In the process of mold injection molding

Update:09-03-2019
Summary:

In the process of mold injection molding, the gate some […]

In the process of mold injection molding, the gate sometimes sticks to the sprue bushing, and it is not easy to come out. Causes crack damage to the product during mold opening. The operator must use the tip of the copper rod to knock out from the nozzle to loosen the broken plastic before demoulding, which seriously affects the efficiency of production. The main reason for this failure is that the taper hole surface of the sprue bush has a poor finish, and sometimes the inner hole has a knife mark in the circumferential direction. Secondly, if some of the injection molding materials are too soft, the small-end of the tapered hole of the mold will be deformed or damaged after a period of use. If the curvature of the nozzle of the sprue sleeve is too small, the gate feed will produce a rivet head here. The taper hole of the sprue bushing is difficult to process. Standard parts should be used as much as possible. If you need to process it yourself, you can also use your own or purchase a special reamer.

The guide post mainly plays a role of fixing and guiding in the mold to ensure that the core and cavity forming parts of the mold do not collide with each other under any circumstances, but the guide post must not be used as the force point or the positioning part of the mold. . For example, when moving and fixing the mold, a large lateral offset force will be generated: when the wall thickness of the plastic part is not uniform, the flow rate of the material passing through the thick wall is large, and a large pressure is generated here; if the side of the plastic part is In the case of asymmetry, such as a mold with a stepped profile, the opposing pressures on the opposite sides of the mold are not equal.