Metalworking fluids, particularly those which are synthetic and mixed with water are susceptible to microbes damaging their performance and safety. With various types of microbes affecting the way fluids can perform as well as being a risk to those who are in the vicinity of fluids, which can disperse microbes into the atmosphere as they form vapours during the process of application. To ensure the safety of fluids, biocides have typically been introduced to lubricants, however because these chemicals also have potentially dangerous effects, there is a push towards using fluids without biocides included.
There are three different types of microbes that are commonly found to create problems in metalworking fluids. These are aerobes, anaerobes and fungi. As their names suggest, aerobes are those bacteria which require air in order to survive, and anaerobic being those which don’t. The growth of large populations within fluids causes blockages in the fluid delivery apparatus of metalworking systems. Naturally, this significantly reduces the effectiveness of fluids to perform their function, be it cooling, lubricating or carrying away waste bi-products of machining processes. Combined with the associated health risks of infected fluids and it is apparent that a solution to these microbes is needed.
One such solution is to introduce Biocides to fluids. These chemicals which are developed for a variety of purposes, whether it’s to increase crop yield or to prevent infection within metal working fluids derive their name from the fact that they are essentially poisons which are targeted towards living pests, whether it’s insect which are attack crops, or bacteria and fungi which infect lubricants and cooling fluids. These materials are also highly problematic however, with chemicals causing serious health risks, the use of biocides is know closely monitored by the World Trade Organisation. With the risk of materials being accidentally introduced to water systems, the food chain, and through atmospheric exposure.
There is also an element of unpredictability to many biocides, because they are needed to be used in combination in many cases, as often fungi and bacteria require different biocides to be used within the same fluid. The risk of the combination of chemicals producing unpredicted effect due to their combination, or synthetic effects, is another reason why biocide free metalworking fluids are required.
The solution has been to develop bio-resistant fluids rather than fluids which need biocides added to them. These reduce bacterial and fungal growth and reduce the need for dangerous biocides to be introduced to the fluids. Water miscible fluids in particular have needed the development of bio-resistant formulations, being more susceptible to infection.