Shanghai Daoqin Plastics Co., Ltd.

        PP plastics shrinkage rate control is PP modified important 方面, shrinkage rate 控/ made good for polypropylene (PP) modified material use has important 意义. especially is application modified polypropylene (PP) 取代传统 engineering plastics, shrinkage rate this 一点显 十 separation important. in modified process in, for PP plastics shrinkage rate generate effect/influence has which factors 呢?

        一, mineral filled

        PP plastics modified use material additives main/primary has carbon acid 钙, slip powder, powder and other, for PP plastics molding shrinkage effect/influence comparison obvious.

         main/primary in 三 方面: is material add agent 本身不 shrinkage, it add from overall ratio/proportion upper reduce polypropylene (PP) modified material shrinkage rate;二 is material add agent add 入必然 effect/influence polypropylene (PP) crystallization degree, from effect/influence shrinkage rate;三 is micro fine material agent add rear, to types nucleating agent function, polypropylene (PP) structure 状态, large 球晶 形 formed, effect/influence polypropylene (PP) molding shrinkage.

        二, glass fiber reinforced

         glass fiber reinforced is PP plastics modified types important 手段, glass fiber (GF) for PP modified material molding shrinkage effect/influence most large. glass fiber content to 30%时 above 时, PP plastics molding shrinkage from 1.8 decline 至0.5, but also surface treatment glass fiber (GF) for molding shrinkage effect/influence large 于未进行处理 glass fiber (GF).

         glass fiber (GF) add bad PP crystallization degree, effect/influence shrinkage rate, meanwhile glass fiber made PP plastics crystallization shrinkage.

        三, polyethylene (PE) add 入

         polyethylene (PE) is types high crystallization degree plastics, molding shrinkage very large, in add polypropylene (PP) in rear versus different degree bad crystallization degree, make overall molding shrinkage decline.

        四, PP plastics 自身MI(melt flow index) 变化

         polypropylene (PP) molding shrinkage its crystallization degree effect/influence, crystallization degree also its molecular weight large small effect/influence. 当MI increase large 时, molecular weight decrease small, its crystallization speed degree increase large, molding shrinkage increase large. polypropylene (PP) MI变化时 for molding shrinkage has effect/influence.