April 15, 2023
Reaction Injection Molded Car Bumper Parts
Project Overview:
Manufacturing Process: Reaction Injection Molding (RIM)
Tooling Material: Epoxy Resin, Silicone Rubber
Molding Material: Hei-Cast 8636-75A (Black) and 8636-B
Quantity: 3 Units
Lead Time: 25 days
Customer was an automotive design and engineering company in USA, wanted to test impact and high temperature resistance of this bumper by low volume rapid prototypes. Though customer was new to our RIM technique, found it was a proper and economical solution for this project.
Reaction Injection Molding (RIM, also named Low-Pressure Injection Molding) is an ideal process to low volume manufacturing the large plastic parts quickly and economically. Firstly, the liquid bi-component polyurethanes are injected into a mixer at certain amount ratio and meanwhile mixed well by the mixer, then the mixture is injected into the tooling cavity quickly at room temperature and low pressure to form the parts.
The finished RIM tooling. Injection molding by room temperature and fairly low pressure delivered the low mold locking pressure by simple clamps. The fairly low viscosity of the bi-component polyurethanes delivers high flowability that allows for the low injection molding pressure as well as temperature, which brings the feasibility of low tooling performance. So our RIM toolings are mostly made of epoxy resin and silicone rubber (sometimes aluminum or ABS) instead of mold steel.
Being different to injection molding by steel mold, our RIM had simple demolding system, and worked fine for insert molding and overmolding. The maximum weight by one shot of injection molding was 35 kilograms, so our RIM process was available for molding the vast majority of parts.
The trimmed, deburred, sandblasted and painted black parts. Customer was satisfied with the bumper's flexibility after impact resistance testing. We are the RIM expert in China to provide customers quality RIM material, cheap and rapid tooling, fast delivery, especially for automobile field.
