How To Pick A Hot Runner System

A lot of mold makers might look through some catalogs and quickly pick a hot runner system for their application. This is not the way to decide on a hot runner system!

Get involved with the manufacturer from the beginning. This is their area of expertise, and they will be able to guide you in choosing the best system for your application. Not only that, but you will save yourself a lot of aggravation and money!

One size does not fit all

Just as each injection mold is unique, so are the requirements for hot runner systems. Unless the molds are virtually identical, you will need to communicate with the manufacturer in order to come up with a successful plan for your hot runner application.

Even with the newer, standardized systems, it is still in your best interest to include the hot runner manufacturer in the design process. Not only will your system be a better fit, but you will make more money!

Consider your application

Because hot runner systems have so many configurations, you need to first of all consider just what your application is. Are you trying to gate directly into the part? Or are you planning on using a sub-runner that is attached to the part. ? This will directly affect your choice of hot runners.

Perhaps you have a high volume project with the need for very close spacing of the cavities. This will completely change the application and require a much different system.

Or you might be using an expensive, highly engineered resins with a very high melt temperature. Once again, this will determine the type of high performance nozzle. You cannot just use a standard nozzle and expect good results.

Other considerations

The type of material being molded also influences the type of hot runner system you will need. Another thing is the color and how often you might be changing colors. Some systems are easy to change colors with and others are not so easy.

Cost is usually one of the main factors in making a decision. Hot runner systems are designed for high production and they are expensive to buy, build and maintain. However, the payback can be relatively quick considering the benefits of using such a system.

Some of the benefits of hot runner technology

• Material savings. There is little or no waste of plastic resin.
• Higher quality parts.
• Better consistency of parts.
• Shorter cycle times
• Less secondary operations required
• Elimination of regrind

Conclusion

Make sure you include the hot runner manufacturer in your planning, mold design and decision making process. You will take most of the guesswork out of the process and achieve better results than if you try it on your own.