It is a grooved air outlet in the mold to discharge the gas from the original and molten material.When the molten material into the cavity, the original in the air in the cavity and the melt into the gas must be at the end of the material flow through the vent to mold discharging, otherwise will make products with porosity, bad, molding, and accumulated due to compressed air to produce high temperature and even burn.
In general, vent holes can be located at the end of the flow of molten material in the cavity, or on the parting surface of the mold.The latter is opening a depth of 0 on one side of the concave mold.03-0.2mm, width 1.5-6mm shallow groove.In the injection, the vent will not leak a lot of molten material, as the melt will be cooled and solidified in this place.The opening position of the vent should not be directed against the operator, in case the molten material accidentally blows out.In addition, the joint clearance between the ejector rod and the jacking hole can be used to exhaust the joint clearance of the top block and the stripping plate and the core.