Above: A setup man places ASKO Inc. knives and spacers onto the slitter head based on the widths a customer wants.

TOLL PROCESSING

New slitter learns and corrects setups for AHSS customers

April 2015 - The metals industry works assiduously to help customers lightweight finished products from cars and trucks to turbines and airplanes. What processors must tackle is how best to slice, dice, flatten and otherwise manipulate these tough materials in an efficient and cost-effective manner. 

A company that prides itself on handling high-strength steels (HSS) since they were first produced in the 1970s has now installed a “monster” of a slitter in East Chicago, Indiana, that cuts through advanced high-strength steels (AHSS) like butter.

Toledo-based Heidtman Steel Products chose Alcos Machinery Inc., Newmarket, Ontario, to install the line. The slitter’s biggest fan is Troy Swaney, operations manager of the East Chicago, Indiana, plant. “This machine is built to process 200,000 tons per year but I could see 300,000 coming out of it. The slitter is a monster.”

Customers for the slit coils include original equipment manufacturers, steel producers, other service centers, and a wide array of traditional service center customers.

Installation began last summer but faced delays as the company first had to jackhammer through 8 feet of concrete to build the foundations and looping pit. There were several layers of concrete from previous operations. “One floor is from the 1930s. Another floor sits on top of that floor. Underneath all that is the post-Ice Age beach and significant amounts of ground water,” Swaney says, adding, “ Our pit is 40 feet deep and we had to dewater and dry out the excavation prior to forming and placing the concrete.”

The 120,000-square-foot, 800-foot-long facility has an illustrious and intriguing 80-year history that includes building Army tanks in the 1940s and hosting illicit activities, Swaney says. 

“They tell stories about this building. In the heyday there were crazy things happening: Loan sharking, prostitution, gambling. Demolition crews took an old crane down and were throwing away the electrical boxes when money started flying out. They found eight grand. Needless to say, as six more cranes were scrapped, they were well checked for cash.”

Plant upgrades

Heidtman installed four new Zenar Corp. cranes. “They are all remote controlled and have motorized rotating crane hooks in order to keep the operators from needing to manually turn coils. We have scales on every one of them so there is no wasted movement to pick it up from a railcar or truck in the receiving bays and then put it on a scale. We also have two new forklifts,” says Scott Carter, Heidtman’s vice president of operations.

The toll processor has an on-site laboratory, the key piece of which is a machine that performs yield, tensile, elongation (Y, T & E) and hardness testing. “We clip a piece from every coil and the machine literally rips it apart.”

A transfer car moves coils down a short stretch of rail from receiving or inventory bays to the slitter. At the entry end of the slitter, Alcos provided a straightener as part of the feed system with the ability to replace it with a corrective leveler if required. “The reason the passline is so tall is that it can run an 84-inch OD coil. I can put an 80,000-pound coil on it,” Swaney says. 

A coil that size can only come from a mill and be delivered by rail; the facility has a siding that leads under the roof. “We can fit three railcars inside at once.” The nearest mill customer is ArcelorMittal at Indiana Harbor Works, about 2 miles away. 

Next stop on the slitting line is the setup area, with tool cabinets and slitter heads on rolling carts. “Depending on the thickness of the steel, they’ll roll into here, pull out the knives and spacers they need,” Swaney says. Heidtman has three heads: Two are 78 inches wide and one is 60 inches wide. 

“My plan is to use the 60-inch head for the AHSS to reduce any deflection in the arbor. This thing is a beast,” he continues, noting that the motors for the line were built to cut 3⁄8-inch-thick steel so that when it cuts gauges up to 1⁄4-inch, the slitter “just eats that steel up.”

Tooling memory

The software that came with the ASKO Inc. knife kit tells the setup man exactly what tooling to put on “so there is no doing it in your head or on a scrap of paper and potentially messing it up,” says Swaney. “It’s accurate every single time. Based on our experience, we will input clearance height, and it will give us the setup: use two of these knives three of these spacers,” for example. 

“The program also learns. Let’s say we put in the width as 10 inches but the cut ends up being 9.99. We put that result into the system along with the characteristics of the steel, the thickness, the hardness and the Y, T & E so the next time I want to run 10-inch widths, the machine will tell me, no, you want to make it 10.01 inches.

“It learns and retains the knowledge better than the old black magic that operators once used to make the strip widths come out right,” he says. “With someone who is new on a slitter, that ability is priceless.” And the variances will be minuscule. 

The software will memorize setups, too, so if the same customer wants the same slitting job week after week, you just push a button. “We download the job as a number and customer name and it comes back up again as the exact same setup. However, if you found that material ran a couple thousandths over or under, you can still tweak it to get the accuracy.”

Two scrap choppers take off the edge trimmings, which are moved by conveyor and separated—cold-rolled and coated materials go in different recycling bins.

The slitter uses rugged AC drives, rather than DC. “The braking system is not what you would typically find on a slitter,” says Swaney. “They energize the motors for the braking system, which creates the drag for your tension.”

Two cassettes are available for shape correction, a light-gauge set and a heavy-gauge set. “Those can also be used to add tension when we run AHSS material. Our drag rolls create nice, tight wraps,” Swaney says.

Heidtman put X-ray gauges in line to constantly measure the thickness of the strip. If the material comes out of spec, red lights flash on the screen and identify where any out-of-gauge material is located. 

Recoiling, packaging

On the exit end, an in-line turret recoiler allows Heidtman to coil each slit strip simultaneously and rotate in a second mandrel, which means the line doesn’t have to be stopped for relatively long periods while banding those mults in line.

With all other slitters, says Swaney, “you stop the line until you get the finished slit mults banded, which can take over 20 minutes depending on the setup. That’s 40 percent of your total coil run time. With the second recoiler rotated in line, that brings it down to 5 percent of run time. That is major. It means we can process three coils an hour. That is fast.”

The packaging operation has an exit coil cart with an extra safety feature. “It has an arm that comes down and holds your cuts. So you have two mechanical arms but also a hydraulic arm over the top so as you are moving it, it doesn’t shake and fall,” says Swaney.

A turntable rotates 90 degrees to put coils on a four-arm turnstile to get ready for banding. The banding line from Pomacon Inc. is “much safer and quicker than others,” he says. “Coils are not pushed off hydraulically. They are picked up individually and taken off. We have cameras on there to make sure we are taking off one cut at a time,” so two coils don’t stick together or have their tails interleaving. The system prevents damage to the material and injury to employees.

Implementation

Heidtman chose East Chicago for this new line because it is centrally located to customers in a 200- to 250-mile radius that takes in northern Indiana, western Michigan, northern Illinois, eastern Iowa and southwestern Wisconsin, Marketing Vice President Mike Kruse says. 

“We can hit that geography more effectively for our existing customer base in many of those areas as opposed to shipping from Granite City [Illinois] or Butler [Indiana]. But the main thing we want to do with the monster slitter is attack those markets that use AHSS,” says Kruse.

Commissioning of the slitter began in December. “There is a learning curve but we are down to the little things now,” Swaney says. 

Carter concurs. “When we are at 90 percent to full production on one shift; then I anticipate we will move to two shifts probably within three months.” MM