射出成型之设计教程幻灯片.pptVIP

* * * * * * * * * 4 然后，浇口凝固，保压完成（压力释放）。 接着进入冷却阶段。这是为了要打开模具必须对产品有足够时间的冷却。在冷却阶段，螺杆后移准备下一次注射。 在冷却完成后，模具打开，顶出产品。 * 4 为进一步说明成型周期，我们以图表来显示液压 (油压缸) 和模穴压力轨迹、螺杆位置和公母模面分离位置 。 * P-V-T图只能对简单外型及制程的产品进行厚度方向尺寸变化的预测，对于复杂外型及非厚度方向的收缩预测则因先天上的限制而有困难之处，但因为资料的取得容易、计算方式较为简单，所以对于生产运用及对收缩理论的观念建立上，有一定的价值及必要。 * * * * Reactive materials include: ? acrylic alkyds allyl diglycol carbonate DAIP DAP epoxy fluorosilicone melamine melamine/phenolic phenolics polyurethane polyols polyurethane isocyanates polyurethane systems silicone silicone/polymide urea unsaturated polyesters * During this session we will review some of the nuisance problems that surface from time to time during the processing of engineering resins. There is usually more than one approach which may be successfully used to correct molding defects. Today we will focus on those we have found to be most practical and effective. We would like this to be an interactive session. If you have had success in ways not covered please share them with the group. A * There are a huge number of variables involved in the injection molding process. Sorting out those which may be a factor in the problem we are attempting to correct is a key to successful troubleshooting. Too often we focus on and solve the wrong problem. Clear understanding of the problem is necessary. This is especially true when dealing with one that is intermittent in nature. Walking up to a press and making adjustments based on intuition works sometimes but it more often leads to complications. The first thing to do when trouble shooting should involve observation and fact finding, not changing conditions. It is also important to stay with the task. This isn’t always possible with a half dozen alarm bells ringing on the shop floor. If there is someone who can be dedicated to the present problem without distraction finding a root cause is much more likely. A * A * * Sinks are one of the most common molding issues. Sinks can be caused by many different rea