Transfer roll with ceramic-fluorocarbon coating containing cylindrical ink holes with round, beveled entrances

摘要

An ink transfer roll composed of a steel base covered by a ceramic- fluorocarbon outer layer into which are formed generally cylindrically shaped ink holes having a hemispherical bottom, a generally cylindrical intermediate portion and a rounded, beveled entryway. The ink holes are produced using a pulsed high energy source, such as a pulsed laser. An intermediate layer of corrosion resistant metal and fluorocarbon may be deposited between the steel base and the outer layer of ceramic- fluorocarbon material. Adhesion of the ceramic-fluorocarbon layer to the transfer roll is improved if corrosion resistant metal- fluorocarbon material is contained in the ceramic-fluorocarbon layer such that the quantity of corrosion resistant metal-fluorocarbon material in the ceramic-fluorocarbon layer gradually decreases in the direction away from the intermediate layer-outer layer interface, the quantity of corrosion resistant metal-fluorocarbon material in said outer layer being greatest at said interface.