Solution to the problem of inability to exhaust the injection mold

2021-03-23 15:28:49 admin

Solution to the problem of inability to exhaust the injection mold

When the injection mold is opened by injection molding, the mold often has a situation where it cannot be exhausted. How to solve this situation?

From the perspective of the design process of the injection mold, the exhaust of the injection mold is exhausted through the gap between the parts of the injection mold. Most of the injection molds with small volume can use the mold parting surface gap, the fit gap of the push rod and the push rod hole, and the fit gap of the movable core hole to naturally vent.

For example, if it is said that when some special large-volume injection molds cannot be vented normally, we can use injection molds as much as possible without affecting the appearance and dimensional accuracy requirements of the injection mold products. Inlaid splicing structure, large injection molds can be exhausted by the gap of insert splicing. Moreover, the structure of splicing the inserts with each other can reduce the difficulty of making the mold structure of the large injection mold, and even the maintenance is very simple.

Exhaust plugs are made by sintering metal blocks of special materials, so that there will be many tiny gaps in the sintering process of special materials, and these gaps are just right for exhaust. In some cases, the post-filling part of the cavity is not on the parting surface, and there is no active clearance around the part that can be vented. In this case, the vent plug can be embedded in the deep part of the cavity. The air plug is likely to leave contact marks on the surface of the plastic product, so care should be taken to set the vent plug in a hidden and difficult place inside the product, and the diameter of the vent hole should not be too large to avoid the vent plug When the force is deformed.

Some common plastic melts that are prone to produce gas during the forming process, or when there are thin-walled products during the injection molding process and injection molds that use rapid injection technology, we can open several rows of exhaust grooves on both sides of the core for exhaust gas. However, in order to facilitate the manufacturing and cleaning of the mold surface in the future, the exhaust groove should be opened on the side of the cavity on the parting surface as much as possible.