Page 13 - MetalForming May 2010

Overhead shelf-mounted robots along B line transfer tub-bottom stampings to keep the front area of the press clear to accommodate die changes.
“The fact that we apply the lube inhouse,” says Hipsher, “creates a chal- lenge for us. Rather than having the lube applied at a service center on a long line that allows the lube to cure before blanking and stacking, our rela- tively short line limits the curing time for the lubricant. This means that the lube has to finish curing in the stack (you can actually feel the heat coming from the stacks as the lube cures). This can cause the blanks to stick together, more so in the humid summer months.”
Blank adhesion from curing dry lube once caused headaches for the plant’s press-line operators, until ABB’s press- automation team took on the new automation project for Hipsher and his group. To ease robotic destacking at the front of the press lines, ABB
tub wrappers and includes a conveying line with a pick-and-place robot to automate parts cleaning. Press capacity ranges from 200 to 600 tons. B and D lines hit the production floor in mid- 2008; A line was delivered in February 2010 and was being installed during my visit to the plant in mid-March, with a scheduled startup date of April 10.
The plant’s robotic supplier of choice: ABB Inc.’s press-automation systems group, in Brampton, Ontario, Canada. ABB also integrated new blank- destacking technology and developed custom vacuum-cup-style end-of-arm tooling to handle the various blanks, including the double-wide blank used to stamp the tops two-out. Several of the press-to-press transfer robots on A and B lines (model IRB 6650S robots, 3.5-m reach, 125-kg payload capacity) mount overhead on shelves, keeping the front of each press clear
to facilitate die-cart access for simplified die changes. Destacking and unloading robots, as well as inter-press robots on D line, are floor-mounted IRB 6640 models—3.2- m reach, 130-kg load capacity. Accompanying the move to robotics was an upgrade of
all press controls to new OmniLink 5000 press and automation controls, with Omni-link II oper-
ator terminals, from
www.metalformingmagazine.com
METALFORMING / MAY 2010 11
Link Systems.
Inhouse Dry-Lube Application a Sticking Point
Stainless steel comes in the door in coils weighing as much as 20,000 lb, and route through the plant’s shear line, complete with straightening and leveling operations and the application of a dry lubricant—Chemform from PPG. The line then cuts and stacks blanks.
End of line B, where an operator stacks completed tub bottoms and sends them on their way to the clinch-seaming machine for assembly to the tub wrapper. Seaming requires a very thin and tightly toleranced flange around the perimeter of the part — the accuracy and repeatability of the press-loading robots ensures the precision of this flange dimension to avoid a problem at the seaming line, where one misstep means scrapping out an entire tub.