FAQs

RIM or Reaction Injection Moulding is the result of a reaction between two liquid components (reagent A: Polyol and reagent B: Isocyanate) as they are injected into a closed mould at a low pressure. A chemical reaction occurs when the two liquids meet and the increase in energy from the reaction results in heat forming within the mould. As the mixture cools and the chemical reaction completes, polymer cross links develop and a strong, robust plastic product is formed.

In simple terms we pour/inject liquid plastic, allow it to cure in a mould tool to create a cast, plastic part which can then be finished to the desired finish. 

The material is thermoset which means it cannot be re-processed in the same way but can be recycled via alternate methods.

RIM Moulding does not require elaborate heating and cooling systems such as those used in conventional injection moulding methods and tooling is manually operated therefore production costs are drastically reduced.

Polyurethane mouldings (PU moulding) are the resulting parts produced from the RIM moulding process at Midas and can be used to develop a wide range of parts with particular properties and performance requirements. The technology used at Midas ensures that precision, quality parts are created to meet specific customer requirements.

RIM moulding offers you freedom in design thanks to the versatility of the process. Factors such as no sink allow for thick and thin wall sections, complex undercuts and side apertures can be incorporated at a fraction of the cost of more automated processes and the ability to produce parts as heavy as 30kg or as large as 3m in length makes the process very desirable. 

Large enclosures manufactured as a single item can be very appealing both cosmetically and financially. It can reduce the need for constructing complicated assembly joints, it helps avoid dirt traps, minimises EMC continuity issues and reduces the overall assembly time of your product on the production line. These factors all combine to provide you with a process to create the most stylish product without affecting functionality.

Reaction Injection Moulding offers the perfect solution when large, multi-assembly parts are required to fit seamlessly. A single one-off part or prototypes with rapid turn-around times can also be supported using this method. The key benefit to this process is the flexibility it offers. With manageable costs to suit market demands, using low-cost tooling and low volume orders, you don’t need to worry about expensive costs and large MOQ’s.

Polyurethane mouldings created through RIM moulding can be used across a variety of industries and sectors, from medical to marine and transportation and everything in between. These PU mouldings can play a crucial role in these industries where reliability and durability can be life-saving.

Whether you are working in the medical industry to provide cancer support components or in the automotive section and need specialist vehicle bonnets, RIM moulding can create precision parts that offer structure, quality, traceability and confidence when it counts.

For more examples of RIM moulding in practice, visit our case studies section.

Although Reaction Injection Moulding can be used to process other materials, at Midas we only offer polyurethane mouldings (PU Moulding).  If you would like to understand more about the materials we use, we can discuss this in more detail and provide you with relevant data sheets and even material examples when appropriate.  Contact the team now to set up your meeting.

At Midas we manufacture a soft tool and a hard tooling system.  We refer to these as our FASTrim prototype tooling system and our production MRIM system but it really does depend on your own personal requirements and volumes.  We consider both our tooling systems to be Rapid as they are typically manufactured in 3-6 weeks unless you have a very large assembly.

The main difference between the tooling systems is the construction of the tool.

• FASTrim offers you up to 30 off parts for items that are up to 1M cubed so it’s great for the smaller parts where you need a handful of parts or speed is of the essence.
• MRIM offers you tooling that is guaranteed for 5000 off shots so ideal for on-going production requirements or bridge tooling where you may eventually move over to injection moulding as volumes increase.

Midas is located in Bedford, which is centrally placed between the M1 and A1 and ideally located between the London, Cambridge and Oxford Triangle.  You can find directions to our factory on our contact us page.

All Midas polyurethane mouldings are painted before we ship them to you.  We use very hard wearing 2 pack paint systems, typically 2 pack polyurethane paint but can also supply acrylics and epoxies when necessary. 

All Midas PU mouldings are manufactured using a certified UL94 V0 flame retardant material which is only supplied in either beige or Black – if we pigment the material the certification would not be valid. 

Whilst black may be a suitable colour for your next scientific enclosure, the base PU material is not UV stable and as all our mouldings are cast, we need to remove feed systems and flash so it is essential that we paint the surfaces to achieve a top quality part.

If you are at the early stages of a project and need an introductory chat to our process and service offerings or to set up a face to face meeting then call the office on 01234 358394. Rachel, our Sales and Marketing Manager would be happy to talk through any initial questions you have.  If email is more your thing then drop us a line at sales@midas-pattern.co.uk and we will get back to you as soon as we can. 

If you have a current polyurethane moulding project with 3D data which you are happy to send, you can email it directly, again to sales@midas-pattern.co.uk. We can read all standard export formats such as step, iges and x_t. 

If you would prefer that we review your Non-Disclosure Agreement (NDA) before any data is released, this is perfectly understandable and we ask that you send your copy through.

Details to include are

Registered Office - 22 Shuttleworth Road, Bedford, MK41 0RX United Kingdom 

VAT number: - 657 8224 07

Registered in England, Registered number 3132694

In addition to email we also have our request a quote service on the website which helps guide you through all the typical questions we need answering to help us give you the most accurate quote.  You can upload data at any time of the day or night and we will review on receipt so you receive a speedy response back.

This is a tricky question to answer as it really will depend on each individual project but as a rule of thumb, on large panels which have a reasonable amount of 'B' surface complexity we would expect our MRIM production tooling to be 1/10th the cost of a comparable metal injection mould tool. 

RIM moulding provides a low cost solution to enable you to get to market with stylish and very functional covers.  For example, you can have moulded in brass inserts or hinge pins, ribbing for support or mounting surfaces and edge details for gaskets.  Low cost also means low risk which can be beneficial when launching a new innovation or as a Start Up company where every penny counts.

At Midas we do not offer a design service because we have the privilege of working with so many of the UK’s best design agencies/companies.  Over the years we have worked with a very board range of companies from individual designers through to large companies and are always happy to make recommendations or point you in the direction of designers who have a lot of experience in the design of Scientific or Medtec devices using reaction injection mouldings manufactured by Midas.

Manufacturing polyurethane mouldings using reaction injection moulding can be classified as both a prototyping technology as well as low volume manufacture.  Depending on the particular size of your part, the number of parts you need, RIM moulding using our FASTrim soft tooling process is certainly an example of Rapid Tooling and can compete directly with alternate RP processes such as Vacuum Casting or layer build 3D printing methods.

We would always review your project in full to ensure we gave you the best advice as it is our intention to build long term relationships so we want to ensure you receive the part manufactured from the right process – even if that is not us!

Our general statement is bigger than A4 is when we start to become cost effective.  We have made smaller parts than this but typically they are associated with a larger multi-assembly where it makes sense to have all the parts from the same material and supplier.  If you are not sure, then always ask and we will give you an honest answer.

At Midas we excel at making large parts and multi panel assemblies and to-date this means single mouldings up to 3m long or 30Kg’s in weight.  We take in to account the combination of the XYZ sizes, the geometry as well as the overall shot weight of polyurethane required.  If you are looking to clad a floor standing scientific device such as a mass spectrometer or trolley for example, reaction injection moulded panels are ideal in providing you with robust parts that help enclosure your high value science in beautifully styled panels. We would work with you to determine the ideal number of parts that work well for both the moulding process but also assembly, servicing and packing.