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Last updated: January 2026
This directory lists 26 reaction injection molding companies across the United States, from specialized urethane molders focusing on highly cosmetic medical enclosures to large-scale industrial suppliers capable of multi-part assemblies for heavy equipment.
Buyers are often solving challenges related to manufacturing large, complex parts that require internal encapsulated components, or seeking lightweighting solutions for structural covers and housings. The unique low-pressure injection process allows for intricate designs and often facilitates significantly lower-cost RIM tooling compared to traditional high-pressure injection molding, addressing a major barrier for lower-volume production.
Suppliers in this space range from niche shops specializing in highly cosmetic in-mold coated parts for consumer electronics, to those excelling in robust structural foams for heavy machinery, or even those focused solely on custom urethane systems for specific electrical or sound dampening applications. Their core competencies might be centered around advanced meter-mix dispense equipment setup, specialized secondary finishing operations, or proprietary material science.
To engage effectively, buyers should come prepared with detailed CAD models, anticipated annual volumes, critical cosmetic requirements, and any specific material performance data needed, such as UV stability or chemical resistance. Suppliers will expect clear tolerance specifications and an understanding of the trade-offs involved with RIM part design versus other manufacturing processes.
26 companies nationwide
Based in East Syracuse, NY, Armstrong RM Corporation is a manufacturing supplier established in 1968. The company specializes in Reaction Injection Molding (RIM), producing metal and plastic components. They provide casting, molding, and machining services for prototype and low-volume production quantities, from 1 to 5,000 parts.
Based in Denver, PA, Ephrata Precision specializes in polyurethane casting services, leveraging over 40 years of industry experience. The company provides custom casting solutions, emphasizing superior customer service and quick turnaround times for industrial and commercial applications.
Based in Corona, CA, Elastomer Technologies, Inc. specializes in custom elastomer part fabrication. The company provides a wide range of services including compression, transfer, prototype, and rubber & injection molding, with expertise in liquid injection molding for engineered parts.
Based in Grand Rapids, MI, Grand Rapids Foam Technologies (GRFT) is a large, family-owned polyurethane foam manufacturer. They provide custom molded foam systems and fabrication services, specializing in a comprehensive range of polyurethane solutions. Capabilities include specialized molded chemistries and automated/robotic molding for diverse industries like automotive, medical, furniture, and marine.
Based in Port Washington, WI, Molded Dimensions Group is a manufacturer specializing in custom molded polyurethane parts and components. They provide engineering and production services for diverse applications, focusing on delivering tailored urethane solutions to meet specific client requirements.
Osborne Industries specializes in thermoset molding and manufacturing, providing innovative solutions for plastic challenges. Their capabilities include Reaction Injection Molding (RIM), high-pressure molding, resin transfer molding, and vacuum molding, serving a diverse range of industrial and commercial clients.
Based in Washington, PA, Pleiger Plastics Company manufactures custom cast polyurethane products and molded urethane foam parts. They provide engineering, prototyping, and testing for industrial and commercial applications. A licensed Vulkollan processor, the company offers over 60 years of experience in high-performance elastomer solutions.
Based in Lewiston, ME, Polymer Laboratories & Solutions manufactures highly engineered molded and self-skinning polyurethane components. They provide diverse PU material systems for critical applications in defense, medical, footwear, and impact protection. The company is ISO 9001:2015 Certified and produces components 100% in the USA.
Premold Corp specializes in Reaction Injection Molding (RIM) services with over 40 years of experience. They provide custom low-volume polyurethane parts like molded housings, bezels, and skins. Serving medical and laboratory instruments industries, Premold Corp operates facilities in Oconomowoc, WI, and Monterrey, Mexico.
Based in Weatherford, TX, RIM Manufacturing, LLC specializes in custom Reaction Injection Molding (RIM) services. They manage the entire production process, from part and mold design to manufacturing, part production, and secondary operations like painting and assembly. The company focuses on producing strong, lightweight thermoset polyurethane parts.
Based in Morgan Hill, CA, Rimnetics specializes in reaction injection molding. The company manufactures structural parts, enclosures, encapsulation, and overmolding. It provides RIM molding, design, and tool-making services for industries such as medical devices, electronics, IT, construction, and defense, and is ISO 9001:2015 Certified.
Based in Romeo, MI, Romeo RIM specializes in Reaction Injection Molding (RIM) and Long Fiber Injection (LFI) manufacturing. The company provides integrated design and production services for complex, durable parts, serving demanding applications across industries like agriculture, mass transit, medical, and industrial equipment.
Solidify MFG, based in Rogers, MN, provides high-volume plastic part molding. They specialize in transfer, compression, and injection thermoset molding, adept with materials like SMC, BMC, TMC, and granular compounds. Leveraging precision molding and advanced automation, Solidify offers manufacturing and supply chain management for various industries.
Jefferson Rubber Works, Inc. (JRW) has manufactured custom molded rubber parts since 1975, specializing in precision custom rubber molding. Based in Worcester, MA, they offer a one-stop resource for diverse industrial needs, including liquid silicone injection molding (LIM) and compression molding, ensuring high-quality and durable products.
