Newly developed thermoplastic polyurethane overmolding for busbars is more resistant to thermal cycling due to optimized thermal linear expansion with low processing temperature, low density, and colorability.

The transformation of the car from the combustion engine to the electric powertrain is progressing. Highly efficient battery systems are the key to success of electromobility as the power is transmitted from the charging components to the battery and from there to the electric motor. This is done by metal busbars. Plastic overmoldings ensure electrical insulation of the busbars and, thus, safe distribution of the high-voltage currents.

Optimized thermal linear expansion
BASF is expanding its portfolio with a newly developed thermoplastic polyurethane (TPU) from its Elastollan product line for these busbar holders. Compared to standard engineering plastics, Elastollan R 2600 FHF particularly stands out due to the optimized thermal linear expansion. Its linear thermal expansion coefficient is close to copper and comparable conductor materials. This reduces the risk of cracks occurring during temperature changes which increases the safety standard. Furthermore, Elastollan is halogen-free flame retardant achieving the classification UL94 V-0.

The TPU also has three convincing advantages compared to materials such as polyphenylene sulfide (PPS). It can be processed at lower temperatures, has a lower density and, due to its white color, can be easily colored even with bright pigments.

Simulation supports customers in product design
BASF can also simulate the design of busbar holders. Due to their mechanical processability, busbar holders made of Elastollan contribute to the mass production capability of electric cars and form an important piece in the mosaic of future mobility.