Industry Leader in Reaction Injection Molding

Specializing in molded housings, bezels, and skins for medical industries and more.

Who We Are

Premold Corp is a privately owned business with over 40 years of experience in RIM led by President Ximena Schweitz. We operate out of two facilities based in Oconomowoc, WI and our newest facility in Monterrey, Mexico. Both facilities serve a variety of industries while focusing on medical and laboratory instruments for custom low volume polyurethane parts.

about premold team

What is RIM?

Reaction Injection Molding is the process of two liquid components injected into a mold where a chemical reaction creates rigid polyurethane plastic parts using low molding pressures and low mold temperatures. For more information about the RIM process and its capabilities please take a look at


Large Parts

Low Volumes

Low Tooling Cost

Design Freedom

Complex Geometry

Varying wall thickness with no sink

Advantages of RIM vs. Other Processes

High Pressure Injection Molding

Thermoforming & Vacuum Forming

Structural Foam

Ken Schweitz

In Memory of Ken Schweitz

On June 30th, 2022, Ken Schweitz sadly passed away. As a founder and president since 1995, Ken’s tremendous work ethic, high standards, and dedication to the company, employees, and customers have helped Premold Corp become North America’s largest supplier of World-Class Reaction Injection Molding. His values and standards have become engrained in Premold’s culture and will ensure enormous support for continuous success and growth going forward. By leaving behind his legacy of what Premold Corp has become the team thanks Ken Schweitz for all his work and care over the past decades.

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