Shanghai Daoqin Plastics Co., Ltd.

injection speed degree control injection speed degree control is will screw injection separation is 3~4 stage/phase, in stage/phase in separation use 各自适当 injection speed degree. 例如: in melt plastics rigid through gate decrease slow injection speed degree, in process in using/adopting high speed injection, in 充模结束时 decrease slow speed degree. using/adopting this methods, can anti material, remove flow marks and decrease/reduce products residual stress and other. low speed 充模时流 speed 平稳, products dimensions comparison stability, relatively small, products internal stress low, products inner outer toward force 趋于一致（例如 will certain poly carbon acid made parts 浸入四 chlorine carbon in, use high speed injection molding made parts has cracking toward, low speed cracking ）. in relatively is slow conditions lower, material temperature 差, especially is gate front rear material temperature large, has 助于避免 shrink and 凹陷 发生. due to time relatively long easy make made parts delamination and combined defect 熔接痕, effect/influence appearance, but also make machine strong/high degree large large reduce. high speed injection 时, material speed degree fast, high speed 充模顺利时, material very fast type 腔, material temperature decline less, degree decline less, can using/adopting relatively low injection pressure, is types hot material 充模态势. high speed can made parts gloss degree and slip degree, remove 接缝线 phenomenon and delamination phenomenon, shrinkage small, color uniform 一致, for made parts relatively large separation can ensure 丰满. easy generate products 发胖起泡 or made parts 发黄, 甚至烧伤变焦, or formed demolding difficult, or 出现充模不均 phenomenon. for/regarding high degree plastics has can can melt 破裂, make made parts surface generate 云雾斑. lower 列情况 can using/adopting high speed high pressure injection: （1） plastics degree high, cooling speed degree fast, long process/workflow made parts using/adopting low pressure slow speed can full type 腔各 角落; （2）壁 thick thin made parts, material to thin easy cold 凝而滞留, must using/adopting one-time high speed injection, make material can amount a large amount of consumption front 立即进入 type 腔; （3） use glass fiber reinforcement plastics, or has relatively a large amount of filling material plastics, flow property 差, is to surface light slip uniform made parts, must using/adopting high speed high pressure injection. for high grade precision products, thick made parts, thick large and tool has relatively thick and made parts, most good using/adopting more grade injection, grade, grade, grade 甚至五 grade. injection pressure control usually will injection pressure control separation formed is one-time injection pressure, injection pressure （ holding pressure ） or above injection pressure control. pressure 切换时 machine is 否适当, for/regarding anti inner pressure high, anti material or material and other is non important. products ratio 容取决于 holding pressure stage/phase gate 封闭时 熔 material pressure and temperature degree. if from holding pressure to products cooling stage/phase pressure and temperature degree 一致, that products ratio 容就不会发生改变. in 恒定 模塑 temperature degree lower, products dimensions most important parameters is holding pressure pressure, effect/influence products dimensions most important amount is holding pressure pressure and temperature degree. 例如: in 充模结束 rear, holding pressure pressure reduce, table/sheet formed thick degree 时, holding pressure pressure again upper rise, this can using/adopting low clamping force molding thick large products, remove and flash. holding pressure pressure and speed degree usually is plastics mold cavity most high pressure and speed degree 50%~65%, holding pressure pressure ratio injection pressure large low 0.6~0.8MPa. due to holding pressure pressure ratio injection pressure low, in can holding pressure time inner, negative low, solid use lifespan long, meanwhile electrical machine consumption electrical amount reduce. grade pressure injection can make made parts 顺利充模, also 不会出现 weld lines, 凹陷, flash and warpage deformation. for/regarding thin made parts, more small parts, long process/workflow large type made parts 模塑, type 腔配置不太均衡 and clamping 不太紧密 made parts 模塑都 has benefits. mold cavity inner plastics filling amount control using/adopting adjustment good 一定 计 amount, make in injection 行程 终点附近, screw still has a small amount of melt （缓冲 amount ）, according to inner filling 情况进一步施 add injection pressure （二次 or injection pressure ）, less melt. this 样, can anti products or adjustment products shrinkage rate. screw back pressure and speed control high back pressure can make material obtain strong/high 剪切, low speed make plastics in machine inner to relatively long time. currently relatively more use for back pressure and speed meanwhile 进行程序 design control. 例如: in screw amount full 行程先 high speed, low back pressure, again to relatively low speed, relatively high back pressure, rear formed high back pressure, low speed, most rear in low back pressure, low speed lower 进行塑化, this 样, screw front material pressure to large separation 释放, decrease/reduce screw 转动惯 amount, from improve/increase screw amount 精确程 degree. high back pressure 往往造 formed color agent color degree increase large; machine combined machine screw machine abrasion loss increase large; cycle long, production efficiency decline; nozzle easy 发生流涎, recycled material amount increase; make using/adopting 自锁式 nozzle, if back pressure high design elastic 簧闭锁 pressure, 亦会造 formed fatigue bad. therefore, back pressure pressure need 调 恰当.