The Purpose of a Cooling System for a Plastic Molding Project


If you are an experienced CNC technician working with molds, you already know that the purpose a cooling system is to bring down the temperature of the mold and to make the ejection time of a finished product as short as possible to complete the production process swiftly and effectively. As it stands, a well-designed cooling system has a substantial influence on the quality of the product as well as the performance of the mold and molding cycle itself.

Cooling System for a Plastic Molding Project

How Does a Cooling System Work?

The short answer is: depending on the type of materials that are being handled for the project.

This is because the specs of every manufacturing project are different and the mold manufacturer needs to know this data tell the technician how to handle the coolant system. Materials that shrink, such as PVC and light resins work with a cooling system that is deployed at the shrinkage direction of the product that is being created.

When a project requires the mold to keep consistent the strength of the material, the cooling system needs to be close to the mold cavity. It can also be located near the mold core surface as much as it’s needed. In some instances, it can also be located close to the molded product itself.

A mold that adopts an inserting structure that is big needs to be cooled separately. There are ring-like cooling systems that are designed to be used with circular molds inserts, such as it’s done with gear inserts. If you are working with large sliders, they need to be cooled separately as well.

Relevant Data for Proper Cooling Systems

Some projects call for a uniform reach of the cooling system. This happens pretty often with special alloys. Cooling channels also need to function properly when forming an overhead crossing or something akin to it. There is a minimum space for each channel of 3mm if the width of it is small. Anything larger than that can work with a space of 5mm.

It’s important to notice that the cooling systems cycles have to be programmed to avoid affecting the ejector pin as well as ejector sleeve, the ejector guide pin, the lifter, any screws, or any other moving part. If the mold is designed to work with an early ejector return, the water pump should be located strategically to avoid any interference with it.

A mold manufacturer also has to mark the “In” and “Out” venue of each water pump if the project he’s working on requires two sets of cooling systems. They also have to be numbered appropriately to indicate the right connection sequence.