Customised speciality plastics compounder Witcom Engineering Plastics believes the ever-changing requirements of the EV industry means there is a need to be able to react quickly. “Even though new requirements for EV cars are not all known or set by Tiers and OEMs yet, our agility and material know-how help us build new solutions quickly together with our customers,” says Christine Van Bellingen, Business Development Manager, Conductive Compounds.
“Metal replacement for weight reduction, coupled with electrification and digitalisation, open new opportunities for EMI shielded plastics compounds. The challenge is to keep performance at lower thickness and at an acceptable cost. At Witcom, we have developed cost-effective EMI solutions to shield over various frequencies, making the switch from metal to functionalised plastics more attractive to the automotive industry. Final parts include sensors and housings,” she says.
“For over 15 years, we have been the worldwide reference supplier of radar absorption compounds used in RF absorbers and brackets for blind-spot detection and cross-traffic alert, for example. Our radar grades are based on many different polymers, including PA, PP, PBT and PC. This proven safety experience, together with the trust built over the years with our customers, make development engineers confident of specifying them for autonomous driving systems up to the highest levels,” Van Bellingen says.
Aside from the obvious mechanical, electrical and fire properties, the move to electric vehicles brings some perhaps less obvious requirements. “EVs make no noise. This means that any squeaking noise inside the car is uncomfortable. For that reason, we have seen an increase in demand for low friction, low wear technical compounds. For instance, our lubricated PA compounds exhibit a stable coefficient of friction over time, which is also independent of temperature and humidity, resulting in constant low wear and low noise. Applications include gears and bearings. PTFE-free solutions are part of our offering,” says Van Bellingen.
“There is some hope – although movement is slow so far – that new developments in the battery field will include more speciality plastics solutions to reduce weight and fabrication steps,” she says. “The two major fields that have been overlooked are EMI shielding and thermal conductivity for battery housings and cooling systems. However, technical targets are complex and intelligent mixed materials solutions will certainly have to be considered.” Van Bellingen says she sees one of Witcom’s key strengths is its ability to formulate compounds with multiple properties, combining EMI shielding, thermal conductivity and flame retardancy, for example.