The flow balance of air trap and plastic mold must be considered in the injection molding process.Let the injection products to achieve high quality.
Relationship between mold gate position and gas trap
Gas trap refers to the defect caused by the gas and the vapor released by the molten glue in the injection mold processing cavity. The existence of gas trap can cause short shot or coke mark, which affects the appearance of the injection product and the compressive strength.The probability of mold cavitation is increased with each increase of the gate runner.If the distance between plastic parts wall thickness is very large, or the gate position is not set properly, it will cause gas trap.
Relationship between mold gate position and flow equalization
When the plastic melts and fills the cavity at the same time, it is called flow equilibrium.If it's a single cavity.A good flow balance design scheme will make the working pressure, volume shrinkage rate and temperature of the mold melt glue are very evenly spread, and the quality of plastic parts is better.For the design scheme with the same number of runner gates but different location of gate, the design scheme with less injection working pressure and clamping force is also a design scheme that takes into account the flow balance of the mould.
If it is a multi-cavity mold, in the multi-cavity mold with uneven net weight of commodity size, the length of the separation channel between the stainless steel plate of the injection molding mold and each cavity of the mold is not the same or the size and specifications of the cavity are different.At this time, the profile size of the secondary separation channel upstream and downstream of the gate can be adjusted to achieve the goal of flow balance of the mold as far as possible.General adjustment of gate size is not desirable, one is not a long-term measure, and if the gate thickness can be adjusted anytime and anywhere, it will destroy the gate as a delimit the role of setting time
Therefore, we should pay special attention to these aspects in the injection molding process, reduce the damage rate of injection molding products, and improve the quality of injection molding products.