Shanghai Daoqin Plastics Co., Ltd.

crystallization property plastics has obvious melting point, solid separation 子呈规则排列. 规则排列区域称 is 晶区, 无序排列区域称 is non 晶区, 晶区 占 percentage is crystallization degree, usually crystallization degree in 80% above polymer is crystallization property plastics. Common crystallization property plastics has: polyethylene (PE) PE, polypropylene (PP) PP, polyoxymethylene (POM) POM, polyamide (PA) PA6, polyamide (PA) PA66, PET, PBT and other. 　　 crystallization for plastics property can effect/influence 　　1) force property can 　　 crystallization make plastics 变脆(resistant impact strong/high degree decline), tough property relatively strong/high, property relatively 差. 　　2) optical property can 　　 crystallization make plastics transparent, is and non interface 会发生 light dispersion 射. decrease small dimensions to 一定程式 degree, not only improve/increase plastics strong/high degree (decrease small defect) but also improve/increase transparent degree, (当球晶 dimensions small light long 时不会 generate dispersion 射). 　　3) thermal properties 　　 crystallization property plastics in temperature degree rise high 时不出现 high elastic 态, temperature degree rise high melt temperature degree TM时, viscous 流态. therefore crystallization property plastics use temperature degree from Tg(玻璃化 temperature degree) improve/increase to TM(熔 melt temperature degree). 　　4) resistant solvent agent property, property and other to improve/increase, is crystallization separation more add 紧密. 　　 effect/influence crystallization factors has which? 　　1) polymer/macromolecule structure, for property good, 无支链 or very less or 侧基体积 small, large separation function force large polymer/macromolecule easy versus 互靠紧, easy crystallization. 　　2) temperature degree, polymer/macromolecule from 无序 卷团移动 to positive in long surface, mold temperature relatively high improve/increase polymer/macromolecule active property from add fast crystallization. 　　3) pressure, in cooling process in if has outer force function, can promote polymer crystallization, production in can high injection shot pressure and holding pressure pressure control crystallization property plastics crystallization degree. 　　4)形核 agent, due to low temperature has fast speed 形核, decrease slow formed long, therefore is remove this 一矛盾, in molding material in add 入形核 agent, this make plastics can in high mold temperature lower fast speed crystallization. 　　 crystallization property plastics for injection molding parts machine and mold has what requirements 　　1) crystallization property plastics understanding need relatively more can amount 摧毁晶格, therefore solid 体转化 is melt melt need relatively more hot amount, therefore injection molding parts machine can force need large, most large injection amount need versus improve/increase. 　　2) crystallization property plastics melting point scope/range narrow, is anti 止射咀 temperature degree reduce material crystallization 堵塞射咀, 射咀孔径应适当 add large, add can mono control temperature degree hot 圈. 　　3) due to mold temperature degree for crystallization degree has important effect/influence, therefore mold water 路应尽 can can more, ensure molding mold temperature degree uniform. 　　4) crystallization property in crystallization process in relatively large shrinkage, relatively large molding shrinkage, therefore in mold design in need true its molding shrinkage 　　5) due to toward property significantly, internal stress large, in mold design in need attention/notes gate and large small, add strong/high and and large small, 否则容 easy warpage deformation, rear need molding process improvement is versus difficult. 　　6) crystallization degree and parts thick has 关, thick cooling slow crystallization degree high, shrinkage large, easy shrink 孔, gas 孔, therefore mold design in need attention/notes control parts thick control 　　 crystallization property plastics molding process 　　1) cooling 时释放出 hot amount large, need separation cooling, high mold temperature molding attention/notes cooling time control. 　　2)熔态 and solid specific gravity large, molding shrinkage large, easy shrink 孔, gas 孔, need attention/notes holding pressure pressure setting 　　3) mold temperature low 时, cooling fast, crystallization degree low, shrinkage small, transparent degree high. crystallization degree and parts thick has 关, parts thick large cooling slow crystallization degree high, shrinkage large, material property good, therefore crystallization property plastics requirements must control mold temperature. 　　4)各 toward property significantly, internal stress large, demolding rear crystallization separation has crystallization 化 倾 toward, can amount balanced 状态, easy deformation, warpage, 应适当 improve/increase material temperature and mold temperature degree, in and other injection pressure and injection speed degree.