower volume composites applications, the difficulties in processing these resins has limited their use in larger volume applications.
Thermoplastic compositions, in contrast, are more difficult to impregnate into the reinforcing material because of comparatively higher viscosities. On the other hand, thermoplastic compositions offer a number of benefits over thermosetting compositions. For example, thermoplastic prepregs can be more rapidly fabricated into articles. Another advantage is that thermoplastic articles formed from such prepregs may be recycled. In addition, damage resistant composites with excellent performance in hot humid environments may be achieved by the proper selection of the thermoplastic matrix. Thermoplastic resins are long chain polymers of high molecular weight. These polymers are highly viscous when melted and are often non-Newtonian in their flow behavior.

When boatbuilder Sea Ray investigated closed molding methods in the late 1990s, existing preforming methods were not cost-effective for building the company's wide range of pleasure boats. The company considered hand layup of preforms too labor-intensive. In addition, preforming materials — conformable mat and stitched fabrics — were expensive. Even more expensive were the dedicated, net-shape preforming molds. The alternative, sprayup of chopped glass preforms, was little more appealing. While faster in production, the sprayup technique would require even greater capital investment in robots, as well as tools made with air-permeable metal screen and the associated vacuum systems, with custom-designed plenums and baffling, and other related equipment. These considerations drove a corporate decision to invest in a more cost-effective preforming system, says Scott Lammers, executive director of manufacturing technology for Sea Ray (Knoxville, Tenn., a business unit of the Brunswick Corp.'s Boat Group). The company needed a more effective method to accommodate its boat size range (from small 18-ft/5.5m sport boats to 68-ft/21m yachts). The result was RIMFIRE.
Short for Robotic In-Mold Fiber Reinforcement, RIMFIRE (pats. pend.) is a robot-based system, which borrows the concept of robotic application from traditional sprayup preforming, but bypasses entirely the need for preforming tools. The system's heart is the working end of the robot arm, called the "end effector." It consists of three integrated components: a dual-sided, servo-motor-driven chopper gun capable of putting out 9 kg/20 lb or more of glass per minute; a binder mixer/spray head; and a heating system for the binder, featuring a pair of flame burners fueled by remote bottled propane gas or natural gas. Temperatures at the burners can be as high as 538°C/1,000°F and the heat zone temperature can be varied from 93°C/200°F to 204°C/400°F. The end effector chops dry gun roving, combines it with a powdered binder, then mixes and sprays the combination directly over the gel coat in the part mold. "You just spray it in the mold and you're done," Lammers says. "You don't touch it again."

Pat. No. 5,094,883. Thus, for those skilled in the art, there are multiple methods to coat and/or impregnate a fibrous substrate given the available process equipment, and proper selection of polymer product form (flake, fine powder, film, non-woven veil, pellets) and melt viscosity. Known methods for the fabrication of composite articles include manual and automated fabrication. Manual fabrication entails manual cutting and placement of material by a technician to a surface of the mandrel. This method of fabrication is time consuming and cost intensive, and could possibly result in non-uniformity in the lay-up. Known automated fabrication techniques include: flat tape laminating machines (FTLM) and contour tape laminating machines (CTLM). Typically, both the FTLM and the CTLM employ a solitary composite material dispenser that travels over the work surface onto which the composite material is to be applied. The composite material is typically laid down a single row (of composite material) at a time to create a layer of a desired width and length. Additional layers may thereafter be built up onto a prior layer to provide the lay-up with a desired thickness. FTLM's typically apply composite material to a flat transfer sheet; the transfer sheet and lay-up are subsequently removed from the FTLM and placed onto a mold or on a mandrel. In contrast, CTLM's typically apply composite material directly to the work surface of a mandrel. FTLM and CTLM machines are also known as automated tape laydown (ATL) and automated fiber placement (AFP) machines with the dispenser being commonly referred to as a tape head.
The productivity of ATL/AFP machines is dependent on machine parameters, composite part lay-up features, and material characteristics. Machine parameters such as start/stop time, course transition time, and cut/adding plies determine the total time the tape head on the ATL/AFP is laying material on the mandrel. Composite lay-up features such as localized ply build-ups and part dimensions also influence the total productivity of the ATL/AFP machines. Key material factors that influence ATL/AFP machine productivity are similar for a thermoset resin matrix composite when compared with a thermoplastic matrix composite yet there are a couple of key differences. For thermoset resin matrix composites, key factors are impregnation levels, surface resin coverage, and “tack”.

|Número de publicación||US5565162 A|
|Tipo de publicación||Concesión|
|Número de solicitud||US 08/315,751|
|Fecha de publicación||15 Oct 1996|
|Fecha de presentación||30 Sep 1994|
|Fecha de prioridad||30 Sep 1994|
|Número de publicación||08315751, 315751, US 5565162 A, US 5565162A, US-A-5565162, US5565162 A, US5565162A|
|Inventores||Thomas M. Foster|
|Cesionario original||Composite Manufacturing & Research Inc.|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (19), Citada por (28), Clasificaciones (10), Eventos legales (4)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
The present invention relates to the manufacture of fiber reinforced composite articles, and more particularly to capillary resin transfer molding.
Due to the high strength to weight ratio, fiber reinforced composite structures have become attractive for aerospace application, such as for example, parts for airframes and propulsion power plants, and for reinforcing various type structures. Molding of such parts has been expensive, relatively time consuming and labor intensive because of the need to position elements accurately in the mold, and to carry out the process slowly to avoid porosity, air entrapment and other internal and surface defects during polymerization, cross-linking or hardening of the resin in the fiber material. Additionally, systems have required the generation of high pressures to uniformly spread the resin in the fiber.
Fiber reinforced organic resin composite structures are fabricated using two basic forms of materials, prepreg, "B" stage, resin impregnated fiber forms, and wet resin impregnation of fiber forms.
In the prepreg process, woven cloth or fabric is impregnated at one facility, with a prescribed amount of resin. The resin is staged and dried, to a "tacky" or "B" stage condition in a partially cured condition. The material is then packaged between layers of separation film and stored in containers for extended periods of time before the fabric is used and fully cured for final part processing.
The prepreg operation has a number of disadvantages.

KraussMaffei will present its High Pressure Resin Transfer Molding (HP-RTM) process for lightweight construction applications to automotive customers for the first time in the US.The partners KraussMaffei, Proper Group International Inc. and Kiefel Technologies Inc. will also present machines and processes for the automotive industry during an Open House on September in Warren, Michigan.
With the HP-RTM process, KraussMaffei offers machines and components on a turnkey basis for the entire process chain from handling of semi-finished products through to finishing of the complete composite fiber part.
“The optimum interaction between all system components, which comprise a press, a mold and a metering machine, is an important criterion in producing highly complex parts with a high fiber volume ratio,” said JP Mead, Vice President of KraussMaffei Corporation, who is responsible for the Reaction Process Machinery Segment in the US. The company has developed special technology as a system partner in the country for multi-process solutions in metering technology for highly reactive resins.
The Open House will also focus on direct processing in an injection molding compounder. An injection molding compounder is especially suitable for large-series production, for example of front end and instrument panel supports, door modules, insulating mats and other noise absorbers, explains KraussMaffei.
The materials are mixed and the components are produced in one machine. The matrix polymer is initially plasticized in a co-rotating twin-screw extruder and mixed with aggregates. Only then are the reinforcement fibers added to the polymer melt. The actual injection molding process then takes place via the injection piston.
Because of this single-stage process, the injection molding compounder ensures good melt homogeneity and a mixing effect, as well as high injection volumes and superb part quality. Components can therefore be combined with any fillers, reinforcement materials and substitution materials.

Henkel has developed a polyurethane-based composite matrix resin that cures faster than the traditional epoxy resins. Composites based on carbon fiber or glass fiber are gaining momentum in various application areas due to the opportunity for enormous weight savings over traditional part construction, with no loss in mechanical performance. Starting in aerospace where pre-impregnated fibers (prepregs) are manually laid up and then baked into composites, many different applications are now penetrating into the automotive industry. New manufacturing methods like resin transfer molding enable economic processes that are suited for high volume automotive production.
For the resin transfer molding process, Henkel has developed a new composite matrix resin based on polyurethane which enables improved economics and throughput in processing. Compared to standard epoxy matrix resins, the new Loctite MAX2 cures significantly faster. During injection, it also enables more efficient impregnation without stressing the fibers due to the lower viscosity of the resin.
The composite properties of Loctite MAX2 were specially developed to provide more flexibility as well as much higher impact resistance than traditional epoxy resins. Henkel is confident that these new generations of polyurethane matrix resins deliver significant benefits for fast and efficient manufacturing.

Furthermore, the consolidation process step using an autoclave or oven requires a “bagging” operation to provide the lay-up with a sealed membrane over the tool to allow a vacuum to be applied for removal of air and to provide the pressure differential necessary to effect consolidation in the autoclave. This process step further reduces the total productivity of the composite part operation. Thus, for a thermoplastic composite it would be advantageous to in-situ consolidate to a low void composite while laminating the tape to the substrate with the ATL/AFP machine. This process is typically referred to as in-situ ATL/AFP and the material used in that process called an in-situ grade tape.
In general, thermoplastic composites have had limited success to date, due to a variety of factors including high processing temperatures (currently around 400° C.), high pressures, and prolonged molding times needed to produce good quality laminates. Most of the efforts have been focused on combining high performance polymers to structural fibers which has only exacerbated the process problems. Because the length of time typically required to properly consolidate the prepreg plies determines the production rate for the part, it would be desirable to achieve the best consolidation in the shortest amount of time. Moreover, lower consolidation pressures or temperatures and shorter consolidation times will result in a less expensive production process due to lowered consumption of energy per piece for molding and other manufacturing benefits.
Accordingly, the fiber-reinforced thermoplastic materials and methods presently available for producing light-weight, toughened composites require further improvement. Thermoplastic materials having improved process speeds on automated lay-up machines and lower processing temperatures, and having no autoclave or oven step would be a useful advance in the art and could find rapid acceptance in the aerospace and high-performance automotive industries, among others.
The discovery detailed herein provides lower melting, slower crystallizing semi-crystalline polymer films that are applied to a surface (for example via lamination) of a core containing a tape or tow impregnated with a higher melting, faster crystallizing matrix polymer, and which can be initially processed at a melt process temperature of the surface polymer, but upon cool down crystallizes at rates intermediate to the faster crystallizing matrix polymer.

Such a wing preform might have a thickness varying between 0.05 inches and 1.5 inches. The wing preform is quite large, and its surface is very complex, usually a compound contoured three-dimensional surface.
The stitched wing preform is transferred to an outer mold line tool that has the shape of an aircraft wing. Prior to the transfer, a surface of the outer mold line tool is covered with a congealed epoxy-resin. The tool and the stitched wing preform are placed in an autoclave. Under high pressure and temperature, the resin is infused into the stitched preform and cured. Resulting is a cured wing cover that is ready for assembly into a final wing structure.
For textile composite technology to be successful, two barriers must be addressed: cost and damage tolerance. Damage tolerance is achieved by making high quality, closely-spaced stitches on the wing preform. The high quality, closely-spaced stitches add a third continuous column of material to the wing preform. If thread tension is not proper, a large number of stitches on the preform will not be of sufficient quality and will reduce the damage tolerance. Improper thread path geometry might also degrade the quality of the stitches and, therefore, reduce the damage tolerance.
Even though the stitches are made by a stitching machine that is computer numerically controlled (“CNC”), it is difficult to make stitches having the high quality required for the wing preform. On a compound, contoured three-dimensional surface, thread tension and thread path geometry must be constantly adjusted for an exceedingly large number of stitches. The CNC stitching machine might make eight to ten stitches per inch, in rows that might be spaced 0.1 inches to 0.5 inches apart, over a surface that might be longer than forty feet and wider than eight feet. The total number of stitching points on the wing preform might exceed 1.5 million.
Much manual labor is required. Because the wing preform has many regions of differing thickness, a machine operator must constantly stop the stitching machine when a new region is about to be stitched, adjust the thread tension and possibly the thread path geometry, and restart the stitching machine. Of course, the CNC stitching machine has multiple stitching heads. At any given time, two or more stitching heads might be stitching different regions having different thicknesses.

Each company who enters into the resin transfer molding processes does so with numerous expectations and personal perceptions, as well as, experience. Most who have not been intimately involved in closed molding for many years have many questions of just what is happening inside the mold as the resin flows, the RTM Lite process with the “see through” upper mold half has been very valuable in answering many questions those new to closed molding have asked.
The introduction of the light RTM process, as originally adopted in France as the “ECO” process which was a process developed as an environmentally friendly low cost closed molding process, which is well suited for low production volume as so common in the European community. This ECO process was built on the design features of a lite weight “see through” upper mold half. Once this tool design and process method was introduced here in North America the name was recognized as the RTM Lite process. The primary promoter of this process in North America has been Chomarat company from France as a means to advance the growth of the closed molding processes and the use of their fiberglass reinforcement ROVICORE, so much of the thanks is owed to Chomarat for their efforts in bringing the RTM Lite innovation to North America.
While the advantage of seeing through the mold allows the molder to actually “see” the resin flow during the injection process, which speaks volumes in advancing the understanding of just how the resin actually fills the mold, it does so at a price.
In order to see the resin we must build the upper from clear gel-coat, initially this was a MAJOR stumbling block for the RTM Lite process as the original clear tooling gel-coats were very rigid and crack very easily. Recent innovations from the gel-coat suppliers has dramatically improved this concern, yet the clear gel-coats still do not perform as well as the more conventional solid color tooling gel-coats. Further, the laminate of the see through upper, must be generally no greater in thickness then 3/16″ (~.180″ or 4.5mm) in order to still maintain the clarity needed to see the resin flow. Tooling of this thickness will perform well for very low to low volume production especially on generally flat shapes. Yet, complex shapes, especially those with solid core materials require a molding staff who pays CAREFULL attention to detail, in order to prevent the mold from being damaged during the molding process.

By pre-impregnating the fabric with resin, under carefully controlled conditions with precision machinery, a material is created with known and repeatable engineering characteristics. This is the prepreg we are familiar with today. More recently tooling prepreg has become the standard method for producing precision composite moulds by employing the same proven principles.”
By slowly improving the characteristics of the material — including the handleability, the life at ambient temperature, the right amount of tack (stickiness) — the tooling route is now becoming easier and more cost effective. A new generation of composites are being used in an increasing number of efficiently engineered applications.
A small team of experts founded Amber Composites in the UK in 1988 to develop and manufacture high performance composite prepreg. Prepreg technology was still in its infancy then and the early team was involved in developing some of its first commercial applications. From its corporate headquarters in Nottinghamshire (the setting for the revolution in industrial textiles and a logical place for the birth of the carbon fibre industry), Amber worked closely with F1 racing teams and a number of other high performance engineers. This demanding customer segment drove the development of the tooling materials that are available today. Today, Amber serves a wide variety of industries worldwide including aerospace, automotive, marine, and communications.
A rough guide to moulding
Vacuum bag moulding
A process using a single side mould set that shapes the outside surface of the panel. On the lower side is a rigid mould and on the upper side is a flexible membrane or vacuum bag. The flexible membrane can be a reusable silicone material or an extruded polymer film. Then, vacuum is applied to the mould. This process can be performed at either ambient or elevated temperature with ambient atmospheric pressure acting upon the vacuum bag.
A process using a single-sided mould set that forms the outer surface of the panel. On the lower side is a rigid mould and on the upper side is a flexible membrane made from silicone or an extruded polymer film such as nylon. Reinforcement materials can be placed manually or robotically. They include continuous fibre forms fashioned into textile constructions. Most often, they are pre-impregnated with the resin in the form of prepreg fabrics or unidirectional tapes. In some instances, a resin film is placed upon the mould and dry reinforcement is placed above. The membrane is installed and vacuum is applied. The assembly is placed into an autoclave pressure vessel.

