May 30, 2018
Volume 3 Issue 8
Landscape Shifts for Metalworking Fluids
MINNEAPOLIS — Environmental regulations, restrictions on chemical use and new lubricant options and machining methods have upped the ante for metalworking fluid formulators and managers to adapt to a rapidly evolving and complex market using long-term solutions instead of short-term goals, an industry insider noted in a presentation given at a conference here last week.
“We all know that metalworking fluids are complex mixtures. The use of metalworking fluids is becoming more restrictive, and the chemistries are more complicated and interactive,” said John Burke, global director of engineering at Houghton International.
Reformulating fluids around regulations such as the European Union’s Registration, Evaluation, Authorization and Restriction of Chemicals and the United Nations’ Globally Harmonized System of Classification and Labeling of Chemicals has changed how products interact with common materials. These include fluoroelastomer seals as well as aluminum body panels and yellow metals, which are favored over steel and iron alloys but have higher potential for staining and rusting, Burke told attendees at the Society of Tribologists and Lubrication Engineers’ annual meeting in Minneapolis, Minnesota.
Regulations such as REACH in Europe and the Toxic Substances Control Act administered by the United States Environmental Protection Agency have limited certain chemicals used to formulate metalworking fluids because of their environmental and health risks. “Certain chemicals are being eliminated, certain chemicals that are under study are likely to be eliminated, and new chemicals are going to be slow to market,” said Burke. “It becomes an issue where there’s less to choose from, and we’re going to have to be a little bit smarter about how we get our raw materials.”
He pointed to the ongoing analysis of risks associated with chlorinated paraffins, restrictions on chlorinated solvents, boric acid, phenol, nitrates and formaldehyde and, most recently, the accumulation of phosphorus in Lake Erie that has led to growth of harmful algae, threatening the potable water supply of its basins.
Phosphorus, one of the four leading types of extreme pressure additives used in metalworking fluids, has accumulated in Lake Erie to such an extent that both the Unites States Environmental Protection Agency and its Canadian counterpart have targeted a 40 percent reduction of phosphorus in the most afflicted basins of the lake by 2025, Burke pointed out.
He proposed that fluid managers outline a master plan with a five-year minimum outlook in order to deal with constant environmental and regulatory developments in the metalworking fluids market. The plan should take into consideration significant trends in dry machining operations, electric vehicle adoption, uptake of biobased lubricants and further limits on usage of certain chemicals, as well as appropriate recycling of metalworking fluids.
Minimum quantity lubrication and dry machining fluids provide some advantages in reducing heat and friction, in addition to cost savings from using less product. But dry machining operations have a major drawback: the emission of hexavalent chromium, which results from heating high chrome alloy materials.
Hexavalent chromium is listed as a known human carcinogen in the Report of Carcinogens from the U.S. National Institute of Environmental Health Sciences. Though Burke clarified that this is not a new development, “there is an issue of [switching to dry machining] and having high chrome alloys, since chrome is an essential alloy agent in metalworking.”
Biobased lubricants are also under consideration for certain metalworking applications because of the lubricity they provide. Burke noted, however, that their biodegradability is a point of concern and that they are not as hydrolytically stable as mineral based fluids.
“The key thing is they are not recyclable [when mixed] with petroleum oils,” noted Burke, If a plant is using both types of lubricants and disposes of them in the same waste tank, “you’ve created a product that nobody wants and that nobody can get rid of.”
Fuel economy demands in the automotive sector are also influencing metalworking fluids as legislation and incentives encourage original equipment manufacturers to invest in hybrid electric and fully electric vehicle technologies. The latter do not require pistons, camshafts, drive shafts, gears and other components of internal combustion engines, and therefore “there could be a massive drop [in demand] for metalworking fluids, rust preventatives and cleaners” in the near future, Burke cautioned.
Recycling metalworking fluids is a trend that some end users are adopting to achieve production and disposal cost savings. However, extending fluid life leads to an increase in tramp metals such as nickel, lead and copper in the lubricant, which can cause respiratory issues, skin diseases and other exposure impacts that can’t be easily predicted, he explained.
Due to the complexity of the issues that metalworking fluid formulators and end users face, short-term planning is not an option, Burke emphasized. “The five trends require a proactive strategy. Reacting point-to-point is a dead-end strategy.”