We have recently started a bespoke enclosure design project for a piece of scientific equipment. All the products that this business develops are high value (£50k +), low volume (100 per annum).

Our design team has developed many such enclosures over the years, so it is useful to take a look at the design options available for such a brief.

Product designers like to have freedom to develop an interesting form factor. Higher volume products often utilise injection moulded plastic components, which can be shaped in an almost limitless manner. But what if your production volumes don’t justify the investment required for injection mould tooling? 

Manufacturing options still fall into two main camps – tooled, vs non tooled. 

Tooled approaches include;

  • RIM Moulding
  • Vacuum Casting
  • Vacuum Forming

Non tooled approaches include;

  • CNC machining / turning
  • Laser cutting and forming
  • Metal stamping

The project we are currently working on will utilise RIM Moulding to create 2 or 3 large components, which as a whole create the enclosure system. Why have we identified this process alone so early in the project?

RIM (Reaction Injection Moulding) Gives us the form factor freedom of injection moulding, but it is much more suited to lower volume manufacture (especially if parts are large). Our client is already familiar with this process as it is used on existing products, so they know the components will be durable and meet UL 94 flammability safety requirements – a must for their products. This choice gives us, as the design team, a great opportunity to explore a unique aesthetic for  the new product, a wide choice of colour finishes, and the knowledge that the end product will have a high quality surface finish with nice, crisp detailing.

Pros

  • Design freedom – create interesting form factors
  • Tooling costs much less than equivalent injection mould tooling
  • Parts are rugged and can be painted any colour
  • Parts can meet UL 94 flammability safety standards
  • Branding can be added
  • Parts don’t suffer from sinkage – thick sections can be added if required
  • Large parts can be moulded (30 kg)

Cons

  • Part price is relatively high (compared to injection moulding)
  • Parts need painting to achieve an aesthetic finish
  • Less choice of material properties (hardness for instance)

Typical use scenarios are large panels on high value products, such as medical equipment, commercial health and beauty equipment, information kiosks. 

We will feature a full case study of this project when the product has been launched.