 RIM vs. Thermoplastic Injection Molding
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 for many features to be incorporated into a mold, but only RIM gives the designer the 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 cost because mold pressures are significantly lower compared to thermoplastics.
While both processes provide a solution for encapsulating metal, the low temperature, low pressure RIM process is superior also safe for electronics and other material encapsulation.
Produced injected molded parts often have a higher quality finish than RIM urethane parts, although RIM parts take paint, silk screening and texturing well for improved branding.
RIM is valuable for producing low volumes at a low cost, reducing risk when launching new products and allowing you to evaluate market success before producing higher quantities. For volumes over 500 per month, thermoplastic injection molding often becomes the more cost-effective processing option.
Exothermic uses in-house, feature-based machining to drastically reduce mold build time and create production molds within 4 weeks.
Because RIM molds can be machined from aluminum instead of steel, the upfront tooling costs are typically one half or less than that of a comparable thermoplastic mold. This is particularly beneficial when part volume is low or when a part size is large. Since RIM tools can be made of softer materials, changes to tooling are also much more cost-effective than changes to thermoplastic steel tools.
The reaction cycles of RIM are measured in minutes, not seconds, allowing for the addition of holes, side action and undercuts without premiums. The stiffness and strength of the polyurethane produced from RIM also eliminates sink marks that can occur in thermoplastic parts.
Though these are some of the main considerations to account for when deciding on a production process, there are many issues to balance when determining the most effective option. Let Exothermic help you uncover the opportunities for success and guide your design concept to meet those process needs. |
