Gas coolants could reduce reliance on cutting fluids

Researchers at Wolverhampton University are using gas to replace fluids used in metal cutting, to help industry reduce costs and environmental impact.

Cutting fluids, also known as flood coolants, are used to lubricate and cool the cutting tool, reducing wear and tear on the machine and removing swarf.

Wolverhampton is investigating dry and gaseous methods which could reduce or replace fluid use altogether. Its research has centred on what effect nitrogen, the gas expected to be most effective, has on tool life, the workpiece and tool material, and the tool-workpiece interface.

Preliminary results have been encouraging. In combination with a small amount of cutting fluid, applied as a mist, adequate lubrication between tool and workpiece can be achieved, preventing grease build-up on the machine.

Claims by machine tool manufacturers that using nitrogen can increase tool life six-fold have yet to be proven, however.

Mark Stanford, senior lecturer at the university’s competitiveness centre, said: ‘The use of cutting fluids has generally been considered a solution rather than a problem in metal cutting. But the financial and environmental costs of using flood coolants are proving a powerful catalyst for companies to seek alternatives.’

The potential for savings is considerable. Globally, industry uses 600 million gallons of fluids annually. In Germany alone in 1994 350,000 tonnes of cutting fluid had to be disposed of. The German automotive industry estimates that fluids contribute from 7–17% of its costs.