Abstract: Pressure rolls useful in printing, embossing, coating, calendering, conveying, and fixing images to substrates. The pressure rolls comprise a cylindrical core provided with an array of axial slots, a heating element disposed in the slots, and a shell around the core. The pressure rolls may be employed in apparatus for fixing a toner material image pattern on a substrate such as a paper sheet. The pressure contact between the sheet and the pressure rolls is established by a hydrostatic assembly which may be pre-set.

Abstract: Pressure rolls useful in printing, embossing, coating, calendering, conveying, and fixing images to substrates. The pressure rolls are prepared by cryogenically cooling a core component to about the temperature of liquid nitrogen, removing the core component therefrom and inserting a sleeve component over the core component. The composite roll is allowed to warm to ambient temperature whereby during warming the core component thermally expands and secures the sleeve component to the core component. Also disclosed is apparatus and a method for fixing a toner material image pattern on a substrate such as a paper sheet.