Selecting the Right Hot Runner System and Preventing Hot Runner Leaks

摘要

For more than 30 years, hot runners have offered molders numerous production advantages. During this time, hot runners have evolved substantially. Many different materials, from commodity resins such as polypropylene and polyethylene to engineering resins such as polycarbonate, glass-filled nylons and polysulfones, are now being processed successfully with hot runner systems. One of the most common concerns expressed by molders about hot runner molds is the threat of a leak of molten plastic causing the manifold pocket to fill. There are several reasons for leaks, all of which can be prevented. We will examine only externally heated hot runner systems as they represent the majority of the hot runner systems in use.