Controlled Defence – Low Volume Production

Malcolm Nicholls Limited (MNL) was asked to produce a small production run of polyurethane casting valves utilising our low-volume production techniques to produce 30 sets of valves for our client a leading boiler manufacturer.

Controlled Defence – Water Boiler Valve System

The Project

A boiler manufacturer approached Malcolm Nicholls Ltd back in 2001 with a new product development project where they wanted to develop a new safety valve system for a mains water inlet. The system’s aim was to provide protection from pressure surges and negative pressure boiler evacuation on a highly efficient domestic water heater.

The Process

Our technical team recommended producing the parts via Vacuum Casting producing 30 sets of polyurethane castings, having received the STL files as the provided design source. Stereolithography, (SLA) masters were built at the ultra-fine layer thickness of 0.05mm.

The silicone tooling is needed to produce the 30 sets of polyurethane castings and enhanced with high-precision metal inserts to maintain the tight tolerances required in some of the bores. (Tolerances as tight as ±0.05mm can now be repeatedly held.) The screw threads that can be seen here were all cast in without the need for post-machining.

Making full use of the silicone tool by trying different materials

The prototypes were put to use in engineering evaluation, fit and function tests and regulatory approval. An increase in the test pressures for water board approval meant that initial polyurethane samples failed. However, subsequent castings, from the same silicone tools, a more resilient glass-filled polyurethane resin completed the high-pressure tests at an internal pressure of 15 Bar.

Our technical team were able to use their expertise to advise the client on utilising their silicone tooling in the new product development phase, the client was able to reuse the tools and try a new resin which completed the high-pressure testing, saving the client time and money.

Why Use Low Volume Production / Low Volume Manufacturing?

With the growing demand for Low Volume Production also known as low volume manufacturing and small batch production Malcolm Nicholls Ltd can produce 1 – 1000’s of parts.

If you’re looking for a one-off bespoke top-quality part such as a trophy, or you require 1000’s customised parts such as widgets, we have the solutions to suit your needs.

It is an increasingly popular option as it allows for a smaller investment in tooling and materials while providing fast access to the market. It also acts to bridge the gap between initial prototypes and mass production.

Historically, manufacturing components in low quantities has always been a costly exercise. With the advent of 3D printing and vacuum casting many constraints previously faced can now be significantly reduced. Technologies such as SLS (Stereolithography) and FDM (Fused Deposition Modelling) can now be used (especially for non-seen parts), to produce components in quantities as low as 1s and 2s and up to thousands, but still with exceptional material properties such as flame retardancy and high-heat requirements. Traditional design constraints, usually associated with injection mould tooling for example, can now be ignored enabling designers to be more efficient and reduce part count within assemblies.

Looking to Produce Multiple Parts?

We can produce anything from one to thousands