Ultrasonically smoothing a magnetic layer on a web

Abstract

A layer of magnetic particles in a resin binder on a carrier is smoothed by effecting relative movement between the carrier and a vibrating ultrasonic horn having a surface in contact with the layer. The carrier can be a web of fully coated magnetic tape or of striped motion picture film; and can be passed over a solid metal anvil or can be drawn tautly over the horn without requiring an anvil. The horn can be perpendicular to the carrier for hammering the layer; or it can be essentially parallel to the surface of the carrier, and either transversely or longitudinally extending, for scrubbing the layer smooth. The smoothing procedure can also be performed while the carrier is immersed in a solvent for removing dirt particles. Advantageously the procedure is performed when the binder is fresh and less than fully cured; but it can also be performed by heating a resin binder to the desired plasticity before the smoothing operation.

Dependencies are inferred from the claim text.