Astenjohnson, Inc.

Brady S Patterson

Marc P Despault

Graham Jackson

A press felt for use in the press section of a papermaking machine is provided. The press felt includes a base fabric layer and at least one layer of a staple fiber batt material connected thereto. The press felt has a paper side surface (PS) which when in operation is in contact with a paper web conveyed thereon and a machine side surface (MS) which contacts various press section components. The base fabric layer includes a regenerated cellulosic component in either or both the MD and CD yarns. Regenerated cellulosic fibers may also be provided in the batt and/or scrims located in the batt to improve dewatering when compared to similarly constructed felts which lack this regenerated cellulosic material.

Press felt with base fabric layer which includes regenerated cellulosic fibers

A press felt for use in the press section of a papermaking machine is provided. The press felt includes a base fabric layer and at least one layer of a staple fiber batt material connected thereto. The staple fiber batt material is includes between 20% to 100% by weight of a regenerated cellulosic staple fiber material, such as rayon, and from 80% to 0% by weight of a polymeric staple fiber, such as nylon. A scrim including regenerated cellulosic material can also be incorporated into the press felt construction, either between two layers of batt material, or between a batt layer and the base fabric. The regenerated cellulosic staple fibers of the batt and/or scrim having a dtex from at least about 1.1 to about 44, and are preferably non-fibrillatable. As a further option, at least a portion of the base fabric includes a regenerated celluliosic material.

Press felt with improved dewatering capability

A press felt for use in the press section of a papermaking machine. The felt is comprised of at least one base fabric to which at least one batt layer is attached by needling or another suitable method. A woven or nonwoven fibrous scrim may be included between the base fabric and the at least one layer of batt material, or between any two or more layers. At least one of the base fabric, the at least one layer of batt material, or the fabric scrim is comprised of polymeric fibers which are blended with fibers whose modulus of elasticity is substantially less than the modulus of elasticity of the polymeric fibers. Press felts manufactured in accordance with the teachings of the invention provide a retarded elastic spring-back in the vertical (or Z) direction of the felt following the mid-nip point in the press section. This retarded elastic spring-back advances the post nip separation position of the felt and the paper web towards the mid-nip point, thus reducing rewetting of the paper sheet. Fibers comprised of regenerated celluosics, such as viscose rayon, have proven effective for use as the low modulus of elasticity component fibers in the press fabrics of the invention.

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Kanata, Canada

Brady S Patterson