New Elastomers Stand Up to Increasingly Hot and Aggressive Underhood Environments

Düsseldorf, Germany, Oct. 17, 2013 – DuPont Performance Polymers has responded rapidly to calls from the automotive industry for hose and sealing elastomers that can withstand increasingly hot and chemically aggressive engine environments – the result of trends in engine downsizing and turbo charging to reduce CO2 emissions and fuel consumption.

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Fluid ageing tests demonstrate the superior volume swell and elongation resistance of DuPont™ Vamac® Ultra HT-OR versus DuPont™ Vamac® Ultra HT, leading to better long-term dimensional stability in finished turbo hoses and other flexible, high-performance automotive parts.

Chart illustrates the superior acid resistance of new bisphenol curable DuPont™ Viton® FKM technology in aggressive acetic acid testing that destroyed standard bisphenol cured FKM, thus offering greater protection against acid gases and condensates in auto hose and sealing applications.

At K2013, the company introduced DuPont™ Vamac® Ultra HT-OR, bringing new levels of temperature and oil resistance to AEM, Vamac® Ultra LS, a high viscosity, low fluid swell, fast curing terpolymer AEM, and the latest bisphenol curable Viton® FKM for outstanding resistance to acids found in exhaust gas and blow-by gas condensates.

“As the automotive industry strives to reduce CO2 emissions, modern engine technologies create more severe environments for hoses and seals. We have developed Vamac® Ultra HT-OR and Vamac® Ultra LS to respond to those tougher requirements with higher standards of temperature and chemical resistance needed in the latest engines. These products push the performance envelope of the Vamac® AEM elastomer portfolio still further, and complement an already versatile set of offerings,” said Patrick Cazuc, Automotive director, Europe, Middle East, Africa, DuPont Performance Polymers.

“Acid-resistant Viton® FKM will provide the industry with an economic and much needed bisphenol alternative to peroxide cured FKM, offering protection against the acid gases and condensates generated by modern engines,” Cazuc added.

Raising Temperature and Oil Resistance in AEM

New Vamac® Ultra HT-OR (High Temperature-Oil Resistant) AEM, introduced at K2013, is an example of recent collaboration with hose manufacturers and OEMs to provide a clear improvement in resistance to hot oil, acid blow-by and recirculated exhaust gases in high-temperature turbo charger hose applications.

Vamac® Ultra HT-OR builds on the step-change improvement in AEM extrusion processing, temperature-resistant performance and customer value achieved when higher viscosity Vamac® Ultra HT was commercialized in 2012, by delivering good performance at temperatures up to 180°C, coupled with a 50 percent improvement in resistance to volume swell in IRM 903 reference testing oil. Along with Vamac® Ultra HT, this new product offers the best dynamic flex fatigue and heat resistance in AEM for turbo hoses.

While it can be considered the best Vamac® grade for HT-AEM turbo charger hose in continuous 165-180°C temperature service, Vamac® Ultra HT-OR is an alternative to HT-ACM at this temperature range, offering similar engine oil resistance and better acid resistance. Vamac® Ultra HT-OR is also tailored for positive crankcase ventilation hoses, and for exhaust gas recirculation sensor and diesel particulate filter sensor hose applications.

Better Processing, Low Fluid Swell with AME

A primary goal in the development of high viscosity, fast curing Vamac® Ultra LS was to provide improved injection moulding performance compared to Vamac® GLS by reducing the frequency of mould cleaning, improving de-moulding, and by helping compounders maintain or improve part performance in DOTG-free compounds. Its high viscosity compared to standard AEM also results in better mechanical properties (tensile and tear strength, elongation at break), and improved performance in major applications such as cam cover and oil pan gaskets, shaft seals, bonded piston seals, and positive crankcase ventilation and oil cooler hoses.

