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How does RIM work?

Reaction Injection Moulding (RIM) is a relatively new process, with its development taking place in 1969. It has quickly shot up to become one of the world’s leading plastic moulding processes, due to its impressive versatility and scalability when it comes to producing high quality plastic parts.

How does RIM work?

The Reaction Injection Moulding utilizes a variety of chemical reactions that come about because of the use of low-thickness liquid polymers. The process utilizes low-pressure meter mix equipment, which is used to separately pump two liquids into a mixing head.

As the liquid polymers require less pressure and lower temperatures than I injection moulding, they can be injected into cost-efficient molds, therefore lowering tooling costs. Once the liquid is in the mould an exothermic reaction occurs which causes the material to cure.

How long does it take to solidify?

It typically takes less than two minutes for the liquid to solidify. However, this can vary from one to ten minutes depending on the size, function and wall thickness of the desired product. The whole process of using reaction injection moulding is thought to be quicker overall when compared to traditional practices.

Advantages of RIM

One of the biggest advantages of using RIM is that the products produced from the process are typically much more economically and environmentally friendly than other moulding methods, as the process uses less energy and equipment than thermoplastics. It also serves as a remarkable low-cost solution that allows projects to get to market with both optimised style and functionality.

Any products made from RIM materials tend to have a longer shelf life when placed in corrosive environments, and also have the capability to possess a lighter weight while also remaining more physically robust. The nature of Reaction Injection Moulding means that an assortment of highly detailed and intricate parts can be made from the same mould part. This can also allow for parts to have different wall thickness. When compared to traditional mouldings, this is a huge step forward in efficiency.

What type of materials do Midas Pattern use?

Reaction Injection Moulding can be used to process a wide range of different materials, however, at Midas Pattern Company Ltd, we specialize in polyurethane mouldings (PU Moulding). If you are unsure on how this affects you, get in touch with us today!

About Midas Pattern Company

With over 33 years of manufacturing experience in the UK, we have grown and developed into a leading moulding and toolmaking business. Our company carries out all engineering and manufacturing processes in-house, to guarantee your products are of the highest quality.

Additionally, all of our processes meet the standards set in BS EN ISO 9001:2015, and we are audited by NQA as part of our accreditation, which includes ISO 14001:2015 and PAS 2060 (through Scope 1,2 and 3). To learn more about Midas Pattern Company Ltd and how we can assist you in manufacturing custom-made polyurethane mouldings, why not contact us today, by calling 01234 358394 or emailing

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