Automobile polypropylene material enters a new stage (3)

Foaming modified PP

 

PP foaming material is a kind of low density material, which is made by increasing the melt strength of PP and thus increasing the foaming ratio. It has the advantages of light weight, heat resistance, high temperature resistance and so on.

 

With the development of automobile lightweight, the choice of PP foaming material has become an important way to reduce vehicle weight. At present, the application of PP foaming material in automobile interior decoration is more and more. The proportion of PP foaming material used in all kinds of automobiles is 45% for cars, 20% for construction machinery vehicles and trucks, and 35% for passenger cars and commercial vehicles.

 

Automotive PP foaming materials are mainly chemical microfoamed materials, because the apparent quality of ordinary microfoamed PP products is not ideal, only suitable for high-end vehicles that require a surface covering, it not only increases the manufacturing cost, but also limits the promotion and application of PP foaming materials; while the chemical microcellular foaming is based on thermoplastic materials and chemical foaming agents are gas sources. By the self-locking process, the gas forms supercritical state, and the gas after injection cavity under the action of diffusive internal pressure, the product is distributed in the middle of the product with a diameter of 10 to several tens of microns, and its ideal bubble diameter should be less than 50μm.

 

Microcellular foaming mainly includes injection molding micro foaming, blow molding micro foaming and extrusion micro foaming, etc. Injection molding micro foaming is suitable for all kinds of automotive interior and exterior accessories, such as body door, rear door, air duct, etc.; extrusion micro foaming is suitable for sealing strip, ceiling and so on; blow molding micro foaming is suitable for automobile air pipe and so on.

 

The use of micro-foaming technology can reduce the weight of PP products by about 10%-20%, reduce the injection pressure by about 30%, reduce the mode-locking force by about 20%, reduce the cycle time by 10% and improve the energy saving of automobiles, improve the warpage and deformation of the products, make the design of product and mould more flexible, in some parts, such as automobile air duct, it can also achieve the effect of heat insulation and noise reduction, and reduce the cost of the latter working procedure.

 

Radiation crosslinked PP high foaming sheet with density of 0.06g/cm3 has good mechanical properties. As the automobile roof, it can reduce the weight of automobile, at the same time, it can also be used for the interior parts of automobile, which is beneficial to the light weight of automobile.