Wuxi No. 2 Rubber Co., Ltd. and Ningbo Joyson Holding choose DuPont™ Vamac® AEM and Hytrel® TPC-ET to meet tough turbocharged hose and air duct demands from SAIC
Wuxi No. 2 Rubber Co., Ltd and Ningbo Joyson Holding chose Vamac® AEM and Hytrel® TPC-ET for hot and cold side turbocharged hoses and air ducts for SAIC’s new 1.9 liter turbo diesel engine, to withstand high temperatures, pressures, and aggressive exhaust gases and fluids.
DuPont™ Vamac® ethylene acrylic elastomer (AEM) and DuPont™ Hytrel® thermoplastic polyester elastomer have enabled Wuxi No. 2 Rubber Co., Ltd. of Jiangsu Province, Ningbo Joyson Holding of Zhejiang Province, China, to meet a challenging turbocharged hose and air duct specification for the high performance IP22-23EU 1.9 liter turbo diesel developed by SAIC Motor Corporation Ltd., China’s largest automaker.
Wuxi No. 2 Rubber Co., Ltd. chose high temperature grade Vamac® Ultra HT AEM, blended with Vamac® GXF AEM, for the extruded hot side turbocharged hose, to withstand peak temperatures of 200°C, pressures up to 3 bars and aggressive exhaust gases and fluids.
The cold side assembly consists of two extruded hoses and a blow molded air duct of Hytrel® HTR 4275 that was produced by Ningbo Joyson Holding. Both hot and cold side units are expected to deliver lifetime service in these demanding operating environments.
“Zero quality issues”
“We recognize DuPont™ Vamac® as the world’s leading AEM material that would offer us zero quality issues and very stable processing. We have also received zero complaints from OEMs,” said Chuntao Sun, Wuxi No. 2 Rubber Co., Ltd. project manager for the SAIC development.
The company, one of the top 10 Chinese rubber product manufacturers and automotive Tier 1 suppliers, has a long experience with Vamac® since first specifying the DuPont AEM in 2002 to resist aggressive blow-by gas in a positive crankcase ventilation hose development for Volkswagen.
Collaboration on design and processing optimization
The successful turbocharged hoses development for SAIC is the result of close collaboration among Wuxi No. 2 Rubber Co., Ltd., Ningbo Joyson Holding and DuPont Performance Polymers. In addition to material selection, DuPont was able to support the project with its own in-house design and CAE analysis, including stress fatigue testing, to ensure easy processing and optimum end-use performance.
“We proposed a blend of Vamac® Ultra HT with Vamac® GXF to ensure better processing, and it proved very effective. By adjusting the Mooney viscosity in this way we were able to improve the extrusion process. Wuxi No. 2 Rubber Co., Ltd. is now mixing the compounds in its own plant, and is realizing cost savings through enhanced process efficiency,” said Zhi Qing Ye, automotive marketing specialist, DuPont Performance Polymers, China.
Turbocharging offers key benefits in improved engine efficiency, reduced fuel consumption and lower CO2 emissions. When the turbocharged components themselves can be made lighter, these benefits can become even more impressive. For example, turbocharged hoses and air ducts of DuPont™ Vamac® and Hytrel® can reduce unit weight by as much as 50% compared with conventional parts made of other materials. These and other DuPont polymers enable integration and reduction in the number of parts, and offer significant lightweighting opportunities through metals replacement.
Vamac® ethylene acrylic elastomers (AEM) are widely used by the automotive industry in an increasingly broad range of engine and transmission seals, gaskets, hoses and air ducts.
A new generation of Vamac® Ultra polymers, first introduced in 2006, provide step-change improvements in processability, performance and customer value compared to standard Vamac® elastomers, thus extending the range of applications for AEM parts.
The latest high viscosity AEM grades from DuPont also provide enhanced long-term heat aging properties—another important advantage for parts that must provide long-term functionality in automotive applications. High temperature Vamac® Ultra HT is being increasingly adopted for turbocharged hoses and air ducts because of its exceptional dynamic fatigue and heat resistance.
Hytrel® thermoplastic polyester elastomers (TPC-ET) provide the flexibility of rubber, the strength of plastic and the processability of thermoplastic, and include special heat stabilized, flame retardant and blow molding grades. They are ideal for parts requiring excellent flex fatigue and broad-use temperature such as automotive hoses and tubing, boots for CV joints, airbag doors and energy dampers.
The DuPont family of Hytrel® thermoplastic elastomers resists tearing, flex-cut growth, creep and abrasion, and offers strength and stiffness plus outstanding toughness while resisting hydrocarbons and other automotive fluids. They can be processed easily by conventional thermoplastic processes such as injection and blow molding, calendaring, rotational molding, extrusion and meltcasting.
Hytrel® HTR 4275 is designed for blow molding or extrusion techniques requiring high melt viscosity, and excellent mechanical properties at elevated temperatures.
Hytrel® RS thermoplastic elastomers containing 35% to 65% renewably sourced material can help reduce environmental footprint without compromising performance. Tests show the same performance and processing characteristics of original Hytrel®.