Medical Micro-Molding Technique Slashes Production Time and Lowers Costs

A new patent-protected method and technology for micro molding medical parts, created by Westfall Technik, eliminates cold runners and increases the allowable residence time of material in the machine. The benefits include slashed production time, lower per-piece cost, and reduced material usage. Vijay Kudchadkar, Director of Advanced Engineering for Westfall Technik, will detail the company’s new technology — developed over the past 10 years — in a June 14 presentation at IM Engineering South in Charlotte, NC. Using newly designed hot runners and designing a new machine around the process, Westfall Technik keeps resins under pressures ranging from 4,000 to 15,000 PSI to prevent material degradation during processing. The company’s new M3-D32 is a 32-cavity micro-molding machine featuring 32 valve-gated hot runner nozzles, eight injection plungers, four plasticating barrels, four hoppers, and four dryers — meaning multiple resins with similar processing temperatures can be processed simultaneously. “In any other conventional hot runner, the material will degrade simply because of residence time,” Kudchadkar explained. “In micro molding, the part volume is so small that if you try to do a high-cavitation micro mold without cold runners and try to use conventional hot runners — even if you go with a polyolefin — the residence time is going to be so large that the material is going to degrade.”