Shanghai Daoqin Plastics Co., Ltd.

poly acid （PLA）以 its good injection molding processing property can, excellent 越 生 material degradation property can and material raw materials 源, by is 本世纪 most tool development outlook/prospects green environmental protection material. poly acid use scope/range day 益广泛, its processing technology 也逐渐受 to industry heavy 视, although can poly acid as types general purpose resin for 待, is and other general purpose resin versus ratio, poly acid injection molding processing process still in 一 独特之处.

mold requirements

injection molding PLA resin 时, for mold has requirements, this 包括: mold cooling need good, must cold water machine, 如200g injection molding machine, 配备2kW cold water machine; due to thick products injection speed degree versus for thin products comparison slow, therefore mold design need products thick degree control in 4mm below/following, mold type 芯, type or front rear sheet/plate, sliding block need water add cooling, mold temperature degree control in 20~30℃ between.

drying conditions

PLA resin in use front must drying 处理. is anti melt viscosity reduce, will wet degree control in 0.025%（250ppm） below/following. type drying conditions is: gas temperature degree 80℃, gas 露点－40℃, gas flow speed rate ＞1.85m3/h·kg, drying 2～3hrs; or gas temperature degree 80℃, true drying 2～3hrs. drying rear resin can 暴露于空 gas in, in has nitrogen gas aluminum bag in, outer add box/case or bag 子保护. use front maintain packaging 密封, use rear speed 密封未 use material material. material material in gas in time ultra- 1h, upper methods heavy new drying.
 
图1 由 filler screw abrasion loss

need attention/notes is, production in must use in drying remove wet machine, ensure add material PLA resin in processing process in 不吸潮. use easy 牌SD-H series 蜂巢转轮 remove wet equipment or has same other equipment.

injection molding processing

in injection molding PLA resin front, need use low viscosity polystyrene (PS) or polypropylene (PP) injection molding machine, rear will temperature degree maintain in stability lower; ensure add material inner gas wet degree to 露点-40℃ below/following, need 避免灰尘污染; in combined upper conditions front lower, will PLA resin injection molding machine in; most rear adjustment equipment temperature degree 至PLA resin processing temperature degree.

in molding process in, if need short time （ generally is semi small inner ）停 machine 时, necessary will material 斗底部 挡 sheet/plate upper, again will material inner material 排空, anti material 喉堵塞. 当确认 need heavy new production 时, can 打开挡 sheet/plate add material material.

if in processing process in material material color and degradation phenomenon 时, 应立即排空 material material, again add new material, material material 状态, is 否恢复 positive 常. positive can production; positive 常, need versus adjustment.

production need machine 时候, need use high viscosity polystyrene (PS) or polypropylene (PP) machine.

recycled material recycling 处理

PLA resin recycled material recycling has types methods: types is in production process in, powder 碎, through upper material methods, to material inner, and new material mixed combined use. this type of methods is efficiency comparison high, use use; types is 累积存放, rear powder drying, again and new material mixed use. attention/notes: recycling material drying conditions and new material is different, time long to 4～6hrs, gas temperature degree decline to 45℃.