Shanghai Daoqin Plastics Co., Ltd.

 一, long ratio for TPE product molding effect/influence

（一）TPE包覆 molding product long degree 取决于材 material melt temperature degree

is obtain excellent overmolding property can, product design long ratio control in 80~120

product long ratio ultra- 150, increase 进点, 建议TPE overmolding thick degree large 于1mm, will effect/influence overmolding property can, if TPE overmolding thick degree relatively thin, increase machine machine 构（参考: polyone）

（二）背景 Knowledge:

流 long ratio: material from nozzle export 处流至 products most 远距离L and products thick H之 ratio

flow ratio is plastics melt in mold in most long flow 时, its material 流通道 and mold cavity long degree and its for 应截面 high degree （ or thick degree ） ratio value combined.

流 long ratio has another 含义, commonly used long degree table/sheet 示（螺旋曲线 thick degree and wide degree is has requirements ）, is 指规定 injection molding temperature degree, injection molding pressure and speed degree, mold temperature degree lower, can generate 螺旋曲线 long degree.

流 long ratio ratio MI指 more 直接 反映 材 material injection molding flow property, 但MI application more 广泛, but also mono from MI一 指数 in can coarse 略 看出材 material property can.

二, , ejection for TPE product molding effect/influence

（一）TPE项出 design:

建议 product demolding degree mono 边1.5~3°

建议 in material rear increase cold material 井

建议顶针 surface increase 皮纹避免 product year in upper

包覆 molding 时, amount will 顶针布置 in hard product upper

（二）背景 Knowledge:

injection molding machine ejection has machine ejection and liquid pressure ejection types , has also has gas ejection system , ejection 次数设 has mono and more types. ejection as can is 手动, can is 自动. ejection as is mold opening 停止限位开关（ or electronics 尺） 启动.

操 as can according to need, through adjustment ejection 行程开关（ or electronics 尺 刻 degree 距离） achieve. ejection speed degree and pressure can through electrical in amount achieve, 顶针运动 front rear 距离由行程开关（ or electronics setting 位置）确定.

三, shrinkage for TPE product molding effect/influence

（一） shrinkage for TPE product molding effect/influence

TPE shrinkage scope/range in 1%~2.5%, engineering plastics shrinkage scope/range 0.2%~1.4%,

建议基材 thick degree 两倍于TPE product thick degree

in 基材包覆 molding upper increase 筋位会导致TPE molding rear outer surface generate hot shrink issues

当TPE材 material 整 包覆于 engineering plastics 时, attention/notes hot shrinkage warpage 曲效应（参考: polyone）

（二）背景 Knowledge:

材 material molding 时, cooling production product dimensions ratio mold dimensions shrink small phenomenon, molding shrinkage use percentage table/sheet shrink small degree. usually crystallization resin ratio non crystallization resin shrinkage more 厉害. molding shrinkage can through adjustment injection molding temperature degree and pressure and other molding conditions to degree adjustment.

generate shrinkage causes :

molding process in, pressure and temperature degree 变化, has can can shrinkage 差异.

injection molding process in, resin 若 存 in add hot and cooling 话, can 按考虑 good filling to mold cavity inner resin shrinkage rate again filling. 但实际 upper, meanwhile to pressure and temperature degree 变化, shrinkage still 会发生.

generate shrinkage process :

injection molding 时, resin add hot melt rear 体积膨胀.

will 体积膨胀 熔 melt resin filling to 空间限定 mold cavity inner rear, cooling, in this process in resin will decrease small, 此时 体积 decrease small rate is molding shrinkage.

四, gas design for TPE product molding effect/influence

（一）TPE排 gas design:

design gas is can 顺利导出 mold inner gas from 而避免 product surface 发生困 gas issues

排 gas design in material flow or mold separation type 面

TPE排 gas deep degree 0.01~0.025mm, generally lower, overmolding force reduce table/sheet overmolding 区域存 in gas issues

包覆 molding 时, has in sheet/plate upper design increase gas 孔

（ above 参考: polyone）

（二）背景 Knowledge:

1排 gas function and design

1.1排 gas function

排 gas function main/primary has 两点. 一 is in injection melt material material 时, troubleshooting mold cavity inner gas; is troubleshooting material material in add hot process in generate various gas 体. 越 is thin products, is gate 部位, gas 槽 开设就显 尤 is important. another for/regarding small type parts or precision parts need heavy gas 槽 开设, is it remove can products surface and injection amount outer, also can remove products various defect, decrease/reduce mold and other. that 么, mold cavity gas how to 才算充 separation 呢? generally 说, most high injection speed rate injection material, in products upper 却未留 lower 焦斑, can is mold cavity inner gas is separation.

1.2排 gas methods

mold cavity gas methods very more, 但每一 types methods must ensure: gas in gas meanwhile, its dimensions design can anti material material 溢进槽 inner; its also need anti 止堵塞. therefore from mold cavity inner surface toward mold cavity outer direction amount, long 6~12mm above gas separation, high degree need large 约0.25—0.4mm. another ,排 gas amount more is has 害. is if function in mold cavity separation type 面未开排 gas separation pressure very large, easy mold cavity material cold or 裂开, this is very 危险. remove in separation type upper for mold cavity gas outer, also can through in system material 流末端位置设排 gas 槽, and ejection 杆四周留出间隙 methods to gas 目. is gas deep degree, wide degree and selection; if 不适当, generate flash 毛刺, will effect/influence products and degree. therefore upper 述间隙 large small anti ejection 杆四周出现 flash is 限. this especially attention/notes is: gears this made parts in gas 时, can can most micro small flash is 不希望 has. this type made parts most good using/adopting below/following methods gas: ①彻底清 remove runner inner gas 体; ② use degree is 200＃ carbon silicon abrasion material for separation type combined surface 进行喷丸处理. another, in system material 流末端开设排 gas main/primary is separation runner 末端位置 排 gas 槽, its wide degree and other separation runner wide degree, high degree material 而异.

五, light mold 面会引起TPE mold sticking issues

（一）皮纹面 has 效避兔TPE product mold sticking issues generate

建议 using/adopting deep degree large in 0.025mm喷砂 or EDM火花纹处理 mold surface

整 runner system 包括进点位置建议 table/sheet use relatively coarse processing, has need, in mold 火花纹 surface upper again increase iron coating

（二）背景 Knowledge:

喷砂, and 火花纹都 belongs to mold surface treatment 范畴, this types surface treatment technology, its in and 皮纹我们 use comparison more, 留火花纹 也 has 一, is more. for/regarding plastics mold 喷砂, and 火花纹 三 types process, 做一 概括 property understanding 释.

皮纹 is through chemical water methods made formed. 皮纹面 types type most more, can made various 效果面. for/regarding processing price versus non large, process technology content high. for/regarding different 皮纹, price versus comparison relatively low. is for/regarding used for automotive inner trim parts mold and home appliances mold and other 立体皮纹, price need more.

喷砂就 is 石英砂 through gas pressure gas toward mold surface, from in plastics mold surface formed abrasion 砂面. plastics mold injection molding product 时候, in product surface formed abrasion 砂效果. generally separation is fine and coarse types. for/regarding 喷砂处理, parts surface easy abrasion 掉.

火花纹指 就 is electrical plastics mold processing rear lower 纹路. for/regarding 火花纹往往 mold electrical processing rear, product surface 留火花纹效果也 can, nano 留火花纹处理. generally 不会特意做 electrical processing 火花纹, that cost relatively high.

for/regarding plastics mold surface treatment technology, use most more is 皮纹. 当然实际 product need using/adopting types surface treatment, also is need according to parts applications 决定.