French Tier 1 automotive manufacturer MGI Coutier (Champfromier) lowers costs and gains performance for engine and under-hood air ducting by specifying Arnitel® thermoplastic copolyester elastomer (TPE-E or COPE) from DSM Engineering Plastics. The diversified auto component maker uses Arnitel PB582-H, a high-performance grade, in clean and charge air ducts for a number of car makers, including Ford and PSA Peugeot Citroën.

“With MGI Coutier’s strong record of innovation in product design, we were pleased to offer both an innovative material and extensive process and design support,” said Bert Blom, Application Development Manager for Arnitel. “We enjoy working closely with MGIC because they proactively seek ways to take advantage of the strengths of our materials.”

The mechanical performance of the thinner Arnitel parts meets or exceeds that of their rubber counterparts. In under-hood air ducts, Arnitel offers greater stiffness and strength under both positive and negative air pressure compared to conventional rubber. The high level of crystallization in this Arnitel grade offers enhanced performance, particularly at high temperatures. As a result, part both wall thickness and weight can be reduced by as much as 40 percent compared to other TPE-E materials (and for wall thickness as much as 70 percent compared to rubber), providing potential cost savings for materials.

Further – again, compared to rubber – Arnitel offers up to 20 percent additional savings in processing, thanks to much shorter cycle times, as well as Arnitel’s fitness for blow moulding. Blow moulding offers easier processing compared to production with mandrels or conventional injection moulding and can additionally reduce the number of parts, so that what was once a fairly complex assembly can be reduced to one or two components.

In addition to strength and processing advantages over competing materials, Arnitel exhibits a range of properties that meet the needs of automotive applications. Arnitel PB582-H has a high melting point, allowing temperature peaks up to 175 C. It meets or exceeds the high temperature oil resistance performance specifications of Ford and other car makers.

Arnitel’s continuous use temperature (CUT) is 800-1000 hours at 150 C, providing an E-modulus three times higher than previous materials. Arnitel remains flexible down to -40 C, provides up to 50% longer life in heat aging tests than previous TPE-E materials depending on temperature level, and, finally, can reduce the noise level of air flowing through the duct.

Under-hood air ducts transport air needed for fuel combustion. They are increasingly complex systems that may include (in addition to the ducts themselves) filters, manifolds, turbochargers and air-coolers. Vacuum ducts and charge air ducts require chemical resistance to fuels and oil vapors, good mechanical strength under positive and negative pressure loads at elevated temperatures, excellent long term oxidative aging, and minimal wind noise through the air pipe.

Arnitel is a family of thermoplastic copolyester based elastomers that combine the strength and processing characteristics of engineering plastics with the performance of thermoset elastomers to provide benefits in processing and productivity. As thermoplastics, they do not require vulcanization, which can lead to substantial cost reduction. Relative to other elastomers, polyester-based materials offer the most consistent performance over their entire operating temperature range, since their properties vary little from low to high temperature extremes.