Shanghai Daoqin Plastics Co., Ltd.

what is thin injection molding? thin injection molding for injection molding machine, mold, plastics has requirements. discussion thin features, 经济效益 and equipment design.

    thin 壁?

    simple method, thick small 于1mm时称 is thin 壁. more comprehensive, thin 壁 定义 and process/workflow /壁 thick ratio, plastics viscosity and hot 系数均 has 关系.

    from mold runner to formed product most 远一点 process/workflow L, remove formed product thick t, is process/workflow /壁 thick ratio. 当L/t＞150时, is thin 壁. process/workflow thick thin 不一致, can separation 段计算.

    process/workflow /壁 thick ratio PP viscosity is 1. one-time 即弃饭 box/case process/workflow 135mm, thick 0.45mm, process/workflow /壁 thick ratio =300. PC viscosity is 2. machine battery outer housing/shell process/workflow 38mm, t=0.25mm, process/workflow /壁 thick ratio =152. upper viscosity is 304, and box/case versus 若.

    generally plastics thermally conductive defect. is increase dispersion hot or to electrical magnetic 波兼容 property, outer housing/shell using/adopting high thermally conductive property plastics. metal powder belongs to high thermally conductive property. upper is injection molding formed product cooling time 公式, its in t=壁 thick, Tm= solvent melt temperature degree, TW=模壁 temperature degree, T= demolding temperature degree, α= plastics hot 系数. L/t need viscosity and hot in inner.

    我 完善一 lower, what is thin injection molding?

    brief overview is need thin injection molding?

    plastics raw materials cost usually products cost large ratio 数, 如50-80%. thin has reduce this ratio 数. due to property electronics equipment machine, MP3播放 machine, versus machine, upper machine small type and light 便化, has 关 塑 parts design 便越 越 thin.

    thin 壁化因 tool has decrease small product weight and outer dimensions, 便于集 formed design and assembly, shrink short production cycle, 节约材 material and reduce cost and other advantages formed is plastics industry target/goal, already formed is plastics molding industry in new research hot 点.

    process thin products design and methods more is complex, 并进一步受 to molding and material selection effect/influence. thin products requirements tool has high impact strong/high degree, good appearance quality and dimensional stability, can large 静态载荷, molding material flow property need good. design process in need focus/key point products rigid property, impact resistant property and can manufacturing property.

    molding thin products generally need design thin products specialized mold. and products standards mold versus ratio, thin products mold from mold structure, system, cooling system, gas system and demolding system and other 都发生 heavy large 变化. main/primary performance in below/following several 方面:

    （1） mold structure: is molding high pressure, thin molding mold rigid degree need large, strong/high degree need high. therefore mold 动, sheet/plate and its sheet/plate weight relatively large, thick degree usually ratio mold sheet/plate need thick. 支撑柱 need more, mold inner can can need more inner 锁, ensure 精确定位 and good 侧支撑, anti bending and 偏移. another, high speed injection shot speed degree increase mold abrasion loss, therefore mold need using/adopting relatively high hardness tool 钢, high abrasion loss, high 冲蚀区（如 gate 处） hardness large 于HRC55.

    （2）浇注 system: molding thin products, especially is products thick degree non small 时, need use large gate, but also gate large thick. is gate 应设置 cold material 井, decrease/reduce gate force, filling, decrease/reduce products remove gate loss bad. is ensure has pressure thin mold cavity, runner system in can can decrease/reduce pressure drop. is 此, runner design need ratio large 一, meanwhile need made melt time, anti resin degradation poor 化. is more 腔时, system balanced property requirements high 于常规 mold requirements. value attention/notes is thin products mold system in also 引入 两项先进 technology, hot runner technology and 顺序阀式 gate （SVG） technology.

    （3） cooling system: thin products 不像传统壁 thick parts that can relatively large hot 不均而 generate residual stress. is ensure products dimensional stability, shrinkage and warpage control in can scope/range inner, must add strong/high mold cooling, ensure cooling 均衡. relatively good cooling measures has in type and mold cavity block inner using/adopting combined cooling 线, add large cooling long degree, can reinforcement cooling 效果, necessary add high rate metal block, add fast hot 传导.

