Full definition
A high-productivity rubber molding process in which compound rubber is automatically fed, plasticized, and injected under high pressure (800-2,500 bar injection pressure) into a closed, heated mold cavity through a runner and gate system. The mold is held closed by a clamping unit (100-5,000 tonnes) while vulcanization occurs at 160-200°C. Cycle times: 30 seconds to 5 minutes (significantly faster than compression molding due to rubber preheating in the barrel and higher mold temperature). Advantages: shortest cycle times, highest automation level, best dimensional consistency (±0.05-0.1 mm), minimal flash, and lowest per-part cost for high volumes. Limitations: highest tooling cost (complex multi-cavity molds with runner system), material waste in runners (cold runner) or complex hot-runner systems, and longer setup time. FIFO (first-in-first-out) barrel design prevents material degradation. Applications: O-rings (multi-cavity molds producing 100-1,000+ per cycle), automotive seals, grommets, bushings, medical components, and any high-volume rubber part. Per standard rubber injection molding practice. Machine brands: REP, Engel, Desma, LWB Steinl, Maplan.