Plasma cutting meets biochemistry

Oct 14, 2024

A plasma system cuts with workpieces immersed in a fluid designed to prevent bacteriaformation and rust. Essentially, the fluid’s chemistry is designed to biodegrade trampoils and bacteria on contact.

When Ben Vroon, a self-described “stubborn Dutchman,” is asked if his GreenCut® Plasma water table fluid is safe, he picks up a bottle of the stuff and takes a drink. He doesn’t recommend people do this, of course, but he imbibes to prove a point: A fluid powerful enough to tear bacteria and tramp oils apart into their molecular elements is, in fact, safe enough to drink.

Vroon, a mechanical and chemical engineer turned entrepreneur, is CEO of LubeCorp in Calgary, Alta., Canada. His company offers fluid that treats the water in CNC plasma tables. Immersed in the green fluid, cut parts emerge with a coating on them that’s designed to biodegrade bacteria, guarding the cut edge and plate surface against rust. To further process the plate for painting or welding, workers rinse parts clean. According to Vroon, no power wash or blast cleaning is necessary.

Guarding against bacteria has been central to the company’s narrative since Vroon started looking into the industrial fluid market in 1987. Back then his research focused on milling and turning applications. “My background is in mechanical engineering in the oil patch, and I worked with a lot of machine shops. I knew about some of the hazards in some of the cutting fluids they were using.” He added that some cutting fluid exposure has been linked to eczema, and long-term exposure has been linked to skin and throat cancer.

After a dozen years of research, Vroon developed his first industrial fluid, mainly used for milling, turning, and sawing. After using it for their machining, customers who also had fabrication departments asked him about plasma cutting: Would his fluid work in a plasma table?

Whence came LubeCorp’s plasma cutting fluid treatment. The fluid’s chemistry had to be tweaked for plasma cutting, but essentially it works by the same principle. The chemistry is polarized so it’s attracted to any metal. This means that, as long as the fluid in the cutting table is circulated properly, the fluid adheres to and coats the workpiece surface and the plasma table.

“It coats at a single-molecular thickness,” Vroon said. “Any thicker than that, and it repels like a magnet. It’s a thin, stable coating that can be washed off if needed for painting and welding.”

The fluid’s chemistry also is designed essentially to biodegrade the tramp oils and bacteria that come in contact with it. So if any microscopic bacteria or tramp oils contact the coating, they are instantly broken into elemental components, including water, carbon dioxide, and a very small amount of biomass.

This biodegrading effect remains constant as long as the fluid-to-water ratio remains at appropriate levels. The company recommends a 20-to-1 ratio—20 parts water to 1 part Green-Cut. If the ratio gets to 50-to-1, the fluid loses its effectiveness.

That’s why the company recommends that users check the pH level of the plasma table fluid every two weeks to ensure it’s between 9 and 10 pH. If it’s less, they need to add more fluid. If the right amount of GreenCut fluid is in the table, the liquid should appear green. Also, because water evaporates, and the fluid does not, additional water will need to be added to maintain that 20-to-1 ratio.

For the fluid to be effective, it needs to come in contact with the sheet or plate being cut, so the company recommends submerging the work in water. Specifically, material less than 0.25 in. thick should be submerged totally to avoid air being trapped underneath, which can form an explosive steam mixture with ambient air. Vroon clarified that this condition isn’t specific to the company’s fluid; it’s just a precaution to take when plasma cutting in a water table. Plate more than 0.25 in. thick can be partially submerged.

Regardless, Vroon said, if the fluid doesn’t make even contact with the workpiece, a fabricator won’t realize the antirust benefits of using the fluid. Circulating the fluid, using pumps or air bubbling, keeps it moving and ensures it contacts all workpieces on the plasma table evenly.

The chemistry itself is, of course, LubeCorp’s secret sauce. According to Vroon, it involves more than a half dozen elements that interact with each other. The result is a fluid strong enough to destroy tramp oils and bacteria while being nontoxic and safe enough to go directly into the sewer—which is a good thing, considering Vroon has put the fluid directly into his stomach.