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Reaction Injection Molding (RIM)

  • Strong (Yet Light) Parts

  • Cost-Effective Medium-To-Large Components

  • Ideal for Automative and Medical Industries

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Trusted by Industry Leaders
Edwards Lifescience
Multilink, Inc.
Paragonix Technologies
Kimball Electronics
Lucid Motors
“Fathom has been a strong partner on our EV programs. They helped us optimize a few key components for weight and manufacturability, and they consistently hit the tolerances we need. Their fast turnaround times have kept our development cycles moving, which is critical in EV work.”
Senior Manufacturing Engineer
EV Systems Supplier
“I’m impressed with your quality, expertise, speed, and customer service.”
Professor James F. Antaki, PhD
Carnegie Mellon University
“The team at ICOMold continue to provide us with great service. Starting with initial DFM reviews, fast tooling development and quick turn-around times, ICOMold is a partner keeping us on track to deliver quality products to our customers. Thank-you to all the ICOMold team.”
Tim Latham / Project Manager
Litepanels, Inc.
“We have been very satisfied with ICO’s performance in every aspect: pricing, delivery, quality, and customer support. It is a pleasure doing business with ICO, and honestly, I wish there were more companies like them.”
Mark Merg / Procurement Manager
Alpha High Theft Solutions
“I want to thank you and the rest of the team for the great support. Over the 15 years that I have been working with mold vendors I have never seen such personal attention and such great communication efforts in addressing my concerns on samples. The fact that ICO went the extra step to provide me with a second set of samples at no cost and in two days to improve my texture concerns goes a long way. I know that I have made the right choice going with ICO. I’m looking forward to a long relationship with you and the rest of the ICO team.”
John Doe
Level, LLC
“This is a huge milestone for our team. This product is no longer a vision… I received the parts today from ICOMold. They look and function great! I don’t see any reason why we cannot move forward now and order parts for the upcoming proto build.”
Dave Boretti
Schneider Electric
“As a small, growing company, we cannot say enough good things about ICOMold. They have been willing and able to adapt to our rapidly changing needs and have helped us get out of a pinch on occasion. Special thanks to Brian and Carla – they have been great to work with!”
Scott
SLight LLC
“It has been a genuine pleasure dealing with the ICOMold team. You have been very patient and have been a wealth of helpful information. Your response times to my questions and comments are superb and your answers are specific and to the point. Thanks for your patience and all the time it has taken to get the details worked out.”
Scott Bixler
Polyvance
“We are very pleased with ICOMold. Response time is fantastic, customer support is great, and the online group project management tool is very helpful.”
Connie Blevins / Quality Coordinator
Leprecon
“I have to say that so far I’ve enjoyed this process – having the customer portal (and your well-detailed DFM reports) makes it very easy to comply with the design requirements.”
Cory Starr
Blaster One
“I just wanted to let you know, we have all been very impressed with the quality and turnaround time of our parts. We have used several shops in the past, but so far the quality of ICOMold has been the best we have ever received.”
Gregg Garrett
VEGA
“I just want to compliment you and your team how you are managing this project with all of the changes on the fly. Kudos.”
Mark Ezzo / Plastics and Composites Engineer
Materials & Chemistry Network of Excellence
“Our SteriPen product must meet the quality standards of a medical device — if it ever malfunctions, people will get sick. Yet it must be economical enough to permit many people to own one. And we need the design flexibility to keep pace with rapidly changing technology. Our production at ICO meets all three challenges.”
Don Snoke / VP of Operations
Hydro-Photon, Inc.
“I was very impressed with your company’s ability and willingness to work with a novice in plastics as I am, and work through some design changes. I have learned a lot from you and hope this is a huge success for both of us. Frankly, I did contact two other companies and they acted like they had no time for me!”
Kevin Jensen
Quik-Load
“After reaching out to over 20 manufacturers, ICOMold was the only one that was able to take on my project, create the molds and manufacture the parts I needed. What impressed me the most is that they were able to work overtime to meet my demanding deadline and get the parts to me on time.”
Aziz Razakov
Berry Good Bottle
“I found it refreshing to work with a company with such a phenomenal online quoting tool. It allowed us to experiment with different materials, quantities, and mold configurations to see the cost impact in real time.”
Mike Yin / Founder
Nunchuck Grips LLC
“The parts came in a few days ago and I wanted to thank you and your team on the very impressive quality of the parts. We were thoroughly impressed by the finish and clearness of the parts. Thank you for the great customer service and we are looking forward to using your expertise in future projects.”
Akash Shankar
PMC Smart Solutions
“We appreciate the effort you put into making our order smooth. The molded parts are used in our device that makes water safe to drink in areas of the world that do not have access to safe water. Thanks again for everything!”
Sarah Yoder
WaterStep
“Fathom brings an open mind to each project with a positive attitude to tailor their processes to meet my needs, from part design to mold build and molding. They work hard to make sure my needs are met with a professional attitude, expertise, on-time delivery and competitive pricing.”
Bob Rohr
RDR Design and Development LLC
“With their response time, quotes and communications, Fathom is highly regarded because they are always upfront. They say what they do and do what they say.”
John Doe
Consumer Technology Company
“It is a pleasure to work with a company whose personnel are willing and able to think out of their box. With your commitment to staying on the cutting edge of technology, you supply tooling to us that is right on time and works first shot.”
Norman R. Akens
Medical Murray
“Quick response time for RFQ, excellent lead time for rushed order and quality parts were manufactured and delivered on-time.”
Manufacturer of Compressed Gas Storage Systems
“The workmanship was outstanding – we are over-the-top happy with the unit! The product that arrived at my door far exceeded our expectations, and all on short notice…amazing. Please pass our very best wishes on to everyone on your team who was involved in fast-tracking our prototype. It all started with you and your can-do attitude, Nate. I cannot thank you enough!”
Larry Cole
TerraCube
“Fit and finish is great and the parts passed all our regulatory tests. Thank you for all your help and for the role you played helping the factory work through some of the stickier parts of the design.”
Drew Macrae
Linkitz
“As a small, growing company, we cannot say enough good things about ICOMold. They have been willing and able to adapt to our rapidly changing needs and have helped us get out of a pinch on occasion.”
M. Nasilevich
Morpho Detection
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How Does Reaction Injection Molding Work?

