“We are working with Ford and others to evaluate higher loading levels of carbon fiber and glass fiber filled materials for more structural applications, which have also yielded mass savings from 23 percent to 33 percent over their aluminum counterparts,” Minnichelli says. “We also continue to develop continuous fiber materials, which can significantly increase strength and modulus for applications that demand even higher levels of performance than injection molded composite materials.”
Research at LANXESS likewise has sought to balance lighter weight with strength. One case in point is a mass-produced van battery console that has used the company’s Tepex solution since 2015. New and more demanding crash test standards prompted a switch to Tepex from an insert that previously relied on a consolidated hybrid yarn fabric made of glass and polypropylene fibers. Today the console is fabricated in a direct long-fiber thermoplastic process from a polypropylene compression molding compound, and then reinforced with long glass fibers and an overlay made of Tepex dynalite. The stiffness, strength and toughness of Tepex dynalite at a wide range of temperatures made it more suitable for meeting this structural need.
And in 2015, a large German car manufacturer began using Tepex dynalite for the mass production of underfloor protection panels. The polypropylene-based, low-weight, reinforced thermoplastics – which are used to manufacture underbody panels due to their sound-absorbing properties – are stiffened with Tepex surface layers. In this application, the panel is made in a one-step thermoforming process. The result, the company reports, is a component that can withstand the mechanical loads associated with operating an automobile under extreme on- or off-road conditions.
Hurdles to Broader Implementation
Although thermoplastic composites have been used in some automotive applications for decades, creating new solutions will require new technology and processes. One area still lacking is software that can accurately predict how thermoplastic composites will perform in an automotive part. “This has made designers and engineers hesitant to use these materials on a wholesale basis,” Wollan says.
Minnichelli elaborates, “One of the significant challenges of injection molded (short and long fiber) composites is the ability to accurately predict part performance using a highly anisotropic material, where material properties in the molded part are influenced by the molding operation and flow-induced orientation.”
BASF has solved this software challenge by developing its own performance prediction technology, which it calls Ultrasim®. According to Minnichelli, the tool enables users to model customer applications and very accurately predict final part performance, including the influence of flow-induced anisotropy.