Shanghai Daoqin Plastics Co., Ltd.

injection molding processing process not only molding parts 形状, but also also has it material features. 图1显示出 in production conditions lower by research sample in generate dimensions and separation 配. in positive by 讨论 情况 in, 球晶直径约 is 18mm. for important property 认识不足 is parts overall structure 决定 每 types lower use property can. this 意味 不 is parts outer in property can process is conditions, inner in property can is 如此. this 也意味 for molding combined material hot machine 械 处理, processing process in pressure, temperature degree and rate 定义, 都决定 production 出 塑 parts material structure （形态）. product outer in and inner in property can product most property can. therefore plastics control parts shrink and its 形状, meanwhile 也确定 材 material use property can. parts property can for/regarding certain types parts 形状不一定就 is most property can, high machine strong/high degree, hardness, good wear resistance. 反, 理想 形态 will can generate stability parts 形状, is 一 不 can can again 改变 一 types 形状. 一旦建立起 process and most quality between versus 互关系, 一 事实就变 清楚: can through for injection molding processing 进行一定 optimization process control, can obtain excellent 质 塑 parts, this type of control 以形态 is focus/key point, 也包括 for 状态变 amount and control. therefore stability process control need process 适应于 by processing plastics. it hot force factors is 基础, for/regarding semi crystallization thermoplastic property plastics, also must to crystallization force 学. however, in plastics processing inner also has for 此 普遍认识, toward 人们灌输 this type of 思想. for processing POM research easy flow POM copolymer （POM） is 例子, 人们就 injection molding processing process in process conditions for made parts most property can effect/influence research and discussion. is this research, according to DIN/ISO 527 standards, in di injection molding processing mold in different injection speed degree and pressure 做出5A type tensile sheet/plate （截面积4×1mm2）. mold cavity through 位于塑 parts 侧翼 侧面 upper gate by filling. injection molding processing mold in gate 处装备 has pressure device, can in tensile sheet/plate in 央肩部位置测 amount pressure 变化. in has testing in, parts production mold temperature by setting in 95℃, is this is Raw Materials manufacturing is high quality parts recommendation temperature degree. in clamping force is 220kN injection molding processing machine upper processing molding combined material. screw is 18mm, machine upper temperature degree is 210℃. 图1: sample in 心球晶 structure micro research 结果一方面揭示出塑 parts inner in and outer in property can between 清晰关系, 另一方面也揭示出 and process conditions 关系. tube/pipe production 出 塑 parts has 几乎一致 machine strong/high degree, different sheet/plate material structure deformation can force has obvious difference. this from fracture different tensile 应变看 very 清楚, especially is types obtain different tensile impact strong/high degree. injection speed degree value by standards is 20cm3/s, tensile impact strong/high degree can reduce 55％, amount weight and shrink 之变化 has 2.5％ or 15％. material is in quality tube/pipe necessary property through hot method （DSC） for different sheet/plate 进行 补充 property research 突出 开始时形态 upper fine micro difference. 换句话说, comprehensive 看, research sheet/plate has uniform crystallization. this 结果也 in cooling （ crystallization hot amount ） in and in add hot stage/phase （ uniform front process rear melt hot ） can to. from 动态差 separation hot amount crystallization process, can obvious to, polymer processing process in injection speed degree grade upper rise 时, relatively low temperature degree lower crystallization hot 由-74J/g increase to -97J/g. this dark use POM材 material is processing causes 而出现变化. material molecular weight and molecular weight distribution improves versus solid property can （ overall crystallization or more or less is 一致 ）, therefore promote different structure （形态） 形 formed, this value high degree and value wide degree ratio value to 证明, its 由2.7 drop to 1.6. in this type of in, 靠DSC（首步 add hot ） 观察 different sample overall crystallization, 会导致 for quality positive assessment, is in this has is easy 见. has structure is in 一 不直接 基础之 upper by assessment 时, this 才会突出存 in difference. in 极化发射 light lower for different sample thin 断面（约10mm）进行显 micro 察, 显示出受 different process conditions control 做出塑 parts structure non 常不一样. injection speed degree improve/increase 时, can to non outer thick degree 由102mm急剧 decline to 30mm, meanwhile lower structure 也经历 变化（图2）. therefore, high injection speed degree lower made 出 塑 parts hardness decline need is material 方面 不理想形态变化. 图2 right 边 示 structure and research parts property deformation property can has 关系, tensile impact testing impact strong/high degree ratio tool has 图2 in left 边 示 structure same parts impact strong/high degree need low upper 100％. 图2: processing for structure function processing for property can effect/influence in different injection speed degree lower processing easy flow POM, obvious for material property can deep effect/influence. polymer 剪切程 degree increase large micro separation 子逐步 链 separation understanding, this also melt flow property （ in injection molding processing mold inner pressure 传送）发生变化, crystallization force 学发生变化. already amount and DSC曲线 table/sheet 示进行 this process. property 调查也确定 this type of performance. use 流变计 is UDS200 Model/Grade. 取100mg 样本, 流变计承受210℃ temperature degree lower, 0.1-100s-1 scope/range inner for increase speed rate, wide degree is 0.1mm. this 结果证明 当 injection speed degree improve/increase 时, processing in polymer separation understanding add 剧. polymer molecular weight according to processing conditions 而进行变化, this is from injection speed degree rise high viscosity decline can 清楚看 to 事情. 结论 报道 research table/sheet 明, different injection speed degree for POM copolymer （POM）材 material injection molding processing parts most quality has effect/influence. parts property can 随剪切而变化, for processing in POM melt function. this type of need 归因于摩尔 quality decline, and molecular weight separation adjustment, this is by data 证明. 随 塑 parts formed process in melt cooling lower 时, POM melt property can and melt temperature degree and melt pressure 一起确定 晶化动 force 学. this 意味 完 full 不一样 structure and high degree use property can can processing conditions 而变化. for/regarding easy flow POM copolymer, is obvious, it reduce thin parts impact strong/high degree 达50％. this research is and in in to is basic upper 一致. discussion phenomenon for/regarding flow property generally polyoxymethylene (POM) is relatively less 出现. therefore 如不考虑形态, is can can for parts quality as 出一 明确说明. therefore tool has most new technology plastics production process need 一定形式 quality tube/pipe 理, it 首先监控塑 parts inner in property can quality （例如监控 mold cavity pressure 曲线）, therefore ensure product in overall upper is high quality, false inner in property can outer in property can is conditions. therefore, already 经 出 research table/sheet 明, is achieve anti property quality tube/pipe 理, application material is in process and rear process control in future is can and has necessary. has this type of methods, has can can large large 避免由 processing as 业引起 use property can separation belt/tape for parts in 伤害. need as 进一步 research, is structure as 出定义, will ensure is thin or small type parts production, achieve parts most stability property can.