Compared to all previous versions in BASF's high performance resin range, Ultrason KR 4113, a representative of the polyethersulfone product line (PESU), offers hitherto unique friction characteristics. This feature is achieved by incorporating carbon fibers, graphite and PTFE (polytetrafluoroethylene). The property was measured precisely for the first time with the aid of state-of-the-art instruments by Nanoprofile GmbH in Kaiserslautern, Germany, which specializes in tribological investigations, i.e. friction and wear testing of high-performance polymers.
In the controlled oil pumps manufactured by Schwaebische Huettenwerke Automotive GmbH (SHW), Ultrason® KR 4113 has become the only plastic material qualified for serial application. Here, the wear-optimized PESU (polyethersulfone) proved to be better than galvanized aluminum. The SHW part is the world’s first production oil pump with need-based variable delivery. Photo: BASF - The Chemical Company, 2010
While the wear rate for classic Ultrason E 2010 is about 420 (10-6 mm³ N-1 m-1), the carbon-fiber-reinforced Ultrason E 2010 C6 has a value of only 3.0 and Ultrason KR 4113 one of only 1.5. In this case, the experts at Nanoprofile conducted unidirectional sliding wear tests using the ring-on-plate principle. In this test, a plastic specimen under a high load slides against a ring-shaped counterbody of hardened chrome steel at a defined speed under non-lubricated conditions. The value measured: the penetration of the counterbody into the test specimen.
First high-volume applications
In addition to the low wear and friction characteristics that were measured precisely and confirmed by an independent entity, Ultrason KR 4113 offers the well-known benefits of the Ultrason family: oil resistance, high dimensional stability and thermal stability up to 200 °C. This makes it ideal for special applications such as the new generation of oil pumps from Schwaebische Huettenwerke (SHW). The material exhibits better wear and sliding friction behavior than galvanized aluminum in SHW's variable-speed pumps.