A study of injection moulding with bismuth alloy

There is a demand to produce parts in small quantities, using cost effective injection moulding processes. The emerging economic case suggests there will be advantages in producing injection moulding tools for short duration low volume production runs where the tool is rebuilt for each manufacturing cycle. CAD/CAM, Rapid Prototyping (RP) and digital technologies help to bring new products to market faster. Mould inserts are traditionally produced using expensive and time consuming CNC machining processes. This article presents development of an injection moulding tool where rapid tooling, bismuth-tin mould insert and injection moulding are used to manufacture one hundred plastic parts. It describes the manufacturing methods applied and the use of manual and 3D scanning methods. It also evaluates the surface finishes and dimensions of the parts produced in the tool.