Injection mold exhaust system is an important part of injection mold design, why do injection mold need exhaust systems?

The pressure in injection molding includes four types: plasticizing pressure, injection pressure, holding pressure, and cooling pressure. These four pressures directly affect the plasticization of plastic and the quality of products.

Injection pressure is the pressure at which the molten plastic is injected in to a mold cavity. It is typically measured in tons per square inch(psi) or megapascals (MPa)