Microbiology – a weapon in the war against contaminants

Bacteria that contaminate cutting fluid systems disrupt production and cause problems in the working environment. The FUCHS microbiology lab has developed a ‘toolbox’ that tests cutting fluid resistance in a more intelligent way, making development more accurate and more closely customised.

When metalworking fluids are broken down by bacteria they lose important properties, change pH, cause corrosion and lubricate less well generally. The issue has kept the industry busy for a long time. 

“The reason is the high water content in the machining process. This creates the ideal breeding ground for bacteria and fungi which degrade the fluids,” says Kenneth Borin, Product Manager Metalworking at FUCHS Nordic.

“Heavy growth of microorganisms, and fungi in particular, can also block filters and adversely affect machining of the metal,” he continues. “But most importantly of all, the growth and spread of bacteria and fungi can be a threat to employees’ health in the form of skin and respiratory diseases.”

Bacteria and fungi often end up in the metalworking fluid via the water that’s used, for example by the staff who look after the machines, or via particles and aerosols in the working environment. Even so, poor maintenance of the fluids is often the main cause of microorganisms spreading.

More effective testing 
To deal with the problem of contamination, the FUCHS microbiology laboratory in Spain has developed a more effective ‘toolbox’, including bespoke load tests. In 2016, the lab also acquired a blast chiller. It maintains temperatures down to -80°C and stores isolated microorganisms for future use in product development. Being able to store bacteria strains for a long time is important – especially seeing as collected, isolated fungi and bacteria are also used to assess the efficacy of biocides. 

“Specially adapted microbiological tests are used to identify different fungi and bacteria in each individual case,” says Kenneth. This enables us to develop more accurate, customer-specific solutions which use the right additives in the right concentrations.”

New legislation – new technology
In recent years, new legislation for biocides and substance classification has led the industry to start using new technology. This means that the products have to be checked to see that their properties have not changed. This is where the FUCHS microbiology lab uses the bespoke load test, which is used to assure biostability in the new technology being used. 

“We use the load test to check that the microbiological resistance is suited to the customer’s needs when we modify and further develop our products. We can compare different products and technologies, and then choose the ones that produce the best results for each customer,” Kenneth explains.

Preventive maintenance – more in focus
Various types of formaldehyde-releasing biocides were previously used as additives in the cutting fluid. From 1 December 2018, these biocides will have more strict labelling and will therefore be phased out.

“With the shift in technology, it will be even more important to keep your cutting fluids in order. After all, poor fluid maintenance is often the main cause of microorganisms spreading. To help our customers we’ve produced a cutting fluids manual with firm tips and advice on how to take care of cutting fluid systems,” Kenneth Borin concludes. 

Read more about handling and preventive maintenance of cutting fluids in our Cutting Fluids Manual.

Read more about new legislation for biocides.