Shanghai Daoqin Plastics Co., Ltd.

melt type rear in mold upper formed thin table/sheet housing/shell, this table/sheet housing/shell in process in to rear material pressure 时, 就会导致 melt 破裂.

一旦 very thin table/sheet housing/shell by or 发生移动, parts surface generate or 皱纹. 例如, in melt relatively small low density polyethylene (PE) parts upper, its surface can to dark strip/profile 形区域, its generate generally gate has 一定距离, 并遍布整 surface, especially is thin parts most easy generate this category of fault/failure, this main/primary is due to material in small 熔腔尚未结束 front to relatively large pressure, melt 破裂, formed surface defects.

usually, decrease slow material in process in cooling speed degree and table/sheet housing/shell 层 形 formed speed rate is remove this category of fault/failure most good method, can through improve/increase mold temperature degree or improve/increase melt 破裂部位 local temperature degree troubleshooting this fault/failure. for/regarding mold cavity surface local add hot, can utilizing in gate and melt 破裂部位 small type tube/pipe electrical add hot device achieve.

熔 material flow features and its property can has 关, also and 决定熔 material in mold 入口处剪切 speed rate gate 截面积 has 关. gate dimensions very small injection speed rate very high 时, material is fine bending 射流态注入 type 腔, material cooling speed degree very fast, and rear 续充模 不规则流 material combined defect, gate generate surface mixed and 斑纹.

has 时, a small amount of cold material mold cavity surface 移动, make surface mixed and generate in gate relatively 远 部位.

usually, crystallization type polymer injection generate surface mixed and relatively difficult troubleshooting, is this category of resin melt temperature degree versus high, and non crystallization type polymer versus ratio, crystallization type polymer solid speed degree fast, processing temperature degree narrow, but also in thick 急剧变化 and material 突然改变 flow direction generate 不规则 flow material and its material in type in combined time comparison short, very easy generate surface mixed and 斑纹.

for/regarding troubleshooting this category of fault/failure, in process as 方面, 应适当 improve/increase mold, material and nozzle temperature degree, reduce injection screw front speed degree.

in mold as 方面, expand large gate dimensions, excellent selection gate, if using/adopting type gate, its dimensions small make gate 处 残 material effect/influence 充模, add material 不规则 flow, 应适当 add large its dimensions; 若 mold gas defect, effect/influence material property flow, 应予以改进.