Why venting important for injection molding
In a sense, the injection mold is also a displacement device where the hot plastic melt enters into the mold cavity while displaces the air in the mold cavity. In fact, the air in the mold is not limited to the cavity, especially the three-plate injection mold, and the air existing in the flow path cannot be ignored. In addition, the plastic melt produces a small amount of decomposition gas. These gases must be discharged in time If the venting performance of the mold is poor, it is easy to produce bubbles, silver streaks, clouds spot, short shot, scorch marks and other defects Therefore, a reasonable layout of the venting structure should be provided on the mold to avoid defective products caused by poor venting. https://www.youtube.com/watch?v=DecwAPl6pvU Venting slot For the molds for making large and medium-sized plastic parts, the amount of gas to be removed is large. Generally, the Venting slot should be cut on the side of the plastic mold on the parting surface. The position of ...