What is a blow molding mold vent

Within the same container molding container, blow molding mould to discharge air volume is larger than the injection mold of many. Injection molding mould to exhaust air volume is equal to the amount of melt injection mold cavity. For blow molding mold, to exclude the air volume is equal to minus cavity container type clamping instantaneous embryo has been completely blow bulge volume, which accounted for larger proportion, but there is still a certain air between stay in embryo with the mold cavity. In addition, with injection molding mould xing ratio, the pressure inside the blow molding mold is very small. Therefore, the exhaust performance requirements for blow molding mold is higher.
if the air between stay in cavity type and embryo can't completely or discharge as soon as possible, type embryo can't blow up quickly, after blowing can't contact with cavity is good, can make the product defects such as surface roughness, dent, surface character, design is not clear, affect the performance and the external appearance shape, especially when type embryos extrusion streaks or melt fracture occurs. The venting is not good will also prolong cooling of the products, reduce its mechanical properties, caused by the uneven distribution of wall thickness. As the time, try to improve the exhaust performance of plastic mold.