A process for eliminating tiger skin pattern of polypropylene composite material

Abstract

The invention provides a technology method for eliminating tiger patterns on a polypropylene composite material. The technology method comprises the following steps: (1) weighing each material according to weight percentages in a recipe of the polypropylene composite material for later use; (2) placing the material weighed in the step (1) into a high-mixing machine for 5 min for uniform mixing, and discharging the material; (3) placing the uniformly mixed material into an injection machine for injection molding to obtain an end product, wherein the conditions of injection molding in the step (3) are that the injection pressure is 80 MPa, the holding pressure is 50 MPa, a sprue is large and round, and has the diameter of 5-6 mm and the length of 0.5-2.0 mm, the runner is round, the injection speed is 80, the mold temperature is 70 DEG C, and the injection processing temperature is 230 DEG C. The technology method and the recipe materials, both provided by the invention, can excellently solve the problem of the tiger patterns of the polypropylene composite material, and the method is novel and affordable.

Description

technical field [0001] The invention relates to a polymer material technology, and more specifically, to a method for eliminating tiger skin patterns of a polypropylene composite material. Background technique [0002] With the development of the automobile industry, more and more non-ferrous raw materials are directly used for injection molding large parts such as automotive interiors and exteriors. The larger the product, the more system functions and features need to be integrated, and the manufacturing of related injection molds has also changed. more complicated. Polyolefin is a common injection molding resin, but when thermoplastic polyolefin is used for injection molding of large molds, material flow instability often occurs, especially when the flow distance is long. This flow instability can cause visible defects, commonly known as tigers. Skin grains and tiger skin grains affect the appearance. [0003] According to the classic theory, the tiger skin pattern is c...

AI Technical Summary

Problems solved by technology

At present, in order to eliminate the tiger skin pattern produced on the surface of PP, there are mainly two methods involved: one is the new injection molding technology, which has the advantage of more process flexibility, but it also has the need to design updated materials, which is time-consuming and expensive. The disadvantage of high cost; the second is to increase the melt index, although the flow distance is increased, but the physical properties of the material are reduced

However, none of these methods can solve the tiger skin pattern well at present.