What the Future of Composite Materials Means for the Aerospace MRO 9Maintenance, Repair, and Overhaul) Sector
With a constant need for lighter and more efficient aircraft, the aerospace industry has been especially welcoming of developments in composite materials. Over the past several years, the industry has adopted more composite materials, drawn by such benefits as increased durability and heat resistance, better aircraft life cycle, flexibility and more.
As composite material production evolves, and design and production processes improve, we can expect to see even greater adoption of composite material in the aerospace industry. In fact, the market is expected to grow from $26.87 billion in 2017 to $42.97 by 2022, according to Research and Markets’ aerospace composites market report and global forecast – a CAGR of 9.85%. Boeing and Airbus have both shown increased investment in composite material use, with the 787 and A350 composed of roughly 50 percent composite materials. For the aerospace MRO sector, composites offer several benefits.
Airbus reported a 60% reduction in fatigue- and corrosion-related maintenance tasks for its A350 XWB since adopting composites, based on the amount of time spent on each check and the amount of checks required during the aircraft life cycle. This translates to faster and less frequent repairs, which can keep aircraft off the ground and in the air for longer periods of time.
Better fatigue resistance
Prepregs are reinforcement materials pre-impregnated with thermoplastic or thermoset resin. These create lightweight, high-strength composite laminates that have increased fatigue and corrosion resistance and more controlled fiber volume fraction and can be used to strengthen internal or external aircraft features.
Traditional materials can wear down over time, but composites like carbon fiber, epoxy and other structural adhesives help improve the aircraft’s life cycle – again, thanks to their corrosion resistance and ability to withstand high temperatures and pressures.
Less material waste
Composites make it easier to conduct on-wing repairs, which means less material waste and, in turn, lower cost.
Less time spent on MRO tasks
Less maintenance means less cost and more in-flight time. In addition, the technique of bonded repairs can be more easily performed than standard repairs, and in less time – only 8-12 hours.
Composites One is the leading supplier of composites for the aerospace industry
Composites One is the leading supplier of composite materials throughout North America.

Although the traditional hand lay-up process will remain the process of choice for some applications, new developments in pultrusion, resin transfer moulding, vacuum infusion, sheet moulding compound, low temperature curing prepregs and low pressure moulding compounds are taking the industry to new heights of sophistication, and are now being exploited in high technology areas such as the aerospace industry.
To further investigate the potential suitability of composites for your needs, use the links to contact engineering and design consultants experienced in the use of composites.
Send mail to email@example.com with questions or comments
about this web site.

When producing with transfer technology you load a preformed rubber part in a slot and then the machine press a plunge into that slot. In the bottom of the slot you have holes into the cavity. so the material is pressed through the hole and the part is produced.
Saves some times compared to compression. Both in curing time and that you can preform bigger rubber details per cavity.
Disadvantage compared to injection moulding is that you need to produce the preformed rubber parts.
The mould is a little bit more expensive compared to compression moulds.

The extra material left behind in the mold must be disposed of, since cured thermoset material from sprues and runners cannot be reground and reprocessed, as opposed to thermoplastic injection molding. When the mold cavities are filled, the parts must cure to a solid form. The mold opens for part removal, and parts are ejected and removed by hand or automated equipment.
Thermoset Transfer and Compression Molding Advantages
- High temperature thermoset materials
- more dimensionally stable
- less wall thickness variations
- less expensive tooling

Automated tape placement and complex stamp forming is one area of focus because it holds such great potential for rapid processing. Yet much remains to be learned in order to achieve consistent quality on an industrial scale, Akkerman observes.
“Issues involve getting the right quality – no wrinkles, not tears, no delaminations – in the final product,” he says. “To be able to produce proper components requires a lot of experience with thermoplastics processing, which often is lacking in industry. So we are trying to develop the CAE tools and characterisation methods to simulate the process and demonstrate to industry how it should be done.”
Material screening is ongoing at the TPRC.
“We keep a technology watch on what’s new on the market, looking at material properties and how we can tailor them and possibly improve them,” he continues. “We’re focusing on the ‘high-tech, high-spec’ materials, trying to meet industry’s demand for a material with the performance of PEEK, but at lower cost.”
Development work on joining technologies is another priority. The centre is planning to start up work with hybrid constructions, incorporating metal and composites.
“There’s not one solution for all problems," notes Akkerman. “You will always end up with hybrid constructions. The challenge is to produce them efficiently.”
Recyclability is high on the centre’s list of priorities.
“If institutes like TPRC are successful and composites deployment grows rapidly, then we need to face the issue of what happens after end of life. Should we have a desert full of aircraft and car components, or do we do something with them? I think it’s most relevant to think about either recycling or renewable materials and things like that,” he comments.
Flooring for helicopters
Fiberforge, Glenwood Springs, Colorado, USA, a manufacturing company that has developed a patented production process for continuous fibre reinforced thermoplastic parts, is in the final stages of development of a project to produce a composite floor for the large Sikorsky CH-53K transport helicopter used by the US Marines.
The contract represents about 300 shipsets of panel assemblies, with each shipset incorporating 38 different thermoplastic composite panels that are welded together into an assembly to form the floor, relates Josh Taylor, Director of Business Development. The largest panel is under 1 m2.

He commented that they had started with the “lite RTM tooling standard” one where his operators could watch the resin flow, then they moved to what they call “Not so Light RTM” in which they too have added tooling structure and more conventional tooling materials to their tooling designs.
Keeping in mind that the MAJORITY of the cost in building the mold is NOT the materials it is the labor and time especially in the proper application of Sheetwax, it is not a major cost impact to add some stiffness and use conventional tooling materials when building RTM Lite tooling.
The most profound change I have seen in the closed molding processes in the last 25 years has been the change from center injection to perimeter injection. That is to create a CONVERGING flow from the standard as it had been for the last 30 plus years of a DIVERGING flow path. This change came about from the introduction of the RTM Lite tool design. This what might appear as a subtle change is the most radical change in recent closed molding history. Keeping with that change and using then conventional tooling materials, with about 30% of the tooling structure as common to previous RTM tooling we have now a more robust closed molding process, with less scrap and more consistent part thickness then we had with the conventional RTM processes of the past.
Today, JHM Technologies offers three types of tooling structure to accommodate all levels of experience and production needs to their customers.
The first level is a “BASIC” level one built with all of the of the latest flow channel details to enhance even and uniform resin flow 360 degrees around the mold perimeter, as well as, can be fitted with either replaceable “tubes” or the latest in Automatic injection ports or vents. The ability to “see through” the upper is maintained to allow the new user the ability to evaluate the mold process as well as train their molding operators on troubleshooting their molding process. The Basic tool is made of high quality Vinyl Ester gel-coat and hand laid fiberglass reinforced Vinyl Ester laminate. Additional backing structure is added using steel box tubing as needed for stiffening and operator handling. The Basic tool is capable of producing the same level of part quality as either the “MAGNA” or “CONDITIONED MAGNA” series of tooling, the only compromise is that the BASIC series of tooling requires a bit more care and will not produce at the same rate as the MAGNA series.

Prepreg a semi-finished composite.
It is shorthand for “pre-impregnated” and is associated with continuous fiber reinforced materials. Prepregs have the greatest strength to weight ratio of any composite material. This is a result of having the highest fiber volume fraction relative to other composite manufacturing techniques. Being semi-finished, prepregs must be further processed or fabricated into a fully cured state. Many process options are available, each with distinct advantages. These processes include:
- Press Molding
- Various winding processes
- Automated Tape Placement
- Out of Autoclave
In order to successfully process or fabricate a prepreg, any process must create conditions that allow for good consolidation of the material and apply heat in order to initiate and maintain the cure process. Norplex-Micarta produces prepreg in a solution coating process. Compared with other prepreg manufacturing techniques, this method assures even resin impregnation, fast production speeds, and normally results in a tack free prepreg that is well suited for high volume, automated, fabrication.
Norplex-Micarta is always developing new materials.
Many structural applications require a speed of processing that is not achievable in many of the standard composite fabrication techniques, such as autoclave.
Norplex-Micarta is investing in technologies and techniques that allow for the co-curing of prepreg materials with other thermosetting material forms so that near net shape, complex cross section, and mass production targets can be achieved.
Sheet materials are readily available for fabrication into parts.
Manufactured from Norplex-Micarta’s prepregs, sheet products provide unique advantages to designers of composite parts and structures. These include:
- Sheet sizes from 36 inches by 48 inches up to 48 inches by 120 inches
- Thicknesses from 0.010 inches to more than 8 inches
- Easily customized with different surface or core materials, including traditional materials like rubber or metals
- High volume, consistent, and predictable
Sheets can be fabricated using various standard machining and stock removal processes, such as:
- Milling, turning, grinding
- Punching, routing, sanding
- Water jet cutting, shearing, sawing
- Norplex-Micarta is always developing new materials.
Many structural applications require a more complex shape than can be produced from a sheet. Nevertheless, these sheet materials allow for a detailed, yet timely, understanding of various material properties to establish a baseline for design work in other geometries.

Spirit AeroSystems [NYSE: SPR] announced today its Advanced Technology Centre in Prestwick, Scotland, has developed an improved method for manufacturing composite parts.
Spirit AeroSystems uses some of the world’s largest autoclaves to support the company’s composite fuselage business. The new intelligent heated tool technology can cure composite parts 40 percent faster and at half the cost without using an autoclave.
In collaboration with the University of Strathclyde and the Scottish Innovation Centre for Sensor and Imaging Systems (CENSIS), Spirit developed an intelligent heated tool for curing composite components. The new technology can cure composite parts 40 percent faster at half the cost and supports a wide range of composite components across industries, from wind turbine blades to the next generation of composite aircraft.
"Instead of curing components at a standard temperature for hours at a time, we can now tailor the cycle time to match individual part geometries," Stevie Brown, lead engineer at Spirit's Advanced Technology Centre in Prestwick, explained. "The autoclave has been a bottleneck in manufacturing lines, and removing it will reduce cycle times for components, cut production costs and decrease energy consumption."
Typically, high-performance composite materials are layered on a specially formed surface, or tool, and then placed in an autoclave, where a combination of heat and pressure accelerate the hardening of the material. Spirit's new technology introduces an intelligent, multi-zone heated tool, removing the need for an autoclave. The tool enables complete control of the curing process through real-time monitoring and feedback.
CENSIS supported the collaboration with funding and provided project management expertise. The University of Strathclyde provided technical support and developed the control algorithm and software for the intelligent tool.
The collaboration will continue through 2018, and Spirit has already begun applying the technology in research and manufacturing projects.

An option for such geometries is to spray the preform over a convex mold and then move the preform into the main mold, a procedure similar to traditional preforming.
BASICALLY, IT'S THE BINDER
The real secret to RIMFIRE success, however, is the binder, a blend of powders that can be tailored to produce desired properties. "Basically, it is a thermosetting material that has thermoplastic-like properties," says Lammers. The material melts when heated in the preforming stage. But once cooled and solidified, it will not re-melt, and it retains its physical and mechanical properties during the heat/cure cycle.
In raw form, the different binder powders are stored separately in hoppers. Under computer control, powders are metered into a mixing tube that conveys the blend of mixed resin powders, in the required percentages for the weight of the glass specified for an individual application, to the chopper/spray head. The glass and binder pass through the heat zone together. As it is exposed to the heat, the binder activates, becoming tacky and interspersing with the glass as it exits the gun, causing the fibers to adhere to each other and to the mold surface, where it cools and solidifies.
For the system to work properly, all preform fibers and sizings as well as the matrix resins, must be compatible with the binder. Therefore, selection of glass fiber type and fiber sizing are important factors in preform design. "The type of sizing on the glass can make the material stiffer or softer. This affects how the roving runs through the chopper gun," Lammers says. "So the set up of the rollers and blades may vary for different types of material." All incoming raw materials are qualified using a standard set of tests. Before production starts, coupon samples of the proposed layup are tested for mechanical properties. Various types of E-glass from PPG Industries (Pittsburgh, Pa.), Saint-Gobain Vetrotex (Valley Forge, Pa.) and Owens Corning (Toledo, Ohio) have run successfully through the robot. For the matrix resin, a low-profile polyester resin system from AOC Resins (Collierville, Tenn.) is used. The preform system also has worked with vinyl ester and polyurethanes.

The production capacity of the GRP rotor blades was successfully multiplied within a very short time, with a significant increase in quality and a material and weight saving of 25%.
From 1994, the world-famous stunt flying planes from EXTRA-Flugzeugbau (FAR23) were also manufactured with ES-Laminatic® machines. These are still valid (at least in the air) as indestructible!
Since the restructure of Germany’s energy sector, the Energiewende, lightweight construction has become more and more important in other areas, such as the automotive industry and rail technology. Increasingly, composite materials are being used in large aircraft construction in order to save fuel and at the same time increase transport capacity.
With increasing component size and quantity, the demands on quality and short cycles as well as resilience increase. Meanwhile, several resin manufacturers have responded to these demands of the industry by developing new, faster resin systems that cure in less than 15 minutes. Halogen-free, self-extinguishing resin systems for the commercial aerospace industry according to FAR25/26 as well as for the railway industry are now available.
However, those systems need extremely precise mixing (<0.6 GT). Therefore, ES-Schmid GmbH has anticipatorily developed special, high-precision and extremely reliable matrix flow meters with <± 0.1 GT accuracy. When dosing 2K systems, the maximum deviation at <± 0.2 GT is far below the permissible deviation and is already a big step ahead of the state of the art.
Compared to the vacuum infusion process, the ES-Laminatic® technology has significant advantages in the production of high-quality sandwich components with honeycomb core, like FAR25/26 resin systems. Due to the vertical precision impregnation, the honeycomb cores will not overflow and the negative "filter effect" in resin systems with fire-retardant additives is completely eliminated.
Rainer Schmid - CEO
Federal Aviation Regulations (FAR)
FAR Part 23 - details the airworthiness standards for airplanes with a maximum take-off weight of less than 12,500 lbs., such as the Cessna 172 and Cirrus SR20.
FAR Part 25 - details the airworthiness standards for airplanes with a maximum take-off weight of 12,500 lbs. or more, such as the Boeing 737 or Airbus A320.

The organic matrices commonly used are broadly divided into the catego- ries of ther-moset and thermoplastic; organic matrices commonly used on air- frame structures are given below:
• Expoxy • Polyethylene
• Polyester • Polystyrene
• Phenolics • Polypropylene
• Bismaleimide (BMI) • Polyemeretherketone (PEEK)
• Polyimides • Polyetherimide (PEI)
• Polyethersulfone (PES)
• Polyphenylene Sulfide
• Polyamide-imide (PAI)
The relative advantages of thermosets and thermoplastics include: THERMOSET MATRICES THERMOPLASTIC MATRICES
• Undergo chemical change when cured
• • Non-reacting, no cure required
• Processing is irreversible
• • Post-formable, can be reprocessed
• Low viscosity/high flow
• • High viscosity/low flow
• Long (2 hours) cure
• • Short processing times possible
• Tacky prepreg
• • Boardy prepreg
• Relatively low processing temperature
• • Superior toughness to thermosets
• Good fiber wetting
• • Reusable scrap
• Formable into complex shapes
• • Rejected parts reformable
• Low viscosity
• Rapid (low cost) processing
•Infinite shelf life without refrigeration
•High delamination resistance (Disadvantages)
•Long processing time
• Less chemical solvent resistance than thermosets
• Requires very high processing temperatures
• Outgassing contamination
•Limited processing experience available
• Less of a database compared to thermoset
Compared to thermoplastics, thermoset matrices offer lower melt viscosi- ties, lower processing temperatures and pressures, are more easily prepregged and are lower cost. On the other hand, thermoplastic matrices offer indefinite shelf life, faster processing cycles, simple fabrication, and generally do not re- quire controlled-environment storage or post curing.
The most prominent matrices are epoxy, polyimides, polyester and phe- nolics.
Thermoset matrix systems have been dominating the composite industry because of their reactive nature. These matrices allow ready impregnation of fi- bers, their malleability permits manufacture of complex forms, and they provide a means of achieving high-strength, high-stiffness crosslinked networks in a cured part.

