July 2011 - A rebuild can extend the life of a slitter head for many years - giving companies an updated machine that can provide quality cuts at a lower cost than purchasing brand-new replacement equipment.
"I think everyone is very cost conscious today," says Peter J. Korcusko, a principal at K&S Machinery, Linden, N.J. "If you have the right rebuilder, you can save a lot of money and wind up with a machine that is just as accurate as new."
For a slitter head, refurbishment is a good option because the technology has not changed dramatically over the years as it has for other types of equipment, such as lasers, says Felip Boixareu, CEO of Franklin Stainless, Port Washington, N.Y. Franklin Stainless has been a part of the Barcelona, Spain-based Irestal Group since 2008. "Even if they are very old, if they are well-repaired, they could last for a long time," he says. "I think it's a good opportunity to revamp a slitting head."
Franklin Stainless has four slitting lines that range from 24 inches up to 48 inches. Its products range from 0.01 inch up to 0.125 inch thicknesses and from 1/4 inch up to 60 inches wide in cold-rolled stainless coils or sheets. The company carries stainless alloys 201, 301, 304, 316L, 409 and 430 and serves a range of sectors, including construction, catering, automotive, general fabrication, section rolling, semi-conductors, pharmaceutical and power generation.
The service center has more than 55 years of experience providing products and services to its customers, and the company prides itself on its customer service. "We give very good service, and we are very fast because we are integrated, so we can do all the processes here," says Boixareu, noting the company also has a cut-to-length line for material up to 60 inches wide, a sheet polisher up to 60 inches wide, a 30-inch coil polisher, a deburring line, two shears and a small strip polisher at its facility.
Irestal Group, a global stainless steel service center network, has 33 processing and distribution centers worldwide and a commercial network covering the Spanish, Portuguese, English, French, German and Central and Eastern European markets along with the United States and China.
Slitter head rebuild
Recently K&S Machinery rebuilt Franklin Stainless' 48-inch-wide slitter head, which the company uses to process light-gauge precision coil, because it was not operating with consistent quality. The bearings were beginning to fail, and the slitter head needed a complete refurbishment to bring it up to A-1 condition.
Franklin Stainless' 48-inch slitter head was worn out, which meant the company was seeing a lot of bad cuts and burr, says Korcusko. It was difficult for operators to hold tolerances on slit width, as well. An inspection of the line by a K&S service engineer revealed Franklin Stainless would either have to replace it or rebuild it from the ground up to improve the cut quality.
"In the proposal from K&S Machinery, we saw an opportunity to improve our quality and run our equipment more efficiently," says Boixareu. "We had to do something."
K&S Machinery spent roughly four weeks in late 2009 rebuilding the slitter head for Franklin Stainless. The company has been designing and manufacturing new coil-processing equipment along with rebuilding slitter heads for more than 30 years.
When rebuilding a slitter head, there's a detailed process to disassemble, clean, re-machine and re-fit most of the components, says Korcusko. "We may use the old arbors, but we regrind them undersize and chrome-plate them oversize then finish-grind them to the new tolerances. Then we replace all the bearings and seals with precision bearings, which are usually a higher tolerance grade than what would originally be in the machine so it will be accurate enough to work with shimless tooling," he says. "We are actually re-manufacturing that machine."
A well-maintained new machine likely can operate for approximately 10 to 15 years before requiring a major rebuild, but the length of time depends on the level of use and conditions at the facility, says Korcusko. "If they are running three shifts a day, five days a week, it might be closer to 10 years. If they are running less, it probably would be close to 15," he says.
Prior to the rebuild project, Franklin Stainless operators worked with shims manually to achieve different thicknesses, says Boixareu. "If you are working manually with shims, you can adjust them even if the arbors are no good," he says. "Now all the new tooling that people are buying is shimless tooling, so they get better precision, but you can not compensate if there is a problem with the arbor, so that means the slitting head has to be perfect," he says.
At Franklin Stainless, the existing condition of the equipment was not accurate enough to use shimless tooling. "You would never put shimless tooling on a worn-out head because shimless tooling is very accurate and the head would need to be rebuilt to improve its accuracy in order to benefit from that tooling," says Korcusko.
Without the need to adjust shims manually, operator training time has been reduced greatly, says Boixareu. Previously, it could take an operator up to six months to learn how to operate the slitting line. After the rebuild, an operator can learn how to use the equipment in roughly one month. "It has become much easier. You don't need as much expertise," he says. Operators work with a computer program that enables them to input the number of cuts they want and it tells them the required setup.
Operator training after a rebuild project often is easier because the revamped machine is very tight and accurate and employees no longer have to deal with operational quirks. "When a machine is worn out and sloppy, your operator has to deal with the machine and its inaccuracies," says Korcusko. "Once a machine is rebuilt and it's tight and accurate, there's no need to deal with those issues. You just make an accurate tooling setup and run the job."
Franklin Stainless and K&S Machinery have worked together for several years, first with K&S's sister company Joco Precision to regrind Franklin Stainless" slitting knives and rubber stripping rings and most recently with the slitter head rebuild project, notes Korcusko.
"We know them," says Boixareu. "Every time we have worked with them, they have been very reliable." MM