The benefits of hot runner systems are numerous and provide a more efficient method of molding plastic parts. The cost savings can be substantial, and the part quality is often better than a cold runner system.
With the increasing sophistication of today’s plastic injection molds, the use of a hot runner system is becoming one of the industry standard injection mold components. Many applications simply are not possible with the old standard sprue and cold runner system. Hot runners offer a great way to maintain uniform wall thickness and eliminate knit lines and flow lines, among other things.
As plastic injection mold making becomes more complicated, companies the world over are turning to hot runner systems to meet the rigorous demands.
Benefits of hot runner systems
- Ability to minimize gate vestige
- Uniform wall thickness
- Lower cycle times
- Less waste
- Reduction or elimination of knit lines
- Great for high cavitation molding
- Often the only method for micro-molding. The center to center distance of the hot runner tips is as little as 17 mm.
- Standardization of components can mean significant savings in material and manufacturing
- Many large molds rely exclusively on hot runners. Cold runners cannot meet the demands
Hot runner system maintenance
Hot runner systems require a new level of expertise on the part of the mold maker. However, this does not mean that it is overly complicated or highly specialized. A well designed system is relatively free from maintenance, once it is properly installed.
It can, and does happen, that mold makers become frustrated with hot runner systems and swear that they are too much trouble. This is usually due to the fact that the system is not properly installed or incorrectly operated in the molding process.
The leading hot runner system manufacturers have a well-trained team of specialists on hand to assist in the proper installation and operation of the systems. The time spent listening to these specialists is time well spent!
Hot runner systems are a global enterprise; just look at the supplier base: Canada, USA, Germany, Italy, Ireland, Japan, China, etc.
There are almost as many types of hot runner systems as there are suppliers! Most share some common features, however. There are sprue gated systems, valve gates, tip gates (the most common), and edge gates. Any of the major suppliers can describe in great detail why their system is the best for your application.
Long term benefits of hot runner systems
Even though there is an initial investment with hot runner systems, it is easy to justify the long-term benefits. Without increasing the complexity of the design of the mold, a hot runner equipped mold can significantly reduce costs. Because the hot runner is designed and manufactured independently, yet concurrently, the lead times are not affected.
Mold makers should always suggest methods for his customer to reduce molding costs and increase the output of the mold. Being knowledgeable with hot runner systems is a good way to demonstrate an active role in helping the molder’ s bottom line. This in turn makes the likelihood of increased business even greater for the mold maker.