时间：2006-10-09 12:00:00 点击：114
3.机台马达启动温度视乎机台不同而不同,一般出于对机台油路中的油封保护需要,油温较好能控制在40度-60度,以免油封长期高压而变化,缩短使用寿命,造成成型不稳定.
Pump turning on temperature is different depending on type of injection molding machine. To protect oil seal of machine it set oil temperature within 40.C-60.C, If oil seal work on condition that high pressure and damaged It’s work time will be shorter, it can cause molding stable.
*三节注射及熔胶(加料)工艺条件设定
Injection and plastic Technique parameter setting
一.注射
Injection
*四节常见塑料原料的有关温度值.
原料
Resin名称
Name熔点℃
Melt’s成型温度℃
Molding Temperature(’c)分解温度℃
Decomposing Temperature(‘C)模具温度℃
Mold Temperature(‘c)干燥温度℃
Resin dry temperature(‘c)
注射是把塑料原料经加热后射进模腔的过程,它一般可分为**级,*二级,*三级,*四级及保压几段:
Injection is a step which inject melt resin material into mold. It consists of stepl,step2 ,step3,step4 and holding pressure step:
1.**级注射一般是注射料头段.具注射量一般可根据料头的轻重来估计其行程,当然也可以依据公式来计算,如公式:
Step l injects usually tunnel material, Injection Volume can be estimated according to the weight of course it can be calculated by formula:
L=Si=Vi/0.785Ds2
L:注射行程; Si:注射行程;
L: injection stroke Si: injection stroke
Vi:理论注射容积; Ds:螺杆直径;
Vi: injection volume of theoretical Ds: diameter of screw
0.785:是Ω/4的值.
0. 785: value ofΩ/4.
当然,如果我们在成型时每设定一个参数都要计算一次,要成型出一个产品就要几个小时才能完成了.
But it cost a lot of time to produce one product if every time molding parameter is setting by calculation.
2.*二级是注塑产品约2/3的阶段,当然,根据产品特殊需要,也允许成型不到2/3阶段,比如避免结合线问题,这一阶段的成型速度及压力一般是整个成型段的较大值段,如果排的产品与机台基本是相吻合的.模具结构合理,排气良好,这一段的压力一般也不会**过80%.速度侧视产品需变,可能大到95%也可,自然一般都是在55%-80%间.
Step 2 inject 2/3 of product. It can lower 2/3 of product according to requirement of product. For example to prevent weld line. Molding speed and pressure on this step is the maximum of whole molding section. If Mold suit the injection molding machine and mold structure reasonable and eject air well, pressure of this step should lower 80%. Molding speed setting within 55-80% but it may setting 95% for especial product.
3.*三段是注射余下的1/3段,其速度和压力根据产品的需要,一般是小于*二段,速度和压力存在于一个往下降的过程.主要是为了防止产品毛边的产生,但同时又必须把产品充填饱满.
Step3 inject remain 1/3 of product. According to product molding speed and pressure lower than that of step2 To prevent flash speed and pressure should decrease but it can’t shot short.
4.*四段:一般**台还有*五,*六段,这段的成型速度和压力相同前,都存在两段一个递减过程.其作用都是起到一个再次充满的作用.
Step4 section: Some injection machines have step5,step6 which are same as former molding speed and pressure this step should diminish and inject once more.
5.保压段:不论成型什么产品,都存在一个保压过程.任何产品都不同程度的存在一个厚薄不一的问题,正常情况下,较厚的部分都可能存在一个收缩凹陷的现象,为了解决这种现象,就应应用到保压,保压一般来讲都应用较慢的射速,而压力的设置则应看缩水的情况如何,小到25%,大到80%都有可能.
Holding pressure step: No matter what product there is a holding pressure step. Any product can’t molding a same thickness. Usually the deeper section may sink mark . To prevent this defect it should set holding pressure, The injection speed of holding pressure step is slow but holding pressure setting within 25-80% depending on sink mark.