Causes and solutions of shrinkage marks of defects in injection mold

Injection mold molding defect shrinkage is mainly for the surface appearance requirements of the molding products, mainly refers to the surface of the molding products due to shrinkage and slight depression phenomenon. The design of injection mold can be considered by reducing the thick wall part of the molded product or using non-crystalline resin to reduce the production of shrinkage defects.

The main reasons for the shrinkage of defects in injection mold are: 1. Improper control of forming conditions; 2. 2. Mold defects; 3. Raw materials do not meet the requirements of forming conditions; 4. The structure design of plastic parts is unreasonable; 5 product wall is too thick or corner heat concentration, products are difficult to cool.

From the injection molding process to consider, the relevant solutions are: 1. Extend the pressure holding time; 2. Increase the holding pressure; 3. Improve the injection speed; 4. Reduce the nozzle temperature; 5. Increase the measurement value; 6. Increase the buffer; 7. Replace the injection molding machine; 8. Replace the check ring of the injection unit.

From the injection mold level to consider, the relevant solutions are: 1. Reduce the surface temperature of the cavity; 2. Expand the size of gate; 3. Expand the size of the runner; 4. Bold main channel; 5. Rearrange the cooling loop of the mold to improve the cooling efficiency; 6. Change the cooling structure; 7. Increase the number of gate; 8. Change the gate position to the part with thicker wall thickness.

In a word, we can improve the defect of shrinkage mark by pressure adjustment, time adjustment and injection mold temperature adjustment. If we still can't improve it is not the problem of process. The mission of Fanstar is to master the core technology of injection molding production, communicate and analyze the technology before mold production with customers from the production needs of finished products, so that the mold delivery time is short, the life is long, the mass production is fast and the finished product quality is excellent! Have the need of injection molding mold welcome to contact us!