    （4）排 gas system: thin injection molding mold generally need has good gas property, most good can 进行抽 true as. due to filling time short, injection speed degree high, mold separation gas especially is flow front poly 集区 充 separation gas non important, anti gas 引燃. gas usually through type 芯, 顶杆, add strong/high 筋, and separation type and other 处排出. runner 末端也 need separation gas. Japan Sumitomo company use more tool small parts solution small parts products gas issues.

    （5） demolding system: is thin products and very thin, non easy loss bad, but also thick degree direction shrinkage very small, make add strong/high and other small structure very easy bonding, meanwhile high holding pressure pressure make shrinkage more small. is 避免顶穿 and mold sticking, thin injection molding use ratio injection molding amount more more, dimensions more large ejection 销.

    injection molding machine very difficult in thin parts injection molding in has use 武之. ratio thin injection molding filling time very short, very more filling time 不足0.5s, in this short time can can speed degree or pressure, therefore must use high analysis degree micro device control injection molding machine; in thin products injection molding process in, meanwhile 各自独立 control pressure and speed degree, injection molding machine stage/phase use speed degree control, holding pressure stage/phase again is pressure control methods already suitable. therefore machine equipment manufacturing and research machine 构共同 combined as force, made specialized injection equipment. Taiwan in machine company VS-100 thin injection molding machine, Germany Dr．Boy company development Boy type series injection molding machine and Battenfeld, Arburg and JSW and other injection molding machine production development specialized injection molding machine.

    thin injection molding material flow property need good, must has large flow long degree. also has tool has high impact strong/high degree, high heat deflection temperature (HDT), good dimensional stability. another, also need 考察材 material heat resistant property, flame retardant property, machine assembly property and appearance quality and other and other. currently, thin injection molding is application material has polycarbonate (PC) （PC）, acrylonitrile — butadiene — styrene （ABS） and PC/ABS blending material and other.

    technology injection molding filling process and cooling process is in 一起, polymer melt flow 时, melt front to versus for temperature degree relatively low type surface or type 腔壁, in its surface formed cold 凝层, melt in cold inner toward front flow, cold thick degree for polymer flow has significantly effect/influence.

    need for thin injection molding in cold property 质进行 more in-depth, more comprehensive research. therefore has thin injection molding value also in below/following 几方面做 very more as.

    （1） more in-depth comprehensive research thin injection molding 理论, especially is cold property 质, 以便提出 more add combined false conditions and conditions. upper analysis can 知, in thin injection molding process in, its very more conditions and injection molding has very large different. 模拟时, melt flow 数学模 type many false and conditions in thin injection molding in need 进行适当 adjustment.

    （2）确定 in thin injection molding in increase factors, positive 确 考虑 this factors. in injection molding in can factors, 往往会 for thin molding melt flow generate relatively large effect/influence. ratio 如, in thin injection molding in viscosity for pressure has obvious property, in injection molding in has; weld lines strong/high degree for parts property can effect/influence very large, especially is thin parts, weld lines strong/high degree and temperature degree and pressure has 关, 但常规数 value 模拟时没 has pressure effect/influence; material ratio hot, hot and pressure loss and other. has product value soft parts due to this effect/influence factors, in forecast thin injection molding filling 时会出现不一致 phenomenon.

    （3） application true positive 三维数 value 模拟. has product 化 数 value soft parts is use 二维, semi elements table/sheet 三维几何图形 简化模 type, has material amount in thick degree direction upper 变化. flow 区域即拐角处 flow, thick degree 变化区域, melt front 端喷泉效应 in has value soft parts in also can table/sheet 示, it in thin injection molding in important function.

    （4） injection molding full process 模拟. currently soft parts main/primary filling, flow, holding pressure, cooling, and warpage analysis and other block, block development is 基于各自独立 数学模 type, versus between effect/influence. is, from injection molding process process 看, plastics melt flow, holding pressure and cooling and other is in 一起并 versus effect/influence, this in thin injection molding in is obvious. therefore, flow, holding pressure and cooling analysis and warpage block must has machine combined 起, 进行耦 combined analysis, can comprehensive 反映实际 injection molding.