Following the carbon main frame of the HP4 Race model, BMW Motorrad has now presented a lightweight rear swing arm. As part of the MAI Hiras+Handle project, a process was developed for the cost-effective series production of Carbon Fiber Reinforced Plastics (CFRP) in highly stressed and permanently stressed structural components. “Our production technology provides CFRP in the form of strong continuous fibers for parts exposed to high stress levels, while injection molding with short CFRP recycled fibers is used when the requirements are not quite that high. In this way, we have realized a cost-effective design that can be scaled according to requirements by inserting more or less strong continuous fibers into the same tool,” Elmar Jäger, Head of Project, says.
In addition, various composite and metal inserts are to enable further scalability. This means that the component properties can be specifically adjusted with just one tool at cycle times of less than one minute. This allows a wide range of different components to be produced. The maximum strength is adjustable by additionally attached, thermoplastically joinable CFRP plates.
Cost-effective Carbon Fibers for Lightweight Design
The so-called Com-Carbon technology from the Fraunhofer Institute for Applied Polymer Research IAP will enable carbon fibers to be produced cost-effectively for the mass market in the future. About half the cost of producing conventional carbon fibers is incurred in the production of the precursor, the Polyacrylonitrile Fiber (PAN). This so-called precursor fiber cannot be melted and is produced using the expensive solution spinning process. “We have developed an alternative PAN-based precursor technology that saves about 60 % of the precursor costs. It is based on a cost-effective melt spin process using special, meltable PAN co-polymers that we developed for this purpose,” explains Professor Johannes Ganster, Head of the Biopolymers Research Department at IAP. “Once they are converted to an unmeltable state, these cost-effective precursor fibers can then be processed into carbon fibers in the same way as conventional precursors using the established production routes,” he says.
High-strength UD Fabric for Rotor Blades
Saertex presented a newly developed glass fiber reinforcement material used in the production of rotor blades for wind turbines. The unidirectional, high-strength fabric should allow up to 20 % better values in terms of tensile strength. The product is an improved version of the textile unidirectional fabrics used in the belt. The aim of the development was to achieve better mechanical values and easier handling of the materials. The fibers now remain stretched and the composite component offers up to 20 % higher tensile strength than conventional glass fiber underlay. Infusion with resin also reduces resin accumulation between fiber strands and improves laminate quality. Shaft-free depositing in the mould not only makes handling easier for the customer, it also reduces the laying time during the production of the rotor blades by up to 15 % according to the manufacturer’s specifications.
Splice Film for Aircraft Construction
3M is launching a splice film with high storage stability which can be used almost universally, according to the company. The Scotch-Weld AF 3074 FST expanding structural adhesive film is designed to combine the advantages of the recently introduced Scotch- Weld splice film AF 3014 with FST (Flame, Smoke, Toxicity) properties and improved stability. It can be used in all areas of aircraft manufacturing, for example in landing flaps, engine casings or luggage compartments. The FST properties ensure that the film is particularly flame retardant and meets the requirements for applications in the aircraft cabin. This means that components inside the cabin of an aircraft can also be spliced safely. At the same time, the splice film is lighter and the degree of expansion reproducible. This means that the components can be manufactured more easily and less rework is required. The product also has a high storage stability at room temperature. This offers the advantage that it does not have to be frozen during transport and can be carried in the aircraft. The material also provides benefits from an occupational safety perspective, as it is not classified as hazardous to health. The splice film AF 3074 is available in different thicknesses.
Nibblers for Fiber Composites
With the Trutool FCN 250, Trumpf has developed a new nibbler which, according to the company, is the first of its kind in the world capable of separating various fiber composite materials. Components made of fiber composite material with a material thickness of up to 2.5 mm have so far primarily been separated using saws, milling cutters and angle grinders. However, high accuracies and clean cutting edges can hardly be achieved. In addition, smoke and hazardous dusts are generated when these tools are employed. With the now developed nibbler, these emissions are reduced, so that in most cases personal protective equipment can be dispensed with. The tool separates Carbon Fiber-Reinforced (CFRP), Glass Fiber-Reinforced (GRP) and Aramid Fiber-Reinforced (AFRP) Plastics both as thermosets and as thermoplastics. To make this possible, Trumpf has adapted the cutting geometry and the cutting tools to the new material.
Rosswag, Intec International, Cassini Systems, Tecosim, Altair and Fabrikado
Individualized Product in Real Time
Rosswag, Intec International, Cassini Systems, Tecosim, Altair and Fabrikado have jointly presented a demonstrator for a complete digitized development chain. The demonstrator is an additively manufactured seat carriage for the Paralympic biathlon. To start the process chain, sensors first determine the individual weight of the person to whom the carriage is to be adapted. This value is then transferred to a Product Lifecycle Management (PLM) system, which serves as an interface for data exchange and which also stores the CAD data of the seat. Using simulation, the structure of the seat is then adapted to the individual weight and simultaneously subjected to optimization. This not only results in an improved product, but also reduces the amount of material used. The optimized CAD data is transferred via the PLM system to an online platform, which automatically requests quotations for prices and delivery times from suppliers. The PLM system comes from Cassini Systems, Rosswag additively produced the seat carriage.
Joining Pressure Bulkhead of CFRP Thermoplast
The German Aerospace Center (DLR) has demonstrated a technology that allows the welding of pressure bulkhead made of thermoplastic Carbon Fiber-Reinforced Plastic (CFRP). The DLR Center for Lightweight Production Technology (ZLP) in Augsburg, Germany, was able to join a 1:1 scale demonstrator component within a very short time. The near-production pressure bulkhead for the A320 family was designed by the aerospace supplier Premium Aerotec and manufactured in cooperation with several research institutes. The research center shows that the welding process can also be applied to large, curved components with long welds. With this project the scientists aim to ensure that the potential of thermoplastic technology for short process times, low process costs and high production rates can also be used for large aircraft components in the future. So far, the use of thermoplastic materials has been limited to smaller parts such as thermoplastic clips employed in the CFRP fuselage of the A350 XWB. A total of eight equally sized segments of the pressure bulkhead were joined by means of electrical resistance welding. The welding process allows a flat and material-locking connection. In addition, unlike a metal pressure cap, no rivets are required, which results in weight savings — with shorter production times and economical manufacturing costs at the same time. Since the bores are omitted, the load-bearing fibers remain intact and no dust is produced. Further advantages are high process reliability and extensive possibilities for integrated quality assurance. Since the welding process has a high automation potential and enables simple tolerance management, it is well suited for efficient series production.
Thermoplastics Combined with Elastomers
Krauss Maffei presented for the first time a Fiberform application in connection with swivel plate technology for multi-component injection moulding. According to the company, the combination of hard and soft components together with high component strength opens up new fields of application for vehicle construction and other sectors. The company has now demonstrated that the Fiberform process, which combines thermoforming of organic sheet and injection molding in a single process, can also be joined efficiently with multi-component injection molding. A spinform with indexable insert technology produced a center armrest for the vehicle interior. A 1 mm thick continuous fiber-reinforced organic sheet was first overmolded with Polypropylene (PP) and then directly overmolded with a Thermoplastic Elastomer (TPE). According to Krauss Maffei, using organic sheet results in increased stiffness and strength of the component. This is said to make the reinforcing ribs and the component itself thinner-walled, resulting in a reduction in weight. The company sees application potential for the technology in vehicle construction for semi-structural lightweight components in the interior or between passenger compartment and engine compartment.