Eighty to 85 percent of Singer’s shipments are to laser fabricators, the majority of which are Tier 1 suppliers to major OEMs, so the recent installations were tailored to a large and lucrative market. Product applications include non-automotive transportation--off-road, rail and military are the big three--plus farm implements and electric utility cabinets. Heavy-gauge material is the norm, and many of Singer’s customers process plate.

Flatness is a huge issue in laser processing. Steel that’s cosmetically level isn't enough; it must be fully stress-relieved throughout the entire cross section to be compatible with CO2 lasers. The focused heat of a high-powered laser will release trapped stresses in a sheet, and a buckled surface can wipe out the optics of a cutting head. Count the loss in the thousands of dollars.

"Flatness is as much a requirement of manufacturing processes as it is customer appeal," Bruce Alexander confirms. He's president and co-owner of Singer Steel, which has been in the hands of the same extended family since its founding in Cleveland as a warehouse operation in 1923. Alexander and fellow owner Eric Shaw, vice president and CFO, are both members of the third generation to operate the company, and the fourth generation is also involved.

"If you can give fabricators a product that they can run through their lasers and have it stay flat," Alexander says, "it will save them a lot of money downstream in their plants."

Laser cutting isn’t the only process that requires stress relieving. Nesting parts for automatic press feeding and welding with robotic equipment also require parts that remain flat. Robots can’t adjust to distorted metal, and any deformation of the workpiece will result in misfeeds or unsound welds.

Bringing operations in-house
The new equipment installed six months ago at Singer's 100,000-square-foot facility was built by Red Bud Industries, Red Bud, Ill. It produced both the cut-to-length line with the stretcher leveler and the equipment for the SCS (smooth, clean surface) panel washing system. SCS is patented technology developed and licensed by The Material Works (TMW), also of Red Bud, Ill.

The cut-to-length line includes an 80,000-pound-capacity, dual-mandrel uncoiler with a peeler-breaker, an entry crop shear, and an 11-roll flattener to remove coil set and crossbow. The stretcher leveler is next, followed by a full-width shear and heavy-gauge stacker.

"A line like this is a much different animal from the majority of Red Bud lines," says Dean Linders, Red Bud’s vice president of marketing and sales. "It’s massive. It's a behemoth. Our image has been built on light-gauge precision multi-blanking lines. We’re now expanding into the big bruiser market."

Particularly impressive is the power of the stretcher, which pulls 25 feet of strip at a time. "Ninety-thousand psi is a very high yield strength for 1/2-inch-thick metal," he adds. "The people who run plate that thick will sit up and take notice."

The flattener is also notable for its size and brawn. The unit weighs 100 tons and is driven by a 600-horsepower AC motor.

Pop-top flattener
Linders points out a feature he calls unique to a flattener this large. "Press a button and the top frame opens like a book for cleaning and maintenance," he says. "It's a pop-top flattener. This feature has been limited to relatively small machines, but we’re doing it with a 50-ton top roll set. To our knowledge, it’s never been done before on a machine this massive."

"The flattener handles strip from 0.071 inch (14 gauge) up to 1/2 inch," Alexander points out. And, the automatic stacker handles sheets up to 20 feet long, but the runout table will accommodate longer material for manual handling. Lengths in excess of 20 feet are produced by cycling the stretcher multiple times for each shear cut, and one customer orders 80,000-psi minimum yield blanks that are 407 inches long.

Clean cleaning
SCS sheet cleaning is a capability that's new to Singer Steel but is also readily marketable to what Alexander calls his "fussy" laser clients. The technology scrubs the metal with three stages of rotary brushing. A closed-loop water cycle washes away scale. Singer's installation is one of the largest-capacity units built to date and will run 1/2-inch hot-rolled plate at 30 feet per minute.

The SCS process, according to TMW, gives hot-rolled steel the cleanliness and brightness of cold-rolled material. Brushing removes high-oxygen content magnetite (Fe2O3) and hematite (Fe3O4), leaving a more stable layer of wustite (FeO) that protects the surface against corrosion without applying lubricants. Triple filtration of the wash water produces a waste product considered nonhazardous by the EPA. A magnet removes metal fines, a paper filter traps larger particles, and finer particles are retained by a cartridge filter. The paper filter is changed automatically, using a sensor that detects reduced water flow. It signals for a clean filter to index into the water stream and for the spent filter to be ejected into the scrap bin.

"SCS is another measure to reduce cost in our customers' plants," Alexander says. "They can increase the cutting speed of their lasers because the scale is removed from the surface and the metal cuts faster and cleaner. It saves them time and money in welding and in prepainting prep.

"SCS also helps the environment because there's no acid or solvents used in cleaning," he says. "It's win-win for both Singer and our customers."

Today and tomorrow
The ability to laser cut and weld metal without costly cleaning and lubricant removal represents a considerable saving in process cost, and already about 20 percent of Singer’s laser steel orders specify SCS cleaning. "That will grow as people become aware of its advantages," Alexander says. "Also, any new process takes time to be accepted because our customers have to obtain OEM approval.

"The stretcher leveling line is an investment for today," he continues. "We look at SCS cleaning as an investment for the future."

And it's a substantial investment that Singer has made at a time when many corporations are cutting back on capital improvements.

"With our leveling operation in-house, we do have better control of our costs, but installing stretcher leveling and the SCS cleaning were not cost-driven projects. Our goal is to control quality and service, and to give our customers a better product.

"Our segment of the market demands quality and service," he says. "We're a custom business, not a commodity supplier, and we're custom both in the products we produce and in meeting the needs of the end user." MM