Creping process on a felt with prolonged production cycle and improved drying

摘要

A method of manufacturing an absorbent cellulosic sheet (44) creped on a felt, comprising (a) compacting a paper pulp suspension to form a continuous cellulosic sheet and simultaneously applying the continuous sheet to a heated rotating support cylinder (60) ; (b) creping on a felt the continuous sheet from the surface (64) of the heated support cylinder, at a consistency of about 30% to about 60%, using a structured creping felt (18), the creping stage being produced under pressure on a creping tangency line (76) defined between the surface (64) of the support cylinder and the creping felt (18), in which the felt travels at a second speed slower than the speed of the surface (64) of said support cylinder, the felt structure being selected, parameters of the tangency line, delta velocity and consistency of the continuous sheet so that the continuous sheet is creped from the surface (64) of the support cylinder and it is transferred to the creping felt (18); (c) providing a resinous adhesive coating composition to a surface (86) of a heated dryer cylinder (80) of a Yankee dryer (20) so that a resinous adhesive coating is formed, also having the Yankee dryer (20 ) a hood (88) of the dryer with a characteristic operating temperature limit; (d) transfer the continuous sheet from the creping felt (18) to the surface (86) of the heated dryer cylinder (80) of the Yankee dryer (20) so that the continuous sheet adheres to the dryer cylinder (80) by the resinous adhesive coating; (e) drying the continuous sheet on the surface of the dryer cylinder (80); (f) separating the dry continuous sheet from the surface (86) of the drying cylinder; characterized by (g) periodically separating at least a portion of the resin adhesive coating from the surface (86) of the drying cylinder when the characteristic operating limit of the drying hood temperature (88) of the Yankee dryer (20) is reached ; wherein the composition of the pulp suspension and resinous adhesive coating is selected and heating of the support cylinder (60) and the drying cylinder (80) is controlled so that a production interval between successive coating separations of The adhesive of the drying cylinder (80) has a duration of at least 4 hours and during which production interval a predetermined target speed of dry leaf production is satisfied.