The component was fabricated by Cutting Dynamics of Avon, Ohio USA, in collaboration with TenCate Advanced Composites (TC1100 PPS unitapes), Ticona Engineering Polymers (Fortron PPS resin) and A&P Technology of Cincinnati, Ohio, which used a unique, high-speed moulding process to produce a complex-geometry hollow structure from tape. The tape was braided into a biaxial tubular shape around the edge of the seat back.
TenCate displayed the award-winning component in its booth at JEC 2011 in Paris. Also on display in the booth was a rudder for Boeing’s Phantom Eye long endurance unmanned vehicle that was fabricated with TenCate Cetex PPS RTL laminates and induction welded by KVE Composites Group, the Netherlands. The thermoplastic rudder replaced a thermoset design, achieving weight savings of 25% and cost savings of 5%, reports TenCate. Welding eliminates the cost and weight of fasteners.
The latest product from TenCate is Cetex TC900 Nylon 11, a thermoplastic prepreg system for industrial applications. The Nylon 11 polymer is based on renewable soy bean oil and is said to be resistant to most solvents. TC900 can be processed and formed at moderate 350-400°F (177-204°C) temperatures.
Concept car demonstrators
Baypreg® F polyurethane (PU) composite from Bayer MaterialScience was used in Mazda’s MX-0 concept vehicle to demonstrate that a lightweight vehicle could be mass produced using materials technologies that exist today. Baypreg was used to produce a bonded, two-piece monocoque structure, similar to those used in Formula 1 cars, for the safety cell, subframes, body panels and interior surfaces.
Mazda designers, who patterned the structure after the MX-5 sportscar, determined that the manufacturing of the structure could be automated using composite sandwich materials. The result was a structure weighing only 100 lbs (45 kg), compared with 665 lbs (302 kg) for the production MX-5.
Baypreg F is a two-component PU system used in compression moulding of natural fibre mats alone or fibre reinforced sandwich panels to produce a variety of composite automotive parts.

The global trend towards lightweight construction is particularly evident in the aviation industry. In the development of new civil aircraft generations, innovative materials such as carbon fiber reinforced plastics (CFRP) are being used in load-bearing structures. The A350 from AIRBUS, for example, developed a civil aircraft for the first time, the majority of which consisted of CFRP.
The production of the skin sections from the fuselage area of this aircraft type is often carried out using Automated Fiber Placement (AFP). Automated Fiber Placement is one of the leading manufacturing technologies in the field of cost-effective, high-quality series production of lightweight structures.
The use of AFP processes significantly reduces the loss of expensive CFRP material.
The carbon fibers used are several millimeters wide and impregnated with resin, so-called tows, must be placed on a tool surface as load-free as possible. In contrast to Automated Tape Laying (ATL), the considerably narrower tow widths make it possible to apply the material very close to the desired contour of a component to be produced, thus reducing loss to a minimum and increasing the material usage rate.
Often, load-free storage paths are not guaranteed by today's path planning algorithms due to a lack of material models and path planning optimization algorithms that are only inadequately suitable for CFRP, especially not for complex components. As a result, gaps, overlaps and detachments of the material occur which do not meet the requirements of component design and the structural requirements (design requirements) placed on them.
Due to the increasing geometric complexity of component surfaces and the high structural requirements placed on CFRP laminates, AFP system programming is often still carried out manually and with great effort even today, in compliance with strict rules and regulations. Once programming is complete, additional time-consuming testing procedures are used between the individual production steps to locate and classify defects in the laminate.
Components that do not pass an inspection, go through a large part of the process chain and cause additional costs without contributing to added value.
The problem here lies on the one hand in the development of a defect location and on the other hand in the time it takes to detect the defect.
A very time-consuming visual inspection, as frequently required within the scope of quality control by process supervisors for every position of the CFRP component, can only partially detect these defects and also causes high inspection costs.
The undiscovered and uncorrected defects also cause repair costs at a later point in time, mostly with considerable scope and costs.

Automated tape laying (ATL) and automated fiber placement (AFP) are processes that use computer-guided robotics to lay one or several layers of carbon fiber tape or tows onto a mold to create a part or structure. Typical applications include aircraft wing skins and fuselages.
CGTech helps demystify the process of programming automated composite machinery by introducing the key components of machine independent off-line programming software.
A view of the trends in automated fiber placement and automated tape laying from inside the supply chain.
Read complete article
Machinery manufacturer Mikrosam featured its new automated tape laying (ATL) system, developed for a civil airplane parts manufacturer.Coriolis celebrates aerospace history, anticipates automotive future, at JEC CompositesWorld
Coriolis Composites (Queven, France) held a press event at its stand to celebrate its 15th year at the JEC Europe event.Trends in automation: ATL and AFP technologies increase speed, flexibilty CompositesWorld
Many automated production solutions were on offer at JEC Europe 2015, and several companies made announcements.What is the genesis of automated tape laying technology? CompositesWorld
CW Editor-in-Chief Jeff Sloan seeks and finds the roots of automated tape-laying technology in the work done by close associates of legendary composites-industry pioneer Brandt Goldsworthy.Automated composites manufacturing, past, present and future CompositesWorld
CW guest columnist Rob Sjostedt is a partner and CEO at VectorSum Inc. He recalls his days at Goldsworthy Engineering and reminds CW readers that today’s product requirements are more challenging than ever, and creative new approaches are required.

Integrated fabrics, braids, preforms and pre-pregs are used in rapid fabrication of door inner, floor, seat back rest, roof, trunk and under the hood auto components, wind turbine blades and composite tanks (See Figure 3). Advanced manufacturing techniques such as injection overmolding, stampable preforms, locally stitched preforms, high-pressure resin transfer molding are some examples that reduce composites manufacturing costs and energy consumption and improve component performance and recyclability. Figure 4 illustrates a locally reinforced preform to provide directional properties. IACMI has partnership with the Long Island, N.Y.-based Composites Prototyping Center (CPC), for prototyping and fabrication.
Composite recycling is of growing interest to the composites community. The next-generation technologies feature novel and increasingly complex combinations and formulations of fiber-reinforced composites, but these are difficult to recycle using current practices. Since recycled chopped carbon fiber costs 70-percent less to produce and uses up to 98-percent less energy to manufacture compared to virgin carbon fiber, recycling technologies are creating new markets from the estimated 29 million pounds of composite scrap sent to landfills annually. Advances in recycling technologies including pyrolysis, solvolysis, mechanical shredding and cement kiln incineration are enabling recycle, reuse, and remanufacture of products. IACMI has strategic partnerships in the recycling technologies with the American Composites Manufacturer’s Association (ACMA) and Composites Recycling Technology Center (CRTC), Port Angeles, Washington.
Additive technologies in composites manufacturing offer a high-rate, low-cost alternative to traditional tool-making approaches, and shows promise as an effective processing method for printing composite structures from reclaimed structural fibers. Additive approaches have the potential to significantly reduce composite tool-making lead times and increase the recovery and reuse of structural carbon fibers.
Advanced thermoplastic resins into current production processes: Thermoplastics have shorter cycle times and are more suitable for recycling. Increasing the use of thermoplastics for requires a variety of activities, including developing of novel in situ polymerization methods to improve thermoplastic fatigue performance, and establishing design-for-recyclability methods.
Design, Prototyping, and Validation (DPV) are integral steps to turning conceptual designs into high-performance components and verifying that these components meet their intended product requirements.

It should be noted that the originators of the ECO or RTM Lite process live in a culture in which a higher level care is taken by the operator then common here in North America, this not a slight on the North American molding operator, we here are focused on VOLUME in our production, in Europe there is commonly lower volume and thus the culture is not so hurried as is the case here. In any event, light weight tooling will perform well if very careful attention is paid to all aspects of molding process. This is to mean that details such as gel-coat application, fiber loading, core placement, mold halves registration to each other during closure, amount of flange vacuum, and cavity vacuum levels all must be carefully controlled, while this is true of any of the vacuum assisted closed molding processes, it is especially true of the RTM Lite process when the upper mold half is built to a standard which allows for the resin to be seen as it fills the mold.
For the last 4 years JHM Technologies has been offering RTM Lite and ZIP RTM tooling which is built with added strength and design features that perform to a higher level of performance then the conventional “see through” RTM Lite tooling. Our focus has been on tool life and production performance, while we may not have given enough consideration to the fact that many are just entering the closed molding environment and can benefit from the learning one receives from actually watching the resin flow during the injection. Further, the majority of the molders who begin with their conversion into closed molding do so with choosing one of their “lower volume” parts, so the conventional RTM Lite tooling standard will perform well, especially if added care is provided in the molding process.
It should be noted however that building a more rigid upper mold, built with conventional tooling materials and added stiffening structure will OUT PERFORM the lighter “see through” mold.
Recently, I received a call from one of our long term customers who called mainly to say hi and to ask what is new in the industry. During our conversation we discussed many tooling standards in use today, one of his comments I thought was rather profound and further supports this article. He being a longtime closed molder who has multiple plants throughout the USA, and has been had many different forms of closed molding running in production for many years.

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|US20050236736 *||20 Dic 2004||27 Oct 2005||Formella Stephen C||Composite product and forming system|
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|US20060134251 *||22 Dic 2004||22 Jun 2006||General Electric Company||Apparatus for fabricating reinforced composite materials|
|US20070052136 *||8 Sep 2005||8 Mar 2007||Hiroshi Ohara||Exclusive molding method for producing cloth-based parts of loudspeaker|
|US20070182071 *||16 Feb 2005||9 Ago 2007||Toshihide Sekido||Rtm molding method and device|
|US20090142496 *||26 Oct 2007||4 Jun 2009||General Electric Company||Method for fabricating reinforced composite materials|
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Luciano De Oto joined Automobili Lamborghini S.p.A. in 2001 as an engineer for the Body-in-White of the Gallardo and in 2006 became manager for the interiors and exteriors engineering and development for all Lamborghini products. De Oto is now Lamborghini’s division chief for the Advanced Composites Division, which embraces all composites-related activities across products, line-ups and departments in the company.
CM Interviews spoke with Mr. De Oto about his role to aggressively pursue the implementation of out-of-autoclave technologies to increase production rates and reduce costs for future products.
What are the driving forces for an automotive company like Lamborghini?
We are a niche within the automotive industry. We’re not dealing with high volume production, so for us it is more important to focus on the process to achieve good quality results and to match the target weight to power ratio. Weight is the key to our success, which is why we are focusing on composites structures.
Processability is often cited as a major adoption challenge for composites. Do you agree?
Processability is a current challenge for the composites industry. Compared to other materials, it simply takes too long and therefore is too expensive. For example, when manufacturing composite parts through RTM, there is a huge bottle neck in the preform process, which is why composites are not suitable for high-volume automobiles. SMC has more potential in terms of production rate but has not yet reached the performances of traditional pre-preg or RTM processes. The technology used is strictly dependent on the daily production rate. Overall, we are consistently looking at our processability because we know if we can reduce process time that lowers overall costs.
How is Lamborghini addressing this issue?
At Lamborghini we have developed a patented process – RTM Lambo – that manufactures composite parts under low pressure molding that is repeatable in low volumes and meets the very high quality standards needed for our vehicles. This isn’t the ideal process for manufacturers that have to produce large numbers of vehicles per year. For this reason, we keep an eye on process improvements both in aerospace and high-performance manufacturing because there may be a process adaptable to higher volumes that we can be adapted for those models.
What are the challenges and/or drawbacks to including carbon fiber for automotive parts?
Speaking generally within the automotive industry, the main challenge today is the cost.

A drawing of bus parts and a photo of the bus with parts made of glass fiber-reinforced material
We produce RTM molds (made of glass fiber-reinforced plastic) that enable us to achieve minimum production costs
An RTM mold for the production of bus parts
The final polymer composite parts (made by RTM) have the necessary inserts to make the assembly process easier.
Assembly of a bus with polymer composite parts

The main barrier to recycling has been the type of resin used; thermosetting resins predominate but these cannot be readily recycled.
“We have been working with the AMRC and a series of large trial panels have been produced using an innovative process which can readily be automated. These trials have demonstrated that recyclable composite panels can be produced at a rate and cost to suit many industries.
“The unique feature of the P2T process is the reduced tooling cost and lead time compared to existing metallic or composite solutions.”
Traditionally, the composites industry has been based on the supply of rolls of ‘pre-preg’ (woven fibre sheets pre-impregnated with resin) which customers then lay up in moulds to produce 3D parts, curing through heating and pressurising to fix the final shape. Thermosetting resins are considered convenient materials to support this supply chain but, as tighter end-of-life regulations are introduced, better alternatives are required.
The advantages of composites produced by the P2T process is that they can be recycled multiple times. The highest mechanical properties are obtained during first use of the virgin fibres, enabling highly-loaded structural items to be manufactured.
At the part’s end-of-life, the fibres and potentially the resin can be recycled, supplying much of the raw material for a secondary part, such as a body panel. When the secondary part reaches the end of its life, being thermoplastic, it too can be chopped and remoulded into new parts with properties suitable for 3D solid components. This tertiary part can itself be recycled several times into lower grade parts.
The ongoing research between the AMRC and Prodrive Composites is set to expand considerably over the coming year and is being closely monitored by numerous companies in various industries looking to improve their environmental impact with high performance, light-weight components.
Image provided by AMRC
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Analyzing pros and cons of two composite manufacturing methods
“Frontal polymerization doesn’t use an autoclave at all, so it doesn’t require that huge upfront investment,” said Bliss Professor Philippe Geubelle in the Department of Aerospace Engineering at the U of I. “It’s a chemical reaction sustained by the release of heat as the front propagates. It can save a lot of energy and it generates much less carbon dioxide, so that’s an environmental benefit.”
Geubelle said they began comparing the two methods by looking at the thermo-chemical equations in order to model the two polymerization processes. In that way, they could compare the methods for a variety of composite materials, and particularly, the time duration each method takes to manufacture the same part.
“The key contribution from the theoretical point of view is we've rewritten the reaction-diffusion equations to extract the two most important nondimensional parameters,” Geubelle said. “Using just these two parameters allowed us to look at a wide range of chemical parameters, such as the activation energy and the heat of reaction, and at the impact of the initial temperature of the resin”.
Geubelle said this method helped to compare the composite manufacturing processes based on bulk and frontal polymerization in terms of the time it takes to manufacture a part. The study found that there were instances when one or the other was faster.
“Imagine you want to make something that is one meter long. Frontal polymerization will be able to do complete the task before bulk polymerization starts to kick in,” Geubelle said. “On the other hand, if you want to make something that is 10 meters long, then bulk polymerization may actually take place before the front reaches the other end of the part. It's the competition between these two processes that we analyzed in this study.
He went on to say there are several ways to speed up the process for frontal polymerization: start the front at both ends so it goes twice as fast, or heat it from the bottom by using a heated panel beneath it. “That process is so fast, we refer to it as flash curing”, Geubelle said, “but it does use more energy than for a single front”.
Manufacturing composite parts using frontal polymerization instead of bulk polymerization has a lot of advantages.
“With frontal polymerization, you don't need the large capital investment of the autoclave, making it a very attractive option,” Geubelle said.

Over 1200 large holes ranging from 3/8" - 3/4" in diameter need to be drilled into the side-of-body fittings on the 787 fuselage over four different assembly lines. The material stacks are 4" thick and consist of several layers of titanium and CFRP which must be drilled for one-up-assembly (meaning no deburr). These parameters stressed the manual drilling process in meeting hole quality and build times. The problem is complicated by the location of the fitting, which is over 4 meters above the factory floor.
The main focus on finding an automated solution was stabilizing the drilling process for Titanium/CFRP stacks in the existing assembly lines. The solution was designed around a natural frequency of greater than 10Hz with a machine that weighed less than 8000lbs. Stabilization of the drilling process was achieved by focusing on three aspects: clamping on the fitting with double the drill thrust loads (up to 1200lbs), minimizing overall machine deflection to less than 0.020", and maintaining the relatively high natural frequency. Each machine is capable of being moved between production lines and both sides of the aircraft, allowing for increased production and maintenance flexibility. The drilling feed and speed are both servo-motor driven which allows for the drilling process to be controlled layer by layer. The on-board controls also monitor drill thrust and drilling profile for each drill bit at each layer to determine drill life. The result is improved hole quality, improved process reliability, and decreased manpower.

