Process Problems in Injection Mold Processing

During the injection molding process, a multi slot mold is used to connect the main flow path and various cavities. In order to fill the molten material at a uniform rate in each cavity, the arrangement of the diversion channels on the mold should have symmetry and equal distance distribution. The cross-sectional shape and size of the diversion channel affect the flow of plastic melt, the ease of product demolding, and mold manufacturing. For the same amount of material flow, the flow resistance on a circular cross-section is small.

However, the cylindrical flow path is smaller than the surface, which is not conducive to the cooling of excess material in the flow path during injection mold processing. Moreover, the flow path must be opened in pairs, which is easy to trouble and align. Therefore, trapezoidal and semicircular cross-sectional flow paths are often used, located on half of the mold with a release rod. The surface of the flow path needs to be ground to reduce flow resistance, and the filling speed is fast.

The size of the injection mold processing flow path depends on the type of plastic, product size, and thickness. For many thermoplastic materials, the cross-sectional width of the diversion channel is below 8m, with oversized ones reaching 10-12m and particularly small ones ranging from 2-3m. On the basis of meeting the demand, try to reduce the cross-sectional area as much as possible to avoid the increase of excess things or longer cooling time in the diversion path.

A pathway connecting the main flow path and the cavity. The cross-sectional area of the access road can be equal to that of the main road, but it is usually reduced. Therefore, it is the small cross-sectional area of the entire injection mold processing channel system. The shape and size of the gate have a significant impact on the quality of the product.

The design of the shape, size, and position of the injection mold processing gate depends on the properties of the plastic, the size, and structure of the product. The cross-sectional shape of a general gate is rectangular or circular, with a small cross-sectional area and short length. This is not only based on the above effects, but also because small gates tend to become larger, it is difficult for large gates to shrink. The gate position is usually a place where the product is thick and does not affect its appearance. The design of gate size must consider the properties of the plastic melt.