Dried highly fibrillated cellulose fiber
View Patent ↗A mixture of lyocell fiber and low DP or standard DP cellulose pulp fiber having a Canadian Standard Freeness of 250 mL CSF or less is dried and has a Canadian Standard Freeness of 250 mL CSF or less. The pulp is 10% to 75% of the total weight of fibers in the mixture. Both the dried product and the process of making it are disclosed.
1. A dried fibrillated mixture of lyocell fibers and softwood cellulose pulp fibers, the mixture having been formed by fibrillating the pulp fibers together with unfibrillated lyocell fibers and then drying;
wherein the mixture has a Canadian Standard Freeness of 250 mL CSF or less,
wherein the softwood cellulose pulp fibers in the mixture is in the range of 20% to 70% of the total weight of the fibers in the mixture, the lyocell fibers is in the range of at least 20% of the total weight of the fibers in the mixture, and the mixture has a water content from 0% to 30% of the weight of the fibers in the mixture and water, and
wherein the Canadian Standard Freeness does not exceed 250 mL CSF upon re-slurrying.
2. The mixture of claim 1 wherein the softwood cellulose pulp has a DP of 200 to 1000 as measured by ASTM Test D 1795-96.
3. The mixture of claim 1 wherein the softwood cellulose pulp has a DP of greater than 1000 as measured by ASTM Test D 1795-96.
4. The mixture of claim 1 wherein the mixture has a water content from 0% to 10% of the weight of the fibers in the mixture and water.
5. The mixture of claim 4 wherein the softwood cellulose pulp has a DP of 200 to 1000 as measured by ASTM Test D 1795-96.
6. The mixture of claim 4 wherein the softwood cellulose pulp has a DP of greater than 1000 as measured by ASTM Test D 1795-96.
7. A method of providing a dried fibrillated mixture of lyocell fibers and softwood cellulose pulp fibers, the method comprising:
fibrillating a mixture of unfibrillated lyocell fibers and softwood cellulose pulp fibers in water to a Canadian Standard Freeness of 250 mL CSF or less, wherein the softwood cellulose pulp fibers in the mixture is in the range of 20% to 70% of the total weight of the fibers in the fiber mixture and the lyocell fibers in the range of at least 20% of the total weight of the fibers in the mixture; and
drying the fiber mixture and water until the water content of the mixture is 0% to 30% of the weight of the fibers in the mixture and water.
8. The method of claim 7 wherein the softwood cellulose pulp has a DP of 200 to 1000 as measured by ASTM Test D 1795-96.
9. The method of claim 7 wherein the softwood cellulose pulp has a DP of greater than 1000 as measured by ASTM Test D 1795-96.
10. The method of claim 7 wherein the water content of the mixture is 0% to 10% of the weight of the fibers in the fibers in the mixture and water.
11. The method of claim 10 wherein the softwood cellulose pulp has a DP of 200 to 1000 as measured by ASTM Test D 1795-96.
12. The method of claim 10 wherein the softwood cellulose pulp has a DP of greater than 1000 as measured by ASTM Test D 1795-96.
13. A fibrillated mixture of lyocell fibers and softwood cellulose pulp fibers, the mixture having been formed by fibrillating the pulp fibers together with unfibrillated lyocell fibers;
wherein the mixture has a Canadian Standard Freeness of 250 mL CSF or less;
wherein the mixture comprises softwood cellulose pulp fibers in the range of 20% to 70%, and lyocell fibers of at least 20%, of the total weight of the fibers in the mixture;
wherein the mixture has a water content greater than about 30% of the weight of the fibers in the mixture and water; and
wherein the Canadian Standard Freeness of the mixture does not exceed 250 mL upon drying the mixture to a water content of below 30% of the weight of the fibers in the mixture and water.