The Role Of Hot Runners In Plastic Molds

- Aug 11, 2018-

In injection molding, hot runners work in conjunction with molds and play a very important role. For example, in the injection molding of ultra-thin parts (such as mobile phone battery covers), high-precision, high-quality products can be easily produced by using hot runners; for injection molding materials with poor fluidity, raw materials can be significantly improved by using hot runners. The fluidity ensures smooth production of injection molding; for some large injection molded parts, such as bumpers and door panels of automobiles, rear casings of TV sets, air-conditioning enclosures, etc., the use of hot runners makes the very difficult injection molding relatively simple.


In multi-cavity mold injection molding, the lack of hot runners cannot be formed at all. It can be said that the hot runner is the best technique to ensure the balance of the runner. Due to the shearing force of the plastic in the flow channel, no matter how reasonable the geometric balance of the mold, the weight of the formed product is difficult to be consistent, especially for the multi-cavity mold, if the hot runner is not used, it is formed. The outside of the product will be lighter than the inside.


For plastics processors, the use of hot runners is quite economical as long as there is a certain amount of injection molding. This is because hot runners help companies eliminate nozzles in injection molding. In most cases, the nozzle cannot be reused. Sometimes the weight of the nozzle is almost the same as the weight of the product. If the traditional nozzle injection method is used, it means that the wasted material is as much as the raw material used in the product.


Based on this calculation, after using the hot runner, it can save 30% to 50% of raw materials. In addition, the hot runners help to reduce mold wear and extend the life of the mold. In general, the service life of hot runner molds is twice that of thin nozzle molds. Although the composition of the hot runner is relatively simple, each component plays an important role. In general, good quality hot runners have high requirements for structural design and materials. In addition, hot runner suppliers need to help customers design and install suitable hot runner systems based on the customer's plastic products and the mold used.