Pre-compounds take the heat

Paul Boughton

DuPont Vamac VMX5000 is a new and commercially available family of ethylene acrylic elastomer (AEM) pre-compounds that extend the upper temperature limit for AEM applications by 15 to 20°C – offering heat resistance 'as yet unmatched' in AEM, coupled with a long-term improvement in static heat ageing.

The new Vamac AEM pre-compounds, currently under evaluation by major auto OEMs and Tier 1 suppliers for seals and gaskets, air management system applications and high-temperature coolant hose covers, are expected to offer a viable alternative to fluoroelastomers (FKM) at significantly lower cost and lower specific weight, in a temperature range between 160°C to 190°C – especially where standard acrylic, ethylene vinyl acetate or AEM elastomers are no longer considered.

Vamac VMX5000 is designed to meet new challenges to automotive hoses and seals imposed by new industry trends such as high-pressure turbo charging, exhaust gas recirculation and other technologies requiring resistance to higher temperatures and aggressive fluids. The new Vamac pre-compounds also exhibit improved acid and base resistance compared to bisphenol cured FKM compounds, a feature of increasing importance for parts in contact with new oils containing aggressive additive packages or Blow-By.

Additionally, products in the Vamac VMX5000 Series incorporate a new filler system enabling much easier production of coloured non-black parts, leading to better optical colour control combined with superior compression set resistance.