Pulp and fibrillated fiber composite
View Patent ↗A cellulose pulp sheet is provided that is formed from never-dried kraft pulp and fibrillated fibers, such as lyocell. The pulp sheet provides several beneficial features as a result of both the use of fibrillated fibers and never-dried kraft pulp, particularly when the pulp sheet is used to form air-laid absorbent materials that include superabsorbent polymers.
1. A wet-laid cellulose pulp sheet formed from:
unfibrillated, never-dried kraft pulp; and
fibrillatable fibers;
wherein the pulp sheet is from 1-10 weight % fibrillatable fibers; and
wherein the kraft pulp has fibers with an average length of from 2-3 mm.
2. The pulp sheet of claim 1 , wherein the kraft pulp is a southern bleached softwood kraft.
3. The pulp sheet of claim 1 , wherein the kraft pulp has fibers with a coarseness of from 12 to 30 mg/100 m.
4. The pulp sheet of claim 1 , wherein the fibrillatable fibers have an average length of from 2-25 mm.
5. The pulp sheet of claim 1 , wherein the fibrillatable fiber is fibrillated.
6. The pulp sheet of claim 1 , wherein the pulp sheet has a density of 0.4 to 1.5 g/cc.
7. The pulp sheet of claim 1 , wherein the pulp sheet has a fiberization energy of less than 160 kJ/kg.
8. The pulp sheet of claim 1 , wherein the pulp sheet is such that if it is fiberized into substantially individual fibers and the fibers are formed into an air-laid sheet with a superabsorbent polymer, when tested by the rotap method the air-laid sheet will retain 25% more SAP and fines than a pulp sheet that does not have fibrillatable fibers.
9. The pulp sheet of claim 1 , wherein the pulp sheet is such that if it is fiberized into substantially individual fibers and the fibers are formed into an air-laid sheet with a superabsorbent polymer, the air-laid sheet will pass the hang test.
10. The pulp sheet of claim 1 , wherein the fibrillatable fiber is selected from the group consisting of a natural fiber and a synthetic polymer fiber.
11. The pulp sheet of claim 1 , wherein the fibrillatable fiber is lyocell.
12. The pulp sheet of claim 5 , wherein the fibrillated fiber is lyocell.
13. A wet-laid cellulose pulp sheet formed from:
unfibrillated, never-dried kraft pulp; and
fibrillatable fibers;
wherein the pulp sheet is from 1-10 weight % fibrillatable fibers, and has a density of 0.4 to 1.5 g/cc.
14. The pulp sheet of claim 13 , wherein the kraft pulp is a southern bleached softwood kraft.
15. The pulp sheet of claim 13 , wherein the kraft pulp has fibers with one or more of a fiber length from a coarseness of from 12 to 30 mg/100 m and an average length of from 2-3 mm.
16. The pulp sheet of claim 13 , wherein the fibrillatable fibers have an average length of from 2-25 mm.
17. The pulp sheet of claim 13 , wherein the fibrillatable fiber is fibrillated.
18. The pulp sheet of claim 13 , wherein the pulp sheet has one or more of a density of 0.4 to 1.5 g/cc and a fiberization energy of less than 160 kJ/kg.
19. The pulp sheet of claim 13 , wherein the pulp sheet is such that if it is fiberized into substantially individual fibers and the fibers are formed into an air-laid sheet with a superabsorbent polymer, when tested by the rotap method the air-laid sheet will retain 25% more SAP and fines than a pulp sheet that does not have fibrillatable fibers.
20. The pulp sheet of claim 13 , wherein the pulp sheet is such that if it is fiberized into substantially individual fibers and the fibers are formed into an air-laid sheet with a superabsorbent polymer, the air-laid sheet will pass the hang test.
21. The pulp sheet of claim 13 , wherein the fibrillatable fiber is selected from the group consisting of a natural fiber and a synthetic polymer fiber.
22. The pulp sheet of claim 13 , wherein the fibrillatable fiber is lyocell.
23. A wet-laid cellulose pulp sheet formed from:
unfibrillated, never-dried kraft pulp; and
fibrillatable fibers;
wherein the pulp sheet is from 1-10 weight % fibrillatable fibers, and
wherein the pulp sheet contains no binder or filler.