When we are processing injection molded parts, we often encounter some unnecessary defects due to minor reasons, which in turn cause certain troubles for our injection molding processing. Among these defects, the most common one is crack defect. So, what are the causes of crack defects in injection molded parts processing?

1. A large proportion of recycled materials are added to the raw materials, resulting in significant shrinkage directionality of the raw materials or uneven distribution of fillers;

2. The raw plastic materials are contaminated, contain volatile substances or are poorly dried;

3. Improper demolding design, small demolding slope, thin product walls with sharp corners and notches, resulting in stress concentration;

4. The holding pressure and injection time are too short, and the cooling time is either too long or too short.

5. Low or uneven temperature of the working die, slow injection speed and low pressure;

6. Improper forming conditions, excessive stress and poor ejection;

7. Improper use of mold release agents and uneven cooling after demolding of products, etc.