Rubber products for vehicles need to adapt to new standards for automobile manufacturing
Jiangyin Longchang Machinery Manufacturing Co,Ltd , https://www.jylongchanggrinderline.com
"In 2007 and 2010, China will implement the national III and the State IV automobile exhaust emission standards respectively, and the fuel efficiency of vehicles will gradually increase. This requires that the heat resistance and oil resistance of automotive rubber products must be improved accordingly." This is Beijing Rubber. Professor Xie Zhonglin of the Industrial Research and Design Institute recently introduced it in an interview with reporters.
According to Xie Zhonglin, the National III standard limits the emission of nitrogen oxides from light vehicles to within 0.15 g/km, and the National IV standard to less than or equal to 0.08 g/km. In order to meet the exhaust emission standards of automobiles, the fuel efficiency of automobiles is continuously improving, and the temperature of engine hood and exhaust emissions is also correspondingly increased. This imposes higher and higher requirements on the performance of rubber products, especially rubber compounds, at high temperatures. Xie Zhonglin suggested that vehicle seals can be made of fluoroelastomer (FKM) materials, such as crankshaft oil seals with FKM instead of nitrile rubber (NBR) or acrylic rubber (ACM), stem oil seals can replace ACM with FKM, fuel injection device O-rings The FKM can be used for oxygen sensor bushings, electric fuel pump check valves and vane coupling seals. In addition, the special amine-resistant FKM is more suitable for applications in automotive power system seals. The use temperature of automotive heat-dissipation hoses should be increased from the current 125°C to 150°C, and later it may be increased to 175°C. The heat-dissipation hose material should be converted from the currently used sulfur-vulcanized EPDM to peroxide-cured EPDM. Further turn to silicone rubber or ethylene-acrylate copolymer elastomer (AEM). "The automotive timing belts are required to operate at 150°C (instantaneous 175°C), and the currently used neoprene (CR)/glass fiber cords are difficult to meet the requirements," said Xie Zhonglin. "The current trend is to use hydrogenated butyronitrile. (HNBR)/Aramid cords. Compared to CR timing belts, the durability of the HNBR timing belt can be increased by 2 to 6 times, and the heat resistance can be improved by more than 30°C."
Xie Zhonglin believes that vehicle rubber products must also improve fuel resistance. FKM's fuel resistance is the best, its fuel transmission rate is much smaller than NBR, so in recent years, the use of FKM to replace NBR in the application of fuel hose inner liner. For domestic ethanol (methanol) gasoline being promoted, FKM's ethanol-resistant (methanol) gasoline performance is also the best, and it is most suitable as the inner glue of fuel hose.