Vamac® Ultra LS combines excellent resistance to dry heat at up to 170°C, and exhibits good sealing performance and low swell in the hot air, acids, petrol fumes, engine and transmission oils present in auto powertrain engine, transmission and air management lines. Peak operating temperatures of 190-200°C are possible, while at the other end of the scale it retains good low temperature flexibility at -30°C.

The new Vamac® grade outperforms standard AEM in compression set and compressive stress relaxation testing, while offering better resistance to hydrocarbon-based automotive fluids than Vamac® Ultra IP. It is the AEM material of choice for low hardness static engine seals and gaskets.

Acid Resistance Comes to Bisphenol FKM

At K2013, DuPont released early information about a new bisphenol curable 'acid proof' Viton® FKM precompound that delivers improved organic acid resistance versus conventional FKM copolymers cured with bisphenol and standard metal oxides. The new Viton® precompound also offers a lower cost solution than peroxide cured FKM.

Aimed specifically at hose and sealing applications in automotive air management systems, acid proof bisphenol cured Viton® delivers excellent resistance to acid condensates found in blow-by and exhaust gases, and in aggressive biodiesel.

Major automotive applications for the new Viton® FKM precompound include sensor hoses for positive crankcase ventilation, and for exhaust gas sensors and diesel particulate filters, air intake manifold gaskets, quick connector O-rings and seals, intercooler and exhaust gas recirculation cooler seals, and rubber sleeves for plastic air ducts.

Elastomers portfolio

These products illustrate the DuPont Performance Polymers approach in bringing innovation to the automotive industry and are developed as a result of listening to customers’ needs, and then giving automotive OEMs and FTS the elastomers they need to fulfil engine performance, fuel economy and emissions challenges. The portfolio includes:

DuPont™ Vamac® ethylene acrylic elastomer (AEM) products – a family of heat and fluid resistant elastomers for flexible applications ranging from hoses, dampers and boots to seals and gaskets providing significant performance advantages over low temperature ACM and HNBR grades, including better low temperature resistance, high temperature performance up to 175°C, and opportunities for substantial cost savings compared to HNBR.

DuPont™ Viton® fluoroelastomer is available in many types that differ in chemical resistance and mechanical properties to meet specific end-use and processing needs. They offer excellent resistance to temperatures from -40°C to 200°C, and to aggressive fuels and chemicals in automotive, chemical processing and many other industrial sealing applications.

DuPont™ Hytrel® – an extensive range of thermoplastic polyester elastomers providing the flexibility of rubber, the strength of plastic, and the processability of thermoplastics for parts requiring excellent flex fatigue and broad use temperature. It resists tearing, flex-cut growth, creep and abrasion, and offers strength and stiffness plus outstanding toughness while resisting hydrocarbons and many other fluids.

DuPont Automotive offers more than 100 materials and product families for the global automotive industry. Through its global application development network, DuPont Automotive is committed to collaborating with customers throughout the value chain to develop new products, materials, components and systems that help reduce dependence on fossil fuels and protect people and the environment. For more information, visit automotive.dupont.com.

DuPont Performance Polymers is committed to working with customers throughout the world to develop new products, components and systems that help reduce dependence on fossil fuels and protect people and the environment. With more than 40 manufacturing, development and research centers throughout the world, DuPont Performance Polymers uses the industry’s broadest portfolio of plastics, elastomers, renewably sourced polymers, filaments and high-performance parts and shapes to deliver cost-effective solutions to customers in aerospace, automotive, consumer, electrical, electronic, industrial, sporting goods and other diversified industries.

DuPont (NYSE: DD) has been bringing world-class science and engineering to the global marketplace in the form of innovative products, materials, and services since 1802. The company believes that by collaborating with customers, governments, NGOs, and thought leaders we can help find solutions to such global challenges as providing enough healthy food for people everywhere, decreasing dependence on fossil fuels, and protecting life and the environment. For additional information about DuPont and its commitment to inclusive innovation, please visit www.dupont.com.

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10/17/13

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