With the vigorous development of the automobile industry, various raw materials for manufacturing automobiles have also been rapidly developed and updated, and more and more automobile parts have begun to use modified plastics to replace metal parts. The application of plastics in automobiles has a history of nearly 50 years. At present, the use of modified plastics for automobiles has become an important indicator of the level of automobile design and manufacturing. The large-scale application of plastic trims has promoted the weight reduction of automobiles. Energy-saving, improving the beauty and comfort of the car.
　　PP has been widely used in automobiles due to its low density, high cost performance, excellent heat resistance, chemical resistance, rigidity, easy molding and processing and recycling. Recently, there is a trend to unify the automotive interior and exterior materials into PP series materials. Due to the long development and production cycle of high-performance basic resin, huge investment, high technical requirements, and the need for high-precision integrated advanced comprehensive technology, the existing PP resin needs to be more extensive, more effective, more economical and more practical. Sex. Microcellular Foaming refers to the use of thermoplastic materials as the matrix and densely packed closed micropores with sizes ranging from ten to tens of microns in the middle layer of the product. Micro-foam injection molding technology breaks through many limitations of traditional injection molding. On the basis of basically ensuring product performance, it can significantly reduce the weight and molding cycle, greatly reduce the clamping force of the machine, and has small internal stress and warpage. High straightness, no shrinkage, stable size, large molding window, etc., especially in the production of high-precision and more expensive products compared with conventional injection molding, it has become an important direction of injection molding technology development in recent years. Polypropylene micro-foaming material can meet the requirements of large-scale micro-foaming automobile injection molding parts.

　　As the car is light With quantitative development, the use of PP foam materials has become an important way to reduce the weight of automobiles. At present, its applications in automobile interiors are also increasing. Among them, the use of PP foam materials in various automobiles accounts for the proportion of cars. 45%, trucks, construction machinery vehicles accounted for 20% , passenger cars, commercial vehicles accounted for 35% .

　　PP foam materials for automobiles are mainly chemical micro-foam materials. The apparent quality of ordinary micro-foamed PP products is very unsatisfactory, and is only suitable for high-end cars that require surface covering. This not only increases the manufacturing cost, but also limits the promotion and application of PP foaming materials; while chemical microcellular foaming is Using thermoplastic material as the matrix and chemical foaming agent as the gas source, the gas forms a supercritical state through a self-locking process. After the gas is injected into the mold cavity, under the action of the diffuse internal pressure, the diameter of the product is from a dozen to a dozen. Micron closed microcellular foam, and its ideal cell diameter should be less than 50μm, but the microcellular diameter of the micro-foamed PP actually produced in the domestic industry is about 80-350μm.

　　Microcellular foaming mainly includes injection molding microfoaming, blow molding microfoaming and extrusion microfoaming. Injection molding microfoaming is suitable for various automotive interior and exterior trim parts, such as body door panels, Tailgate, air duct, etc.; extrusion micro-foaming is suitable for sealing strips, ceilings, etc.; blow-molding micro-foaming is suitable for automobile air ducts, etc.

Using micro-foaming Technology can reduce the quality of PP products by about 10% to 20%. Compared with traditional materials, it can achieve a maximum weight reduction of 50% on parts, and the injection pressure can be reduced by about 30% to 50%. The clamping force is reduced by about 20%. % , the cycle cycle is reduced by 10% to 15%, and at the same time, it can also improve the energy saving of the car. Compared with traditional materials, it can achieve up to 30% energy saving, and can improve the warpage and deformation of products, so that the design of products and molds can be improved. flexible.

　　The radiation cross-linked PP high foam sheet has good mechanical properties. As a car roof, it can reduce the quality of the car. At the same time, it can also be used in the interior of the car, which is beneficial to the lightweight of the car. .

In summary, the application of polypropylene micro-foam materials in the automotive field Extensive, but need to pay attention: 1. Micro-foaming is a technology that has been verified by different products in various industries around the world. It has a wide range of markets, but its application in China is still new. 2. Micro-foaming can provide higher quality (reduce deformation, improve flatness, roundness and dimensional stability, no shrinkage mark) and lower cost (weight, molding cycle and molding tonnage reduction, and more material-saving product design ). 3. Micro-foaming can create new business opportunities-high-end applications and cost savings. 4. Not all products are suitable for micro-foaming technology, so we need to cooperate in finding suitable products.