For example, multi-part moving parts such as ball bearings can be manufactured in a single production step.
In almost every case, additive manufacturing processes are slower and more expensive than established technologies. Nevertheless, there are cases in mass production where the additive approach is superior to conventional methods. The points mentioned show where: Whenever it is about
- individualized parts
- very complex parts
- parts with a very high metal removal rate and expensive raw material, or
- where a free interior design offers advantages,
additive manufacturing is worth considering.
The Advantages Outweigh the Disadvantages
There are a number of interesting examples for the benefits of additive production, even in the field of conventional manufacturing. Cooling channels in injection molds can only be produced by drilling the parts in the conventional process. Therefore, the manufacturer is limited to drilling straight holes into the block behind the mold cavity; if it is to be around the corner, several holes must be drilled in such a way that they merge with each other and the superfluous parts of the hole are plugged. This is complex and results in a very unfavorable flow shape of the channels.
If, on the other hand, a mold is produced in 3D printing, the channels in the mold block can be designed as desired, i. e. they can run directly underneath the surface of the cavity, allowing the mold to be cooled extremely efficiently and quickly, thus dramatically reducing cycle times.
One of the best-known examples of additive metal fabrication is the fuel injector of the new GE jet engines installed in the A320 Neo or Boeing 737 MAX. The internal design of the nozzles is crucial for optimum fuel distribution — the better the atomization process, the less fuel is consumed by the engine. GE's engineers have known for a long time how the optimum nozzle should look like on the inside, but this complex shape could not be produced and so far, these nozzles have been made up of more than 20 parts that were welded together. This was laborious, expensive and inaccurate.
Today, GE is printing these nozzles with an optimum geometry and, based on its experience, is embarking on additive metal production. GE plans to produce 40,000 of these nozzles per year by 2020 — 19 of these nozzles are installed per engine. In addition to the significant fuel savings enabled by the optimum design, GE saves 435 kg per engine.

SGL Group exec shares his journey in automotive space
FORT WORTH, Texas–Carbon fibers will not make it into the next generation of single aisle planes–unless manufacturers learn from “the painful lessons the automotive industry suffered from,” Andreas Wüllner, chairman, business unit composites–fibers and materials at SGL Group, said at the Aerodef show here recently.
“The usage of carbon fibers in the next generation of single aisle planes, which may enter into service during the second half of the next decade, will heavily depend on two factors,” he added. “First, is there a viable business case for the use of CFRP (carbon-fiber-reinforced plastic) in comparison to other materials? And, second, will the required low takt times be achieved with capable manufacturing technologies? Looking at the state-of-the-art autoclave production value chain, I’m skeptical that this will be the path forward.”
Takt time is the average time recorded between the start of production of one unit and the start of production of the next unit, when these production starts are set to match the rate of customer demand.
Highly automated, out-of-the-autoclave technologies must be implemented to achieve low takt times, said Wüllner, who has worked at the SGL Group longer than 20 years.
That’s because build rates of the single-aisle airliners will grow going forward: “Think about 10 to 12 twin aisles, A350 or B787, aircraft per month. Doing the math with 20 average workdays results in .5 aircraft per day or a takt time of something like 2,880 minutes. Compare this to a takt of approximately 5 minutes, which comes close to the BMW 7-series production!”
Building the Airbus 350 or Boeing 787 requires a production rate of one wing per day by 2020, he said.
“This is doable with autoclave technologies. But, imagine if six wings per day for the single aisle planes, A320 and B737, had to be manufactured with CFRP. How should this be achieved? Who could and would afford such investments?”
In automotive, carbon fiber composites evolved from carbon fiber prepreg monocoques—vehicle structures in which the chassis is integral with the body–for racing and super sports cars cured in autoclaves in the 1980s.

Pultrusion picks up speed in automotive applications
The automotive industry has been using pultrusion more and more.
According to CompositesWorld.com:
“Pultrusion is one of the most cost-effective processes for manufacturing high-volume composite parts. Most commonly associated with glass fiber-reinforced profiles used in construction and corrosion-resistance applications, tailored pultrusions for automotive applications — including bumper beams, roof beams, front-end support systems, door intrusion beams, chassis rails and transmission tunnels — were highlighted as a key area for growth by the European Pultrusion Technology Association (EPTA, Frankfurt, Germany) in its 2018 World Pultrusion Conference report.
“Two commercial launches highlighted at CAMX 2018 (Oct. 16-18, Dallas, TX, US) seem to confirm this technology/market fit. L&L Products, Inc. launched its Continuous Composite Systems (CCS) pultrusions, which use polyurethane resin for automotive applications such as side sills and crash structures. Designed to replace traditional metal structures that require bulkheads for necessary stiffness, CCS pultrusions offer light weight — 75% less mass than steel and 30% less than aluminum — at an economic price. Continuous fiber profiles include three variations: CCS Set using glass fiber, CCS Hybrid using a customized mix of glass fiber and carbon fiber, and CCS Extreme using only carbon fiber. A short-fiber version co-extruded with adhesive comprises a fourth product, CCS Co-Ex. The three continuous-fiber products may also be combined with L&L’s adhesives as part of the company’s in-line processing, further reducing manufacturing costs and time-to-delivery. Beyond automotive, CCS products are also aimed at wind turbine blade spar caps and industrial and architectural applications.
“Shape Corp. (Grand Haven, MI, US) also is developing pultrusions for automotive, but with a curve — literally. The company has the first operational installation of Thomas Technik & Innovation’s (TTI, Bremervoerde, Germany) Radius-Pultrusion system, which was exhibited at CAMX 2018. Shape Corp.

RAKU® EI-2510 Structural Liquid Resin System
With this resin system, RAMPF has developed a product to match the performance of toughened high Tg prepreg epoxy systems for vacuum infusion and RTM processing. RAKU® EI-2510 has a very low viscosity (200 mPas @40 °C) to allow for low-cost infrastructure and tooling while having an excellent pot life of 2 hrs and a short cure time (2 hrs @120 °C). Fully cured, the system has a dry Tg of 210 °C and excellent hot-wet properties. The system is designed for high fracture toughness and an excellent candidate for applications that are exposed to a harsh environment and high mechanical, thermal, and vibrational loading. Applications include cascades, control surfaces, and structural components.
RAKU® EI-2508 FST System for Interior Applications
This unfilled epoxy system combines excellent FST properties with the strength and performance of a toughened epoxy system. Its low viscosity and a temperature-activated cure profile allow for fast cycle times (full cure can be achieved within 15 min). The system is ideal for higher-volume aerospace components like seats (structural and non-structural), pack boards, wall and ceiling panels, overhead bins, and lavatory components.

The rubber transfer molding process is used to produce a full range of precision molded rubber, rubber-to-metal, rubber-to-fiberglass rod bonded components etc. The benefits of transfer molding are seen in mid to high volume production, tight tolerance, over-molding and applications with colored or translucent materials. The transfer molding process combines attributes of both injection and compression molding making it an ideal manufacturing method for many applications.
Rubber Transfer Molding Process Description:
Transfer molding, unlike compression molding uses a closed mold system. The process begins with a piece of uncured rubber that has been preformed to a controlled weight and shape. The preform is placed into the portion of the mold called a “pot” located between the top plate of the mold and the ram. The ram is closed which distributes (transfers) the uncured rubber into the cavity(s) through a runner and gate system. The material is held under high pressure and temperature to activate the cure system in the rubber compound (rubber is vulcanized). The cycle time is established to reach an optimal level of cure. At the end of the cycle, the parts are removed or ejected from the cavities and the next cycle begins.
Advantages of Rubber Transfer Molding
- Shorter production cycle times compared to compression molding
- Supports high precision molding applications
- Supports molding of complex geometries and over-molding
- Advantages for colored or translucent compounds
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Layers of material 14 may be in the form of dry fibers, woven cloth, braided cloth, knit cloth, mat, stitched layers of material, tow, yarn, tape, and the like. The fiber reinforcement can be comprised of, for example, various materials, including glass fiber, carbon, graphite, boron, aramide, and such materials marketed as Kevlar, and the like. Carbon reinforcement materials are particularly preferred due to their high strength and high modulus.
Tool 12 includes a continuous seal 20 around its perimeter for receiving an inflatable bladder or bag 22. Bag 22 is disposed within mold 10 to provide a cover for the layers of material 14 and is in direct contact with the top layer 14 of the ply of layers 14. Bag 22 engages seal 20 of tool 12 and is held in place utilizing a vacuum created within seal 20 through the use of a vacuum applied via a conduit 30. This seal is in place to create a positive control area for the resin. This seal could be a mechanical or a solid glued seal. The intent is to have control over the resin to allow the process to occur. During the process of fabricating a reinforced article in accordance with the present invention, bag 22 is periodically inflated and deflated through the use of a fluid supply, air or liquid, introduced into bag 22 through a conduit 32.
Resin is introduced into mold 10 for application directly to layers 14 utilizing conduits 36 and 38. The supply source for resin introduced into conduits 36 and 38 is located external of mold 10 and is movable with respect to mold 10 to move upwardly from bottom 10a of mold 10 to the top 10b of mold 10. During the course of manufacturing articles in accordance with the present invention, the top 10b of mold 10 must be elevated with respect to bottom 10a. Resin 10 utilized with the present invention may be selected from various resin systems including, for example, epoxy, epoxy novolacs, and other thermosetting resins, such as for example, vinylesters, polyesters, polyimides, both condensation and additional types, phenolic resins, and the like. The resin system is selected with respect to a particular fiber reinforcement for producing a finished article with the desired mechanical and environmental properties.

This discovery is useful, for example, in developing an in-situ grade thermoplastic tape and towpreg that can be processed on an Automated Tape Laydown/Automated Fiber Placement (ATL/AFP) machine at comparable speeds as a thermoset based tape, with the exception that no post autoclave or oven step is required after lay down. Cost modeling of the part fabrication has shown that 30% of the fabrication cost (recurring) can be saved by eliminating the post-processing (autoclave/oven) step. Furthermore, this discovery will also reduce the initial capital and facility cost investment to produce large composites.
Accordingly, the invention described in detail herein provides, in one aspect, thermoplastic compositions having a core composite layer that includes a fibrous substrate and at least one high performance polymer, and a surface layer polymer chosen from an amorphous polymer, a slow crystallizing semi-crystalline polymer, or combinations thereof, such that the surface layer polymer is applied on at least one surface of the core composite layer and forms a polymer blend with the high performance polymer, and wherein the Tm and Tprocess of the surface layer polymer is at least 10° C. less than the Tm and Tprocess of the high performance polymer of the core composite layer.
In another aspect, the invention relates to articles of manufacture made from the thermoplastic composites according to the invention described herein. Such articles are useful, for example, in the aircraft/aerospace industries among others.
Also provided by the present invention are methods for manufacturing the thermoplastic compositions described in detail herein by impregnating and/or coating the fibrous substrate with at least one high performance polymer, and applying a surface layer polymer as described in detail herein on at least one surface of the core composite layer, thereby forming a polymer blend between the surface layer polymer and the high performance polymer of the core composite layer.
In-situ grade thermoplastic composite tapes for use on an automated tape laydown or automated fiber placement machine are also provided.
These and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying Figures and Examples.
As summarized above, the discovery provides thermoplastic composite containing a unique resin-rich layer on one or more surfaces of a core composite layer containing a fibrous substrate that is impregnated with one or more high performance polymer.

The increasing use of carbon fibre reinforced polymer (CFRP) composites in aviation and automotive industries has led to the adoption of automated production methods such as pultrusion or resin transfer moulding (RTM) for cost reduction in the production lightweight structures. These processes however, offer limited freedom to locally reinforce structures. This paper describes an approach to utilise a basic geometry for several similar parts and add local reinforcement patches only in regions of load introduction or high local stress. The approach offers the benefit of being able to combine automated production methods with unprecedented design freedom. The specific bearing performance for three different local reinforcement using (1) add-on CFRP patches, (2) surface mounted steel foils and (3) steel foil interleaving in replacement of 90° plies with foils of the same thickness as the CFRP plies (0.125 mm) is compared by double lap bearing tests. The bearing strength improves with the addition of patches, for surface mounted steel foils, more so as CFRP co-cured patches, and most as an interleaved configuration. Quasi ductile failure of the bearing joints was maintained due to additional plasticity of the steel foils, producing a joint that fails safely while enhancing the bearing strength. When examining the hybrid laminates, all samples buckled and failed in bearing compression/shear. Brooming was evident on the compressive side of the hole where the bolt indented the laminate. Indentation led to shear kink bands along the washer supported region and appear as large compression/shear damage above the washer confined region of the laminate. When normalised by weight, the three approaches show similar bearing performance. However, each approach has specific advantages with regards to processing, electrolytic potential, or absolute bearing strength, depending on the design of the load introduction.

Engineers could use carbon fiber reinforced 3D printing to quickly build low-cost, lightweight, composite parts using an automated, digitally-run machine.
The Additive Advantage
Additive Manufacturing Technology and Innovation: 3D Printing Aircraft Parts
By Kelly McSweeney
Additive manufacturing, commonly called 3D printing, is no longer an emerging manufacturing technology. It has recently become more accessible for consumers, and it’s not uncommon to find a 3D printer in schools or homes. However, this type of on-demand manufacturing has been evolving in the aerospace industry for decades — and Northrop Grumman has been leading the charge.
Leveraging Different Materials for 3D Printing
The 3D printers most people know involve plastic. The printer heats plastic until it is soft enough to mold into the desired shape. Then hardens when cooled down. Advanced manufacturing, however, involves materials that have been designed to meet specific objectives. For example, in some situations, you may need a durable material, while in others, you may prioritize flexibility. In aerospace, engineers evaluate materials based on many factors, such as the ability to handle extreme temperatures and electrostatic discharge.
“We are now using five different additive manufacturing materials in our products – more when considering tooling,” says Barnes. He adds that they are investigating additional materials that can’t yet be announced.
Engineers have a variety of options depending on their program’s requirements. “The choice of material depends on the requirements and the cost benefit,” Barnes says. He explains that polymers are a cost-effective option for many applications, but in scenarios such as supersonic aircraft that get hotter than 300 degrees Fahrenheit, a metal such as Titanium is often the right choice.
The Advanced Manufacturing Methods for 3D Printing
Some industrial applications use the type of additive manufacturing you see available to consumers, in which a nozzle “prints” the object. This is called fused filament fabrication.
“We are using some of that, except the materials, the controls and the equipment are much more sophisticated and expensive than what you would use at home,” Barnes explains.
Other advanced methods are available, including a process called “powder bed fusion” in which powder is heated and sintered, often by a laser. Northrop Grumman does a specialized type of powder bed fusion in which the power source is an electron beam that produces parts even faster than a laser.

Kneath added, “The design flexibility of the materials, along with the technical support from Victrex, enabled us to engineer and manufacture a PAEK bracket that can be produced in minutes compared to the hours it would take for a metal or thermoset equivalent.” This improvement in manufacturing efficiency translates into less processing time, lower energy requirements, and reduced waste for Tri-Mack. Those benefits, paired with eliminating steps such as edge sealing and X-ray inspections, help to reduce overall part costs. The benefits are not only limited to aerospace designs. The overall mechanical properties, weight savings, and processing efficiencies offer a step-change for the automotive, energy, and consumer electronics industries as well.
VICTREX PAEK solutions and information on the hybrid molding process for the aerospace market can be found at www.victrex.com. To learn more about Tri-Mack’s engineering and manufacturing expertise, please visit www.trimack.com.
About Tri-Mack Plastics Manufacturing
Located in Bristol, Rhode Island, Tri-Mack Plastics Manufacturing is an innovative engineering and manufacturing company specializing in high temperature thermoplastics and thermoplastic composites. For 40 years, customers have relied on Tri-Mack to identify the best material, part design, and manufacturing process for their critical applications. Engineering expertise, cutting-edge technology and a commitment to quality enable Tri-Mack to support projects from initial concept to commercial production. Tri-Mack’s manufacturing capabilities include automated composite processing, injection molding, tool making, multi-axis machining, bonding and assembly. ISO 9001:2008 and AS9100 certified, Tri-Mack serves the aerospace, industrial equipment, chemical processing and medical industries. For more information, visit www.trimack.com.

