Most of the injection molding tools contain air inside the cavity when tightly closed. When plastic is injected the air needs to squeeze and go out somewhere. Mold venting enables air to pack and free up space for the plastic. The Problem With Poor Mold Venting Failure to vent a mold properly increases mold temperatures and increases the melt’s pressure. The combination of these issues can extremely heat the oxygen in the mold, causing an array of visual defects and part int