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 variationsâ€”typically from .125â€ to 1.125â€ 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, â€œ5 Reasons to Use RIM for Complex Partsâ€. Download the paper at www.exothermic.com