注塑产品设计.上海.May 2010.pptVIP

Both ribs and base plate are 1.5mm thick. PA, 浙江省杭州市, 缩痕, 2003. 4. 19. 缩痕 Sink Mark 从成型容易的观点来看，突出件的高度以产品公称壁厚的2.5到3倍为宜。 From an ease of molding perspective, the height of projections should be limited to 2.5 to 3 times the part nominal wall thickness. 突出件高度Height of the Projection 距离应大于产品公称壁厚的2倍。 使得模具钢材具备足够的强度以抵抗弯曲，并且提供足够的吸热区，以免产生缩痕和成型应力。 The distance between a projection and the parts vertical sidewall, or between closely spaced projections should be at least 2 times the part’s nominal wall thickness, so the mold steel provide enough strength to resist bending and enough heat sink to avoid sink mark and molded-in stress. 突出件和侧壁/突出件的距离The Distance between Projection and Side Wall/Projection 孔设计 孔 Holes 以注射成型而言，圆孔形状理想，原因是塑料冷却时，会收缩紧扎在型芯销上，若销为圆形，应力会均匀的分布在孔缘塑料表层中。 孔 Holes 这一尼龙风扇因安装孔的直线孔缘末端的锁入应力而损毁。 This nylon fan failed due to molded-in stress at the end of the straight section on the mounting hole. - Glenn Beall, IMM, June 2001 - 孔 Holes Failures at sharp corners were eliminated by outwardly extending radiuses in this part. - Glenn Beall, IMM, June 2001 - 孔 Holes 最初，此一玻纤补强的尼龙计时链轮中央的方型驱动轴孔，有四个锐角。 使用几个月后，这些链轮，从方孔的锐角，到其附近的链轮齿根，产生裂隙而报废。 后来，在方孔的四个角落，加了向外延伸的小孔之后，链轮便不再开裂。 The glass-fiber-reinforced nylon timing sprockets were introduced with sharp corners on the square drive shaft hole. These sprockets failed after several months in the field due to cracks radiating from a corner on the square hole to the root of a nearby gear tooth. These field failures were eliminated by adding the outwardly extending radiuses. 孔 Holes 孔A和B能以简单直接开模的方式成形，孔C则须要一较复杂的侧向运动型芯，方能成形。 Holes A and B can be molded with a simple, straight opening mold. Hole C requires a more complex side-acting mold. - Glenn Beall, IMM, Aug. 2001 - 从易于成型的观点来看，相邻二孔缘的距离，或是孔缘和产品边缘的距离，至少要有壁厚的两倍，而绝对不可小于壁厚。 From an ease of molding perspective, the distance from one hole to the next , or to the edge of a part, must be at a minimum two times the part’s wall thickness, and never less than the part’s wall thickness. - Gle