Soft absorbent sheets, structuring fabrics for making soft absorbent sheets, and methods of making soft absorbent sheets
Soft absorbent sheets, structuring fabrics for producing soft absorbent sheets, and methods of making soft absorbent sheets. The soft absorbent sheets have a plurality of domed regions or projected regions extending from a surface of the sheets, and connecting regions form a network between domed regions. The domed and projected regions include indented bars that extend across the domed and projected regions in a substantially cross machine direction of the absorbent sheets. The absorbent sheets can be formed by structuring fabrics that have long warp yarn knuckles.
1. A method of making an absorbent cellulosic sheet, the method comprising:
forming an aqueous cellulosic web on a structuring fabric in a papermaking machine, the structuring fabric including knuckles formed on warp yarns of the structuring fabric, with the knuckles having a length in the machine direction (MD) of the absorbent sheet and a width in the cross machine direction (CD) of the absorbent sheet, wherein the ratio (KR) of the MD length of the knuckles to the CD width of the knuckles is at least about 7, and wherein a planar volumetric density index (PVDI) of the structuring fabric multiplied by the KR (PVDI-KR) is at least about 43;
dewatering the cellulosic web on the structuring fabric; and
drying the cellulosic web to form the absorbent cellulosic sheet.
2. A method according to claim 1 , wherein the length of the knuckles in the MD of the structuring fabric is about 2.2 mm to about 5.6 mm.
3. A method according to claim 1 , wherein a pocket density of the structuring fabric is about 10 cm −2 to about 47 cm −2 .
4. A method according to claim 1 , wherein the PVDI-KR is about 43 to about 50.
5. A method according to claim 1 , further comprising:
creping the web under pressure in a creping nip between a transfer surface and the structuring fabric.
6. A method of making a fabric-creped absorbent cellulosic sheet, the method comprising:
compactively dewatering a papermaking furnish to form a web having a consistency of about 30 percent to about 60 percent;
creping the web under pressure in a creping nip between a transfer surface and a structuring fabric, the structuring fabric including knuckles formed on warp yarns of the structuring fabric, with the knuckles having a length in the machine direction (MD) of the absorbent sheet and a width in the cross machine direction (CD) of the absorbent sheet, wherein the ratio (KR) of the MD length of the knuckles to the CD width of the knuckles is at least about 7, and wherein a planar volumetric density index (PVDI) of the structuring fabric multiplied by the KR (PVDI-KR) is at least about 43; and
drying the web to form the absorbent cellulosic sheet.
7. A method according to claim 6 , wherein the length of the knuckles in the MD of the structuring fabric is about 2.2 mm to about 5.6 mm.
8. A method according to claim 6 , wherein the PVDI-KR is about 43 to about 250.
9. A method according to claim 6 , wherein the transfer surface is part of a backing roll or an endless belt.
10. A method according to claim 6 , wherein a creping ratio is defined by the speed of the transfer surface relative to the speed of the structuring fabric, and the creping ratio is about 3% to about 25%.