This invention provides a lightweight, low-linear-expansion, low-shrinkage polypropylene composite material and its preparation method. The material comprises the following components and weight parts: 30-100 parts of PP, 2-20 parts of talc powder, 2-16 parts of special mineral, 5-20 parts of toughening agent, 0.5-2 parts of antioxidant, and 0.1-1 part of lubricant; the special mineral is basic magnesium sulfate. The preparation method involves weighing each component according to the weight ratio, mixing them in a high-speed mixer for 4-6 minutes, and then feeding them into a twin-screw extruder through a hopper. Part of the PP, special mineral, and lubricant are fed in through side feeding. After melting and homogenization, the material is extruded and granulated to obtain the lightweight, low-linear-expansion, low-shrinkage polypropylene composite material. Compared with the prior art, this invention can significantly reduce the shrinkage rate and linear expansion coefficient of the product, effectively improving the dimensional stability of large-sized parts, especially bumper products. In addition, the density of this composite material is lower than that of materials of the same grade, which can effectively reduce the weight of the product, which is of great significance to the goal of lightweighting automobiles.
Country Code: CN
Application Number: CN202311804946.9
