Monthly archive for January 2020

Reaction Injection Molding Technique Introduction This process involves the high pressure impingement mixing of two or more reactive liquid components and injected into a closed mold at low pressure. With RIM technology, cycle time of 2 minutes and less have been achieved in production for molding large and thick parts. Principal plastic used is thermopolyurethane (PUR). other material s used are thermoplastic nylon; thermoset polyester and epoxy. The advantages of the RIM over injection molding include the molding of the parts larger than 10 pounds, they can be made on the production basis using thinner walls because of the lower processing viscosities, or using very thick walls because curing is uniform throughout the part. There are problems associated with this method, however. The lack of the suitable internal release has made the RIM process labor-intensive, but changes are now occurring to significantly reduce or eliminate this problem. The molded polyurethane faithfully reproduces the surface of the mold and tends to stick to them. Originally the application of the mold-release agents was necessary with each cycle of the RIM technology. After