Shanghai Daoqin Plastics Co., Ltd.

一, polyethylene (PE) PE molding processing properties 　　PE is crystallization property raw materials, wet property small, ultra- 0.01％, therefore in processing front 无需进行 drying 处理. 　　PE separation 子联链 flexible good, function force small, melt viscous property low, flow property good, therefore molding 时无需太 high pressure can molding thin long process/workflow products. 　　PE shrinkage rate scope/range large, shrinkage value large, direction property obvious, LDPE shrinkage rate is 1.22％ left right, HDPE shrinkage rate in 1.5％ left right. therefore easy deformation warpage, injection molding parts mold cooling conditions for shrinkage rate effect/influence very large, 故应该 control good injection molding parts mold temperature degree, maintain cooling uniform, stability. 　　PE crystallization can force high, injection molding parts mold temperature degree for parts crystallization has very relatively large effect/influence. mold temperature high, melt cooling slow, parts crystallization degree high, strong/high degree high. 　　PE melting point high, specific heat capacity relatively large, therefore 塑化时 still need consumption relatively more hot amount, requirements plant/unit need has relatively large add hot rate, improve/increase production efficiency. 　　PE soft temperature degree scope/range relatively small, melt easy oxidation, therefore in molding processing in can can melt and oxygen 发生接触, reduce parts quality. 　　PE made parts relatively soft, easy demolding, therefore parts has shallow 侧凹槽时 can strong/high force demolding. 　　PE melt non property obvious, speed rate for viscosity effect/influence relatively small, PE melt viscosity temperature degree effect/influence relatively small. 　　PE melt cooling speed degree relatively slow, therefore must separation cooling. injection molding parts mold has relatively good cooling system. 　　若PE melt in injection using/adopting 直接进 material material, easy increase large force and generate non-uniform and direction property obvious increase large deformation, therefore attention/notes selection material parameters. 　　PE molding temperature degree relatively wide, in flow lower, temperature degree less 许波动 for injection molding parts molding has effect/influence. 　　PE heat stabilized property relatively good, generally in 300 degree below/following obvious separation understanding phenomenon, for quality what effect/influence. 　　二, PE main/primary molding conditions 　　 material temperature degree: material temperature degree main/primary is and PE density high low and melt flow rate large small has 关, another also and injection molding parts machine type type and property can, grade parts has 关. due to PE is crystallization type polymer, in melt 时晶粒 need absorption hot amount, therefore material temperature degree high it melting point 10 degree. degree 于LDPE 说, material temperature degree control in 140-200℃, HDPE material temperature degree control in 220℃, material rear most small value, front most large value. 　　 injection molding parts mold temperature degree: mold temperature for parts crystallization has relatively large effect/influence, mold temperature high, melt crystallization degree high, strong/high degree high, shrinkage rate increase large. usually LDPE injection molding parts mold temperature degree control in 30℃-45℃, 而HDPE temperature degree versus again high 10-20℃. 　　 injection molding parts pressure: improve/increase injection molding parts pressure has 利于熔 material 充模, due to PE flow property very good, therefore remove thin fine long products outer, 应该精良 selection relatively low injection pressure, generally injection pressure is 50-100MPa. simple. rear relatively large parts, injection pressure can low, 反之则 high.