Munro Tech Spotlight: Presidium Part Two – Benefits of RevoTherm®
In part two of our Tech Spotlight: Presidium, we’re highlighting the benefits of the company’s product, RevoTherm®, which stands for revolutionary thermoset. RevoTherm is a polyurethane-based thermoset resin system with material properties capable of replacing traditional composite materials in either a lightweight “neat” or reinforced system.
RevoTherm® is created in a two-part chemistry using a traditional isocyanate and Presidium’s “secret sauce”, a modified polyol that has structural properties up to five times stronger than typical urethanes. However, it retains the benefits of a urethane system with low viscosity that flows like water and cures into a finished part. This allows the material to easily flow into tools to make parts, so you can use low-pressure tools and processes that are relatively inexpensive compared to other industry equipment.
The RevoTherm® system is a clean (non-styrenic) and low-labor process suited for numerous manufacturing applications including closed- molding, pultrusion, RIM, and vacuum infusion using commercially available meter mix equipment and low-cost tooling. Compared to many traditional composite processes, the RevoTherm® system produces minimal waste and low VOCs.
In addition, part design freedom is expanded with the ability to add-in thick-to-thin areas, embosses and textures with no read-through. Being a polyurethane-based material, the end product has optimal adhesion properties for coatings and adhesives.
To learn more, visit: https://www.presidiumusa.com/revotherm.
Next week, we’ll share the last post for this Tech Spotlight series and highlight RevoTherm’s applications.
To view part one of this series, click here!

Other press improvements included innovative short-stroke designs that allowed a secondary hydraulic system to drop and lock the upper platen into position just above the tool and a much shorter, high-pressure stroke to be initiated from the lower platen." In addition to faster closing limes, the lower posit ion of the locked upper platen increased the effective rigidity of the press, enabling thinner parts to he molded with improved tolerances.54
Despite all of the improvements made in composites processing since the first Corvette, comparativeyl long cycle times still limited SMC' applications to lower-volume vehicles heading into the 1980s. The five-minute cycle time required in MFG's preform molding in 1953 had only been reduced to three minutes for a typical SMr molding by 1983. Between 1983 and 1988, however, a series of process improvements were developed to reduce cycle time (Figure 14).55
Vacuum-assisted molding was a key technology developed for shorter cycles. Removal of the air ahead of closing the press allowed use of thinner, higher diecoverage charge patterns without fear of air entrapment and blister formation. Thinner charges allow etl for faster mold closing times, which in turn enabled faster chemistries that would otherwise have led to pre-gel. Perhaps even more significantly, vacuum-assisted molding led to improved surface quality and allowed for the elimination of in-mold coating (Figure 16). This alone accounted for a 30 percent cycle time improvement.56
In the mid-1980s, improved microprocessor controls gave SMC presses unprecedented control of platen parallelism and closing speed. These presses thickness and therefore enabled thinner wall sections to be molded.57 In addition to cost and mass reduction, thinner parts also enabled shorter cycle times. By 1988, press improvements in combination with vacuum assisted molding enabled SMC productivity to finally meet the elusive 60-sccond cycle time that translates to better than 250,000 parts per year from a single tool.
Automation and robotics entered into the SMC molding process in the mid-1980s. Automated charge cutling, robotic charge placement, robotic demolding, and automated routing/ deflashing stations were gradually introduced into SMC plants.58 In terms of annual SMCproductionperworker. in 1985 the average was 12.5 tons; by 1990, this increased to 18 tons per worker.

To achieve these exceptional strength properties, various different plastic composite formulations can be used, of which include:
- Short Glass Fiber-Reinforced Plastic
- Improved strength, stiffness and heat detection properties
- Preferred material for cylinder heads and cooling components used in vehicle engines
- Long Glass Fiber-Reinforced Plastic
- Improve the high-performance and lightweight properties of vehicles
- More expensive as compared to other plastic materials3
- Reduces costs as a result of its lower specific gravity
- Carbon Fiber-Reinforced Plastic
- Reduces the weight of large vehicle parts (e.g., side panels)
Ease of Fabrication
Both metal and plastic materials require a series of fabrication methods to cut, shape or form the material prior to their incorporation into any product. The type of plastic materials being used plays an important role in determining the type of plastic fabrication method that will subsequently be performed; however, plastic materials offer significant advantages as compared to metals when considering the manufacturing process.
For example, the particularly low melting point and high malleability of plastic allows these materials to be easily formed into a wide variety of complex shapes; thereby contributing the ease of forming this material without requiring the use of any forming or machining procedures. Furthermore, plastic materials also typically exhibit a greater chemical resistance as compared to metals against potentially hazardous chemicals, such as those that cause oxidation or rusting when applied to metals4. Despite these advantages, plastic materials are not as heat resistant as metals, which can be concerning for industries that require their equipment and other products to be exposed to extremely high heat levels. Overall, plastic materials can be produced at a much faster rate as compared to their metal counterparts at a lower cost.
With this information in mind, it is clear why so many different industries have made the transition from metal to plastic. One of the most notable examples of an industry that has actively participated in this material replacement is the automotive industry. Some ways in which automobile manufacturers have replaced metal with plastic materials include:
- Exterior vehicle parts
- Front-end modules
- Trunk lids
- Deck lids
- Body panels
- Floor panels
- Air-bag containers
- Seat components
- Air ducts
- Chain Tensioners
- Belt pulleys
- Oil pans
- Cylinder head covers
- Gear components5
The aerospace industry has also actively looked to replacing their metal aircraft components with high-performance plastic materials.

Additive Manufacturing Additive Manufacturing - Arrived in the Mainstream
Additive manufacturing technologies are becoming a versatile production method for series production. However, you should be aware of its advantages and disadvantages if you want to use this technology efficiently.
Since man has first worked with materials, he has done it by removing parts of a blank. From stone-age man, who carved works of art from mammoth tusks in the caves of the Swabian Alb, to today's computer-controlled multi-axis milling/turning machines: the principle has always been the same: material is removed from a blank until only the desired geometry remains —be it a lion-man or a complex technical component.
These processes are quite flexible, as each part is manufactured individually. In mass production, however, automated processes are applied frequently and individually formed parts are considerably more expensive than identical serial parts. A further disadvantage of ablating processes is that the more complex the component is, the more expensive the production process becomes, and the more material is lost. For example, 98 % of the huge raw part made from the finest special aluminium that is used in the production of the wing frames of the Airbus A380 is transformed into inferior shavings, which can only be used to a limited extent.
Last limitation: The blank can only be machined from the outside. Although modern five-axis milling machines can move their tool very freely, the milling cutter must still be able to reach the point where it is removed — the inside of a workpiece can only be machined to a very limited extent.
Complexity is for Free
Additive processes — however different they may be in detail — are based on the principle that a material is applied layer by layer to create the component. Since the material is not removed, but added at the places where it is needed, hardly any waste is produced. In addition, the printer doesn't care how complex the form is — a cube is created just as quickly as a complex component: "Complexity is for free" is the motto. Equally, the printer doesn't care if each part has a different shape, since there is no shape to follow. In this way, individualized components can be produced just as quickly as identical parts.
Completely new possibilities are offered by the layered construction for the interior design of the component. Since the part is created layer by layer, the inside of the workpiece can also be designed as desired — with some restrictions.

The Brazilian company Edra Equipamentos has developed a sustainable technology for the molding of composite parts. Named RTM-G or Resin Transfer Molding – Glass, the process combines the injection of resin into the mould with the use of post-consumer waste from tempered glass, which acts as reinforcement material in place of traditional fibreglass or glass mat.
As well as allowing the reuse of the glass that would be discarded, the RTM-G only uses colourless resins derived from renewable and recycled sources and the peroxide used for curing or hardening the polymers is free of phthalates, which are substances considered harmful to the environment.
Initially, RTM-G will be used by Edra Equipamentos to produce furniture, in the initial testing phase tempered glass waste has rendered a very interesting aspect to the tables and benches that they produced.[rssless][connections id=’171′][/rssless]

Exothermic Molding is committed to the RIM process.
Reaction Injection Molding is ideal for producing highly designed parts of complex geometry, and strong and lightweight parts which can easily be painted. It also has the advantage of quick cycle times compared to typical cast and vacuum formed materials.
The thermoset mixture injected into the mold has a much lower viscosity than molten thermoplastic polymers, therefore large, light-weight, and thin-walled items can be successfully RIM processed. The low temperature, low pressure process allows numerous design freedoms including variable wall thicknesses ranging from .125″ to 1.125″ within the same part, and easy encapsulation of a variety materials including batteries, electrical circuitry and structural members.
This thinner mixture also requires less clamping forces, which leads to smaller equipment and ultimately lower capital expenditures for molds. Another advantage of RIM processed foam is that a high-density skin is formed with a lower density core creating robust, durable parts.

21 - 23 September 2016
Hall 1, booth 335R
Carbon Composites e.V.
29. November – 01. December 2016
Hall 8B, Booth F40
Global conference on MW wind blade design, composites manufacturing, performance and maintenance
12 - 14 December 2016
Maritim Hotel, Dusseldorf
14. – 16. marc 2017
Hall 5A, booth N6
Specially devised to facilitate the vacuum infusion process in intricate components, VAP® 3D ready-mades reliably remove air and gas residues from the matrix around where they are deployed. Thanks also to their semi-permeable characteristics, they support use of VAP® membrane systems over entire component surfaces in exacting fabrication and repair assignments.
As part of the AZIMUT and RoCk projects and working in response to calls for automated and optimized process chains, Trans-Textil and Composyst have developed a new made-to-shape approach especially devised for large aviation structures that need to be fabricated in one integral process. Starting with the geometry data of the Airbus A350 pressure bulkhead, this involved compiling the layers in the VAP® process lay-up into a VAP® 3D material kit made up of instant-use textile auxiliaries that have been tailored to the precise shape of the component mold.
The large-scale, multi-layer made-to-shape VAP® 3D solutions come with robot grip straps for swift, automatic and precisely-positioned layer stacking in the mold. This almost entirely eliminates the need for laborious cutting work and other preparatory tasks such as joining, positioning, repositioning and fixing the layers by hand. The VAP® 3D material kit has already proved its worth in a trial involving a full-size Airbus A350 pressure bulkhead in the RoCk Projekt.
New membrane products and enhanced fabrication technology at the JEC
The VAP® membrane-assisted vacuum infusion process has become a standard in serial production of high-quality fibre reinforced polymers components. Manufacturers worldwide have come to appreciate the high process stability delivered by the process with the help of semi-permeable membranes from Trans-Textil GmbH and Composyst GmbH. The two partners will be celebrating this success and showcasing related technology and products at the JEC Europe 2015 in Paris (hall 7.3, booth D6).

Using composite materials is hardly a new phenomenon. A trip to the British Museum will show you that the Ancient Egyptians constructed their tombs using bricks made from a primitive, yet effective, mix of straw and mud.
Today the moulds used for forming composites, also known as tools, can be made from virtually any material. For parts cured at low temperature or for prototyping where tight control of dimensional accuracy isn't required, materials such as fibreglass, high-density foams, machineable epoxy boards or even clay or wood models are often suitable.
For parts cured at higher temperature, or if high dimensional accuracy is required, or if the mould is expected to be used for high-volume part production, then higher-performance tools must be used. Materials for these tools include Invar (a nickel steel alloy), steel, aluminium, nickel, and carbon fibre.
Selection of the tooling material is typically based on the coefficient of thermal expansion (CTE), expected number of cycles, end item tolerance, desired surface condition, method of cure, glass transition temperature of the material being moulded, moulding method, the available curing equipment, and cost.
Steel and aluminium had traditionally been the materials of choice for high-performance tooling, but they can have major drawbacks when used to make composite parts. During autoclave cure, the CTE mismatch between the tool and the part is often too extreme for compatibility. Higher-priced metal alloys, such as Invar, can offer closer CTE matches but the high cost of machining and, for larger parts, the sheer size and weight of the tools makes them difficult to machine, move and store.
A new direction
Composite tooling, made of similar material to the final part, can offer a high-performance result without the high costs of metal. Once an art known only to a few dedicated aerospace and Formula 1 (F1) technicians, composite tooling is now widely in use, from weekend club race car builders to aerospace industry leaders like Boeing and Airbus. After decades of development and refinement, composite toolmaking has become less of an art and more of an easily repeatable, high quality process with predictable results.
“The use of industrial composites has been under development for over 50 years,” explains Jed Illsley, European Sales Manager for Amber Composites. “First, wet lay-up methods were used with resin and dry fabric — but obviously this wasn't an accurate method of controlling the amount of resin or the impregnation of resin in the fabric.

- Seamless hollow parts: hollow parts are seamless and do not require any bonding.
- Ideal for manufacturing simple shapes such as bottles: Simple shapes such as bottles can be produced at a fast rate and low cost.
Disadvantages of blow molding:
- Part geometry is limited and restricted to basic forms: blow molding is ideal for parts with simple geometry
- Tooling cost is very high: tooling is high and is approximately 6-10 times the cost of rotational molding tooling.
- Low volume production quantities are costly: due to setup costs, producing lower quantities drive prices higher.
- Surface finish is not aesthetic: parting lines can be pronounced and surface texture is not always desirable.
What are the advantages and disadvantages of Rotational Molding?
Advantages of rotational molding:
- Low cost tooling: tooling cost is low in comparison to blow molding due to the low pressures involved.
- Consistent wall thickness: because the process uses gravitational forces to spread the plastic inside a mold, parts form with uniform wall thickness.
- Double wall construction: double wall parts can be formed which are ideal for cases and containers.
- High strength and durability: structural features can be designed into parts providing additional strength and support for large flat surface areas.
- Seamless hollow parts: the parting lines on rotationally molded parts are discrete.
- Ability to mold complex geometry: design flexibility provides the ability to mold very complex and detailed assemblies.
Disadvantages of Rotational Molding
- Cycle times: the only disadvantage of rotational molding vs. injection molding and blow molding is the cycle times, however this can be overcome with multiple low cost tools.
Is Rotomolding Right for You?
When deciding whether rotomolding is the right process for you it is important to consider the following.
- Is low cost tooling an important factor?
- Does the design have a degree of complexity to it that prevents it from being blow molded?
- Does the project require a short production run to begin with and then ramp up afterwards?
If the answer to any of those is yes then rotomolding is the right process for your project. That is to say, if you are looking for a rotomolding company in California, contact us today for a free quote.
Most importantly, blow molding is ideal for simple tanks, however when it comes to manufacturing parts with more detail there can be additional tooling and process costs for secondary processes.
Roto Molding vs.

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Solution for Automated Drilling and Lockbolt Installation in Carbon Fiber Structures
ISSN: 1946-3855, e-ISSN: 1946-3901
Published November 10, 2009 by SAE International in United States
Citation: Schwarze, K. and Mehlenhoff, T., "Solution for Automated Drilling and Lockbolt Installation in Carbon Fiber Structures," SAE Int. J. Aerosp. 2(1):188-192, 2010, https://doi.org/10.4271/2009-01-3214.
Manual drilling and Lockbolt installation in carbon fiber structures is a labor intensive process. To reduce man hour requirements while concurrently improving throughput and process quality levels BROETJE-Automation developed a gantry positioning system with high performance multi-function end effectors for this application.
This paper presents a unique solution featuring fully automated drilling and Lockbolt installation (inclusive of automated collar installation) for the vertical tail plane (vertical stabilizer) of large commercial aircraft. A flexible and reconfigurable assembly jig facilitates high access of the end effectors and increases the equipment efficiency. The described system fulfils the demand for affordable yet flexible precision manufacturing with the capacity to handle different aircraft model panels within the work envelope.

