BASF (Ludwigshafen; www.basf.com) has introduced two “Ultradur” HR PBT grades that combine a high level of hydrolysis resistance (hence HR) with flame retardance and laser transparency for applications in automotive drives and other under-the-hood applications such as plugs, connectors and housings for electronic components.

The company said the materials pass climatic cycling tests to class 5 United States Council for Automotive Research (USCAR) standard. They also underwent accelerated climatic testing at a temperature of 85°C and a relative humidity of 85%. Test specimens were typically stored in this climate for up to 3,000 hours. It was found that the tensile strength remained constantly high over the test period. To identify the limits of the material, the company extended the test to 8,000 hours – this showed that the tensile strength was gradually impaired only after 4,800 to 6,000 hours.