Abstract: A transfer roll cover has an inner surface made of conductive and elastic material to fit snugly around and make conductive contact with a transfer roll, and an outer surface made of looped yarns which are attached to the inner surface and have outer looped ends which make light rolling contact with a sheet transported over the transfer roll. The looped yarns are a composite of a cleaning yarn for cleaning particulate contaminants and an antistatic yarn for removing static charges from the transported sheet. In a preferred embodiment, the transfer roll cover has an inner surface made of nylon knitted yarn as a base yarn that holds the cover together and a LYCRA.TM. inlayed yarn which has an elasticity that allows the cover to stretch over and fit snugly onto the transfer roll. As an alternative, a heat-shrinkable polyvinyl acetate (PVA) yarn may be used as the elastic material. The preferred outer surface includes rayon knitted yarn with looped outer ends as the cleaning yarn, and BEKINTEX.TM.

Abstract: An anti-marking covering for use on a printing press transfer cylinder to prevent ink marking of printed sheets is made of a material having a high axial air permeability through the material parallel to its surface and a substantially uniform surface structure free of raised areas. A preferred material is 100% rayon hydroentangled nonwoven fabric subjected to comb-roll microcreped compressive forming of microcreped areas closely spaced about 1/16 inch apart. The preferred fabric has an axial air permeability of about 0.279 cfm. When the material is wrapped tightly onto a press cylinder, the high axial air permeability allows an air layer to be maintained under the printed sheets, and the uniform surface structure is free of high points that might protrude through the air layer and contact the printed sheets. Other fabrics and materials suitable for the anti-marking covering include woven and knitted fabrics, nonwoven fabrics, and open-celled foam.