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1、主流道粘模Sprue sticking1）何谓主流道粘模（外观）1) What is Sprue sticking ? (appearance) 主流道残留是指成型品的主流道未能脱离模具的一种现象。 如果长时间施加保压以致主流道尺寸增大，或模具的主流道部分有伤，则会产生阻力，从而使主流道在开模时不能脱落。Sprue sticking is a phenomenon that the sprue of a molded product can not be separated from the mold. It occurs when sprue size is much large by lo
2、ng holding pressure time or when scratch on mold surface of sprue has friction图1. 主流道没有脱落而是粘着在固定侧的 120平板Figure.1 Stick flat plate（2）主流道粘模的生成原因2) Causes of Sprue Sticking2-1) 主流道固化不充分2-1) Insufficient sprue solidification主流道尚未完全固化时，由于此刻的收缩量很小，主流道紧贴模具，强度也偏低，因此如果此时就要使主流道退出，则会非常容易折断。这样一来，主流道就残留下来了。树脂温度、
3、模具温度以及周期（冷却时间）等对主流道固化都有影响。When sprue is has not been solidified completely, adhesion to the mold for low shrinkage and weak strength at that time tend to produce the sprue break on pulling it out. As a result, the sprue is left in the mold. The sprue solidification is affected by resin temperature,
4、mold temperature, cycle time (cooling time), and so on.图2. 主流道尚未完全冷却时容易粘模Figure.2 When sprue is has not been solidified completely, sprue is left2-2) 过度施加保压2-2) Too high holding pressure主流道部分离机筒喷嘴最近，因此便于施加保压。因此，施加高保压后，主流道的尺寸便会增大，而且脱模时的阻力也会相应地增大，从而容易发生主流道粘模。The sprue part is nearest to the cylinder n
5、ozzle and is the position to which holding pressure is most easily applied. Therefore, high holding pressure application increases the sprue size so the resistance to drawing out of the mold to tend to cause sprue sticking(2-3) 模具构造方面的问题(2-3) Problem of mold structure主流道部分的斜度偏小时，固定侧脱模的阻力会增大。虽然为了从固定侧
6、拔出主流道而设置了主流道锁定，但如果很脆弱，锁定就会受损，从而使主流道从移动侧脱落。另外，如果使用的是分流道锁定，由于它过于牢固，主流道和分流道有时会粘附到固定侧。When the taper of the sprue part is small, the resistance to drawing out also increases. Even if a sprue lock is installed on the moving side to draw out the sprue from the fixed side, if the lock is weak, the lock is
7、released and the sprue comes off the moving side. Also, when a runner lock is used, too strong locking may cause sticking of sprue and runner to the fixed side2-4) 等级固有的问题(2-4) Problem of grade proper与标准等级相比，耐冲击性等级或合金材料的收缩更小，更容易粘附到模具上，而且强度也更低。这样一来，主流道粘模就更容易发生了。Impact resistant grades and alloy grade
8、s have lower shrinkage than the standard grade and a tendency to stick to a mold. The strength is also lower. These factors often lead to sprue sticking.（3）主流道粘模的对策(3) Countermeasures against Sprue Sticking3-1) 使主流道充分冷却并固化后再开模(3-1) To open the mold after cooling and solidifying the sprue sufficientl
9、y降低模具温度并延长冷却时间。特别是对于强度小而固化慢的材料，降低模具温度将是一种有效方法。Lower the mold temperature and extend the cooling time. In particular, in materials of weak strength and those of slow solidification lowering of mold temperature is effective3-2) 降低保压3-2) To lower holding pressure降低保压也是有效的。施加在产品模腔上的保压会在浇口封闭后变为0，因此，如果此后不
10、施加保压，则主流道就不会承受无用的保压。但过度降低则容易导致注塑量不稳定，因此需要注意。Lowering of holding pressure is also effective. Since the holding pressure applied to the product cavity becomes zero after gate seal, lowering of holding pressure after that can protect the sprue from unnecessary holding pressure application. Note, howeve
11、r, that too much lowering may produce shot to shot variation. (3-3) 改善模具3-3) To improve mold主流道斜度所必需的角度尚未有专门的规定 。但如果可能出现主流道粘模，则增大角度也是有效的。强化主流道锁定（加大尺寸并增强斜度）也是有效的。相反，由于有可能因顶出而变得难以脱落，因此需要在实际成型的同时进行调整。分流道锁定过于牢固时，请将该部分的尺寸略微改小The angle necessary for sprue taper is not definitely decided. If sprue sticking occurs, increase of the angle is effective. Though intensification of sprue lock (size expansion and taper increase) is also effective, it may cause hard release in ejection. So, the adjustment must be done under actual trial.If runner lock is too strong, modify the size of this part smaller.
