Fit and Trim

With the weak economy and global competition, there?s more pressure than ever on roll form and tube fabricators to produce more, more safely, at lower cost. Whether slitting continuous lengths of metal to size or finishing metal tubing, one brake on profitable output has been the limitations of traditional scrap handling for edge trim and tube scarf.

Scrap winders, for instance, expose operators to sharp, fast-moving edge trim and tube scarf while requiring frequent handling and monitoring, plus production line stoppage to change out heavy, awkward ?scrap balls.? Manual handling of such scrap can be even more labor intensive and potentially hazardous.

Some companies, however, are gaining a competitive edge in how they manage edge trim and tube scarf. They?re turning to safer, more efficient handling of slitter line trim and tube scarf via scrap choppers at the point of generation to add to the bottom line.

Precoat Metals, a leading supplier of coating services for coils of flat rolled substrate, for instance, is using scrap choppers on slitter line edge trim to improve safety and increase productivity and scrap value at its Birmingham, AL site. ?Using Sweed scrap choppers, we produce more, more safely, and give better service to our customers,? says Anthony Fleischmann, the plant manager of the Birmingham facility. ?They?ve boosted the value of our scrap and almost completely automated our edge trim handling.?

TRADITIONAL DRAWBACKS

Traditional scrap winders, which wind scrap under tension into ?scrap balls? which the operator must change out, remain dangerous and labor intensive. Despite guards and guardrails, they can expose the operator to sharp, edge trimmed scrap or hot, sharp tube scarf, often moving hundreds of feet per minute on production lines. When sharp edge trim or tube scarf breaks, it can whip around uncontrollably until it?s caught by the operator and re-threaded into the scrap winder.

Not only does the operator have to manually thread the edge trim or tube scarf scrap into the winder at the start of every metal coil or tube batch processed, but also each time the scrap thread breaks. This requires production downtime to re-thread the edge trim or tube scarf into the scrap winder. More downtime is required to change out the resulting sharp, bulky scrap ball, which is typically hoisted by crane, forklift, or manhandled by operators into various scrap hoppers for removal. Each time an operator replaces a scrap ball from a winder, they?re at risk from cuts and back injury, not to mention burns from hot tube scarf.

Before turning to the slitter line scrap choppers, the plant faced a less than satisfactory situation using a scrap winder for slitter line edge trim. ?From a safety standpoint, we tried everything from safety guards to guardrails but weren?t satisfied,? notes Fleischmann. ?Scrap winding fast-moving edge trim was considered one of the parts of our operation that needed improvement.?

In the plant?s high-volume slitter line operation, the scrap winder was a bottleneck.?With the scrap winder, edge trim wider than ½ in was too unwieldy to wind,? explains Fleischmann. "Edge trim often broke and had to be re-threaded, causing line stoppage. We often had to take apart the scrap winder to rethread it. Removing scrap balls took time, especially when they unwound.

?Too much of our day was taken up dealing with the edge trim,? adds Fleischmann. ?We needed more productivity out of the line.?

A COMPETITIVE EDGE

Fleischmann turned to Sweed (Gold Hill, OR), a manufacturer of linear material reduction equipment. The company custom-installed a pair of scrap choppers, along with a conveyor, to chop and transport waste edge trim on the fly. Coordinated by a frequency drive that makes automatic adjustments, a stand accommodates material width while the chopper and conveyor match slitter line speed.

Chopped scrap goes directly into a storage hopper inside the building. This saves the operator a ten-minute trip outside several times a day. Previously, the operator had to deposit bulky scrap balls in a 40 ft container outside.

Because the chopped scrap is more highly valued than unprocessed scrap, scrap dealers pay more for it. ?We?re getting an extra $10 per ton for our scrap since it?s in a more valuable scrap category,? remarks Fleischmann. ?The extra income, which is more than $10,000 per year, is an untapped resource that?s going straight to our bottom line.?

According to Fleischmann, the plant also saves about 200 hours of labor annually with the slitter line scrap choppers. The operator feeds the start of the trim into a chopper and the scrap handling is virtually automatic. This allows the slitting operation to safely work at full speed without scrap-related delays or production bottlenecks.

With the system, the slitter line can handle edge trim up to 3 in, versus ½ in previously. This provides more flexibility in meeting customer demands. ?The scrap choppers are helping us keep customers and provide a safer working environment for our workers,? states Fleischmann. ?They?ve really helped improve our slitter process and will achieve ROI within a year.?

Wayne Dalton, a leader in the garage door industry, is also using slitter line scrap choppers to competitive advantage. Previously, on a commercial door slitter line that processed metal coils in Portland, OR, edge trim scrap had to be manually folded and tossed in a hopper. Changing coils and set up was also necessary when running narrow doors on the slitter line.

"The operator wore butcher gloves to avoid getting cut on the scrap, and the process was time consuming, ? says Mike Pfeiffer, a supervisor in Wayne Dalton?s tool and die shop, which is located in Portland. To increase safety and streamline production at its Portland site, Wayne Dalton also turned to Sweed, which custom-installed a pair of scrap choppers and a conveyor that fit the site?s existing equipment layout.

?We?re safely getting about 7 percent more production uptime now without manually handling the edge trim,? says Pfeiffer. ?No one misses handling the sharp scrap.? He estimates saving at least 100 hours of labor a year in scrap handling. The system also enables a single coil size to be used for both standard and narrower doors, eliminating the cost of keeping an extra coil size in inventory.

?ROI could be as fast as six months for the slitter line scrap choppers,? notes Pfeiffer. ?They?re safer, trouble free, and a real competitive edge.?

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Del Williams is a technical writer based in Torrance, CA.