MidWest Materials invests in a Leveltek stretch leveling system to ensure customers receive high-quality, memory-free material
November 2012 - This year, Perry, Ohio-based MidWest Materials, which was co-founded in 1952 by Joseph Koppelman, celebrated its 60th year in business. The company has grown from a one-room sales office in Cleveland to its current 240,000-square-foot operation. To increase its competitiveness in the marketplace, MidWest Materials installed a 1,400-ton Leveltek stretch leveling system in December 2011.
The capital expenditure was part of a multi-year, multimillion dollar expansion that included property improvements, upgrades and additions to facility equipment and technology, replacing facility lighting with energy-efficient fixtures, and new
Peterbilt trucks for the company’s fleet. The company also has enhanced its corporate identity with a new logo and website.
Engineering flat material
Ensuring manufacturers can participate in a cutthroat global market is a growing challenge for service centers, says Brian Robbins, CEO of MidWest Materials. “Our customers are competing directly with manufacturers from outside the shores who are coming in with lower-cost products. In order to make them competitive, they need higher-quality steel at a lower cost. That requirement has been pushed both downstream and upstream to us, so those distributors with a long-term vision need to invest in themselves if they want to continue meeting industry needs.”
Beyond leveling and cut-to-length, the most quickly advancing technology for fabrication of metal sheets is laser cutting, says Bob Sipp, director, sales and marketing at Leveltek International LLC, Benwood, W.Va.
“Laser technology does not like memory in the metal,” he says. “When it has memory, the metal begins to move up and down, and it has the capability of destroying the laser head. If it does that, the line shuts down, production goes to zero, it needs mechanics to fix it and the laser heads are worth between $4,000 and $10,000 each.”
Robbins says processes such as roller leveling are “extremely efficient and able to unroll coils of steel and corrective level them so they are flat.” However, he points out it’s similar to rolling up a piece of paper and letting it go—it’s still curled up at the ends. “That is why it needs to be leveled,” he notes.
“Corrective leveling will flatten the steel, but under certain stresses the material could revert back to its original coiled shape, and the memory may return,” he says.
“We continue to use corrective leveling to provide flat steel for many of our customers,” Robbins continues. He notes, however, MidWest invested in the stretch leveling system as a result of increased demand for memory-free steel.
Leveltek has been involved with stretch leveling systems since 1993. The company designs, manufacturers and installs leveling systems, new light to heavy-gauge cut-to-length and coil-to-coil lines. It also provides toll processing services.
Leveltek equipment has the capability to stretch level all types of ferrous and nonferrous coiled material—carbon steel, stainless steel, titanium, aluminum, brass, copper, high-temperature alloys, galvanized steel, as well as painted and embossed carbon steel and floor plate.
“We built the first machine for ourselves,” Sipp says. “It was a coil-to-coil machine for the stainless steel industry. We intended to be a toll processor for specific accounts.”
Less than a year later, a company from Italy approached Leveltek, curious about the company’s ability to stretch level bright annealed stainless without marking it. “They came to our plant, brought a coil with them and wanted us to stretch level it,” Sipp says. “So we put their coil on, stretch leveled it without marking it, recoiled it and they were so pleased that they wanted one of the machines. That was our entry into the machine-building business.”
The company’s experience as a toll processor gives it an around-the-clock laboratory to test and improve its technology for all types of material, particularly specialized materials, such as high-nickel alloys, stainless and titanium.
“We’ve seen just about every defect on the toll processing side,” says Amy Dieffenbauch, sales and marketing manager at Leveltek. “Our guys can make modifications to equipment to accommodate the types of defects that we’re seeing on a continuing basis.”
“Because we actually invented the technology of nonmarking stretch leveling, there are no operators in the world that have more experience with stretching metal than ours in our toll processing facilities in two plants,” Sipp says. “We have people that have been stretch leveling material in excess of 20 years. More than likely, our operators have seen it before because they’ve been doing it longer than anybody else.”
Stretching out stress
Stretch levelers pull the material to the point where it eliminates its memory, Robbins says. He notes stretch leveling technology is not new. For decades, MidWest Materials had a sheet stretcher that would clamp down on an individual sheet and pull, “similar to the medieval punishment of the rack. When we couldn’t get steel flat enough, we would stretch it.”
However, using that stretcher was a time-consuming process, and it left marks on the steel. Leveltek’s technology grips the steel without slipping or leaving marks, while still providing “100 percent equal contact across the entire width of the coil,” Sipp says. “We are able to align grains within the metal perfectly across the entire width, and that creates, in the colloquial terminology, memory-free steel,” removing shape defects such as edge wave, center buckle, quarter buckle, camber, crossbow, mandrel or coil breaks, some types of chatter, mill chop and twist.
MidWest Materials came to Leveltek with the goal of achieving memory-free carbon steel. “We designed a machine that would do that and retrofit into their existing roller leveling line,” Sipp says. Leveltek inserted the stretch leveler into the line between the roller levelers and the shear.
“There are only five moving parts on the line,” Robbins says, making installation a relatively painless three-week process. “The disruption was minimal, so we could still run our operation as they installed it.”
Since the first Leveltek line was built in 1994, the total machine population averages 99.3 percent uptime, which Sipp attributes to a simple design with few moving parts. In addition, he notes, “Leveltek stretch leveling machines require no foundation beyond a flat concrete floor. This enables us to install or retrofit lines in only two weeks with minimal loss of production time.”
At MidWest, using the two leveling processes in tandem increases efficiency of running coils, Robbins says. On the line, material is uncoiled and then is corrective leveled with MidWest’s roller leveler.
“We actually work and level the steel first with two corrective levelers,” Robbins says. “The significance of that, especially on heavy-gauge or high-strength tensile material is we’re able to get the coil set or crossbow out of the steel. Systems that only have a flattener and not a corrective leveler may remove the steel’s memory but run the risk of not getting the steel totally flat across its width.”
After corrective leveling, the steel continues through the stretch leveler. “Gripper pads come down, and 2.8 million pounds of force stretch the steel several inches throughout a 50-foot length,” Robbins says. “One of the reasons we chose the Leveltek system was due to their unique gripping technology that does not mark the steel when it is stretched. The steel then proceeds to the shear, where it is cut to its specified length. It is then stacked, and the flat, memory-free bundles are ready to go.”
Robbins says it’s paramount to listen to customers and adjust processes to provide high-quality steel at a low cost. “We’ve had customers that have come back and been blown away with the quality we’ve been able to provide them [using the Leveltek equipment],” Robbins says. “Companies that have used temper-passed material before were so impressed with the steel that we were able to provide them, they now use stretch-leveled steel for their memory-free needs.
“Being able to provide non-marked, memory-free sheet steel from 0.054 inches to 5⁄8 inches thick and up to 100 inches wide in mild through ultra-high-strength complements our other corrective levelers, slitters and shears,” Robbins continues. “Our state-of-the-art equipment along with our seasoned and experienced workforce are able to provide the service, quality and value American manufacturers need to remain competitive nationally and globally.” MM
Interested in purchasing reprints of this article? Click here