Shanghai Daoqin Plastics Co., Ltd.

近几 year, melt make 百业萧 strip/profile, is can electronics product from in day 夜赶工, 供不应求者却 large has in. can electronics product short small light thin, outer housing/shell thin to will 近1mm, small 于1mm时, for/regarding material 商, product and injection molding parts mold design engineering 师, injection molding parts mold injection molding parts processing, molding injection molding parts processing and molding machine equipment manufacturing injection molding parts processing is large 挑战. 本文针 for thin housing/shell molding from material selection, product and injection molding parts mold design, CAE analysis, injection molding parts mold manufacturing molding setting to molding machine and equipment selection as focus/key point introduction. can 抛砖引玉, innovation machine. for solid electronics product 而言, thin housing/shell make cost reduce, ring time shrink short, production force improve/increase. for/regarding can electronics product 而言, thin housing/shell make weight light, dimensions decrease small. can electronics product demand year formed long 达30%, in the future year formed long more fast. due to has this type of product also very less － in USA less 于5%, full world less 于1%－整 market large 惊人. type thin housing/shell long for thick ratio scope/range is 100: 1 to 150: 1 or more large. need to this high ratio value increase gate, must need using/adopting high melt temperature degree, high pressure and very high speed. C-MOLD injection shot molding using/adopting Cross-WLF黏 degree 模式如 lower: 此一模式 can in wide molding conditions scope/range inner 适切 描述黏 degree, benefits is relatively good 处理黏 degree for temperature degree and pressure property (黏 degree for pressure property temperature degree reduce increase). in Cross-WLF黏 degree in, pressure for degree effect/influence 以D3显示. in molding conditions lower, pressure for degree effect/influence obvious, D3 can is 0. in high pressure lower, pressure for degree effect/influence important, D3必 must 决定, make 模拟 结果 can pressure 效应. need obtain D3 combined value, 特殊 黏 degree testing 程序以 and data analysis is necessary. if has pressure for degree effect/influence, system pressure increase 时, forecast pressure 误差会愈 愈 large. lower 图 平碟模 is very good 例子, non pressure for degree effect/influence 项D3 can 改进充填 and rear 充填模拟 pressure forecast. using/adopting polycarbonate (PC) (PC)材 material, 平均壁 thick is 1mm, long is 170mm. pressure for degree effect/influence 项D3并入计算 rear, forecast pressure obvious improve/increase, and pressure versus combined. 经由浇道 gate, gate, hot gate and other 直接进浇 to thin 壁, use gate 井, decrease/reduce gate force, 帮助充填, will products in gate loss drop to most low. thick small 于1.2mm时, use large thick gate, 以助流, in gate front, formed 适当 填 pressure. is has pressure thin type 腔, runner pressure drop most good need ultra- machine can provide pressure 15%. use relatively runner large 1.25 to 1.4倍 runner. more has selection hot runner add upper gate has reduce pressure to value. hot runner inner generally large 于13mm, can has and 死区. using/adopting outer hot add hot device is positive 途. is can high pressure 进浇, gate must 安装, is can formed 障碍. hot runner can large large decrease/reduce pressure drop and ring time, however plastics hot runner make melt in high temperature lower time add long, thin housing/shell molding material amount relatively 之传统者 is small, if plastics in material tube/pipe and hot runner in time long, make material poor 化. plastics time can lower 式计算: 1.4x use plastics specific gravity x material tube/pipe material amount x molding ring time polystyrene (PS) specific gravity x射 material amount 1.4 is 一乘数(generally in 1 and 2 between) most short and most long time 应遵照材 material injection molding parts processing 商 建议. if 特定 指示无 from obtain, most short and most long time can 1.5 and 4 separation is 准. in thick small 于1.2mm thin housing/shell application, product rigid property design important. must need rigid property can 藉几何特 micro and assembly methods 巧思而 obtain. relatively large product rigid property can 经由材 material selection, design and assembly 一体考虑而达 formed. high speed make gas more is important, anti gas 困引燃. type separation 模面排 gas is 0.01~0.04mm deep, 5mm wide, 甚至沿 separation full long gas. in type 心销, ejection 销, and 螺柱处排 gas is very has use. runner 末端 充 separation gas and for type true can decrease light type gas negative 荷. for 冰箱蔬果盘之 type large parts 而言, material 往往占 cost 50% above. for small thin parts 而言, molding machine use can to cost 90%, material 6%, injection molding parts mold 占4%. small thin product relatively thick more can from cooling improvement obtain 效益. thin housing/shell product 不像传统壁 thick generally can relatively large hot 传不均而 generate residual stress. is will shrinkage control in can 接受 程 degree, cooling design non important. thin housing/shell products ejection is tool property, is: 1） high pressure make pressure relatively 紧, shrinkage relatively less and 2） thin and thin make product relatively easy loss 毁. is 避免顶穿 and mold sticking, use relatively more but also relatively large ejection 销. thick small 于1.2mm时, can use more to 2倍 but also large to 2倍(直径>6mm） ejection 销. high speed injection shot plastics increase injection molding parts mold abrasion consumption. thin housing/shell molding using/adopting relatively P20 hard tool 钢, high abrasion consumption, 冲蚀区尤然. use hardness large 于55(如H13 and D2) gate block. 公, sheet/plate and sheet/plate thick degree can is sheet/plate thick 两倍. 支撑柱 need more, in 近浇道 in and type 腔处应预 negative 荷0.1mm. H13钢 屈服 strong/high degree relatively NAK55 or P20 high 15% to 25%, value selection. is melt fast speed belt/tape thin type 腔, need use high pressure and short injection shot time. injection shot time small 于0.5秒时, in has how much time can use speed degree or pressure, therefore high separation rate micro device control molding machine necessary. high pressure thin housing/shell molding must need in injection shot mono upper add pressure device, fast speed clamping requirements make pressure device 变 颇 has 帮助. for certain parameters (如 holding pressure pressure and to holding pressure 转换) control is important, injection shot and clamping 行进曲线 control can force and made 程追踪 and upper product tube/pipe soft parts is necessary.