When conducting large-scale injection molding, sometimes products may experience cracks, which not only affect the appearance of the product, but also seriously affect the quality of the product. So why do crack defects occur? Let's briefly introduce it to everyone below.
1. The proportion of recycled materials added to raw materials is large, resulting in large directional shrinkage of raw materials or uneven distribution of fillers;
2. The raw material plastic has pollution, volatiles, or poor drying;
3. Improper demolding design, small demolding slope, thin product walls with sharp corners and notches, resulting in stress concentration;
4. Short holding and injection time, long or short cooling time;
5. Low or uneven mold temperature, slow injection speed, and low pressure;
6. Improper forming conditions, high stress, and poor ejection;
7. Improper use of release agents, uneven cooling after product demolding, etc.