One of the major obstacles in the metalworking fluids industry is how to detect and reduce bacterial contamination. These fluids are used to cool and lubricate machinery, inhibit corrosion and reduce swarf. But once bacterial growth starts in a fluid, it can lead to reduced fluid performance, machine breakdown, and even sick machine operators if they inhale potentially toxic fumes.
A fast but accurate method is needed to evaluate and predict the antibacterial capacity of fluids—but such a tool is currently lacking.
A team of veterinary scientists at the University of Gent, in collaboration with Quaker Chemical Corporation, may have found a solution. They have developed a new tool based on flow cytometry (FCM), a cell analysis technique currently used in the medical field. FCM uses a laser to measure the volume of cells in a rapidly moving stream of fluid.
The team found that, just as FCM is a valuable tool to take measurements of cells in a solution in a medical setting, it can also be used to determine the antibacterial potential of newly-developed metalworking fluids.
The team used the bacteria F. solani as a model to measure fungal viability in metalworking fluids, mixing viable and dead bacteria into the fluids and analyzing them with FCM. They compared the results with those of new metalworking fluids run through the same test. Within five hours of incubation, FCM was able to distinguish between live and dead bacteria cells. Within a day, it was able to reliably predict the antibacterial capacity of metalworking fluids. By comparison, conventional assessment methods in the industry depend on bacterial growth in a fluid to measure its antibacterial capabilities—which can take up to eight weeks.
“New regulations restrict the use of certain biocides and the market demands us to find alternative chemistries,” said Fred Hoogendoorn, a research scientist at Quaker Chemical. “This new technique, flow cytometry…allows us to dramatically speed up development work, while offering more flexibility in the choice for microorganisms in our studies.”
Not only does the experiment show that FCM can be used to assess antibacterial strength of fluids, it also implies that FCM can be implemented as a rapid detection tool to estimate the extent of contamination in an industrial process. This could lead to significant reduction in bacterial contamination in metalworking processes in a variety of industries.
“This really is a huge step forward,” said Hoogendoorn.
Read more about metalworking fluids at The True Cost of a Lubrication Cycle.