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Where is Reaction Injection Moulding used?

Reaction Injection Moulding (RIM) is a low pressure, low temperature process used to mould many different types of plastic parts. Reaction Injection Moulding is often used for the moulding of strong, lightweight parts that are easily painted. Over the years, the RIM process has become popular due to its design flexibility and cost-effectiveness when compared to other manufacturing processes. RIM uses low viscosity polyurethane liquids, making it easy to create uniquely designed, large plastic parts without compromising performance. It also has a high cosmetic surface finish, which accommodates for finer design details. Finally, the chemical reaction used to form parts is highly customisable, giving designers better control to vary wall thickness and eliminate sink marks.

This makes reaction injection moulding perfect for use in a variety of different industries, including:

Healthcare Industry

While the RIM process is more widely known for its ability to create large parts, the healthcare industry utilises RIM to design and manufacture intricate parts for medical devices, such as ophthalmic enclosures for eye examination equipment. In some cases, the RIM process can be used to create whole devices, such as a DNA analyser, electronic spray system and full-body analysis machine.

The robust mouldings play a crucial role in industries where reliability and durability can be life-saving. Polyurethane housings are used within the medical and scientific industries to provide parts for innovative cancer treatments, robotic surgery and laboratory testing equipment. The versatility of plastics used in the RIM process allows for the material process to be used in medical environments that demand compliance against all regulatory standards as well as UL94 V0 flammability ratings and the option for EMC shielding.

Scientific Industry

The versatility of materials used in the RIM process, such as polyurethane, means that the process is ideal to develop various different items used in the scientific industry, including but not limited to: lighting equipment, electro-medical equipment, cell assay machines and housing for solar radiation measurement equipment. The corrosion resistant materials are perfect for creating tough, but low maintenance parts.

Automotive Industry

Reaction Injection Moulding is widely used in the automotive industry. Most car manufacturers use RIM to create large parts, including bumpers, quarter panels, decorative trims and wheel arch liners. The durability and flexibility of the hardened polyurethane used in the process provides these parts with the perfect tensile strength and shock resistance. It is also common for some automotive brands to use reaction injection moulding to create prototypes for testing purposes and cars designed specifically for showroom displays.

At Midas, all our parts are painted with highly complex and precise masking between colours. Multi part, large complex sets of mouldings are often used to enshroud large instruments, some of our projects boasting both 26 and 28 parts, with some mouldings measuring 3m x 2m x 1m.  We feel privileged to work with many of the UK’s brightest and most innovative companies work to make the world better by advancing science, testing and medical capabilities. Our RIM mouldings help bring life to the vision of the many talented designers we work with. The key to Midas success over the last 33 years is the development of our own unique tooling system – MRIM Tooling. That coupled with the fact that we carry out all processes in house and do not sub contract any aspect of our process gives us total quality control. All paint, finishing, shield coating, screen printing and assembly processes are all carried out in house.

If you want to find out more about our RIM services and how they can be used to support you, please contact us today at +44 (0)1234 358394 or email us at

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Where is Reaction Injection Moulding used?