High-fluidity high-apparent-performance low-VOC long-glass-fiber reinforced polypropylene composite material and preparation method therefor

Abstract

The invention discloses a high-fluidity high-apparent-performance low-VOC long-glass-fiber-reinforced polypropylene composite material and a preparation method therefor. The polypropylene composite material is prepared from the ingredients in percentage by mass: 30% to 60% of long glass fibers, which are arranged in a manner of being parallel to particle length, and 40% to 70% of polypropylene modified resin, wherein the polypropylene modified resin is prepared through modifying commercial polypropylene resin on the market by a twin-screw extruder. According to the polypropylene composite material and the preparation method therefor, by adding low-melting-point polypropylene, processing windows of extruding and injection molding are increased, and the polypropylene resin can better impregnate glass fibers, so that injection-molded parts are good in apparent performance, free of glass fiber exposure, free of warping and easy in processing; and by the method, the application of a flow modifier in long-glass-fiber reinforced materials is avoided, the VOC can be effectively reduced, and the product prepared by the method has good mechanical properties and has very good application in the aspects of instrument board skeletons, front-end frameworks, automobile stern doors and the like.

Description

technical field [0001] The invention relates to a polypropylene composite material, in particular to a high fluidity, high apparent performance, low VOC long glass fiber reinforced polypropylene composite material and a manufacturing method thereof. Background technique [0002] With the rapid development of the automobile industry, the lightweight of automobiles has attracted more and more attention from automobile companies and consumers. To achieve lightweight automobiles, in addition to optimizing the design of structures and processes, the selection of automobile materials is also a very important aspect. Substituting plastics for steel has become an important aspect of automobile lightweighting. The focus of quantitative research. [0003] Long glass fiber reinforced polypropylene material has good dimensional stability, excellent fatigue resistance, low creep performance, excellent mechanical properties, low density, etc., and long glass fiber reinforced polypropylene...

AI Technical Summary

Problems solved by technology

[0005] The infiltration quality of long glass fiber reinforced polypropylene materials produced by melt impregnation plays a decisive role in the mechanical properties of long glass fiber reinforced polypropylene materials. The infiltration quality is directly related to the production process, equipment and material formula. In terms of material formula , the flow rate of the melt, the crystallization temperature, and the interface bonding force between the melt and the surface of the glass fiber have a direct impact on the wetting quality. Usually, high fluidity and low crystallization temperature have a positive effect on the wetting quality. The better the wetting effect can improve The apparent quality of the product, lowering the processing temperature, has a positive impact on the odor, VOC and other emission properties. However, in the current production process, flow modifiers or high-fluidity PP raw materials are generally used to improve the fluidity of polypropylene. The production process of the neutralizing agent is accompanied by the problem of chain scission, which reduces the molecular weight, and at the same time the mechanical properties and emission properties are also deteriorated, and the scission of molecular chains in the production process is an uncontrollable process, which leads to batch failure. The deterioration of production stability during the period cannot meet the increasingly stringent requirements of the automotive industry for the mechanical properties and emission properties of long glass fiber materials

The price of high-fluidity polypropylene raw materials is high, and the selection space is small. Once the apparent quality is poor during the molding process, it is difficult to improve through formula design, and the dependence on raw materials is high, which is not conducive to cost control and formula design.

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