These topics are solved by Airborne as follows:
The injection of thick walled large structures in a one-shot-process that is highly industrialised is a challenging concept. Airborne’s dedicated research & development department (Airborne Technology Centre) is therefore essential in creating the opportunities for our game-changing manufacturing technologies. Through Airborne Technology Centre, we have built up significant experience on a wide range of process technologies, among which the mentioned Resin Injection Technology.
A major and ultimately decisive topic in today’s development of the growing Tidal Energy market is bringing the Cost of Energy (CoE) down.
Managing the CoE is a challenge tidal turbine manufacturers are facing today. The CoE of tidal energy should be at least equal to the CoE in today’s offshore wind energy industry.
Tidal turbines are positioned 20 meter below sea level in open sea. Easy and quick repair of it is therefore not straightforward. As a result, maintenance costs are an important factor in the total cost of ownership of tidal turbines. The reliability of the turbine system and reliable blades are therefore essential conditions for success.
Another factor to bring the CoE down is directly related to the efficiency of the tidal turbines.
The efficiency of the turbine depends partly on the performance of the blades of the turbine.
Because of this, Airborne Marine focuses its efforts in the tidal turbine blades design and manufacturing on enhancing their reliability and performance.
Airborne addresses the reliability of the tidal turbine blades from the very beginning of the concept design process.
Most current tidal turbine blades design is based on two shells bonded together, as is routinely done in wind turbine blade design. Seawater conditions however are dramatically different from the air in which wind turbines perform.
To date, it remains unknown how the dynamics that are present in sea water will affect the performance of adhesive bonds over a longer period of time. When applied in structural composite products such as tidal turbine blades, it remains unpredictable what the effect of enduring heavy loads and fatigue on the blades will be on the long term.
For this reason, Airborne Marine’s standpoint is that tidal blades must be designed without adhesives in order to maximize the reliability of the blades. Based on hydrodynamic and maritime engineering experience, Airborne Marine has decided to reduce the risks caused by adhesive bonding. The application of the sophisticated and new to tidal energy Resin Transfer Moulding technology (RTM) will reduce that risk featuring double-sided tooling for thick-walled structures.

The structural foam made of polymethacrylimide, which was unexpectedly created during an experiment in the late 1960s, has some outstanding properties: it is extremely stiff, yet at the same time very lightweight and highly heat-resistant. In short: the ideal core material for composite parts. In a sandwich-design composite part, it can be easily bonded to carbon fiber facings, resulting in an extremely strong component that weighs much less than similar structural parts made of metal. “Such composites can then be processed without any problems at 180 °C (356 °F) and extremely high pressure, so they can be produced very quickly and efficiently - in this respect, ROHACELL® has huge advantages over other core materials,“ says Roth. That‘s why the polymethacrylimide foam has been used in lightweight construction applications worldwide for almost 50 years: found today in airplanes, helicopter rotor blades and drones. In other words: a material that seems to have been made for air taxis long before they existed.
The right composite materials deliver the right performance
Each air taxi model must prove two things above all: That they can fly safely - and that they can achieve acceptable speeds and distance ranges. Experts estimate that the eVOTL aircraft should reach speeds of at least 100 to 150 kilometers per hour - otherwise it would hardly be possible to save time compared to other means of transport. Currently, most developers are planning cabins that accommodate between two and five passengers. And, of course, the air taxis should be able to fly far enough at full load capacity before needing to refuel or recharge. Less weight means less energy consumption - or more energy for faster speeds and longer distances. The right composite design and materials will be very crucial here: The solution is a lightweight sandwich structure with carbon fiber reinforced plastics on the outside and ROHACELL® as a structural foam core on the inside. In addition, there is the important issue of sustainability: The lighter the air taxi, the more we can support their argument for being energy-saving, sustainable alternatives in the transport mix of the future.
The combination of materials and the associated production costs become all the more important when it comes to complex components, complicated shapes or a wide range of force effects. This is where ROHACELL® is a stand-out material solution, since its high temperature resistance allows manufacturers to significantly reduce both production time and cost.

As a result, areas of air remaining within material layers 14 in the cured articles produced in accordance with the present invention are kept to a minimum. Air is also removed from mold 10 through the process of convection, the property of a gas or liquid to rise when heated. The resin sets creating an exothermic reaction and the generated heat from the setting resin drives air bubbles upwardly, displacing air voids.
During the process of resin moving upwardly within mold 10, the source container of resin is also moved upwardly external of mold 10 above the wick line, the boundary between resin impregnated fiber and non-impregnated fiber. When the resin has reached top 10b of mold 10 and saturated the entire layers of material 14, excess resin is removed via conduits 40 and 44.
The wicking action utilized in order to move resin from bottom 10a of mold 10 to the top 10b of mold 10 thereby saturating layers of material 14 is accomplished without the use of vacuum or extreme pressures as utilized with previously developed methods. Any configuration of a part can be fabricated utilizing the present method determined by the shape of tool 12 and the number of layers of material 14 utilized. Areas of the part which require reinforcement can be provided within tool 12.
Once the resin has risen to the top 10b of mold 10, the supply of resin to mold 10 is terminated. Pressure may be increased within bag 22 in order to squeeze excess resin from layers of material 14. After a predetermined time interval, the resin is allowed to cure. Once cured, the part may be removed from tool 12 and mold 10.
It therefore can be seen that the present invention provides for a method of producing a fiber reinforced article utilizing wicking and capillary action of the resin moving through the fiber. High pressures such as those associated with autoclave techniques or vacuum techniques are not utilized with the present method. High fiber volumes with low air voids can be achieved utilizing the present method. The present method has achieved aerospace quality composite parts having fiber volumes of over 50% with less than 2% air voids.

Whether for aerospace components, prototypes in automotive manufacturing or chemical engineering, conventional industrial manufacturing processes come up against their limits wherever small component lots contributing high value are concerned. In situations like this, 3D printing enables considerable cost savings as well as new design options. In future, 3M will be offering precisely that for fully fluorinated polymers such as polytetrafluorethylene (PTFE).
The industry has been striving for years to manufacture components in ever bigger lots. Optimised production processes involve very high start-up costs for tools and require complex steps to be programmed. These costs are recovered very quickly, however, owing to the scale effects which result from the manufacture of hundreds of thousands or even millions of the same component. The most common processes are thermal ones in which metals or plastics are fluidised and cast in prefabricated moulds. They are often subtractively machined afterwards. Special tools such as drills or milling heads remove material until the desired geometries are achieved.
Limits of conventional manufacturing
These conventional manufacturing processes require a lead time, for example for ordering tools and programming the machining operations. Furthermore, design engineers are obliged to ensure that components can be manufactured using conventional methods. More complex components with several functions therefore generally consist of various individual parts that must be assembled afterwards. This in turn creates sealing points.
Non-melt-processable materials necessitate subtractive machining from blanks. This produces considerable quantities of unusable production waste – which is very uneconomical when expensive materials are a must. A further disadvantage is that moulded PTFE parts manufactured in the conventional way are almost always solid, thereby increasing the component weight. This is detrimental for aerospace or automotive engineering, where every additional gram counts.
Small lot sizes
In contrast to established large-scale manufacturing, the trend in Industry 4.0 is moving towards economical production of very small lots. Additive manufacturing is an important link in a digital engineering chain. In future, it will be possible to manufacture lightweight, ready-to-install, multifunctional moulded parts from CAD data in a single step, avoiding tool costs and long lead times.
In additive manufacturing without tools, the parts are printed in 3D. Based on digital design data, each component is built up layer by layer through the deposition of material. Unlike in the private sector, additive manufacturing processes are already widely accepted in numerous industrial applications.

Victrex has developed a new PAEK-based polymer and an innovative hybrid moulding technology. This allows engineers to overmould a PAEK-based composite with fiber-reinforced PEEK injection moulding materials. The polymeric advancement allows engineers to design stronger, lower cost components that are up to 60% lighter than typical metal and thermoset systems. By working together, Victrex and Tri-Mack Plastics Manufacturing Corporation have engineered an aerospace bracket using this new polymer and technique with the demanding performance requirements of loaded applications in mind. Victrex will be exhibiting its latest aerospace solutions at the Aircraft Interiors Expo on October 14-16, 2014 in Seattle, Washington, at the Fakuma show on October 14-18 in Friedrichshafen, Germany, as well as delivering a paper on hybrid moulding at ITHEC which is held on October 27-28, 2014 in Bremen, Germany.
The development of technologies for the Aerospace industry is making significant progress not only from a material perspective, but from a processing standpoint as well. Engineers are requiring lightweight, complex parts at lower costs, higher processing efficiencies, and improved mechanical properties. This can be delivered by using the hybrid moulding process.
Victrex, an innovative world leader in PAEK (polyaryletherketone) polymer solutions, has collaborated with Tri-Mack Plastics Manufacturing Corp., a distinguished moulder of high temperature thermoplastic resins and composites for the aerospace sector, to deliver unique structural aircraft solutions.
Commercial aircraft use thousands of brackets from the cockpit to the tail of the plane. The total amount of brackets on an aircraft can add a significant amount of weight especially if they are made from metal. The hybrid-moulded VICTREX™ PAEK-based composite bracket is able to deliver up to 60% weight savings compared to stainless steel and titanium while offering equivalent or better mechanical properties such as strength, stiffness, and fatigue. “These technologies are enabling engineers to design lighter, stronger and more cost-effective solutions like the new bracket,” stated Tim Herr, Aerospace Strategic Business Unit Director for Victrex. Herr says, “This game-changing advantage over metals and thermoset composites is a result of our dedication to the future of flight.”
Tri-Mack has a long-standing relationship with Victrex in the development of high-performance aerospace components using PAEK polymers.

The lower mold is transported to a demolding station, where the cured hull is demolded and moved to a robotic trimming station. Meanwhile, the empty mold is returned to the pre-loading station for mold prep.
BIG BOATS AND BEYOND
Hulls for Sea Ray's larger cruisers and yachts are still open-molded in some Tennessee facilities and in three plants in Florida. The company is looking into converting these facilities to RIMFIRE and the Seemann Composites Resin Infusion Molding Process (SCRIMP). The latter is a patented VARIM process licensed by TPI International (Warren, R.I.), which substitutes for the upper tool a special resin distribution medium and silicon vacuum bag.
Sea Ray is now in the process of running tests to scale up RIMFIRE for cruisers in the 25-ft to 34-ft (7.6m to 10.4m) range. In time, it is possible that the company will employ RIMFIRE on its largest yachts (up to 68-ft/20.7m).
Licenses for RIMFIRE equipment and technology are available to custom molders outside the marine industry. Although RIMFIRE hulls are currently made in concave (female) molds, the process also works with convex (male) molds, and research is underway to incorporate longer fibers (up to 203 mm/8 inches long) and to enable spraying of fibers in directed orientations. Moreover, carbon fibers appear to be viable for RIMFIRE processing, but more R&D would be necessary before carbon preforms could be put into production.

Aeronautic & Automotive
OTEMAN technology offers automation and durable solutions for the aerospace and automotive industry. Our versatile machines allow cutting the most difficult shapes and the strongest materials such as carbon fiber, laminated materials, fiber glass, mat, glass reinforcements, woven roving, aramid, nylon, polyamide, foams, honeycomb, carpet and sandwich materials.
Oteman offers powerful solutions to optimize your workflow saving labor costs.
- 3D software for the design and simulation of models.
- Fabric optimization.
- Spreading and cutting equipment for fabric or leather.

CAMX 2018 preview: Matrix Composites
Appears in Print as: 'Composites design, manufacturing services'
Matrix Composites Inc. (Rockledge, FL, US), a designer and manufacturer of a range of high-performance composite components and assemblies, is emphasizing its design, development, tooling, fabrication, testing and integration services.
#autoclave #outofautoclave #camx
Long on technology firsts, this optimized, automated manufacturing process produces nothing short of the “perfect” bike frame.
Resin transfer molding makes CFRP passenger cell mass-producible for new model supercar.
When open molders turn to infusion, careful planning, material selection and training precede process efficiency.

Unlike filament winding, which requires a comparatively minimal level of human involvement, lay-up manufacturing involves manually stacking layers of resin-impregnated roving cloth, usually of fiberglass or carbon weave, in an open mold, and compressing them to form a solid composite product. Depending on the application, a mold or other tooling can be used to form the outer profile, while a technician can utilize various instruments such as squeegees and rollers to force the layers together and to impregnate additional resin throughout the stack. Further consolidating forces, such as vacuum bagging or mated molds, can add extra compression if the application warrants it. After the desired geometry has been formed, the composite is placed in an oven to cure.
Flexibility in forming composite structures.
The lay-up manufacturing systems allows for a high degree of craft and technical virtuosity on the part of a composites technician. A skilled technician can create complex composite structures that would be much more difficult via other production technologies. Additionally, the technician can manually orient the fiber arrangement for optimal strength and durability. Because of its labor-intensive nature, however, lay-up is primarily suited to low-volume runs or the production of specialty composite items that would be prohibitively difficult or low-volume for filament winding or compression molding techniques.
Wide-ranging potential for diverse composites applications..
Using the lay-up system, ACI has produced custom composite products from fiberglass, carbon fiber and aramid for everything from communications structures to defense armaments and ballistics applications.

- Vinyl - Window frames.
- Polyethlene - Grocery bags.
- PVC - Piping.
- PEI - Airplane armrests.
- Nylon - Footwear.
Many thermoplastic products use short discontinuous fibers as a reinforcement. Most commonly fiberglass, but carbon fiber too. This increases the mechanical properties and is technically considered a fiber reinforced composite, however, the strength is not nearly as comparable to continuous fiber reinforced composites.
In general, FRP composites refers to the use of reinforcing fibers with a length of ¼" or greater. Recently, thermoplastic resins have been used with continuous fiber creating structural composite products. There are a few distinct advantages and disadvantages thermoplastc composites have against thermoset composites.
Advantages of thermoplastic Composites
There are two major advantages of thermoplastic composites. The first is that many thermoplastic resins have an increased impact resistance to comparable thermoset composites. In some instances, the difference is as high as 10 times the impact resistance.
The other major advantage of thermoplastic composites is the ability reform. See, raw thermoplastic composites, at room temperature, are in a solid state. When heat and pressure impregnate a reinforcing fiber, a physical change occurs; not a chemical reaction as with a thermoset.
This allows thermoplastic composites to be reformed and reshaped. For example, a pultruded thermpostic composite rod could be heated and remolded to have a curvature. This is not possible with thermosetting resins. This also allows for the recycling of the thermoplastic composite at end of life. (In theory, not yet commercial)
Because thermoplastic resin is naturally in a solid state, it is much more diffcult to imprenate reinforcing fiber. The resin must be heated to the melting point, and pressute is required to impregnate fibers, and the composite must then be cooled under this pressure. This is complex and far different from traditional thermoset composite manufacturing. Special tooling, technique, and equipment must be used, many of which is expensive. This is the major disadvantage of thermoplastic composites.
Advances in thermoset and thermoplastic technology are happening constantly. There is a place and a use for both, and the future of composites does not favor one over the other.

“Given our expertise in the industry, we were excited to use a new polymer and process to develop an innovative product,” said Tom Kneath, Director of Sales and Marketing for Tri-Mack. Kneath added, “The design flexibility of the materials, along with the technical support from Victrex, enabled us to engineer and manufacture a PAEK bracket that can be produced in minutes compared to the hours it would take for a metal or thermoset equivalent.” This improvement in manufacturing efficiency translates into less processing time, lower energy requirements, and reduced waste for Tri-Mack. Those benefits, paired with eliminating steps such as edge sealing and X-ray inspections, help to reduce overall part costs.
The benefits are not only limited to aerospace designs. The overall mechanical properties, weight savings, and processing efficiencies offer a step-change for the Automotive, Energy, and Consumer Electronics industries as well.
Tri-Mack Plastics Manufacturing Corporation is an innovative engineering and manufacturing company specializing in high temperature thermoplastics and thermoplastic composites. For 40 years, customers have relied on Tri-Mack to identify the best material, part design, and manufacturing process for their critical applications. Engineering expertise, cutting-edge technology and a commitment to quality enable Tri-Mack to support projects from initial concept to commercial production. Tri-Mack’s manufacturing capabilities include automated composite processing, injection molding, tool making, multi-axis machining, bonding and assembly. ISO 9001:2008 and AS9100 certified, Tri-Mack serves the aerospace, industrial equipment, chemical processing and medical industries. For more information, visit www.trimack.com.

“This type of design has a number of advantages: Primarily for this project, it lends itself to FDM technology due to the smooth leading and trailing edges over each half-span.”
This configuration allowed all geometry to remain below the critical angles beyond which support material would be required as well having aerodynamic advantages over conventional fuselage and wing designs.

