HOT RUNNERS: Gate Selection Tips

摘要

Here we will review three gate types, which are selected based on the shape and size of the part and the resin being injected. The tab gate (Figure I) - the most commonly used of the three - consists of a trapezoidal block milled into the parting line on an exterior surface of the part and is usually placed in a thicker wall section rather than thinner areas. Its position usually makes it easy to trim off, and while it typically leaves the largest vestige of the three gate types, its position at the parting line affects only the edge of the part, where it usually does not interfere with function or cosmetics. It is easy to manufacture, maintain and process, and there is typically a great deal of latitude in its placement along the parting line. Also, being relatively large, it is ideal for use with filled resins, which can be difficult to inject through smaller types of gates.