Plastic spray device cuts waste

A hi-tech manufacturing process originally developed to build up metal components has been adapted to create a method of ‘spray painting’ with plastics.

The technique is claimed to be more efficient than existing methods of polymer coating components such as dipping, which creates large amounts of waste.

It is the latest development to emerge from a Liverpool University research centre dedicated to developing applications for a process that is known as cold gas dynamic manufacturing (CGDM).

The process was first devised for use with aluminium and its alloys, but the research centre is also seeking to widen its capability to create components made of titanium. The first commercial application of CGDM is expected to be announced later this year, said Dr William O’Neill of the Manufacturing Science and Engineering Research Centre at Liverpool University.

‘The aerospace industry is interested in its applications for titanium and its alloys. Titanium is difficult to process and with CGDM we can make novel composites for lightweight and strong materials. The automotive sector, particularly Formula 1 companies, want to be able to make engine components in the same way.’

The CGDM process builds up structures by firing particles of certain plastics or metal at a target in a high-speed stream of helium so that they bond with each other on impact.

Helium is used because it travels faster than other gases when under a given pressure.

But as it has to be mined, rather than drawn from the atmosphere, this makes it expensive. As such, the research team is also looking at ways to recycle helium to reduce process costs. At the moment it costs £500 per hour, the target is £100.

The University of Liverpool is also seeking to build a national network to further the development of CGDM.

O’Neill wants this cold gas consortium to help widen the types of materials used. ‘Eventually we could possibly aim for a world network. Manufacturing is a global enterprise and solutions for British industry can be found outside the UK.’