Hot Runner Systems in Injection Molding
The use of hot runner systems in the injection molding is rising due to the fact that they provide a more perfect technique of molding plastic parts. The cost saving can be substantial, and part standard is very often much excellent than cold runner.
With the rising sophistication of today’s plastic injection molds, the use of warm runners is becoming an industry standard. Many application just are not possible with old standard sprue and chill runner system, and warm runners provide a best way to maintain uniform wall thickness and get rid of knit lines and flow lines.
What are the benefits of warm runner systems?
- Capability to decrease gate vestige
- Uniform wall thickness
- Lower cycle times
- Elimination or reduction of knit lines
- Less waste
- Best for high cavitation molding
- Generally the only technique for micro-molding. The center to center distance of the warm runner tips is as little as 17mm.
- Many big molds rely exclusively on warm runners. Cold runners cannot meet the demands.
What about the maintenance of warm runners?
Warm runners systems need a new level of skill on the part of the mold maker. Anyway, this does not mean that it is overly hard or highly specialized. A well designed system is relatively free from maintenance, once it is rightly installed.
It can, and does happen, that mold makers become upset with these systems and swear that they are too much issue. This is generally due to the fact that the system is not rightly installed or badly operated in the molding process.
The leading system producers have a well-trained team of experts on hand to help in the right installation and operation of the system. The time spent listening to these experts is time well spent!
Long term advantages
Even though there is a primary investment with hot runner systems. It is simple to justify the long-term advantages. Without rising the complexity of the design of the mold, a hot runner equipped mold can significantly decrease costs. Because the hot runner is designed and produced independently, yet concurrently, the lead times are not affected.
Mold maker should forever advise techniques for his customers to decrease molding costs and rise the output of the mold. Being knowledgeable with different runner system is a best way to demonstrate an active role in supporting the molders bottom line. This in turn makes the likelihood of increased business even bigger for the mold maker.