Shanghai Daoqin Plastics Co., Ltd.

         injection molding parts is in plastics mold inner formed and cooling solid 化, due to types resin requirements formed temperature degree and 玻璃化 temperature degree different, therefore, plastics mold must has temperature degree adjustment system, can combined types resin formed 形, high 效 进行 production.

         in injection shot formed in, in mold inner 时, melt material temperature degree generally in 150~350℃ between, due to mold temperature degree generally in 40~120℃, therefore formed material belt/tape hot amount 会逐渐 make mold temperature degree rise high. 另一方面, due to add hot nozzle and mold 注道衬 sleeve/set 直接接触, nozzle temperature degree high mold temperature degree, make mold temperature degree upper rise. if method will more hot amount belt/tape 走, mold temperature degree 必然继续 upper rise, from effect/influence molding product cooling solid 化. versus 反, from mold in belt/tape more hot amount, make mold temperature degree decline, effect/influence molding product quality.

         for formed viscosity low, flow property good plastics (如 polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS and other), generally requirements plastics mold stability relatively low (generally low 于80℃);

        而 for/regarding degree high, flow property plastics (如 polycarbonate (PC), polysulfone (PSU), polyphenylene oxide (PPO) and other), is improve/increase type property can, or plastics mold relatively large, dispersion hot 面积广 and other 情况, its plastics mold not only need cooling system, also need add hot system, in injection molding front for mold add hot.

         has plastics formed 形, need mold cooling system and add hot system. mold temperature degree to plastics formed process requirements 时, can add hot system, if in injection time rear, mold temperature degree high plastics formed process requirements 时, need mold cooling system, make mold temperature degree in requirements temperature degree lower temperature.

         for/regarding small type thin parts, formed process requirements mold temperature high 时, can 不设置 cooling plant/unit 而靠自然 cooling.

         mold temperature degree for products effect/influence

        (一) formed property and formed efficiency

         mold temperature degree high 时, formed 形空间 inner melt material flow property improvement, can promote filling. formed efficiency (formed cycle)而言, mold temperature degree degree decrease low, can shrink short material cooling solid time, improve/increase formed efficiency.

        (二) molding product material property 质

         usually melt material formed 形空间时, mold temperature degree relatively low, make material speed solid 化, is filling, need very large formed pressure, therefore, solid 化之际, add molding product 一部份 pressure 残留于 internal, formed is 谓 残留应 force.

         for/regarding PC or property PPO之 type hard material, 此残留应 force large to certain types degree above 时, 会发生应 force crazing phenomenon or formed molding product deformation. PA or POM and other crystallization property plastics crystallization degree and crystallization 化状态 significantly 取决于 its cooling speed degree, cooling speed degree slow 时, 结果愈 good. upper can 知, mold temperature degree high, 虽不利于 formed efficiency, 但却常 has molding product quality.

        (三) molding product 形状

         molding product thick, large 时, cooling separation, its surface 会发生 shrinkage lower 陷, make thick 适当, cooling methods defect, molding product separation cooling speed degree different, 也会因 hot shrinkage 而引起 warpage, and other deformation, 因而需 make mold separation uniform cooling.

         mold cooling and add hot

         generally mold, usually normal temperature water cooling, its temperature degree control water amount adjustment, flow property good low melt material large 都以此 methods formed 形. has is shrink short formed cycle, must will water again add cooling.

         small type molding product injection shot time, holding pressure time short, formed cycle 取决于 cooling time, types formed is improve/increase efficiency, 经常也以 cold water cooling, use cold water cooling 时, large gas in water separation poly formed 形空间 surface, formed molding product defect, must add attention/notes.

         formed high melt material or relatively thick, flow long molding product, is anti short shot or 应变 发生, has for water tube/pipe temperature water. formed low melt formed material 时, formed 形面积 large or large type molding product, will mold add hot, use hot water or hot 油, or use add hot device control mold temperature degree. mold temperature degree relatively high 时, 需考虑 mold sliding 部位 间隙, mold hot 膨胀而动 as defect.

         generally in melt formed material, has molding product quality or flow property use add hot methods control mold temperature degree, is make material solid is most temperature degree uniform 化, use separation add hot methods, anti 止残留应变.

         above 述, mold temperature degree control is utilizing cooling or add hot methods adjustment.

         cooling system design 原则

        (1) cooling tube/pipe 口径, 间隔以 and formed 形空间 surface 距离, for mold temperature degree control has heavy large effect/influence, this ratio most large value lower:

         cooling tube/pipe is 【1】时, tube/pipe and tube/pipe most large value is 【5】, tube/pipe and formed 形空间 surface most large is 【3】. again 者, molding product thick relatively thick ratio thick relatively thin 处, cooling tube/pipe must shrink small and relatively formed 形空间 surface.

        (2) is maintain mold temperature degree distribution uniform, cooling water from mold temperature degree relatively high 处进入, rear ring temperature degree relatively low again export. usually 注道, gate formed material temperature degree high, therefore cold water, temperature degree low outer 侧部份, ring hot temperature water, ring system tube/pipe 路连接, is in mold inner processing 贯穿孔, in mold outer 连接孔 and 孔.

        (3) formed PE and other shrinkage large material 时, its formed shrinkage large, cooling tube/pipe 路不宜沿 shrinkage direction.

        (4) cooling tube/pipe amount formed 形空间 轮廓 设置, maintain mold temperature degree distribution uniform.

        (5)直径 fine long type or type 销, can in its in 心钻盲孔, again sleeve/set or sheet/plate cooling, method sleeve/set and sheet/plate 时, hot rate good copper alloy as type and type material, or thermally conductive tube/pipe 直接装入盲孔 in, again cooling water as 间接之 cooling, 效果尤佳.

        (6) cooling water flow process in has short or phenomenon effect/influence cooling 效果, but also cooling tube/pipe can can use 贯穿孔 methods, day rear 方便清理.