Composite Components Manufacturing Services
Our Composite Manufacturing Expertise
We excel at a full range of resin transfer molding composites manufacturing services:
- Composite Design and Engineering
- Composites Manufacturing
- Materials Testing
- Prototyping and Process Development
- Tool Design and Fabrication
Our proprietary processes and materials give us a significant competitive advantage, and we use that advantage to deliver the best composite products to industry leaders and innovators from a variety of demanding global markets.
What Sets Us Apart From the Competition
- State-of-the-Art Composite Manufacturing Processes
- Lean Manufacturing Methods
- Statistical Process Control
- AS9100/ISO-9001 Certification
- Nadcap Accreditation
- Implemented Continuous Improvement Plan
- Intranet-Based Quality System
We've established ourselves as an industry leader in the challenging and growing field of advanced composites products with our comprehensive composites manufacturing and engineering capabilities in a full array of advanced composites processes and manufacturing practices.
Our team of composites experts will help you understand which manufacturing method is right for the product you need. From composite molding processes like Composite Lay-Up to Resin Transfer Molding, we harness the latest technology and techniques to ensure your project's success.
Call 321-633-4480 today to get started on your next project

Software to Enable Composite and Assembly Development Processes for Modern Airframes 2009-01-3241
All trends indicate that composite structures are becoming an increasingly large percentage of modern airframes. Because of this, airframes are becoming both more efficient and more complex. This is due in large part to the fact that composite aircraft assemblies have huge volumes of highly interdependent design information. Creating the initial designs and making subsequent changes to these complex aerostructures is both time-consuming and error-prone. In this article you will learn how a tightly integrated suite of software for aerostructure development greatly increases design and manufacturing efficiency of today's complex composite aircraft assemblies.
In the aftermath of the first intensive, large scale, commercial composite airframe programs, exemplified by the Boeing 787 Dreamliner, many aircraft manufacturers are selecting carbon fiber reinforced plastic (CFRP) as the structural material of choice for the fuselage and/or wing of their next project. This is true for all types and sizes of commercial airplanes, including large, regional, business and general aviation aircraft. In this transitional period into a new age for the aerospace industry, lessons on composite engineering and manufacturing must be assimilated quickly to transform or adapt the overall development process to this new reality. The complexity of the multiple interactions between material choices, tooling selection, design methodology and manufacturing processes must be understood in order to devise the most robust and efficient approach.
In this article we describe how VISTAGY has been able to draw on more than 15 years of leadership in composite design, and its close association with the major actors of the global aerospace industry, to propose a global and flexible product development approach for composite airframe development.
The main ingredients of composite airframe development are reviewed in the context of a CAD integrated specialized environment including elements such as the overall fiber orientation strategy, design methodologies such as concurrent design and stress optimization and validation, design for the manufacturing process, design for assembly, and quality control procedures.

High-Performance Board and Liquid Materials for First-Class Modeling Products
RAMPF Group, Inc. is presenting its encompassing range of model, mold, and tool engineering materials for the automotive, marine, and aviation industries at CAMX 2019 from September 23 - 26 in Anaheim, CA – Booth P4.
The company based in Wixom, MI, develops customized solutions that are tailored to meet the specific requirements of customers throughout the entire production chain – from prototyping, model, mold, and tool construction to production. New in the portfolio are liquid resin systems for structural and interior aerospace composites applications.
The product highlights include:
RAKU® TOOL WB-0890 – Epoxy Board for Composite Manufacturing
This brand new board has an extremely fine surface structure, which significantly reduces both finishing and the amount of sealer that has to be used. The surface finish can be transferred from the master model to the prepreg mold, so that no re-sanding of the mold is required and the service life of the prepreg molds is significantly increased. RAKU® TOOL WB-0890 is easy and quick to machine and compatible with all industry-standard paints, release agents, and epoxy prepregs. Tg is 110 °C.
RAKU® TOOL WB-0950 – High Temperature Epoxy Board for Tools & Molds
This epoxy board can be bonded in various shapes and sizes. A special RAKU® TOOL adhesive matched in hardness and color is available. RAKU® TOOL WB-0950 is heat resistant up to 200 °C, has a closed surface structure, and exhibits excellent machinability and good dimensional stability. The board is used, amongst others, for the manufacture of lay-up tools for prepregs and vacuum forming molds.
RAKU® TOOL Close Contour Paste CP-6131
Close Contour Pastes are 2-component epoxy systems that are applied to a close contour substructure by hand or using a CNC machine. Many kinds of supporting structures can be used, including RAKU® TOOL SB-0080 styling board, EPS, and cast aluminum. RAKU® TOOL CP-6131 is easy to process and apply. The production process is fast and efficient – direct tooling does not require the production of a model, and the close contour shape facilitates faster milling times. Furthermore, as with all close contour products, less material is used and less waste produced.

To keep ahead of the competition, manufacturers of automotive components are looking to move from traditional materials such as steel and aluminium to lightweight composite alternatives.
Less weight on body and transmission components means that more technology can be added without increasing overall weight – ergo exhaust emissions – helping the manufacturers comply with increasingly strict emissions legislations.
In a nutshell, composites reduce weight, therefore keeping emissions down, and paving the way to automotive success.
Current composite technology uses Thermoset Plastics to produce parts that weigh less, but the future lies in Thermoplastic technology that can also be reused and recycled – an innovative new composite product that ticks even more green eco-boxes for car manufacturers.
Pultrex is developing this cutting-edge technology right now, striving to be at the forefront of composite manufacturing, to be able to bring improved Thermoplastic composite products to market. This will help companies worldwide manufacture automotive parts that weigh less than ever before, and at the same time manufacture parts with greater recyclability and with the ability to be reformed.
Successful car manufacturers will be the ones who meet and exceed emissions targets – making the switch to composite materials essential for part manufacturers.
Composites vs Steel and Aluminium
- Composites exhibit an improved strength to weight ratio compared to steel.
- Composites are better at handling tension than aluminium, reducing fatigue and maintenance.
- Composites can be custom-tailored to add strength without adding weight, ideal in critical areas that bend or are prone to wear.
- Composites are inherently corrosion resistant, able to stand up to severe weather and wide temperature changes.
- With the exception of carbon-fibre, composites are nonconductive superior insulators, resisting the flow of electric charge and unresponsive to an electric field.
- Composites streamline production and reduce maintenance because a single piece can replace an entire assembly of metal parts.
- Composites precise weight distribution enables balanced loading, less friction, and greater momentum.
- Composites are strong yet flexible, able to bend significantly without snapping.
- Composites absorb and dissipate vibrations, ideal for applications such as equipment mounts.

Resins that offer the highest capabilities are the most expensive, he says, listing the top thermal performers as polyetheretherketone (PEEK) and thermoplastic polyimide (TPI), both costing over $30/lb. That’s why users should not over-specify the thermal requirements of an application in order to needlessly avoid driving up the cost of the composite materials. (See box for Maki’s tips on specifying thermoplastic composites.)
RTP Company has developed high-performance long fibre compounds for metal replacement applications. Long fibre compounds produce tough, lightweight injection mouldable compounds, with reinforcement fibres running the entire length of the pellets. RTP is making long fibre compounds with fibres of more than 0.5 inch (12.7 mm) in length, Maki notes.
“We are able to get much better strengths, modulus and impact combinations, also fatigue endurance values than you can with traditional chopped, shorter fibre lengths and aspect ratios,” he says. “With the advent of long fibres, the use of thermoplastic composites has increased dramatically in automotive structures, specifically in front end modules and door modules, which in the past have used metal for structural support.”
He feels auto makers are gaining more and more confidence in these materials.
“They like the energy-absorbing qualities of these composites in crash situations. The material absorbs a lot of energy and provides improved safety,” he adds.
RTP is also spending a lot of time developing long fibre compounds with bio-based polymers, specifically PLA (polylactic acid). Maki discussed these materials at the Bioplastics Compounding and Processing 2011 Conference in Miami, sponsored by AMI Plastics, in March.
R&D for aerospace
A public/private partnership at the University of Twente in the Netherlands has been focused on thermoplastic composites since 2008, when Boeing, TenCate and Stork Fokker entered into a partnership to explore the potential of these materials for aircraft applications. At the university’s Thermoplastic Composite Research Centre (TPRC), researchers are working on process modeling and simulation of automated production processes. They are also examining the performance of new materials, as well as advanced joining methods for thermoplastics.
Remko Akkerman, Scientific Director of the TPRC, calls the partnership a perfect example of a public/private partnership because the members decide together on the directions the research will take.

transfer molding|
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CRP Technology has 3D-printed a 1:14 scale model of a yacht in carbon fiber composites in order to demonstrate the possibilities of the material used with its selective laser sintering 3D printing process and to give a boost to boat design. (Source: CRP Technology)
FDM is a very effective method for producing prototype parts. Process parameters will have a large influence on part performance. Since we are using a different method, the part results are different. Utilizing a Laser Sintering machine we have the ability to fully melt the material during the layering process, with the energy penetrating to the layer below. The material is non-isotropic, as the microfibers align themselves during the re-coating process, but due to the materials properties and machine settings we do not see layer separations. Even when used in high vibration areas such as the parts that CRP USA (our partner in Mooresville NC) produces for NASCAR teams that race the parts every weekend attached to an engine turning more than 9000 rpm.
Windform compares similarly to several filled plastics utilized in manufacturing. Data sheets are available at Windform.eu as well as charts that rank the materials in the Download section at the website. Ann Thryft has commented that the industry is moving forward to establish testing standards through ASTM Committee F42 (We participated in the kick off of this process a few years back). We encourage people who are interested to join and or follow the progress.
It is interesting that you are looking toward Aerospace. Windform materials have passed Out Gas testing per NASA screening and are being utilized to produce components as well as structures for Cube Satellites.
William, I agree. But we're some ways away from that goal. Lots of R&D is proceeding to establish such metrics, as we've reported several times. Meanwhile this yacht model is more of a proof of concept.
What would be really useful is a comparison of the physical properties of the printed composite object compared to those made in the standard manner. Is there a trade-off, and if so, how much? That is the sort of thing that is usefulk in considering as to if a fabrication method is applicable for some part.
The new composites manufacturing innovation center is intended to be a source of grand challenges for industry, like the kind that got us to the moon under JFK.

A need has further risen for a process of manufacturing composite articles which can be constructed with the strength of additional plies located along predetermined load paths without major changes in existing molds, which parts are fabricated to achieve consistent fiber volumes with lack of air voids throughout the final part.
The present method for manufacturing fiber reinforced composite articles creates articles of aerospace quality through a combination of siphoning, wicking and capillary action.
In accordance with the present invention, a method of molding an article of fiber reinforced material includes a step of providing a mold in the shape of the article for receiving fiber material. The mold includes a top and a bottom. A source of liquid resin located exterior of the mold is provided. The liquid resin is supplied from the source to the bottom of the mold and contacts the fiber materials. The liquid resin is allowed to wick throughout the fiber material from the bottom of the mold to the top of the mold through capillary action while the source of liquid resin is moved from the bottom of the mold to the top of the mold thereby saturating the fiber material with the liquid resin. The liquid resin is then allowed to cure, and the article is then removed from the mold.
For a more complete understanding of the present invention and for further advantages thereof, reference is now made to the following Description of the Preferred Embodiments taken in conjunction with the accompanying Drawings in which:
FIG. 1 is a diagrammatic illustration of a mold utilized to perform the present method; and
FIG. 2 is a cross-sectional view taken generally along sectional lines 2--2 of FIG. 1.
Referring simultaneously to FIGS. 1 and 2, a mold, generally identified by the numeral 10 is illustrated for use in carrying out the method of the present invention. Mold 10 is configured for forming an article of manufacture for impregnating a dry fiber reinforcement with a resin according to the present invention.
Disposed within mold 10 is a tool 12 (FIG. 2). Tool 12 has the configuration of the part desired to be fabricated. Dry fiber reinforcement layers of material 14 are placed against tool 12. FIG. 2 illustrates three layers or plies of material 14 within tool 12. Any number of layers 14 and any configuration of layers 14 to provide areas of reinforcement in the part may be utilized with the present invention to manufacture a fiber reinforced article.

To meet the challenge of producing quality products at a competitive cost, manufacturers long ago began automating as many of their manufacturing processes as they could, with the payoff coming from producing better products, cheaper and faster than their competitors.
The primary objective of automating a process is to reduce, or even eliminate, the manual or “touch” labor involved in a manufacturing process. The utopian vision is fully automated factories that would use intelligent robots and sophisticated machines to fabricate a variety of customized products quickly, inexpensively and without defects.
In businesses that produce a high volume of standardized products, automation can approach that vision. However, industries such as aerospace typically produce relatively small volumes of complex assemblies, in which the manufacturing process simply does not lend itself to fixed automation. Fixed automation systems have yet to reach the level of sophistication and flexibility of the trained human technician so, for example, jet engines are still assembled mostly by hand.
As sophisticated as humans are, they are prone to human error. Distraction, fatigue, illness and interruption, not to mention worker substitution because of absence, can all lead to mistakes. As a result, the most sophisticated assembly resource can be the most vulnerable to inaccuracies.
In spite of the fact that as much as 40% of manufacturing processes occur beyond the limitations of a fixed automation system, manufacturers can still realize benefits from automation in these manual environments. These benefits are derived not from replacing people with machines but from providing workers with right-on-time information that helps them accomplish their jobs accurately the first time, every time.
Simply put, right-on-time information augments human performance. Just as just-in-time inventory control avoids receiving material earlier than needed, providing right-on-time information avoids an operator receiving feedback too late to correct an error as it occurs.
Technologies such as augmented assembly and verification, for example, combine motion tracking, process tracking and real-time feedback to monitor assembly accuracy, detect mistakes and provide the operator with the feedback needed to immediately correct those errors. If the system also can document the resulting assembly accuracy, manufacturers can avoid duplicative manual verification processes.
This blend of man and machine enables the implementation of semi-automated manufacturing processes that leverage the best elements of both manual and fully automated approaches, while protecting against their respective weaknesses.
Moving Beyond Traditional Control Processes
The accuracy of traditional manufacturing processes often varies with the amount of manual labor involved. Take the example of an assembly procedure where human operators are applying fixture bolts with the use of a manual torque wrench.

“Having previously outsourced our thermoforming requirements, we found that we were accumulating significant labour costs and having to contend with lengthy lead times. However, since 3D printing these parts ourselves, we’ve reduced lead times in the conceptual phase by approximately 35%. The technology has enhanced our overall manufacturing process, allowing us to evaluate our designs quickly and eliminate those that are not suitable, before committing significant investment towards mass production,” concluded Cademartiri.
“We are seeing a growing trend among our customers to leverage our additive manufacturing systems as a manufacturing tool for a wide range of applications, in addition to direct prototyping. With the development of some of our recent, more durable materials, our customers can now enjoy flexibility in their choice of methods to create their manufacturing tools and test designs in their final production materials, before investing in costly metal tools,” added Nadav Sella, Senior Manager Manufacturing Tools at Stratasys.

This new resin family boasts better high-temperature and hot/wet performance than epoxy, closer to bismaleimide (BMI) in performance, but much less expensive. Benzoxazine is also room-temperature stable, not needing refrigeration or freezing.
Benzoxazines (a subclass of phenolics) have been known for decades and used in the electronics industry but were not previously marketed for structural aerospace applications. Henkel’s lab name for the resin is Epsilon. It’s available as a one-part, semi-solid resin for structural prepregs and in liquid two-part formulations for RTM. Henkel’s first commercial application is for aerospace tooling.
In other new moldmaking materials, Hexcel Corp. presented a high-heat prepreg called HexTool. It consists of carbon fiber and Hexcel’s HexPly M61 BMI resin. It is said to be very tough and quasi-isotropic, allowing for complex mold shapes. It heats and cools quickly, and is machinable, so molds are easy to repair or modify.
Molds reportedly can be built faster and with better surface finish using new FSP fiber-filled spray putty from Euromere of France. It is based on isophthalic polyester or vinyl ester and its density is 0.6 to 0.8 g/cc, half that of standard putty.
Several companies showed recently developed water-based mold releases. Henkel introduced Frekote 901WB last year for large composite parts. Chem-Trend offers Chemlease Hydrolease for multiple releases and Class A finish. And Axel Plastics showed XtendW-7837D, for producing wind blades with a matte finish.
Wind blade materials
Other new products are also tailored for the burgeoning field of wind-energy blades. As reported in April, Owens Corning came out with WindStrand single-end rovings and knitted fabrics made of a special glass that is up to 35% stronger and 17% stiffer than E-glass. They allow production of bigger blades without the use of more costly carbon fiber.
Gurit in the U.K. (formerly SP Systems) introduced thicker Sprint Triax prepregs (150 to 200 mm) for greater strength in large parts like the outer shell of wind turbines. Sprint Triax is a three-layer prepreg of epoxy film with fabric on two surfaces.

