Medical Device Link.

TECHNOLOGY NEWS: METAL FABRICATION

New grinding technology can perform continuous guidewire grinding, oxide removal from nickel-titanium wire, and braided catheter processing.

A recently introduced system can take a spool of raw material weighing as much as 30 lb, grind the material down to 0.010 in. diam, and feed the resulting wire to a second spool while rotating at 2000 rpm. Developed by Royal Master Grinders (Oakland, NJ, USA; www.royalmaster.com), the spool-to-spool grinder eliminates several steps that typically are done manually on conventional guidewire-grinding systems.

“Normally, wires are cut to length, grouped in lot batches, and fed to the grinder one at a time,” says company vice president John Memmelaar Jr. After that, the wires are taken to a coating station and possibly somewhere else for more postprocessing, he adds. “The spool-to-spool system grinds continuous guidewires and can eliminate the need for all of those steps.” The coating process can be integrated into the automated spool-to-spool system, if desired.

In addition to grinding continuous profiles, the system can be used to grind material to a consistent diameter. Tolerance capabilities are ±1 µm. After the material leaves the grinder, a laser gauge reads the diameter and, if necessary, feeds back to the machine diametrical size compensation data. The gauge also calculates statistical process control data.

The system’s robust design can accommodate 14-in.-diam spools measuring 4 in. wide. A quick-change feature enables seamless changeovers. Equipped with a Heidenhain encoder, the grinder tracks wire output by length and displays the results on a screen. Grinding jobs can be programmed by means of an intuitive touch screen.

Oxide removal from nickel-titanium wire, braided catheter grinding, and the automated grinding of marker bands are among other applications of the system. It is available as a stand-alone unit; alternatively, the manufacturer can integrate the centreless grinder into customers’ systems.