Shanghai Daoqin Plastics Co., Ltd.

  injection molding processing equipment 进一步 development and products quality requirements improve/increase, for injection molding process more high requirements. positive selection injection equipment, combined setting molding process, optimization process conditions, is improve/increase products quality key/critical.

    positive selection injection molding machine

    injection molding machine property can effect/influence injection molding products quality, different specifications and property can requirements injection molding machine, price versus very more.

    in selection injection molding machine specifications 时, need to production mold 状况, is 同一台 injection molding machine need meet/satisfy large small different more mold production, according to made parts weight, mold dimensions and other injection molding machine specifications, injection molding machine most large clamping force and most large injection amount, according to injection molding machine provide specifications Model/Grade selection combined machine type. large separation 厂商都 provide made 化服务, this to injection molding machine provide large 方便; its need is need 一 特殊配置, production PA, PC and other material selection specialized screw, molding belt/tape has 进抽芯 or 脱螺纹 mold 时需配备 versus plant/unit; again 次, need according to mold structure, product quality and other factors is need selection tool has function injection molding machine, molding thin long flow products （ generally 指L/D??300）时, selection high injection speed degree injection molding machine, precision electronics parts selection precision full ring control injection molding machine and other.

    clamping force setting
    upper, clamping force can lower 式进行计算?s
    Fcm>=K × P平均 × A products ×10
    in?sFcm? clamping force, （KN）
    K? safety 系数, generally 取1-1.2
    P平均 mold cavity pressure （MPa）
    A products? products in mold separation type upper most large 投影面积（cm2）
    in production in, clamping force adjustment also 应考虑 mold in production in hot generate effect/influence, generally has 0.1-0.2mm amount; clamping force setting is in ensure product quality front lower low clamping force is 宜.

    injection molding process parameters setting  
    according to different plastics material property can setting screw material temperature degree, material setting temperature degree generally high plastics melting point 10℃-30℃. must attention/notes, different provide material combined formed methods or add additives type type different, it melting point and in material in 允许停留 time has 差异. lower table/sheet 1, for Solutia company PA66（ grade is 21SPC） and Rhodia company PA66（ grade is 25AE1）, it melting point and temperature degree lower 允许停留 time comparison.

    mold temperature degree in setting generally use ring water cooling, in production precision dimensions or surface quality requirements relatively high products 时, according to process requirements use can 够进行准确 control mold temperature machine.

injection holding pressure time, cooling time

    injection time, holding pressure time and cooling time must according to product thick degree, mold temperature degree, material property can and other setting. injection time setting generally large screw formed injection 行程移动 time can, long injection time 不但会 generate machine abrasion loss, can consumption increase and other negative effect/influence, meanwhile 也会延 long molding cycle. holding pressure time setting according to product thick degree setting, thin product in molding can use holding pressure time; in setting holding pressure time 时, need product surface obvious 凹陷即 can, can use heavy method 确定, 逐步延 long holding pressure time product quality again time can is most holding pressure time. cooling time 同样需 according to product thick degree, mold temperature degree, material property can 确定, generally type polymer cooling time need ratio crystallization type polymer time long.

    injection pressure, speed degree

    injection pressure setting need 遵循宜 low high 原则, need can provide 足够动 force to requirements injection speed degree, make melt can 够顺利充满 type can, high pressure easy make products inner generate internal stress; in molding dimensions degree relatively high products 时, is anti product shrinkage degree, can using/adopting high pressure injection decrease/reduce products demolding shrinkage.

    injection speed degree effect/influence product appearance quality, its setting according to mold structure, gas and other setting, generally in ensure good appearance front lower, amount improve/increase injection speed degree, decrease/reduce time. in injection molding in, melt in mold inner flow 时, 模壁会形 formed solid 化层, reduce can flow thick degree, generally according to mold structure and injection speed degree different, 模壁会 has 0.2mm left right solid 化层. therefore molding in usually using/adopting relatively fast injection speed degree.

    injection 行程, more grade injection parameters  

    in molding in, must injection 行程, upper, injection can lower 式计算?s
    S1=4(CVp+Va)/ρDs2
    in?sS1?? injection Vp? product 体积
    ρ? resin density C? type 腔数目

    Va? gate Ds? screw 直径
    in production in, already 知“ product + gate ” weight, can use lower 式 计算 injection 行程?s    
    S1=（M/Mmax）?Smax+(5~10)mm
    in?s S1--- injection 行程, mm
    M?“ product + gate ”总 weight, g
    Mmax? injection molding machine most large injection amount, g
    Smax? injection molding machine most large injection 行程, mm
    由於浇道 system and mold 各部位几何形状 different, is meet/satisfy product quality requirements, in different for melt flow 状态（ main/primary flow pressure, speed degree ） has different requirements. in injection process in, screw toward mold melt 时, requirements achieve in different upper has different pressure and speed degree, is more grade injection molding. generally parts in molding less setting or above injection is comparison 科学, runner is 第一段, separation runner gate is 第二段, product type 腔约90% is 第三段, 剩余部 separation is 第四段, can use weight method 确定各段 切换位置点; production in, according to product quality requirements, runner structure, mold gas and other for more grade injection process parameters 进行科学 analysis, combined setting. usually can using/adopting debugging method setting, will injection 时 需找切换位置点 pressure / speed degree setting is 0, melt toward and product defect 状况, 逐步进行 adjustment, 直至找出 combined 理 位置点. in debugging process in must attention/notes product demolding 状况, in mold certain 凹陷部位因欠注而发生 mold sticking.

    its it process parameters

    in injection molding in, remove molding temperature degree, pressure, speed degree, time, more grade injection 切换位置 and other several main/primary parameters setting outer, also has many its it process parameters, back pressure, screw speed, screw anti 流延以 and its it as parameters setting and other, can overlook its setting.

    process parameters setting 实例

    production nylon belt/tape product is 例, product quality requirements?s product to 规定拉 force standards; surface silver streaks, bubbles, shrink and other type defect phenomenon; molding product property good, 无松脱 phenomenon. use material is PA66; injection molding machine is JSW1000-EⅡ-SP, mold structure is #p# separation 页标题#e# hot runner 式, gate type is gate.

    according to product features and mold structure process parameters setting 原则?s（1）因 product flow long degree relatively long, L/t（ process/workflow and thick ratio ） is 511, selection high speed injection molding; （2） gate type is gate, must use relatively high pressure 以克服 flow retardant force; （3） is ensure product can 顺利充模, material must has good flow property, molding temperature degree 应适当偏 high; （4） high pressure high speed injection 至未端时容 easy generate flash, molding machine must has low property pressure, speed degree 切换; （5）因 product thick relatively small, can use holding pressure;