Role of a Hot Runner in Plastic Injection Molding

It has been more than 50 years since the hot runner system for plastic injection molding process emerged. Ever since it came into existence, manufacturing units started to embrace the injection molding process and used the hot runner technique to prevent runners and material waste. It has been really long since hot runner and cold runner systems became a crucial component of the injection molder, however, it was only during the 1990s that the hot runner system in Injection molding process outperformed the latter. Hire services from the reliable injection moulding companies.

Now the manufacturing units can enjoy a plethora of benefits from using injection molder. For instance, the better quality of molded parts, less wastage and scrap, reduced cost, and improved operational efficiencies. But the question is “What exactly is the hot runner system and what role does it play in the injection molding process”? Let’s discuss hot runner system in brief:

What is Hot Runner System in Injection Molding?

A hot runner system comprises the heated devices that are fitted within the injection molder tool. The main function of these heated components is to get the plastic (which is already converted into a molten state) from the barrel of the molding machine into the cavities. Though hot runner components perform the same function and have the same structure, they may vary in size depending on multiple factors. For instance, the injection speed of your machine, type of resin you have purchased, the complexity of the molded parts, and of course, the fill rate.

A temperature controller is responsible for heating the resin as well as hot runner components inside the molding device to a required temperature. Plus, the controller inserts the resin into the mold. As soon as resin hits the mold, it enters the manifold through inlets. Before entering the ultimate mold cavity where final manufacturing operation is performed, the resin splits to multiple nozzles (there can be as much as 192 nozzles in today’s molding machine). It then finally reaches the mold cavity through injection gates.

How Hot Runner System is Effective than Cold Runner system?

Before the hot runner system emerged, the injection molding process involved cold runner components for processing the molten plastic parts. However, Cold runner system wasn’t effective in terms of passing the resin through the injection gates to the mold cavity. It would either affect the thermal properties of resin or its flow. However, these challenges had escalated when manufacturing units started to mold the complex parts. The cold runner system wouldn’t allow the free and precise flow of the resin to the mold cavity which led to several issues in the quality of the molded parts.

In order to overcome these issues, a hot runner system with enhanced thermal controls emerged. The conveying of a large number of resins to the mold cavity became easier and convenient to the manufacturers.

Now, the hot runner system maintains the temperature of the heated components and ensure a safe and accurate transfer of the resin to the mold cavity. This further results in the proper processing of molten plastic parts and a high-quality molded product. Get the most of services from the professional injection moulding companies.

About Ashly William:

Ashly William is a freelance writer, with years of experience, creating content for varied online portals. Her content is published on many national and international publications. She love to write about business services and education.