Reaction Injection Molding, or RIM, can be a great alternative to achieve the mainstream look of molded parts without the high tooling costs or volumes needed for typical thermoplastic parts. Both processes allow incorporation of many features into a mold, but only RIM gives the designer flexibility to produce parts with significant wall thickness variations—typically from .125” to 1.125” in the same part. RIM can also produce high strength large parts at a lower price because mold pressures and costs are significantly lower compared to thermoplastics.
While both processes provide a solution for encapsulating metal, the low temperature, low pressure RIM process is also safe for electronics and other material encapsulation. Injection molded parts have a higher quality finish than RIM urethane parts, although RIM parts take paint and silk screening well for improved cosmetics and branding.
RIM is valuable for producing low volumes at a low cost, but for volumes over 500 per month, thermoplastic injection molding often becomes the more cost-effective processing option. Because RIM molds can be machined from aluminum instead of steel, the up-front tooling costs are typically less than one half that of a comparable thermoplastic mold. This is particularly beneficial when part volume is low. Since RIM tools can be made of softer materials, changes to tooling are also much more cost-effective than changes to thermoplastic steel tools.
Read more about it in our white paper, “5 Reasons to Use RIM for Complex Parts”. Download the paper at www.exothermic.com