Uncoiling industry challenges
- July 30, 2002
Addressing the need for faster coil changing times, better quality materials
by Mary Scianna
At its best, coil handling is a challenge for fabricators, whether they’re using coils with roll forming machines,
stamping presses or cutting it for specific lengths for use on laser cutting machines.
The shear weight and size of some coils—which can weigh as much as 30 tonnes (66,000 lb) with widths of 2000 mm (78 in.), depending the on application—pose a risk to workers handling them and often take up valuable production floor space.
Add to this the even bigger challenge of operating cost-effectively in a competitive environment and you begin to understand the issues driving fabricators handling coils—the need for faster and more efficient coil changing times, and the need for high quality, flat coils, which in turn is becoming more of a challenge with the growing use of high tensile lighter weight steels in industry sectors such as automotive.
Shop Metalworking Technology spoke to suppliers about the challenges fabricators face and about what they can do to overcome them.
“We have different types of customers using coils and the final use for each is different,” says Franck Hirschmann, head of business segment for ARKU, a coil handling equipment builder based in Baden Baden, Germany, and distributed in Canada by Fabricating Machinery Solutions (FMS), Mississauga, ON.
“So a customer using coils in front of a roll forming machine faces different issues than a fabricator using it in front of a stamping press or a customer cutting coils for specific lengths. However, they do have several things in common, such as the need for very short coil changing times.”
To improve coil change times, supplier says fabricators should consider some of the newer coil handling systems and equipment on the market. For example, for coil preparation for roll forming applications, ARKU’s “Twin Shuttle” system is able to change coil in as little as 90 seconds, says Hirschmann. The company recently installed a double carousel decoiler, TwinShuttle threading unit and strip andwelding system in a shop where the operator is only responsible for loading the unit. “Standstill times of 90 seconds can be achieved.”
ARKU builds parts leveling, cut-to-length and punching lines, press feeding lines and coil preparation lines for roll formers.
In stamping applications, a similar single end decoiler equipped with automation “can cut coil changing time to less than five minutes,”
The most important advice that Jeff Norman, vice president of Mecon Industries Ltd., Scarborough, ON, can offer fabricators is to look at smart ways to cut coil storage and coil handling costs.
Mecon is a Canadian manufacturer of coil handling equipment for the metal stamping industry—uncoilers, straighteners, feeds, cradle straighteners, feeder straighteners, combination cradle straightener feeder, and zigzag feeds, as well cut-to-length or flexible manufacturing lines.
“On the shop floor, savings can be found with reduced handling, faster process speeds, and integrating processes into one system,” says Norman. “There are hundreds of things that can help, but one important thing to remember is that you should order materials that are the right size for the job. You don’t want to have parts of coils remaining that need to be stored. With proper production planning for order sizes, you can eliminate the added cost of storing coil or waste coil.”
While this makes sense, Norman says many fabricators will purchase large coils “because they think they’re getting a deal, but there are hidden costs such as material handling, operator time to load and unload coils, storage and disposing of waste coils.”
As the manufacturing industry continues to ramp up, a growing issue is access to high quality steel. When demand is high and material supply is tight, sometimes there is no guarantee that you’ll receive the flat coil that you need for your fabricating operation.
It’s one reason why there is growing use of precision levelers, says Hirschmann.
“This type of equipment, machines equipped with maybe 17 or 21 levelling rollers, will improve the flatness of the material before it has to run through a press or roll former.”
An added challenge, particularly in the automotive market, is handling coils of high tensile steels, which are being used more to reduce the weight of vehicles.
“The higher tensile steels are more difficult to level and remove the stress, and you need to use specially designed levelers for this type of material,” says Hirschmann.
A big issue many small and medium sized fabricators face is limited floor space. Handling coils in such spaces is an ongoing issue and one way that suppliers have addressed this is by developing combination systems where several processes are combined into one machine, says Norman. Coil stock handling systems combine uncoiling, straightening and feeding functions into one combination unit. An example is a pull-through straightener that combines straightening and feeding functions into a single unit and removes the need for a looping pit.
Norman says double operation units such as feeder straightener combinations are more accurate and faster today, in part, due to high performance motors now available for these units.
Another example comes fromCHS Automation, Roseville, MI, a coil handling and press feeding equipment builder.
Its Space Save coil system consists of a motorized coil reel with hydraulic expansion and a servo feed straightener. The company customized the system for a tool and die company that needed a coil handling system that could accommodate 20,000 lb (9000 kg), 24-in. wide (609 mm) reels of .200 in. (5.08 mm) thick. The reel is equipped with a travelling load car, clockspring guard and featured the company’s space saver loop control. The servo feed straightener has five in. (127 mm) feed rolls, a seven roll “Pull-Thru” straightener with pinch rolls, and an attached peeler-threader hold-down station. SMT