Chapter 2--Gas assistance system for Pressure Reduction technology in Plastic Injection Molding

Principle:

 In fact, pressure must be generated in the production of molded plastic parts. In general, the pressure in the cavity is caused by a slight shrinkage, and its effect is cumulative, and this cumulative effect will eventually lead to the defective plastic injection parts. Typically, when the part is removed from the mold for the first time, it can resist the effect of the in-mold pressure on the structure of injected plastic parts. Plastic parts can cause slight deformation or cracking only at high temperature. In practical applications, all the mold parameters can cause a slight deformation, resulting in in-mold pressure. When these forces act together on the same part, a large amount of extra stress is generated. The forces acting on the part result in the generation of pressure. When the pressure is very small, it will not have a significant impact. However, if the pressure is high enough, the in-mold pressure becomes a factor that must be considered because the combined action with the external force will exceed the maximum value that the  plastic injected partscan withstand.The most serious result is part’s fracture.