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How RIM (Reaction Injection Moulding) Works

Unlike regular injection moulding, where molten thermoplastic is injected under high pressure into a metal mould tool, reaction injection moulding combines two liquid components which are mixed just prior to filling the tool. This two-component mixture is pumped at low pressure into the RIM mould tool, all the while a chemical reaction is taking place. It is this exothermic chemical reaction that helps the material to solidify.

Read more about how we use reaction injection moulding today or check out our FAQs to find answers to some of our most frequently asked questions.

How plastic enclosures are made

Whether for medical, packaging, or electrical use, plastic enclosures are an essential part of modern life. From standard boxes to bespoke, complicated designs, there is a myriad of manufacturing options available including CNC machining, vacuum forming, 3D printing, and reaction injection moulding.

Whether for an easy-clean exterior or a purely aesthetic finish, reaction injection moulding is a cost-effective, reliable way to produce complicated shapes to exact requirements. With a wealth of experience creating enclosures for a diverse range of industries, explore our case studies today for a taste of what RIM can accomplish!

Reaction injection moulding process

Reaction injection moulding works by injecting two chemical components into a pre-made mould tool at low pressure. These two components then react with each other and solidify within the mould in a thermosetting reaction. The solidified shape is then removed from the mould ready-for-use.

Whether you’re creating for production or prototyping purposes, Midas are specialists in the reaction injection moulding process and have extensive experience in creating specialist products for multiple industries, including medical and med-tech. Discover more about how we use reaction injection moulding to provide bespoke solutions today.

RIM moulding materials

Reaction injection moulding relies on the combination of a polyol and an isocyanate element in the mould tool. It is this combination that creates the curing reaction essential to the technique. The mould tool itself is typically made from rubber, composite material, or aluminum.

The exact chemical makeup of the two curing elements will dictate the specifications of the end product, but each material used at Midas is UL94 V0-certified flame-retardant. To cover all design scenarios, we have developed two in-house manufacturing processes, Midas MRIM™ and FASTrim™, for all your production and prototyping requirements.

For more information about our services, or to discuss your project further, contact Midas Pattern Company today by emailing or call us directly on +44 (0)1234 358394.


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How RIM (Reaction Injection Moulding) Works