Update on the Influence of Roll Covers in Film Transfer Size Presses/Coaters, 1998 Metered Size Press Forum II Proceedings

The rapid growth in film transfer size press designs has created a wider range of uses in surface sizing and coating applications. In addition to extending conventional sizing beyond the speed limits of puddle presses, film transfer size presses are being used for pigmented sizing and higher solids coating applications. This has also resulted in a broader potential for grade development. The film transfer size presses have increased the demand for elastomeric roll covers with greater wear resistance and improved film splitting characteristics. This paper examines the various roll cover types used in blade metering and rod metering size presses, for starch sizing and coating applications. A number of important cover properties are reviewed, to include cover hardnesses and the resultant nip width relationships, wear resistance, thermal expansion, swelling, vibration dampening, and surface characteristics. Included are not only rubber elastomeric covers but also considerations for use of polyurethane, resin composite, and ceramic covers in selected applications. This paper is an update of the information published for the inaugural Metered Size Press Forum held in Nashville, TN, in 1996.