Coolant bursts bubble on foam problem

END USER: LB Pipe & Coupling Products LLC, (832) 934-1850, www.lbpipeandcouplingproducts.com.
CHALLENGE: Eliminate coolant foam and chip accumulation in chucks and increase coolant pressure.
SOLUTION: A nonfoaming coolant.
SOLUTION PROVIDER: QualiChem Inc., (540) 375-6700, www.qualichem.com.

Coolant choice is not usually at the top of the to-do list when installing a new machine. That can be a costly mistake, however, because coolant selection can make a huge difference in how equipment operates—just ask Jim Legg, general manager of LB Pipe & Coupling Products LLC, Magnolia, Texas.

LB Pipe had purchased and installed an automated cell from Okuma America Corp., Charlotte, N.C., which was the centerpiece of a new facility for automating the production of API couplings, which meet American Petroleum Institute specifications. The cell included a pair of Okuma 2SP-V60 machines with CV-50 high-pressure coolant delivery systems from ChipBLASTER Inc., Meadville, Pa., and a high-speed robotic arm from KUKA Robotics Corp., Shelby Township, Mich. The system sprays coolant at up 1,000 psi (69 bar) at the tool/workpiece interface to help with lubrication, cooling and chip removal.

Courtesy of Okuma America

Jim Legg, general manager of LB Pipe & Coupling Products, is pleased that a heavy-duty semisynthetic coolant from QualiChem eliminated a coolant foaming problem.

Courtesy of Okuma America

When coolant foams, downtime, coolant consumption, cycle times and part rejections increase.

At the initial machine startup, foam resembling shaving cream started billowing out of the machine and onto the floor, shutting down the high-pressure pumps and creating a maintenance and safety nightmare. “We couldn’t make one part,” Legg said. “Even when operating at 500 psi—half the recommended pressure for the machine—the foaming was so severe we had to keep a pallet of liquid absorbent on hand to capture coolant that spilled onto the floor.”

That wasn’t all. When running at 500 psi, pressure was insufficient to clear chips from the cutting area. As metal chips accumulated in the chuck, the robotic arm could not safely engage and grab the finished part. LB Pipe frequently halted production to manually remove chips and wait for the foam to dissipate. LB Pipe’s multimillion dollar investment in new technology was beginning to look like a disaster. “We couldn’t use the machines unless we could get rid of the foam,” Legg said.

Greg Antoun, president of ChipBLASTER explained: “When coolant foams, it entrains air bubbles, and the density of the coolant drops dramatically. Because the foam itself is so much lighter than water-based coolant, it can’t exert the force required to make a high-pressure system work. For practical purposes, water-based coolant is not compressible, but when coolant foams, the air bubbles are compressible so it can’t be effectively pumped at all. It’s like trying to hammer a nail with a sponge.”

When coolant foams, downtime, coolant consumption, cycle times and part rejections increase. In addition, slippery foam on a factory floor is a safety hazard and boosts coolant disposal costs.