US 7,399,378 B2 · Fabric crepe process for making absorbent sheet

Abstract

A process for making absorbent cellulosic paper products such as sheet for towel, tissue and the like, includes compactively dewatering a nascent web followed by wet belt creping the web at an intermediate consistency of anywhere from about 30 to about 60 percent under conditions operative to redistribute the fiber on the belt, which is preferably a fabric. In preferred embodiments, the web is thereafter adhesively applied to a Yankee dryer using a creping adhesive operative to enable high speed transfer of the web of intermediate consistency such as a poly(vinyl alcohol)/polyamide adhesive. An absorbent sheet so prepared from a papermaking furnish exhibits an absorbency of at least about 5 g/g, a CD stretch of at least about 4 percent, and an MD/CD tensile ratio of less than about 1.1, and also exhibits a maximum CD modulus at a CD strain of less than 1 percent and sustains a CD modulus of at least 50 percent of its maximum CD modulus to a CD strain of at least about 4 percent. Products of the invention may also exhibit an MD modulus at break 1.5 to 2 times their initial MD modulus.

Claims72

Dependent claims

A method of making a belt-creped absorbent cellulosic sheet comprising:

a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;
b) applying the dewatered web having the apparently random fiber distribution to a translating transfer surface moving at a transfer surface speed;
c) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface, the belt pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions;
and
d) drying the web.
wherein the method is further characterized in that:
(i) the web has an absorbency of at least 4.5g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g and a CD stretch of at least about 5% up to about 20%;
or (ii) the velocity delta at the creping nip is at least 100 feet per minute up to about 2000 fpm;
or both (i) and (ii).

6 more elements

A method of making single-ply tissue comprising:

a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;
b) applying the dewatered web having the apparently random fiber distribution to a translating transfer surface moving at a transfer surface speed;
c) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt pattern, nip pressure, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions and (iii) wherein the Fabric Crepe is greater than about 25% up to 80%;
d) drying the web to form a basesheet having an MD stretch greater than about 25% up to 80% and a characteristic basis weight;
and
e) converting the basesheet into a single-ply tissue product wherein the single-ply tissue product has a basis weight lower than the basesheet prior to conversion and an MD stretch lower than the MD stretch of the basesheet prior to conversion.

3 more elements

A method of making multi-ply tissue comprising:

a) compactively dewatering a papermaking furnish to form a nascent web having an apparently random distribution of papermaking fiber;
b) applying the dewatered web having the apparently random fiber distribution to a translating transfer surface moving at a transfer surface speed;
c) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure of 20 pounds per linear inch or more in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased toward the direction between pileated regions and (iii) wherein the Fabric Crepe is greater than about 25% up to 80%;
d) drying the web to form a basesheet having an MD stretch greater than about 25% up to 80% and a characteristic basis weight;
and
e) converting the basesheet into a multi-ply tissue product with n plies made from the base sheet, n being 2 or 3, wherein the multiply product has an MD stretch lower than the MD stretch of the basesheet.

3 more elements

A method of making a belt-creped absorbent cellulosic sheet comprising:

a) applying a papermaking furnish to a papermaking felt in contact with a forming roll provided with vacuum;
b) at least partially dewatering the papermaking furnish by application of vacuum from the forming roll on the papermaking felt to form a nascent web having a generally random distribution of papermaking fiber;
c) compactively dewatering the nascent web having a generally random distribution of papermaking fiber;
d) applying the dewatered web having a generally random fiber distribution to a translating transfer surface moving at a transfer surface speed;
e) belt-creping the web from the transfer surface at a consistency of from about 30 to about 60 percent utilizing a patterned creping belt, the creping step occurring under pressure in a belt creping nip defined between the transfer surface and the creping belt wherein the belt is traveling at a belt speed slower than the speed of said transfer surface by at least 100 feet per minute and wherein the speed of the belt is slower than the speed of said transfer surface by a velocity delta of up to 2000 feet per minute, the belt pattern, nip parameters, velocity delta and web consistency being selected such that the web is creped from the transfer surface and redistributed on the creping belt to form a web with a reticulum having a plurality of interconnected regions of different local basis weights including at least (i) a plurality of fiber enriched pileated regions of high local basis weight, interconnected by way of (ii) a plurality of lower local basis weight linking regions whose fiber orientation is biased along the direction between pileated regions;
and
f) drying the web;
wherein the web has an absorbency of at least about 4.5 g/g up to an absorbency in g/g of about 0.9 times the specific volume of the web in cc/g and a CD stretch of at least about 5% up to about 20%.

5 more elements

Dependencies are inferred from the claim text.

Fabric crepe process for making absorbent sheet

Life of this patent

Fabric crepe process for making absorbent sheet

Life of this patent

Abstract

Claims72