Plastic Spool Mould Injection Gate design should deliver a rapid, uniform and preferably mold-filling patterm,the injection gate location should allow the air present in the spool cavity to escape during the injection phase.Failure to vent the air will result in short or bum marks on the molding.
Gate is a passage way from the subrunner to the mold cavity,and its cross-section is the smallest and shortest part in the injection system. Position ,number, shape and size of the injection gate have a direct impact on the quality and the appearance of the product, and therefore, in the design process attention is required for injection gate style.
It is necessary to following principles as to plastic spool mould injection gate design:
1. Plastic Spool mould injection gate should set on the thickest wall position of molding products, make plastic flow from thick-wall position to thin-wall position to reduce the pressure loss.Melt Plastic should take the shortest possible path(runner), minimal heat and pressure loss, rapid injection to complete the injection process
2. Plastic spool mould injection gate should be set in the position of products where is most likely to be cleared easily.Try to not affect the appearance and avoid flow marks (if possible).
3. Plastic spool mould injection gate location should help make the plastic flow on the uniform parallel direction and is positive to assist air venting.
4. Plastic spool mould injection gate location should set to avoid weld lines, keep clean of the important position of the products, and avoid to reduce the strength of the products.
5. As plastic spool multi-cavity mold, the size and location of the injection gate should be designed on the distance between the injection gate and the runner,on the size of the products .
6. Plastic spool mould injection gate location should avoid directly impact on the thin Core, inserts, sliders to prevent possible deformed products.
7. The consideration of the injection gate design should involve different shrinkage between the transverse direction and the longitudinal direction.Temperature and pressure of the melt from each injection gate into the cavity should be the same to ensure that the same shrinkage for different cavity filling.