INJECTING THERMOSETS WITH WARM RUNNERS

Given today's materials situation, thermoset warm-runner injection molding systems that eliminate runner and sprue losses are attracting increasing numbers of processors. But before purchasing such a tool, several factors, pro and con, need to be analyzed and balanced. Among these are the relative infancy of the state of the art, part size vs. number of cavities, and resin savings vs. cycle times with molding compounds specifically formulated for warm-runner tools. Design details of hot-runner molds are included along with recommendations for injection molding technological conditions.