Shanghai Daoqin Plastics Co., Ltd.

ABS plastics due to tool has relatively large machine strong/high degree and good comprehensive property can, in electronics industrial, machine industrial, 交通运输, construction material, toys manufacturing and other industrial in has important 位置, especially is micro large type structure and force parts, need electroplating trim parts more is 离不开 this type of plastics. according to more year experience, for ABS plastics injection molding process as lower analysis.

(1) ABS plastics drying 　ABS plastics wet property and for water separation property relatively large, in processing front 进行充 separation drying and preheating, mono can remove water formed made parts surface 烟花状泡 belt/tape, silver streaks, but also also has plastics 塑化, decrease/reduce made parts surface color and 云纹. ABS raw materials need control water separation in 013 % below/following. injection molding front drying conditions is: dry 冬季节 in 75～80 ℃ below/following, drying 2～3h, 夏季雨 water in 80～90 ℃ lower, drying 4～8h, made parts need to especially excellent gloss or made parts complex, drying time more long, 达8～16h. micro amount water 汽 存 in made parts surface is by 忽略 一 issues. most good will machine material 斗改装 formed hot material drying device, drying good ABS in material in again degree 吸潮, this category of material need add strong/high wet degree 监控, in production in 断时, anti material hot.

(2) injection temperature degree 　ABS plastics temperature degree and melt viscosity has other type plastics. in process temperature degree rise high 时, its melt upper reduce very small, 但一旦达 to temperature degree (适宜 processing temperature degree scope/range, 如220～250 ℃), if 继续盲目 rise temperature, will heat resistant property high ABS thermal degradation make melt viscosity increase large, injection molding more difficult, made parts mechanical properties decline. therefore,ABS injection temperature degree although ratio polystyrene (PS) and other plastics more need high, can rear that has relatively wide rise temperature scope/range. certain temperature defect injection molding machine, production ABS made parts to 一定数 amount 时, or more or less in made parts upper 发现嵌 has color or color 焦化粒, but also very difficult utilizing add new material for injection and other method will its remove 排出. its causes, is ABS plastics has butadiene formed separation, certain plastics pellets in relatively high temperature degree lower viscous in in 一 不 easy surface upper, to long time high temperature function 时, formed degradation and carbon 化. 既然偏 high temperature as for ABS can can belt/tape issues, has necessary for material 筒各段炉 temperature 进行限 made. 当然, different type type and formed ABS suitable temperature different. 如柱塞式 machine, temperature in 180～230 ℃; screw machine, temperature in 160～220 ℃. especially value is, due to ABS processing temperature degree relatively high, for various process factors is 敏感. therefore material front and nozzle separation temperature degree control separation important. 实践证明, this separation micro small 变化都 will in made parts upper 反映出. temperature degree 变化越 large, will belt/tape 熔接缝, gloss 不佳, flash, mold sticking, color and other defect.

(3) injection pressure 　ABS melt parts viscosity ratio polystyrene (PS) or modified polystyrene (PS) high, therefore in injection using/adopting relatively high injection pressure. 当然并 non has ABS made parts need use high pressure, for small type, simple, thick degree large made parts can use relatively low injection pressure. made process in, gate 封闭瞬间 type inner pressure large small 往往决定 made parts surface quality and silver streaks defect degree. pressure small, plastics shrinkage large, and type surface 脱离接触 machine large, made parts surface 雾化. pressure large, plastics and type surface scratch function strong/high 烈, easy formed mold sticking.

(4) injection speed degree 　ABS material using/adopting in and other injection speed degree relatively good. injection speed degree fast 时, plastics easy or separation analysis gas material, from in made parts upper 出现熔接缝, gloss and gate plastics and other defect. in production thin and complex made parts 时, also is need ensure has high injection speed degree, difficult 以充满.

(5) mold temperature degree 　ABS molding temperature degree versus for relatively high, mold temperature degree versus for relatively high. generally adjustment mold temperature is 75～85 ℃, production tool has relatively large 投影面积 made parts 时, mold temperature degree requirements 70～80 ℃, mold temperature degree requirements 50～60 ℃. in injection relatively large, complex, thin made parts 时, 应考虑专门 for mold add hot. is shrink short production cycle,维持 mold temperature degree versus for stability, in made parts rear, can using/adopting cold water 浴, hot water or other machine type method 补偿原 in type inner cold solid type time.

(6) material amount control 　 generally injection molding machine 注ABS plastics 时, its injection amount standards injection amount 75 %. is improve/increase made parts quality and dimensions stability, surface gloss, color uniform, requirements injection amount is injection amount 50 % is 宜.