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Engineering Plastics

Processing Methods

Hot Runner

Hot runner molds provide advantages vs. cold runner systems, among which the obvious ones are: less material to plastify leading to shorter cycles and no (or minimum) regrind. On the other hand, hot runner molds add complexity and costs. They often require maintenance and skilled molding operators.

By looking at the behavior and the needs of semi-crystalline polymers, such as POM, PA, PPA, PET, and PBT  we will highlight some key factors to look at when choosing a well adapted hot runner system.

Typical layout of a combination of Hot Nozzle with cold sub runners. 

Note: The intent of this technical paper is to aid customers and mold makers with selecting the most appropriate hot runner system to maximize product quality and yield.  It is not an endorsement or  recommendation of any trademark or system.