Modified plastics are better than general-purpose plastics in terms of flame retardancy, strength, impact resistance, toughness and other properties, and have a wide range of downstream applications, of which the automotive industry has become the fastest growing demand for modified plastics. The global market value of automotive plastics is expected to increase to $46.112 billion in 2018, and consumption is expected to increase by 11.3 million tons, and the average annual growth rate of domestic demand for automotive modified plastics is expected to be above 15% in the next few years. This is mainly attributed to: firstly, the global automotive production growth rate is stable; secondly, the lightweighting of automobiles makes the amount of modified plastics in a single vehicle increase. The main applications of modified plastics in the field of automotive lightweighting are as follows.
At present, there are mainly two forms of instrument panels: hard instrument panels and soft instrument panels. Soft instrument panels are generally adopted by more high-grade cars, while buses, trucks and other models basically use hard instrument panels. Instrument panels are generally made of modified PP materials, modified PP is mainly rubber-based toughening agents and inorganic filler materials; instrument panel skin materials are mainly PVC/ABS, PVC is weaker in impact and heat resistance, ABS mechanical properties and molding and processing capabilities are better, and can be combined with PVC, the combination of the two can form a complementary.
Door inner panel
At present, the more commonly used modified plastics for manufacturing inner door panels are ABS and PP, which are used to make the skeleton and have a buffer layer on the surface, and the buffer layer is made of PP foam, TPU, knitted polyester, etc. In some models of GM and Chevrolet, the skeleton, panels are made of glass fiber reinforced unsaturated polyester sheet molding compound (SMC) material, in some cars will also be made of natural fibers and PP hot pressing, this means can effectively reduce the weight of the door, reduce costs, sound insulation performance has been significantly improved.
Body coverings and chassis
Modified plastics to make body coverings, compared with metal coverings, the body is smoother, more accurate in size, and can be more optimized in terms of quality, noise, vibration and other conditions, so modified plastics are widely used in the roof cover, hood, luggage compartment cover, etc.
In the automobile chassis, there are greater difficulties in plasticization because of the large load to be borne. At present, it is mainly in the transmission and suspension system, steering and braking system of wear-resistant moving parts application of modified plastics, such as modified PBT, modified POM and other materials.
The bumper is one of the main parts using modified materials. Most of the bumpers on the market are made of plastic products, with PP, PC/ABS, PC/PBT and other materials for the bumper panel, wood or metal for the skeleton, and PP foam for the middle part. This type of material is not conducive to recycling from an environmental point of view. After continuous innovation in making bumper panels, TPO can be used, the skeleton can be made of glass fiber reinforced PP material, and the middle part can be made of foamed PP, using the same properties of the material used to make the bumper, which can be cleaned and dried before recycling.
Modified plastics also play an important role in the production of fuel tanks, and can be mixed with resin, adhesive, PA and other materials according to a certain ratio and then blow molded. In addition, fuel tanks can be made from materials such as ultra-high molecular weight high-density polyethylene, copolymer PA, and EVOH resin.
Engine Intake Manifold
At present, most of the modified plastics in the manufacture of engine intake manifolds are made using the AIM process. In some models of Chrysler and Cadillac engines, glass fiber reinforced PA is applied to the intake manifold.
The temperature in the operation of the car engine will continue to rise, so the parts around the engine must be able to withstand 220 degrees Celsius high temperature while maintaining high strength, if it is cold weather, but also to have the performance of low temperature, so generally use PA66 material to ensure the performance of plasticized parts.
Clutch actuation system
Clutches often work at high temperatures and are subject to pressure lubricants, so metal is used in the traditional manufacturing process, but in continuous testing, the advantages of modified plastics for clutch actuation systems have become more apparent.