Shanghai Daoqin Plastics Co., Ltd.

          mold fault/failure

         generate mold sticking and demolding defect causes is more 方面, mold fault/failure is its in main/primary causes 之一. its generate causes and product methods lower:

        一, mold type surface coarse 糙, if mold type and runner inner has 凿纹, 刻痕, 伤痕, and other surface defects, parts very easy viscous in mold inner, demolding difficult. therefore, amount improve/increase mold cavity and runner surface light degree, type inner surface most good 镀铬, in 进行抛 light 处理时, light tool as direction and material direction 一致.

        二, mold abrasion loss or block 处缝隙太 large. material in mold 划伤 部位 or block inner generate flash 时, 也会引起 demolding difficult. for 此, 应修复 loss 伤部位 and decrease small block 缝隙.

        三, mold rigid property 不足. if rigid injection mold 就打不开, table/sheet mold due to rigid property 不足, in injection pressure function lower generate 形变. if ultra- elastic property 极限, mold method 恢复原状, can use. make 形变未 ultra- 出 mold elastic property 极限, material in mold cavity inner very high conditions lower cooling solid 化, remove injection pressure, mold 恢复形变 rear, parts to elastic force function by 夹住, mold still method 打开.

         therefore, in design mold 时, must design rigid property and strong/high degree. mold trial 时, most good in mold upper per mille table/sheet, mold cavity and in process in is deformation, mold trial 时 起始 injection injection pressure need high, 应一边观察 mold deformation amount, slow slow rise high injection pressure, will deformation amount control in scope/range inner.

        当发生回 elastic force large 引起夹模 fault/failure 时, add large mold opening force is 不行, upper will mold lower separation understanding, will parts add hot soft rear 取出. for/regarding rigid property mold, can in mold outer made frame 架, high rigidity.

        四, demolding degree or 动, sheet/plate 间平行 degree 差. in design and made as mold 时, ensure demolding degree, 否则塑 parts very difficult demolding, strong/high ejection 时, 往往造 formed parts warpage, ejection 部位发白 or cracking and other. mold 动, sheet/plate need versus for 平行, 否则会导致 type 腔偏移, formed demolding defect.

        五, system design combined 理. if 浇道太 long, small, 主浇道 and separation 浇道连接部 separation strong/high degree 不够, 主浇道无 cold material 穴, gate balanced defect, 主浇道直径 and nozzle 孔直径搭配不当 or gate sleeve/set and nozzle 球面不吻 combined, 都会导致 mold sticking and demolding defect. therefore, 应适当 shrink short long degree and increase its 截面积, improve/increase runner and separation runner 连接部位 strong/high degree, in runner upper 应设置 cold material 穴.

        确定 gate 位置时, can through increase gate and other methods balanced more mold in type 腔 充模 speed rate and decrease/reduce mold cavity inner pressure. generally lower, runner small 端直径应 ratio nozzle large 0.5~1mm, gate sleeve/set semi ratio nozzle semi large 1~2mm.

        六, ejection machine design combined or as 不当. if ejection plant/unit 行程不足, ejection 不均衡 or sheet/plate as defect, 都会导致塑 parts method demolding.

         in conditions 充许 情况 lower, amount increase has ejection 面积, ensure ejection 行程, parts ejection speed degree control in scope/range, can fast or slow. sheet/plate as defect main/primary causes is due to sliding parts viscous 滞.

        例如, sheet/plate slip as 时, slip 芯处无 cooling plant/unit, its temperature degree ratio other type high, in 连续运转时, 立柱本体 and slip 芯间 间隙极 small, generate viscous 滞导致抽芯动 as defect, also 如, 当顶销孔 and sheet/plate toward 销 平行 degree defect or bending 时, sheet/plate 就会动 as defect.

        若 in machine in 不设止销, sheet/plate and sheet/plate has material 时, sheet/plate 倾斜, its rear sheet/plate as defect. in in, large type mold in, if has 一根顶杆 function 时, sheet/plate can 均衡顶推, generate as defect.

        七, mold gas defect or 模芯无进 gas 口也会引起 mold sticking and demolding defect. improvement mold gas conditions, 模芯处应设置进 gas 孔.

        八, mold temperature control or cooling time long short 不适当. if in separation type difficult demolding 时, can improve/increase mold temperature degree and shrink short cooling time. in type 腔面处 difficult demolding 时, can reduce mold temperature degree or increase cooling time. in addition, temperature degree high, 也会导致 demolding defect. mold type 腔材质 is more soft material 时会引起 mold sticking. for 此, use hard 质钢材 or surface electroplating 处理.

        浇道拉出 defect, gate 无拉钓 machine 构, separation type below/following low 凹, type 腔边线 ultra- clamping and other mold defect different degree effect/influence parts demolding. for 此, 应引起 attention/notes 并予以修整.

         process conditions control 不当

         if injection molding machine specifications relatively large, screw speed high, injection pressure large, injection holding pressure time long, 就会形 formed amount filling, make molding shrinkage ratio small, demolding this difficult.

         if material and material temperature degree high, injection pressure large, hot material very easy mold block 间 缝隙 in generate flash, demolding defect.

         in addition, nozzle temperature degree low, cooling time short and material 断流, 都会引起 demolding defect. therefore, in troubleshooting mold sticking and demolding defect fault/failure 时, 应适当 reduce injection pressure, shrink short injection time, reduce material and material temperature degree, long cooling time, and anti material and other.

         raw materials combined use requirements

         if raw materials in packaging and 运输时 mixed 入杂质, or drying and preheating process in different product grade raw materials mixed use, and material and material in mixed material, 都会导致塑 parts mold sticking. in addition, raw materials 粒径不匀 or large for mold sticking has 一定程 degree effect/influence. therefore, for/regarding molding raw materials good 净化筛选工 as.

         demolding agent use 不当

         use demolding agent is decrease/reduce parts surface and mold type surface viscous force, anti 止两者 versus viscous, shrink short molding cycle, improve/increase parts surface quality.

        但 is, due to demolding agent demolding 效果既受 chemical function effect/influence, material conditions effect/influence, but also, molding raw materials and processing conditions has different, demolding agent most product types and use amount must according to specific 情况 确定. if use 不当, 往往不 can generate good demolding 效果.

        就 molding temperature degree 而言, 脂肪油 type demolding agent has as temperature degree generally ultra- 150 degree, in high temperature molding 时不宜 use; silicon and metal type demolding agent as temperature degree generally is 150 degree ~250 degree; PTFE type demolding agent as temperature degree can to 260 degree above, is high temperature conditions lower demolding most good demolding agent.

        就 raw materials product types 而言, soft polymer parts ratio hard polymer parts difficult demolding. use methods 而言, demolding agent need use coating 刷, can spray coating demolding agent use spray coating plant/unit spray coating. due to demolding agent in coating difficult formed uniform 模层, demolding rear parts surface has 波浪痕 or strip/profile 纹, therefore, can can use can spray coating demolding agent.