TMW: EPS Ready for Rollout
The Material Works says its new Eco Pickled Surface steel slurry cleaning system has cleared the shakeout phase and is ready for a widespread rollout as an eco-friendly alternative to acid pickling.
By Tim Triplett, Editor-in-Chief
Much of the activity at The Material Works’ Red Bud, Ill., steel processing center these days is focused on a sheet line with an unusual cube-shaped “cell” in the middle. Though TMW is primarily a toll processor, its president, Kevin Voges, has invested heavily in the design of a new system to strip dirt and scale from hot-rolled black steel. Dubbed Eco Pickled Surface or EPS, Voges claims his method is a more effective and environmentally friendly alternative to acid pickling.
EPS basically uses a high-pressure slurry spray to strip the steel clean. The slurry consists of abrasive particles of carbon steel, along with a cleaning agent and corrosion inhibitor, suspended in a water carrier. The slurry mix is fed into a series of rapidly rotating impellers that propel it at high velocity across the steel. Centrifugal slurry blast heads provide coverage uniformly across a 72-inch-wide sheet or coil.
TMW has been working since June 2007 to perfect the EPS cells. It is now operating its second-generation line, a sheet line with a single cell equipped with eight turbines. It recently sold its original dual-cell coil line to Jeongan Hi-Tube of Daegu City, South Korea. Voges says interest in EPS is high the world over, including Asia where industry is working to improve its environmental record.
TMW has been processing customers’ metal commercially since December 2008. To date, it has run over 1,700 coils through the system. EPS coils have been shown to be fully interchangeable with acid-pickled coils for stamping, roll forming, laser and plasma cutting, punching and tube production. EPS coils also have been successfully cold reduced, annealed and galvanized, Voges claims.
TMW continues to run the line 12 hours a day, five or six days a week, to keep up with demand as the word gets out about this new alternative to pickling. Potential customers include mills, service centers, toll processors, tubing manufacturers, fabricators and any other operations that run pickling lines or use pickled steel. “We are receiving many quote requests for EPS equipment to replace acid pickle tanks in existing pickling lines, as well as in place of new acid pickle lines,” Voges says.
According to TMW, EPS offers several advantages over conventional pickling in preparing the surface of steel for painting or galvanizing:
n EPS pickles steel without the use of hazardous acids.
n EPS is a “green” process, recirculating steel grit and water while producing no harmful emissions. Used carbon grit and slag are recycled with steel scrap.
n EPS burns no fossil fuel for process heat.
n An EPS line costs about 70 percent of the capital required for a comparable pickle line.
n An EPS line has a variable cost of operation around $7 per ton, about 70 percent that of acid pickling.
n An EPS line occupies about 40 percent of the footprint of a comparable pickle line, freeing up facility space. “An EPS line can process roughly four times as much material per linear foot of facility space as a conventional acid pickling line,” Voges estimates.
n The EPS slurry process produces a clean, uniform surface and mitigates minor flaws such as pitting or roll marks. The process can be “tuned” by varying the turbine velocity to achieve a rougher surface for better coating adhesion.
n EPS’d steel is naturally rust inhibitive, so it requires no protective oil that must be removed later. Because the surface of EPS is oil free, it can be welded or laser cut faster while producing fewer fumes.
n EPS offers economies of material management, as users can stock EPS in place of both hot-rolled and P & O.
Voges understands why potential users might be skeptical of his claims that this dry EPS product does not corrode, since pickled steel rusts quickly due to the chloride salts that are a side effect of the pickling process. To reassure them, TMW offers a warranty of 180 days against rust damage. “EPS started out as a pickled replacement, so virtually all EPS was requested with oil. Now we have just two customers who are ordering EPS with oil,” he says.
Rather than charging users an upfront licensing fee and ongoing percentage as originally planned, TMW will instead take a more conventional approach and sell the patented equipment. “Users will still need a license, but we won’t charge for it. They can’t always get financing for a license,” he notes.
Former sister company and neighbor Red Bud Industries is approved as an EPS coil line manufacturer. TMW is recruiting other machine vendors, as well, to make sure they have enough manufacturing capacity to meet demand for the new EPS equipment.
Voges understands the challenge he faces in educating potential users on the benefits of such a new approach to treating steel. “We have to win our business the hard way,” he says. TMW already claims to have many satisfied customers among the market’s largest service centers, toll processors and fabricators. None were willing to comment for this article, however. “They are reluctant to draw attention to the competitive advantage they have gained with EPS,” Voges says.