Dip moulding and 3D printing

A small plastic robot: an example of products produced by 3D printing or Dip moulding.

Dip moulding and 3D printing are different technologies, with very different cost structures.

Dip moulding is analogous to the methods used in traditional industry, such as candle making. A heated metal mould is immersed in a tank of liquid plastisol. The heat from the mould attracts the plastisol, and the part is formed. Parts are cured, cooled and stripped. Typical products produced via this process include low cost items such as gloves and condoms.
3D printing is much more technologically advanced and still relatively new. 3D printing builds up a component layer-by-layer into a physical object from a digital model. Many thin layers of material are laid down in succession to form the part.

“A dip moulding tool may cost around a fifth of the price of a typical injection moulding tool”

Which is the most expensive?

Some dip moulding tools are relatively cheap. For example, a dip moulding tool may cost around a fifth of the price of a typical injection moulding tool. Some dip moulding companies focus on achieving low plastisol costs by mixing their own plastisol and recycling the material. This can cut overall costs substantially. 3D printers vary widely in price. There are many 3D printing technologies on the market, with variations in quality and in the materials they can process. Metals and ceramics are much more costly to process than plastics, and these materials are often the province of industrial machines. However, low cost 3D printers, do-it-yourself kits and open source software are increasingly making 3D plastic printing more accessible.

How 3D printing can reduce tool cost

One area where 3D printers can reduce costs is in the production of moulds and tooling. For example, it is possible to manufacture a 3D printed mould for a fraction of the price of a machined mould in a matter of hours. However, 3D printed moulds are not as durable as machined moulds and are only good for small runs. If multiple moulds have to be 3D printed for one job, then the advantages of 3D printing can start to dissipate. As ever, it’s all about selecting the right tools for the right job.