While thermoplastic composite aerospace components have been of relatively small size in the past, that is changing. “Today we are making the step to large primary structures in thermoplastics, both for the business jet market as well as for the airliner market,” says Offringa. This will require the introduction of processes such as automated lay-up and high-speed welding technologies. Offringa says it also implies the use of unidirectional tapes instead of fabric-based materials, as well as new design concepts such as butt-jointed stiffeners.
Designing for New Markets
It’s not only aerospace and automotive manufacturers who are looking for the performance that LFRTs and CFRTs can provide. “The sports and leisure markets are prime examples of industries that are moving to higher performance,” says Steve Bowen, CEO, PlastiComp. “They are less sensitive to the cost of the material. These are people who are trying to win or perform at a higher level. If the benefit is obvious, they don’t mind paying a lot more to capture the performance advantage.”
Medical equipment manufacturers are also capitalizing on the strength and light weight properties of thermoplastic composites. Frog Legs, which produces wheelchair caster wheels, has replaced the aluminum in its casters with PlastiComp’s long carbon fiber reinforced thermoplastic composites. The thermoplastic injection molding process enabled the manufacturer to produce a much more complex shape, which has reduced vibration for the wheel chair user and reduced the weight of a pair of caster wheels by one third (a half pound). PlastiComp is currently focusing on improving the processing technology for thermoplastic composites. “How do you make bigger parts? How do you design the process? We are working on extruding lineal shapes; that will be a new market,” says Bowen. Applications for materials produced through extrusion could include fencing, shovel handles, lacrosse sticks and even pier supports that need to withstand tough environmental conditions.
DSM is working with the electronics industry to provide very thin smartphone frames and connectors. “You really have to make sure that you fine-tune your materials in such a way that they can be easily molded into those structures,” says Keestra. “You need to make sure that the intrinsic viscosity – the way the materials flow into the mold – is optimized to perform well.”
To encourage manufacturers in new markets to use composite materials instead of metals, material suppliers are constantly developing thermoplastic materials with specialized properties. For example, Arkema has developed three new products geared to specific uses. Kepstan can be used in aerospace and other industries looking for extreme temperature resistance, low smoke toxicity and a continual use temperature that can approach 260 degrees C. The company’s Rilsan® Matrix, a unidirectional polyphthalamide (PPA) tape, was created for lightweight, structural automotive parts and could find a home in oil, gas and chemical industries since it offers good hydrolysis resistance and better mechanical properties than short-chain polyamide thermoplastics, according to the company.