Molded wet-pressed tissue
View Patent ↗Wet-pressed creped tissue sheets exhibit continuous undulating valleys separated by continuous mono-planar macro-ridges running in the machine direction of the sheet, the macro-ridges being of a lower fiber density relative to the fiber density of the undulating valleys. The tissue structure can be created by pressing a densified tissue web against the surface of a Yankee dryer while the web is supported by a texturizing (molding) fabric having a web-supporting surface having highly topographic continuous or substantially continuous ridges and valleys and thereafter creping the web.
1. A creped, wet-pressed tissue sheet of papermaking fibers having a machine direction and a cross-machine direction, said tissue sheet having continuous mono-planar macro-ridges running in the machine direction of the sheet, said macro-ridges being separated by valleys of undulating mini-ridges, said mini-ridges having crests running in the cross-machine direction of the sheet, wherein the macro-ridges have a lower fiber density than the fiber density of the valleys.
2. The tissue sheet of claim 1 wherein the valleys of undulating mini-ridges are continuous.
3. The tissue sheet of claim 1 wherein the macro-ridges are parallel to the machine direction of the sheet.
4. The tissue sheet of claim 1 wherein the macro-ridges are oriented at an angle of from 0 to about ±15 degrees relative to the machine direction of the sheet.
5. The tissue sheet of claim 1 wherein the macro-ridges are oriented at an angle of from about 5 to about 15 degrees or from about −5 to about −15 degrees relative to the machine direction of the sheet.
6. The tissue sheet of claim 1 wherein the macro-ridges are oriented at an angle of from about 5 to about 10 degrees or from about −5 to about −10 degrees relative to the machine direction of the sheet.
7. The tissue sheet of claim 1 wherein the ratio of the average thickness of the macro-ridges to the thickness of the mini-ridges is from about 1.5 to about 6.
8. The tissue sheet of claim 1 wherein the ratio of the average thickness of the macro-ridges to the thickness of the mini-ridges is from about 1.5 to about 5.
9. The tissue sheet of claim 1 wherein the ratio of the average thickness of the macro-ridges to the thickness of the mini-ridges is from about 1.5 to about 4.
10. The tissue sheet of claim 1 wherein the ratio of the average thickness of the macro-ridges to the thickness of the mini-ridges is from about 1.5 to about 3.
11. The tissue sheet of claim 1 wherein the ratio of the average thickness of the macro-ridges to the thickness of the mini-ridges is from about 2 to about 3.
12. The tissue sheet of claim 1 wherein the width of the macro-ridges is less than the width of the valleys.
13. The tissue sheet of claim 1 wherein the width of the macro-ridges is from about 0.5 to about 1.5 millimeters.
14. The tissue sheet of claim 1 wherein the spacing of the macro-ridges, as measured peak-to-peak, is from about 0.5 to about 4 millimeters.
15. The tissue sheet of claim 1 wherein the width of the valleys is from about 0.5 to about 2.5 millimeters.
16. The tissue sheet of claim 1 wherein the machine direction spacing of the mini-ridges, as measured peak-to-peak, can be from about 0.2 to about 1 millimeter.
17. The tissue sheet of claim 1 wherein the height of the mini-ridges is from about 0.05 to about 0.5 millimeter.
18. The tissue sheet of claim 1 wherein the basis weight is from about 10 to about 40 grams per square meter.
19. The tissue sheet of claim 1 wherein the bulk is from about 10 to about 20 cubic centimeters per gram.