Custom Reaction Injection Molding (RIM) Tooling

VMW specializes in building RIM Tooling. The RIM process of manufacturing is rather complex, which is why a well built quality RIM Tool is essential to any projects success. Understanding the process means our customers will have a greater appreciation to the workmanship we put into every RIM Tool VMW builds.

What is Reaction Injection Molding

RIM Tooling

RIM Tooling by EPW – Custom Engineered Tools

RIM is the acronym for Reaction Injection Molding. RIM was developed in the 1960’s by Bayer AG as an alternative to thermoplastic injection molding.

RIM is a process where two liquid materials, Polyol resin and Isocyanate are brought together in a mix head and injected into a single or multi-cavity CNC machined mold. These two materials undergo an exothermic (heat generating) chemical reaction within the mold into the specific shape tooled into the mold and become the thermoset material Polyurethane.

Polyol resins also known as the “B-Side” or “Poly” are numerous due to the different requirements of each RIM part. Polyol’s create the physical characteristics of each part with additives that contain fillers like RRIM (Reinforced Reaction Injection Mold) and SRIM (Structural Reaction Injection Mold).

RIM Possible Physical Characteristics Examples:

  • Rainbow hue of color pigments
  • Surfactants that help with mold release
  • Flame retardants
  • Electrically non-conductive
  • Dimensional stability / strength
  • Surface hardness / durability
  • Sound dampening / vibration reduction
  • Thermal insulation
  • Flexible to rigid (20A soft – 75D hard)
  • Wear resistance

Isocyanate when mixed with the Polyol serves as the catalyst to set off the chemical reaction that causes the resulting thermoset Polyurethane low viscosity material to slowly yet evenly fill the RIM mold.

Reaction Injection Molding has a slow yet evenly flowing process of 50 – 150psi fills a mold. The mold fills in as little as 60 to 30 seconds depending upon the low temperatures of (90° to 105° F) and can be demolded soon after due to the low temperatures.

RIM Tooling

RIM Tooling

VMW has over 30 years of experience in building RIM molds. The fact is anyone can create a thermoset mixture and create a Polyurethane / Urethane plastic part. Experience is what makes the difference. If the liquid materials are not properly proportioned, mixed and injected into a quality mold… the results can be less than satisfactory. VMW can ensure mixing quality not only from 30 years of experience but because of close family company relationships.

Reaction Injection Mold (RIM) Tooling Capabilities

Reaction Injection Mold Tooling

Reaction Injection Mold Tooling

VMW builds RIM Molds / Tools to fit a variety of RIM resin materials. We have the experience that gives us the knowledge to work with common Polyurethanes / Urethanes / Elastomers and the not so common materials. VMW likes to be on the cutting edge of technology. For that reason we are especially involved in medical RIM resins, green resins and all current innovations. VMW has never restricted any of our projects to a particular type of client of material.

VMW has a “Open to Learning” policy to keep us current with the industry and constantly learning. If you are willing to try something new, we are willing to try to make your idea a success. We empower our personnel to be flexible and creative in meeting your short run production and prototyping needs.