Thieme Corporation, based in St. Charles, IL, specializes in reaction injection molding (RIM) services. They support client designs through their RIM process, tooling, and PUR materials, offering custom molding for applications including bumpers and medical technology. The company maintains an ISO Quality Certificate.
Based in New Albany, OH, AdvancTEK specializes in custom plastic manufacturing, including large part injection molding, thermoforming, and reaction injection molding (RIM). They offer design, development, and supply chain management. The company serves diverse sectors such as battery and energy storage, medical, industrial, and agricultural markets.
Based in Franklin Park, IL, Cortina is an American manufacturer specializing in plastic molding, including high-pressure foam molding. Founded in 1969, the company offers comprehensive services from part design through tooling and production. Cortina provides cost-effective plastic components for various industrial, commercial, and specialized applications.
Based in Soquel, CA, Design Octaves, Inc. is a full-service Reaction Injection Molding (RIM) supplier. Since 1979, they specialize in molding complex parts up to 65 inches in low volumes (100-5000 annually). In-house services include tooling, molding, painting, UL certified EMI/RFI shielding, silk screening, and assembly.
Based in Jacksonville, TX, D&L Tooling and Plastics specializes in custom plastic injection molding and Reaction Injection Molding (RIM). Since 1993, they have focused on large part molding, providing comprehensive manufacturing services from tooling to finished products for industrial clients.
Based in Attleboro, MA, Empire Group USA, Inc. provides high-fidelity prototyping and low-volume manufacturing solutions. They utilize advanced technologies such as resin mold and casting techniques, CNC machining, 3D printing, and sheet metal fabrication. The company offers comprehensive services from design and engineering support to production.
Based in Kenilworth, NJ, Exothermic Molding, Inc. specializes in Reaction Injection Molding (RIM) with 50 years of experience. They fabricate high-quality, limited-run large, complex plastic parts, offering superior impact, corrosion, and temperature resistance. Exothermic serves diverse industries including medical, autonomous vehicles, military, sports, and industrial manufacturing.
Gallagher Corporation specializes in designing and molding custom polyurethane components, leveraging the material's liquid state for complex shapes and bonding capabilities. Their precisely molded parts offer exceptional abrasion resistance, dynamic load-bearing, and impact resistance. The company serves industrial clients needing high-performance polyurethane solutions for diverse applications.
Based in Humble, TX, Marine Urethane specializes in designing and manufacturing custom molded polyurethane products for diverse industrial applications. The company offers comprehensive in-house engineering, drafting, and mold production services, producing finished parts from its 16,100 sq. ft. facility. With capabilities for various polyurethane products, they serve all industries requiring custom molded solutions.
Mearthane Products Corporation specializes in custom polyurethane products and engineered elastomers for mission-critical applications. This full-service manufacturing partner provides in-house engineering, custom formulations, rapid prototyping, precision molding, secondary operations, and quality control. They support clients from early design stages through full-scale production.
Based in Fontana, CA, TPC, Inc. specializes in custom polyurethane molding, manufacturing a wide variety of parts and products. With state-of-the-art facilities, they serve diverse industries including athletic equipment, engineering, industrial, food processing, automotive, and construction.
Based in Houston, TX, Thermo-Mold Inc. specializes in custom plastic molding solutions for diverse industrial and commercial applications. The company provides Reaction Injection Molding (RIM) services, ideal for producing large, complex, and high-quality plastic parts. They offer comprehensive manufacturing capabilities from prototyping to high-volume production runs.
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RIM is often superior for parts requiring complex internal features, encapsulated inserts (like mounting hardware or electronics), or variable wall thicknesses within a single part. While thermoforming is great for thin-walled parts and rotational molding for hollow, seamless forms, RIM's low-pressure injection and chemical reaction allow for greater design freedom in terms of intricate details and structural integrity, especially when utilizing specialized urethane systems for structural or aesthetic demands.
RIM tooling costs are primarily driven by the tool material (epoxy, aluminum, or composite), part complexity, and expected production volume. Epoxy tools are the most economical for very low volumes and prototypes, while aluminum offers better longevity and heat transfer for higher runs. Lead times are influenced by tool complexity and the supplier's internal capacity, but generally, RIM tooling is much faster and less expensive to produce than steel injection molding tools due to the lower pressures involved in the molding process.
To specify material properties, you need to provide the supplier with precise environmental exposure data (e.g., direct sunlight exposure, specific chemicals it will encounter, operating temperature range). They will then recommend appropriate urethane systems and additives, such as UV stabilizers or fire retardants. It’s crucial to review provided data sheets detailing properties like durometer, tensile strength, and impact resistance for their recommended formulation to ensure it meets your performance criteria.
Beyond the molding process, common secondary operations include trimming, deflashing, sanding, painting (especially if in-mold coating (IMC) isn't used or sufficient), assembly of components, and sometimes specialized treatments like EMI/RFI shielding. It's crucial to confirm all finishing requirements upfront, such as specific color matching, texture, and acceptable cosmetic defect limits, as these significantly impact overall part cost, lead time, and the supplier's required expertise.