The cost-effective, tool-less production of lightweight components reduces fuel consumption, material costs and CO2 emissions. Engine and turbine parts as well as cabin interior components are typical applications for industrial 3D printing / Additive Manufacturing (AM. This is where the benefits of innovative EOS technology come to the fore: functional components with complex geometries and defined aerodynamic properties can be manufactured quickly and cost-effectively. Material and weight savings lower fuel consumption and CO2 emissions. Manufacturer-specific adaptations and small production runs are further arguments in favour of Additive Manufacturing technology.

Trends In Aerospace Composite Manufacturing
- Use of large, unitized structures is increasing.
- Improved designs and processing are required.
- Large parts are too expensive to be rejected.
- Careful evaluation (and possible repair) is required.
- Current inspection techniques (water- and laser-based) are not cost-effective in a lean environment.
Ideal system has
- Agility (robot-mounted),
- High sensitivity,
- Effective validation for large structures,
- Capability to lower system cost,
- And to move inspection closer to manufacturing operations
- On tool,
- And in uncured state.

Reaction Injection Molding, or RIM, can be a great alternative to achieve the mainstream look of molded parts without the high tooling costs or volumes needed for typical thermoplastic parts. Both processes allow incorporation of many features into a mold, but only RIM gives the designer flexibility to produce parts with significant wall thickness variations—typically from .125” to 1.125” in the same part. RIM can also produce high strength large parts at a lower price because mold pressures and costs are significantly lower compared to thermoplastics.
While both processes provide a solution for encapsulating metal, the low temperature, low pressure RIM process is also safe for electronics and other material encapsulation. Injection molded parts have a higher quality finish than RIM urethane parts, although RIM parts take paint and silk screening well for improved cosmetics and branding.
RIM is valuable for producing low volumes at a low cost, but for volumes over 500 per month, thermoplastic injection molding often becomes the more cost-effective processing option. Because RIM molds can be machined from aluminum instead of steel, the up-front tooling costs are typically less than one half that of a comparable thermoplastic mold. This is particularly beneficial when part volume is low. Since RIM tools can be made of softer materials, changes to tooling are also much more cost-effective than changes to thermoplastic steel tools.
Read more about it in our white paper, “5 Reasons to Use RIM for Complex Parts”. Download the paper at www.exothermic.com

Made of carbon fiber and epoxy, cyanate ester, or phenolic, Ultraflex has a distinctive shape like nested maple leaves, allowing it to conform to bends and curves without collapsing.
A different sort of core material is a very low-density syntactic-foam paste of epoxy filled with hollow glass spheres, used to fill the fan blades in the compressor of Airbus A380 jet engines. Huntsman Advanced Materials won a JEC aerospace innovation award for this Araldite 1641 product, together with co-developers Rolls Royce Engines and the Univ. of Sheffield in the U.K. Fan blades are typically filled with honeycomb for sound damping, but the paste is easier to apply and reportedly gives better sound damping and less vibration.
New resins and more
For styrene-free hand lay-up, Cognis in Germany developed new methacrylate monomers, trade named Bisomer, as styrene replacements in unsaturated polyester. Other chemical companies also are starting to market methacrylate monomer diluents to polyester composites fabricators.
Several companies introduced new epoxies with high-temperature or fire-resistance properties. Huntsman showed a new multi-functional epoxy, MY0600, made with meta-aminophenol, to provide long pot life as well as high modulus in aerospace parts.
Mader in France, in a joint venture with United Paint and Chemical Corp., came up with what’s said to be the first paint for composites that meets an M1F1 classification for extremely low smoke and low flame spread. When it burns, the only emission is water vapor. Up to now, the highest flame classification for composite paints was M1F2 or F3. Mader uses a patented process to graft fire-resistant fillers onto polymer. The product is aimed at automotive.
Ube Industries in Japan recently commercialized (under license from NASA) a polyimide thermoset called PETI-330 with an unusual combination of low viscosity and high-temperature performance. It cures at around 625 F and withstands up to 572 F for RTM molding or carbon-fiber pre pregs for aerospace or engine applications.
Henkel’s Aerospace Group in Bay Point, Calif., has developed a new toughened thermoset resin based on benzoxazine with low viscosity and long pot life for fabricating aerospace parts.

Ultramid B High Speed is said to flow at least 50% farther than standard PA 6, enabling reduced thinner wall thicknesses and lower weight.
Novel composite trailer
A liquid thermoplastic composite technology using Cyclics Corporation’s range of thermoplastic polyesters has been developed that is capable of producing large structural components, including the bed of a 13.5 m (44.3 ft) semi-articulated trailer. CBT® resin, the cyclic form of polybutylene terephthalate (PBT) is being used because of its very low viscosity during polymerisation and negligible volatile organic compounds (VOCs) during processing. Liquid thermoplastics provide toughness, durability, impact resistance and recyclability in low-cost polymers.
CBT resin is produced from standard PBT resin from BASF, which is partially depolymerised at elevated temperatures. The process converts PBT into a lower molecular weight CBT resin. A reversible reaction enables CBT to repolymerise to PBT, an engineering thermoplastic with excellent stiffness and chemical resistance, Cyclics explains.
Processing methods include resin transfer moulding (RTM), vacuum infusion and low-pressure bag moulding. The low-pressure moulding techniques for the trailer bed were developed by EPL Composite Solutions in the UK using prepreg materials from Ahlstrom Glass Fibre, Finland. The trailer was produced with three mouldings, the largest weighing over 1000 kg (2205 lbs). Lifecycle testing is continuing in the UK.
Lanxess, at the recent VDI Plastics in Automotive Engineering Conference in Mannheim, had an exhibit focusing on a new polyamide (PA) composites sheet that can be formed in an injection mould in a one-shot process. The company says it has succeeded in linking the simulation of the forming process with mechanical structural analysis, precisely describing the non-linear anisotropic material behaviour of the composite sheet. Reinforced with continuous fibres, the sheet is designed for automotive metal replacement applications.
In its booth, Lanxess also highlighted lightweight structural applications of its Pocan® PBT and Durethan® engineering thermoplastics based on PA 6 and 66 for electric and hybrid vehicles. Pocan offers high heat resistance, strength and hardness, low susceptibility to stress cracking as well as excellent slip properties and high abrasion and chemical resistance.

Just one layer
Lufthansa Technik Intercoat automates INTERFILL® coating process
INTERFILL® – a high-performance material
Lufthansa Technik Intercoat specializes in the coating of components damaged by wear or corrosion. With the help of an advanced epoxy coating process, components that would have had to be scrapped in the past can now be refurbished and continue to be used. The material that makes this possible is called INTERFILL®. Specially developed and tested for airworthiness, this material gives aircraft components a new life cycle while also improving their operational characteristics. As a result, the repaired components are even better than the original ones. So that INTERFILL® can be used for different components in the aviation, rail and automotive industries, several versions of the material have been developed that differ in terms of their possible applications, abrasion resistance and surface qualities. Up to now, INTERFILL® was applied manually in several layers with a thickness ranging from 0.05 to 0.5 millimeters.
Automation of the coating process
Now Lufthansa Technik Intercoat has accomplished something that was considered impossible for a long time: It managed to automate part of the INTERFILL® coating process. The component is fastened to a rotating device in a working booth. Then a robot arm applies INTERFILL® to the component surface through a fine nozzle. The entire new system was developed in-house at Lufthansa Technik Intercoat and built by an external service provider.
Huge time savings and improved quality
Thanks to the partly automated process, components can be coated in a single working step. A special applicator ensures that the ideal dose is applied with an even layer thickness. The improved application method prevents air pockets from forming within the surface, which reduces the amount of corrective work that used to be necessary at times. The innovative system provides consistent, high-quality results and saves a considerable amount of time.
For example, the time required to coat the component and cure the material could be reduced to a third of the normal processing time. This increases Lufthansa Technik Intercoat’s flexibility, since standardized processes mean the company is now able to process more components.
The next step: complete automation
The system, which has been running since September 2018, is currently able to process components of up to 500 x 500 x 500 millimeters in size and 25 kilograms in weight.

- Materials & Industrial Technology
Manufacturing Processes - Reaction Injection Moulding (RIM)
RIM Fundamentals of Reaction Injection Molding
Reaction Injection Moulding Process (RIM)
This is a permanent mould process that fits in the general category of casting as a manufacturing process and is sometimes abbreviated to the RIM Process.
The general mode of operation of this process is to combine two feeds of preheated, low molecular mass reactants in a mixing head and inject them at high speed into a split die. The mixing head opens to allow the mixed reactants into the die and closes again when it is full. The end result is a high molecular mass casting which can be removed from the mould once set using an ejector arrangement.
As with all casting processes, 3D shapes can be produced and if a low modulus material is used, slight re-entrant angles can be included in the design. This process is used mainly for the production of polyurethane, polyamide and composite components, with a wide range of chemically reactive systems being possible.
- Can produce strong flexible lightweight parts
- Relatively quick cycle times (limited by the reaction time of the polymer) as compared to vacuum cast materials
- Has a lower viscosity than thermoplastic polymers
- Lower pressure means lower clamping forces
- No waste material 100% utilization (providing there is no scrap which cannot be recycled)
- Cycle times are slower than standard injection moulding for RIM
- Raw materials are expensive
- Process is difficult to set up
- Surface textures are variable
- Can suffer flaws as a result of premature reaction
The process is generally likened to injection moulding with the obvious difference in respect to the materials used and it can be used for the production of large, lightweight and thin components. The automotive industry have adopted this process for the production of rigid foam automotive panels.
The use of composites to strengthen components through the introduction into the process of glass fibre or mica is also an attractive option for the production of automobile panels and other large sheet like components. When this is done the process is known as Reinforced Reaction Injection Moulding or RRIM.
R.I.M. Reaction Injection Moulding
Reaction Injection Moulding - Additional Resources
- Manufacturing Processes and Methods
The selection of a manufacturing process is done very much on the basis of a manufacturer choosing the process that best suits his needs.

A programming and simulation solution may take the requirements from the engineering design and convert them into instructions that can be processed by a layup machine. The part programs can be post processed, simulated or directly used by a machine to fabricate a part. The programs may include instructions for fiber placement machines (e.g., path for the head, angular position, and cut and add commands for the different tows), machining, etc.
 At block 160, the programs are used to fabricate the part. The layup may be automated or manual layup, wet or dry, or a combination thereof. The fabric may be deposited by an end effector that performs automated fiber placement (AFP) or automated tape layer (ATL). In other embodiments, the layup may be performed manually. If the layup is dry, resin is then infused. Caul plates may then placed on the part layup (depending on finish requirements). The part layup is then bagged and cured. Afterwards, the cured part may be machined (e.g., trimmed and drilled).
 At block 170, feedback may be provided to validate or modify the rules. For instance, if wrinkles are detected during laydown, and the rules had indicated that no wrinkles were expected, the rules would be modified.
 Reference is now made to FIG. 2, which illustrates a computer 210 including a processor 220, and computer-readable memory 230. A program 240 is stored in the memory 230. When executed in the computer 210, the program 240 accesses an engineering definition of a composite part and applies a set of rules governing material laydown prior to the laydown being performed.
 A method and apparatus herein enables the producilbilty (or manufacturability) of the composite part to be tested before the part is actually fabricated. By considering manufacturability during the design of a part, empirical testing is minimized, thereby speeding up part production. Trial and error are avoided. Multiple iterations of redesigning, refabricating and revalidating a part are avoided. Considerable time and cost is saved from the need to physically build validation coupons and follow an iterative process of testing.
 A method and apparatus herein also enable manufacturing tradeoffs to be made during the design phase. Trades may be made of potentially different tape width material, which provides flexibility in manufacturing, where the choice of automated equipment may be limited.

GETTING THE REACH RIGHT
Any robot with the requisite end effector and reach can be employed for RIMFIRE work. Sea Ray has set up robots made by the Manufacturing Automation Div. within Automation Technology Group of ABB Inc. (Auburn Hills, Mich.) and Nachi Robotic Systems Inc. (Novi, Mich.) and is currently building a system using a robot from Fanuc Robotics (Rochester Hills, Mich.). "Reach" refers primarily to the robot's ability to adapt to part geometry, rather than part size. The most critical elements of reach are the draft (the angle between the side and bottom of the mold) and the aspect ratio of width to depth, or height. Hull length is not a major factor because the robot is positioned in a stationary cell, and the mold moves through the cell while the robot operates. For extremely lengthy molds, multiple robots can be ganged inline to facilitate fast, thorough coverage.
RIMFIRE robots have successfully applied up to 10 oz/ft2 (0.31 g/cm2) of preform materials onto a 5-ft/1.5m high sidewall having slightly less than 3° draft with an 8.5-ft/2.6m wide hull in a concave mold. "Once the draft opens up more than 3° or 4°, we can preform about any size the robot can reach," Lammers says. "It's a versatile process with many options. In some cases, we can index the mold sideways, or rotate it so the robot is not spraying onto a vertically oriented surface," he explains. For a particularly tight radius, Sea Ray may hand lay glass mat into the angle before the mold enters the preform cell, so the robot spray doesn't bridge the angle and leave the area unreinforced and vulnerable to structural damage.
There are exceptions: Some complex geometries with both concave and convex sections or severe aspect ratios present areas the robot simply can't reach. For this reason, Sea Ray has not yet applied the process to decks. "Some of our decks might have sections about 4-inches [102-mm] wide and 2-ft [0.61m] deep, which is nearly impossible for the robot to reach into," Lammers explains.

New Hybrid Molding Process and Material Innovations From Victrex Delivers Next-Generation Aerospace Solutions
October 10, 2014
Victrex has developed a new PAEK-based polymer and an innovative hybrid molding technology. This allows engineers to overmold a PAEK-based composite with fiber-reinforced VICTREX® PEEK injection molding materials. The polymeric advancement allows engineers to design stronger, lower cost components that are up to 60% lighter than typical metal and thermoset systems. By working together, Victrex and Tri-Mack Plastics Manufacturing Corp. have engineered an aerospace bracket using this new polymer and technique with the demanding performance requirements of loaded applications in mind.
The development of technologies for the aerospace industry is making significant progress not only from a material perspective, but from a processing standpoint as well. Engineers are requiring lightweight, complex parts at lower costs, higher processing efficiencies, and improved mechanical properties. This can be delivered by using the hybrid molding process. Victrex, an innovative world leader in PAEK (polyaryletherketone) polymer solutions, has collaborated with Tri-Mack Plastics, a distinguished molder of high temperature thermoplastic resins and composites for the aerospace sector, to deliver unique structural aircraft solutions.
Commercial aircraft use thousands of brackets from the cockpit to the tail of the plane. The total amount of brackets on an aircraft can add a significant amount of weight especially if they are made from metal. The hybrid-molded VICTREX PAEK-based composite bracket is able to deliver up to 60% weight savings compared to stainless steel and titanium while offering equivalent or better mechanical properties such as strength, stiffness, and fatigue. “These technologies are enabling engineers to design lighter, stronger and more cost-effective solutions like the new bracket,” stated Tim Herr, Aerospace Strategic Business Unit Director for Victrex. Herr says, “This game-changing advantage over metals and thermoset composites is a result of our dedication to the future of flight.”
Tri-Mack has a long-standing relationship with Victrex in the development of high-performance aerospace components using PAEK polymers. “Given our expertise in the industry, we were excited to use a new polymer and process to develop an innovative product,” said Tom Kneath, Director of Sales and Marketing for Tri-Mack.