01 Design Preparation

Molds for both RIM and traditional injection molding are designed based on shape, surface finish, draft angles and venting. However, RIM materials expand in the mold and that must be accounted for during design. RIM mold tools can be made from less-expensive aluminum because it uses lower temperatures and pressures than injection molding.

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02 Molding

RIM works by mixing two liquid chemical components, such as propyl and isocyanate, and injecting the mixture into the mold, where it reacts, hardens and solidifies. These polymers are injected at low temperatures and pressures. This works because the subsequent chemical reaction drives the process. The materials also expand, ensuring complete mold fills.

How it works_RIM_process
03 Post Processing

Excess material is first trimmed from the parting line of the mold. This can be done manually, mechanically or cryogenically. The part may be post-machined to achieve specific tolerances. Paint and coating can be applied to improve the parts aesthetics or to protect it. Inserts may be added to the part using heat staking. Ultrasonic welding may also be used to join it to other components.

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Is Reaction Injection Molding a Fit For Your Needs?

Advantages

  • Strong Yet Light Parts

    RIM produces parts that are light weight but still maintain high strength and rigidity thanks to the thermoset polymers used. This makes it ideal for automotive, aerospace and equipment housings where weight reduction is crucial but you can’t compromise on durability.

  • Design Flexibility

    RIM supports complex geometries, varying wall thicknesses and intricate features. Multiple components can be integrated into a single molded piece, providing substantial cost savings on assembly.

  • Material Versatility

    A wide range of polymer mixtures can be used to achieve different mechanical properties. Simply modify the ratios of them to adjust flexibility, impact resistance or thermal stability.

  • Lower Tooling Costs

    RIM operates under low injection pressures, which enables the use of less expensive tooling materials such as aluminum. This significantly reduces the upfront tooling investment compared to injection molding.

  • Low Residual Stress

    Forming parts at low pressures and temperatures minimizes internal stresses. This reduces warping and cracking and improves long-term stability.

  • Cost-Effective For Thick/Large Parts

    RIM is a good match for production of medium to large components because it avoids the high pressures and heavy machinery associated with traditional molding. It also can produce thick cross-sections without sink marks or voids, which results in strong components with consistent density and performance.

  • Finished Surfaces

    Finished parts can have smooth surfaces suitable for painting or coating, minimizing the need for post-processing. Parts also can emerge at the desired color for visually appealing, production-ready components straight out of the mold.

Disadvantages

  • Longer Cycle Times

    RIM generally has slower curing and demolding times when compared to injection molding. This can limit production speed and make RIM impractical for high-volume manufacturing.

  • Limited Material Options

    RIM primarily uses thermosetting polyurethanes, which restrict the range of materials compared to conventional injection molding. Certain applications requiring other plastics, metals or high-temperature polymers may not be a good fit for RIM.

  • Tolerance Challenges

    Material shrinkage during curing can reduce part precision. Components with extremely tight tolerances may require secondary machining or finishing.

What Industries Utilize Reaction Injection Molding?

RIM is a good match for industries that need lightweight, durable parts with design flexibility. These industries also desire cost-effective production for medium-to-large parts.

Automotive

RIM can produce strong, lightweight body panels, bumpers and interior components that improve fuel efficiency without compromising safety. Its ability to mold complex shapes reduces assembly steps.

Medical

RIM enables complex, ergonomic shapes suitable for medical devices and equipment housings. Properly selected polyurethanes ensure parts are biocompatible and comply with hygiene regulations in sensitive medical environments.

Electronics

RIM is ideal for housings, enclosures and structural components for electronics. Surfaces that are smooth and accept paint ensure products are visually appealing. Enclosures are made durable and heat resistant through the versatile materials the process offers.

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Explore Fathom’s Full Range of Manufacturing Equipment

Download our complete machine list for a detailed look at our capabilities across CNC machining, additive, molding, and fabrication.

Download Machine List
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Why Choose Fathom for Reaction Injection Molding

  • Our expert engineers will help you optimize your part designs for production.
  • Our engineering and production teams bring decades of expertise and problem-solving to every project.
  • We offer manufacturing and full post-processing capabilities under one roof for one point of accountability
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