《注塑工艺手册》由会员分享，可在线阅读，更多相关《注塑工艺手册（21页珍藏版）》请在金锄头文库上搜索。
1、工艺注塑手册Injection process handbook一. 基本理念：Basic opinion:1. 什么是最佳的流动状态：What is the best flow state: 流体流动状态应该是喷泉状的，最佳的流动状态是流体前端的流动速度在型腔内处处相等。由于流动方向上截面积的不同，在其变化的位置应进行注射速度的调节（注意：机床上所能设定的注射速度是指螺杆的前进速度）。 The flow state should be like fountain, and the best is that the speed of the front melt is the same eve
2、rywhere in the cavities. For different areas in the direction that is vertical with the flow way, we must adjust the injection speed.(Attention: The injection speed, which we can set on the machine, is the screw forward speed)2. 什么是最佳的压力,温度分布状态：What is the best pressure and temperature state:最佳的压力和温
3、度分布状态是压力和温度分布在型腔内部处处相等，并且随着熔体地逐步冷却而下降并使最终产品的内应力为零。The best pressure and temperature state should be like this that the pressure and temperature everywhere in cavities are the same, and make the force of the part inside be zero finally as the melt solidified.实际压力分布状况是浇口附近最大并随着距离的增加而降低。（记住：螺杆头处的熔体和流动着
4、的熔体前端存在压力差是使熔体发生流动的根本原因）The actual pressure around the gate is the highest and as the distance goes its getting lower and lower。(Remember: Its the pressure in front of the flowing melt is lower than in cylinder that makes the melt flow.) 所以,综合来讲,参数设定的一般准则:(1) 尽量选用高的注射速度(螺杆前进速度)(2) 尽量选用高的料筒温度(3) 尽量选用
5、高的模具温度So the general principles when setting parameters are:(1) As fast injection speed as possible (Screw forward speed)(2) As high cylinder temperature as possible(3) As high mold temperature as possible二. 基本概念：Basic conception:1. 收缩：Shrinkage:（1）收缩的原因：.a.热胀冷缩；.b.熔体结晶；(结晶度越高，熔体收缩越严重).c.分子取向；（一般来说，
6、分子总是沿着流动方向取向的。对于未增强型材料，其熔体在流动方向上的收缩总是大于垂直方向；对于增强型材料，正好相反）. d.状态变化 The reasons of shrinkage: a. Chang from hot to cold; b. Crystallization ;( The more crystallization, the more shrinkage)c. Molecule orientation; (For non-strengthen material, the shrinkage in the flowing direction is more than that, w
7、hich is vertical with the flowing direction; and for the strengthen material, the result is just reverse,) d. Form changing（2）收缩的阶段： The stages of shrinkage: 收缩从注射开始就随着熔体的逐步冷却而开始 The shrinkage starts from injection to forever. 它包括三个阶段：a.从注射开始到保压结束；b.从冷却时 间开始到脱模前；c.脱模后 It contains three stages: a. Fr
8、om injection stage to end of holding stage; b. From cooling stage to demold stage; c. After demold.（3）变形： Deformation 变形的根本原因时收缩的不均匀。造成收缩不均匀的原因有：The root cause of deformation is inhomogeneous shrinkage. The causes of inhomogeneous shrinkage are as follows:a. 冷却(即温度分布)不均匀Inhomogeneous coolingb. 壁厚不均匀
9、Different wall thicknessc. 压力分布不均匀Not average location of pressure location d. 分子取向Molecule orientatione. 脱模受力不均Inhomogeneous forces when demolding 2. 结晶Crystallization: （1）什么是结晶： What is crystallization: 简单的说，结晶就是指分子的有序排列 In a short word, it means to make the molecule in order. （2）结晶的影响因素： Factors
10、affecting crystallization: 结晶的影响因素：冷却速度。冷却速度越快，结晶程度越低。 The cooling speed affects the crystallization. The faster cooling speed the more crystallization （3）结晶对产品性能的影响： How does crystallization affect the parts: 结晶度越高：密度越高 收缩越大 光洁度越好 强度越高 韧性变差 The more crystallization: The higher density The more shri
11、nkage The better surface The stronger of the parts 3. 粘度：（1）什么是粘度： What is viscosity: 粘度是流体本身的一种性能，它的大小是流体流动性能的一种衡量。数值越大，流体的流动性能越差。 Viscosity is a character of the flowing material. Its value is used to measure the flowing character. The bigger value it is, the worse flowing character it is.（2）粘度的影响因素： What affect the viscosity: a.温度 Temperature b.剪切速度 Shear rate c.压力 Pressure 千万注意：往往粘度是三者共同作用的结果。不同的材料对温度，剪切速度和压力的敏感程度是不同的，并且在不同的注射速度下哪一个起主导作用也是不同的 Attention: The three factors affect the viscosity together all the time. Different material are diffe
