issue: June 2003 APPLIANCE Magazine Metalworking Report Taking on New Forms	Share  Printable format  Email this Article  Search
by Lisa Bonnema, Managing Editor Recent trends such as pre-painted metal, servoforming, and reduced inventory are changing the face of appliance metalworking, forcing suppliers to develop technologies that not only cater to these demands, but that do it better, cheaper, and faster than ever before.

As is always the case, most production trends focus on saving the appliance OEM money. To some appliance producers that means outsourcing operations such as metalworking, while to others it means purchasing high-tech automation. Whatever the approach, the goal is to reduce any extraneous operations.

"Through the elimination of in-house processing, customers are finding they are receiving substantial savings and better products," notes John Rapkoch, director of Metallurgical Services for Ryerson Tull (Chicago, IL, U.S.). "For instance, the conversion to pre-painted [steel] can not only save the customer money, but may also improve the overall quality of the product. The quality of the paint used is a much higher grade than in-house operations, and customers can expect a cleaner steel and better pre-treatments when not undertaking the process themselves."

Robert A. Southwell, regional sales manager and market specialist for AIDA Dayton Technologies Corp. (Dayton, OH, U.S.) agrees. "Appliance producers are continuously working toward elimination of secondary operations. This includes working more and more with pre-painted stock and other highly cosmetic-sensitive materials such as brushed and polished stainless steel," he says.

Another trend, according to Mr. Southwell, is the increase of operations such as in-die tapping and hardware insertion in the die. "This trend has led to the use of larger dies and more transfer die operations," he explains.

Mr. Southwell says that these growing requirements have led AIDA in its development of its NST straightside press, which has preloaded roller guides that are lube-free and, thereby, eliminate the potential for oil contamination of the part. The NST is also designed with larger bed areas and window openings to accommodate larger dies, wider material, easy removal of the finished part, and easy inclusion of an in-press transfer system.

Reduced inventory has also played a role in advancing metalworking technologies, making zero changeover almost a requirement, says Ricky Hansson, senior manager of Project Management for Salvagnini America, Inc. (Hamilton, OH, U.S.). "Instead of turning your inventory around maybe once every 14 days, you may need to turn it around once a day," he explains.

To allow for quick changeover, Salvagnini’s bending machines have a tool changing system called ALA (automatic length adjustment) that automatically adjusts the bending length of the tool. "If you’re bending four sides of a refrigerator door, for instance, you must have the right length of the tool, obviously, for the short side and the long side. And, if we have inward bends that are going inward on the panel, we also need to contract this segment so we are able to get off the produced parts and are not ‘locked inside’ a produced part," Mr. Hansson explains.

Responding to this trend, Finn-Power International (Schaumburg, IL, U.S.) recently introduced its E5 Work Center, a 6-axes fabricating system that features a servomotor-driven punch mechanism. According to the supplier, the punching process combines electrical servo technology and mechanical power transmission, enabling strict punch control. A servomotor, together with a lead screw, move a roll that in turn moves the ram by means of a guiding surface.

The E5 can also be equipped with an optional upforming mechanism driven by an electrical servomotor. The mechanism is said to provide an optimal way of forming—by lifting the die upwards.

Globally-Driven Technology

The global marketplace is another factor driving appliance metalworking. "Introduction from overseas competition of the servo (either electric or hydraulic) actuated bending technologies [has allowed] for a quick-change changeover from one radius to another," says Dave Peters, appliance applications manager for Atlas Technologies, Inc. (Fenton, MI, U.S). "Atlas has focused much of our research and development on the servo-hydraulic/adjustable bending technologies. This technology can also incorporate electronic checking of the formed flange.

Adjustments to the bend angle can be made immediately not only the current part, but also for subsequent parts. This feature is helpful when running both stainless and pre-painted CRS on the same machine, since the material characteristics will vary not only between the materials, but also between different coils or stacks of pre-cut blanks."

Most equipment producers agree that servoforming technology is certainly one of the most recent revolutions in metalworking. This was perhaps most evident at the Metalform 2003 show held in June, where several suppliers released new servo-driven systems.

Komatsu America Industries LLC (Wood Dale, IL, U.S.) released the H2F an H1F a.c. servo driven mechanical straight side and gap presses. According to the company, the machines’ slide accuracy is in microns with complete control of slide stroke, speed, dwell, and energy.

"Basically we’ve taken out everything related to a standared flywheel-driven mechanical press, and drive these presses with a high-torque knuckle motion linkage driven by ‘standard’ servo motors," explains Steve Schroder, vice president of Sales and Marketing. "And with that come huge efficiencies and flexibility."

AIDA Dayton introduced a similar concept at the recent Metalform show called ServoProâ„¢. "With ServoPro technology, a high-torque/low RPM servo-motor directly drives the driveshaft of the mechanical press, eliminating the standard main motor, flywheel, clutch arrangement," says Mr. Southwell.

The technology, he says, was developed specifically for the metalforming industry to deliver the full tonnage and torque ratings of a standard mechanical press in addition to delivering full-rated energy at low speeds. "ServoPro allows the user to program the stroke of the press for the specific application at hand. This includes the stroke length, slowing down or pausing the stroke to assist in drawing/forming applications, reducing the velocity in blanking, hardware insertion, or in-die tapping applications, as well as dwelling under load for coining applications. The stroke can also be modified to significantly increase cycle time for automation and, thereby, increase production rates."

As this trend of "servoforming" continues, Mr. Schroder of Komatsu believes that it will eventually override current metalforming technologies. "There is no question in anyone’s minds where we are at," he says. "This will replace all existing mechanical presses with typical motor drives and gearing for generating energy and tonnage. This will be revolutionary."