Shaping modern industrial grinding practices
LJMU researchers have showed how optimising the delivery of coolants during abrasive machining processes has significant performance, economic and environmental benefits for the manufacturing industry.
Grinding makes up around 25% of all machining processes used in manufacturing worldwide. Work and tool temperature are major issues in abrasive machining. Cooling fluids, usually oil-based, are traditionally used both in high volume and under very high pressure to control these temperatures. Purchase costs are high, delivering coolant at large flow-rates and pressures requires specialist equipment, and environmentally acceptable disposal is expensive. Machining fluid may actually consume up to 20% of the total production cost of a component.
Researchers in LJMU's General Engineering Research Institute (GERI) led by Dr Mike Morgan have achieved a far more effective use of coolant. This has involved a sequence of research studies, initially studying and validating the mechanisms of heat transfer present during the grinding process, before exploring the underlying factors involved in the process of getting cooling fluid to the critical areas (effective delivery of fluid as well as the role the fluid undertakes in cooling, lubricating and cleaning the cutting interface).
"The knowledge of GERI in fluid delivery and management has been critical in helping us achieve efficiency with our new abrasive media product…we are now engaged in actions to commence the build of a high volume manufacturing plant to meet anticipated early global demand."
Not only did the research improve coolant flow quality through changes in nozzle design (improving penetration of the coolant into the cutting zone), it went on to show that it was not only possible, but sometimes beneficial, to dramatically reduce coolant flow volume by a factor of up to 20,000.
Industry adoption has been facilitated by the scientific evidence and rigour of the underpinning research. In this respect GERI’s research is influential in shaping modern grinding practice. Nozzle positioning systems and fluid optimisation methodologies have been implemented by a major industrial engineering group of international scope. Additionally, a manufacturer of machine tools and equipment for a wide range of industrial sectors has introduced a novel laser-based nozzle positioning technique on their products based on a design by GERI researchers, to improve process performance and reliability. The company has also implemented GERI’s formal guidance on fluid management and optimisation.
"Our implementation of GERI’s work in the area of cooling fluid delivery leads to significant recurrent annual savings for our customers; for our larger customers we estimate that such cost savings are easily in the region of £100k per annum."
Furthermore, GERI’s research findings have been taken up by a respected expert in the delivery of bespoke grinding training – a third-party American based company “TheGrindingDoc”. The company has a clientele in all areas of the industrialised world and provides training to more than 100 major industrial grinding users and practitioners in over 30 companies. The resulting dissemination via training ensures that GERI’s work influences a world-wide user community.
"The work at GERI was significant in that it established the rules for coolant application which have been relied on by all our machine designers since then...[their] studies have improved the performance of our machines by extending wheel life, reducing heat generation, and keeping grinding power and normal forces low. "