The Polyplastics Group, Japan has introduced a new polybutylene terephthalate (PBT) resin that delivers excellent alkali stress crack resistance for a range of automotive applications. The new grade, Duranex 532AR, also exhibits outstanding hydrolysis and heat shock resistance and electrical performance for components in the chassis and engine compartment.
Duranex 532AR, a product of Polyplastics has successfully reduced the risk of cracking in molded articles by preventing alkali from penetrating the inside of the resin, thus imparting toughness that helps generate less stress. This alkaline can arise due to the formation of rust in metal parts. When treated with a hydrolysis-resistant formula, Duranex 532AR has greater durability than standard materials.
According to recent test, it is observed that when specimens are immersed in alkali, cracking occurs within two hours in standard material Duranex 3300 and in hydrolysis- and heat shock-resistant Duranex 531HS. Unlike this, no stress cracking takes place in Duranex 532AR even when immersed for up to 200 hours.
The sudden change in temperature can cause heat shock fracture issues in electrical components and sensors, which are metal insert molded installed near the engine. This phenomenon occurs due to a difference in the linear expansion coefficients of the metal and resin that differ by roughly a factor of 10. Duranex 532AR has outstanding heat shock resistance and is capable of withstanding these harsh environments.
Parts installed in the chassis section and lower areas of vehicles which can be splashed by water and mud, and come into contact with chemicals such as snow melting agents, have a combination of high reliability and long life even in harsh environments, when made of Duranex 532AR.