Patent ID: 6187140
Filing Date: 2001-02-13
Classification: B31F,D21H

Abstract:
A method of increasing the wet strength of a creped sheet, the method comprising:providing a sheet comprising cellulosic fibers, which sheet has a first side and a second side;applying a low temperature-curing latex adhesive binder composition to the first side of the sheet in a fine, spaced-apart pattern occupying from about 20 to about 50 percent of the surface area of the sheet;adhering the first side of the sheet to a creping surface; andcreping the sheet from the creping surface; wherein the sheet has a basis weight of from about 40 to about 100 grams per square meter;the low temperature-curing latex adhesive binder composition is adapted to adhere the sheet to the creping surface and comprises a functional group-containing latex, a functional group-reactive crosslinking agent, and a volatile base;and wherein the low temperature-curing latex adhesive binder composition is maintained at a pre-cure pH of above about 8.0 until the sheet is creped;the creping surface is heated at a temperature no greater than about 100.degree. C.;when the sheet is removed from the creping surface, the low temperature-curing latex adhesive binder composition has cured to a level which imparts to the creped sheet a cross-direction wet tensile strength which is at least about 50 percent that of an identical creped sheet which has been heated at about 150.degree. C. for three minutes, in which the cross-direction wet tensile is tested in accordance with TAPPI Test Methods T494om-88 and T456om-87; andthe cross-direction wet tensile strength of the creped sheet is at least about 40 grams per centimeter.