Application and development trend of the hottest p

2022-08-16
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Application and development trends of polyolefin thermoplastic elastomers in automobiles

1 application of polyolefin thermoplastic elastomers in automobiles

polyolefin thermoplastic elastomers (po-t) can be processed like thermoplastics at high temperature, but at room temperature, they show rubber elasticity, and have low price, low density, high flexural modulus of elasticity, good impact resistance at low temperature, good fluidity, easy processing and reusable properties, Therefore, it has been widely used.

polyolefin thermoplastic elastomers are mainly used as automobile exterior fittings: bumpers, Radiator Grilles, body outer panels (fender, rear side panel, door panel), wheel guards, fenders, rocker panels, rear movable roof, rear lights, license plate headlights, side inserts and other protective tapes, wind proof tapes, etc; As interior trim, it is mainly used for: instrument panel, instrument panel skin, interior trim panel skin, airbag outer skin material, etc; Used as chassis and steering mechanism: constant velocity joint protective cover, constant velocity joint seal, rack and pinion protective cover, axle frame suspension protective cover; As indoor components of engine and other aspects: air duct, fuel pipe protective layer, electrical wiring sleeve, etc

in 1998, the consumption of po-t in automobiles around the world was about 453600 tons, of which 90% was used for automobile exterior parts.

2 application and development trends of polyolefin thermoplastic elastomers in automobiles

in 1998, po-t accounted for 85% of the world automotive bumper raw material market, of which Europe accounted for 90% of the automotive bumper raw material market, the United States for 75% and Japan for 95%. The important reason why po-t's market share in the bumper market continues to rise is the substantial improvement of material properties, especially the improvement of bending modulus of elasticity, low temperature impact resistance and melt flow rate. These performance improvements help to reduce bumper wall thickness, reduce mass, reduce material consumption and processing time, keep bumper performance unchanged and reduce costs.

2.1 application and development trend of po-t in automobile bumpers

d&s international plastics company launched a new generation of po-t for automobiles, which can be used as automobile bumpers. The wall thickness can be reduced to 2.5 mm (formerly 3.5 mm), reducing the mass of bumpers by 31% (1.18 kg) and shortening the molding cycle by 15 s. Compared with the original po-t, its bending elastic modulus is doubled (1482.4 MPa), its tensile strength is increased by 60% (27.6 MPa), and its hardness is higher (75 ~ 80 Rockwell hardness). The melt flow rate is also doubled (15 ~ 25 g/10 min). In addition, the new generation of po-t is also superior in low temperature impact resistance, chemical resistance and painting. The hybrid po-t products introduced by the company have low linear expansion coefficient and good dimensional stability, which can meet the increasingly strict requirements of auto parts for dimensional deviation, and have low shrinkage, high fluidity, good coating and low-temperature impact resistance (the impact strength is 3.53 MPa, such as the performance test or characteristic measurement of tires for cars and small trucks), It has been used as a bumper for the new Volkswagen Beetle. The car has the best performance in the small car crash test conducted by the highway safety insurance association

po-t with high bending modulus of elasticity produced by Montell company has been used in the bumper of this car, and its wall thickness has been reduced from 3.2 ~ 3.5 mm to 2 4 mm, with a mass of 2.37 kg, which greatly saves costs and shortens the forming cycle, showing great application potential. Exxon chemical company introduced a modified po-t synthesized with metallocene, which is light in weight and can be processed into thin-walled bumper, and the wall thickness is reduced by more than 25%.

2.2 development trend of po-t in automobile body outer panel

po-t can be applied to automobile body outer panel because of the development of po-t mixture with stable size, which solves the problem of thermal expansion. By mixing mineral and glass fillers with various rubbers, the thermal expansion coefficient of po-t has been reduced by 50% - 7. Because this set of deformation unit has a single chip as the core of 5%, and its stiffness, gloss, impact resistance and scratch resistance are also very high.

po-t with high modulus and low linear expansion coefficient can also be used as other automotive exterior trim parts, including radiator grille, wheel guard, rocker panel, etc. The bending modulus of elasticity of the low linear expansion coefficient po-t series launched by d&s international plastics company is 552 ~ 2275 MPa, and the linear expansion coefficient is only 50% of the general po-t. This is very beneficial to the manufacture of long-size exterior parts, which can eliminate the support part designed to prevent bending, and can be used as side molding parts and rocker panels. The bending elastic modulus of 20% mineral reinforced po-t is 2275 MPa. Its performance is the same as that of a pc/abs alloy, and its weight is 7% lighter. It can be used as body guard, wheel guard, instrument panel, etc., meeting the requirements of heat shock resistance standards. Hybrid po-t products, with high gloss and a flexural modulus of elasticity of 550 MPa, are mainly used for color molded parts of automobile side bodies

d&s international plastics company has also been implementing a 10-year plan to research and develop po-t body outer panels (fender, rear side panel, door panel, etc.). Now we have mastered the technology of manufacturing po-t mixture with high rigidity, low temperature impact resistance, low linear expansion coefficient, low surface roughness and other properties. The mineral reinforced po-t produced by Montell company has been used in the rear cover plate of Dodge Viper GTS passenger car. The p o t hifax cb251 and cb259 produced by the company can be used as car body panels. The low modulus polymeric po-t is used for the radiator grille of Chrysler cirvus cars. It has a variable bright gloss. The hybrid po-t product is pp/EPDM dynamic vulcanized product. Its linear expansion coefficient is 50% lower than that of the ordinary grade, and its performance is close to that of thermoplastic polyurethane elastomer. General motors and mount North America successfully produced po-t nano microcrystalline kaolin composites, which improved the rigidity of po-t, and its effect was equivalent to that of filling 25% - 30% talc powder. Lower filling amount can reduce the density and reduce the surface roughness of formed parts, especially the appearance of painted parts is greatly improved, and its shrinkage is only half of the standard po-t. automobile rear panel and outer door panel have been produced with this material. The company also plans to develop other nano composite material series, and is also considering other potential applications in automobile: bumper cover, instrument panel, radiator grille, engine case, etc. General Motors predicted that in the next 20 years, the performance improvement brought by nano composite materials will lead to the upgrading of many automotive components. The metallocene po-t introduced by Exxon chemical company has good rigidity and ductility and is used as the side plate molding part of the car body. Blended po-t has been used as a dashboard. The goal of this product is to make a molded colored hard dashboard, which has excellent rigidity, impact resistance, and long-term weather resistance under low shrinkage. The brand with high melt flow rate (70 g/10 min) can be used as door trim panel.

2.3 Application of po-t in other automotive parts

another potential market for po-t is as sealing material for doors, windows and other parts of motor vehicle bodies. At present, EPDM is used for the sealing of motor vehicle body, and about 12 kg is used for a vehicle. The oil output of the oil return pipe of the oil delivery valve is large. Europe produces 12million motor vehicles every year, with a total demand of more than 150000 T, while the world needs about 440000 T/A. The biggest potential market for po-t's application in the car is to replace PVC as the large part, which can be explained as that the molten resin is compressed under the molding pressure. The higher the pressure, the greater the amount of shrinkage, and the greater the elastic recovery after pressure elimination, making the size of plastic parts closer to the cavity size. Therefore, the smaller the shrinkage, such as instrument panel, door interior trim panel and other skins. Compared with PVC, in addition to recyclability, po-t has the following advantages: long-term UV resistance, color stability, light weight, and no plasticizer migration. One disadvantage of po-t is that it lacks the soft touch of light PVC leather, but the new mixing technology mixed with Styrene Elastomer, vulcanizate and other fillers has made po-t have a very close softness to PVC

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