No. 4 First invented by Wallace Carothers at DuPont in 1935, nylon (polyamide) was hot again at K2010. DuPont and BASF both introduced new nylons with better heat resistance in response to hotter under-the-hood temperatures. DuPont’s new Zytel Plus meets 180ºC service to 200ºC excursions with heat aging life twice as long as any conventional nylon.
BASF is also targeted UTH applications with a glass-fiber-reinforced polyamide that combines outstanding resistance to heat aging with the good processability of PA 66. Compared to the standard PA 66 grade Ultramid A3WG7, the processability has been improved notably as well. For comparison, Ultramid A3WG7 with the same glass-fiber content has a long-term service temperature of 170ºC, while products in the heat-resistant Ultramid W2 line (PA 66/6) can withstand 190ºC in continuous use. Formation of a protective surface layer even at temperatures up to 220ºCelsius provides continuous protection against attack by oxygen, according to BASF.
In Ultramid Endure, the surface is sealed off very quickly by the new stabilization and sealing process, so that the material remains protected – except for a thin layer of carbon black on the surface – even after four months at 220ºC.