Page 15 - MetalForming April 2010

“Customers in this market represent the most innovative and active devel- opers of new products in the world,” says Carl Savage, vice president of sales andmarketing.“Andtheyrequiretheir suppliers to be the same—innovative and creative, and very diversified.”
Rolling Tube in a Prog Die
Since 1986 when the firm stamped its first ligation clip for a medical OEM, Micro Medical quickly found that the catalyst for allowing it to grow its share of medical-device market would hinge on its ability to perform inhouse as many value-added and secondary processes as possible. The results speak for themselves—it now supplies parts and assemblies to nearly every med- ical-device company in the United States. And, since 2005 its medical- device business has more than dou- bled, now representing 60 percent of Micro Stamping’s annual sales.
Among its claims to fame has been the development of a proprietary pro- gressive-die process to manufacture a rolled tube to replace traditional drawn tubing. Developed about 10 years ago for the manufacture of endoscopic instruments, the progressive-die tube- stamping process reduces part costs by as much as 75 percent, partly because
features such as slots and holes can be added in the die rather than as costly secondary processes.
“We can stamp tube from 3- to 10- mm dia.,” says director of technical services Frank Jankoski, “with wall thickness from 0.010 to 0.030 in., and perform operations such as lancing, coining and embossing.”
The process was recently enhanced as a testament to the firm’s dedication to continuous improvement—a must in the medical-supply game—by using laser welding to seal the seam in the rolled tubing.
“Up until a few years ago, we used to seal the joint by covering the tube with a piece of shrink tubing or by spraying on a seal coating,” adds Jankoski. “But that added 0.010 to the tube OD.”
Now the firm can laser-weld the seams, having optimized an automated welding process to fine-tune laser power, beam-spot size and welding speed to minimize tube distortion. It also integrated straightening and leak- testing stations into the process.
“We were early adopters of laser technology for manufacturing,” says Savage, harking back to 1994 when the firm developed laser-assisted metal- forming. “We developed that process for manufacture of titanium ligating
clips, where the wire used to form the clip must be bent back on itself on a 0.014-in. arbor. By firing a laser into the die, timed with the action of the press, we laser-zone anneal the material to avoid tears and cracks in the clip.”
Doing More with Lasers
Yet one more example of Micro Stamping’s ongoing development of laser expertise is the recent redesign of a relatively large stamped part (6 to 12 in. by 3 in., of 0.060- to 0.070-in. stain- less steel) into a fabricated part. “Burrs and scrap rate led the customer to seek another solution,” says Jankoski. “We looked at the complex-shaped part and proposed, at a very large capital invest- ment to us, to laser-cut the part. Scrap rate was reduced by 65 percent and sec- ondary edge finishing eliminated, help- ing to justify our machinery investment as well as making the customer happy.”
“We take reinvesting in this business very seriously,” adds director of mar- keting Al Carolonza. “Even in this trou- bling economy, we continue to invest 10 to 14 percent of our gross annual sales back into the company, whether it be new capital equipment (such as the Trumpf 5000-W laser-cutting machine referenced above) or into our research and development efforts.”
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METALFORMING / APRIL 2010 13
Micro Stamping recently invested in a new high-speed Bruderer press with an integrated inline inspection system (shown here). The system inspects lead-frame stampings at 1200 strokes/min., 12-out
per stroke.