1. The defects in Mold design cause bubbles in the injection mold. For example, the poor position of the injection mold gate, the gate being too small, the asymmetric arrangement of the gates in multi gate parts, the small flow channels, and the unreasonable cooling system of the mold result in a large temperature difference, resulting in discontinuous flow of molten material in the mold cavity and blocking the air passage. 
2. The parting surface of the mold is lack of necessary exhaust holes or the exhaust holes are insufficient, blocked, and in poor position, and there are no machining gaps such as inserts and thimbles for exhaust, resulting in that the air in the cavity cannot leave at the same time when the plastic enters. These reasons can also cause the occurrence of bubbles in injection molds.
3. If the surface roughness of the injection mold is poor, the frictional resistance is high, causing local hot spots and the decomposition of the passing plastic, it will also cause the appearance of bubbles. Of course, in addition to mold related reasons, there may also be reasons such as equipment, process, and raw materials; So in the production and manufacturing process of injection molds, every step needs to be very careful and careful, to avoid the occurrence of bubbles in the injection mold as much as possible, and to reduce the defect rate in the product production process, in order to increase the competitiveness of injection mold manufacturers in the increasingly competitive mold industry. For more information, please follow us!
