Huntington, IN--The voice coil is critical to an audio speaker's performance; coil winding efficiency is critical to production. At Pyle Industries, home of "Made in the U.S.A." sound systems for cars, a problem with sticky arbors slowed voice coil production. Solution? A "synergistic" coating from General Magnaplate, Linden, NJ.

Pyle's coil-manufacturing operation works like this: A polyimide film, measuring 3 or 5 mils thick, wraps around a 6061-T6 aluminum arbor, which ranges in size from .50 to 3 inches in diameter. Insulated magnet wire, coated with a proprietary adhesive system, is then wound wet onto the arbor.

After alignment and application of reinforcing tape, the coils bake for 40 minutes at about 400F. Lead wires are chemically stripped and solder tinned, coils are removed from the arbors, and the arbors recycle back to the beginning of the wet-winding process.

Problem: Following baking, Pyle's workers discovered that the coils adhered to the arbors. "At first we could do the separationby hand," explains Production Manager Brian Miller, "but eventually we found it necessary to set up a pneumatic cylinder with a tooling arrangement that allowed us to step on a pedal and physically drive the arbor out of the coil."

Repeated recycling and the buildup of adhesive residues, however, required more and more separation force. The procedure resulted in damaged arbors. Other attempts to solve the problem also proved unsuccessful.

Solution: Miller found the specialized surface enhancement coating applied by General Magnaplate. Named Lectrofluor(R) 615, the elastomeric treatment process involves applying proprietary blends of polymers to the cleaned surface of the aluminum arbors. Polymer selection depends on several factors: End-use application of the part, its base metal, the kind of hostile environment it will encounter, and the permitted coating buildup.

The "synergistic" coating results in a surface superior in performance to the base metal and to the individual components of the surface enhancement.

"With the Lectrofluor 615-treated arbors," says Miller, "the coils just slide off. By eliminating the pneumatic ramming process, Pyle Industries expects to reduce arbor damage by 75%, and at least double the number of coils they can separate from arbors in a given time.

Additional details...Contact General Magnaplate Corp., 1331 Route 1, Linden, NJ 07036, (908) 862-6200.