SURFACE ENHANCED PULP FIBERS, METHODS OF MAKING SURFACE ENHANCED PULP FIBERS, PRODUCTS INCORPORATING SURFACE ENHANCED PULP FIBERS, AND METHODS OF MAKING PRODUCTS INCORPORATING SURFACE ENHANCED PULP FIBERS
Various embodiments of the present invention relate to surface enhanced pulp fibers, various products incorporating surface enhanced pulp fibers, and methods and systems for producing surface enhanced pulp fibers. Various embodiments of surface enhanced pulp fibers have significantly increased surface areas compared to conventional refined fibers while advantageously minimizing reductions in length following refinement. The surface enhanced pulp fibers can be incorporated into a number of products that might benefit from such properties including, for example, paper products, paperboard products, fiber cement boards, fiber reinforced plastics, fluff pulps, hydrogels, cellulose acetate products, and carboxymethyl cellulose products. In some embodiments, a plurality of surface enhanced pulp fibers have a length weighted average fiber length of at least about 0.3 millimeters and an average hydrodynamic specific surface area of at least about 10 square meters per gram, wherein the number of surface enhanced pulp fibers is at least 12,000 fibers/milligram on an oven-dry basis.
1 . A plurality of softwood pulp fibers that are refined such that:
a length weighted average fiber length of the softwood pulp fibers is at least 60% of a length weighted average fiber length of the softwood pulp fibers before the softwood pulp fibers are refined; and
an average hydrodynamic specific surface area of the softwood pulp fibers is at least 4 times larger than an average hydrodynamic specific surface area of the softwood pulp fibers before the softwood pulp fibers are refined.
2 . The softwood pulp fibers of claim 1 , wherein the average hydrodynamic specific surface area of the softwood pulp fibers is at least 6 times larger than the average hydrodynamic specific surface area of the softwood pulp fibers before the softwood pulp fibers are refined.
3 . The softwood pulp fibers of claim 2 , wherein the average hydrodynamic specific surface area of the softwood pulp fibers is at least 8 times larger than the average hydrodynamic specific surface area of the softwood pulp fibers before the softwood pulp fibers are refined.
4 . The softwood pulp fibers of claim 1 , wherein the length weighted average fiber length of the softwood pulp fibers is at least 70% of the length weighted average fiber length of the softwood pulp fibers before the softwood pulp fibers are refined.
5 . The softwood pulp fibers of claim 1 , wherein the length weighted average fiber length of the softwood pulp fibers is at least 0.40 mm.
6 . The softwood pulp fibers of claim 1 , wherein the number of softwood pulp fibers is at least 12,000 fibers per milligram on an oven-dry basis.
7 . The softwood pulp fibers of claim 1 , wherein the softwood pulp fibers have a length weighted fines value that is less than 40% when fibers having a length that is less than or equal to 0.20 mm are classified as fines.
8 . The softwood pulp fibers of claim 7 , wherein the length weighted fines value of the softwood pulp fibers is less than 22%.
9 . A plurality of softwood pulp fibers having:
a length weighted average fiber length that is at least 0.30 mm;
wherein the softwood pulp fibers are made in a process in which the softwood pulp fibers are refined with one or more mechanical refiners such that the refiner(s) consume at least 300 kilowatt-hours (kWh) per ton, each of the refiner(s) comprising two refining elements that each includes:
a plurality of bars, each having a width that is less than or equal to 1.3 millimeters (mm); and
a plurality of grooves, each having a width that is less than or equal to 2.5 mm.
10 . The softwood pulp fibers of claim 9 , wherein for each of the refining elements of at least one of the refiner(s), each of the grooves has a width that is less than or equal to 2.0 mm.
11 . The softwood pulp fibers of claim 9 , wherein in the process in which the softwood pulp fibers are made the refiner(s) consume at least 650 kWh per ton.
12 . A method of making a plurality of surface enhanced pulp fibers, the method comprising:
refining a plurality of pulp fibers with one or more mechanical refiners, each of the refiner(s) comprising two refining elements that each includes:
a plurality of bars, each having a width that is less than or equal to 1.3 millimeters (mm); and
a plurality of grooves, each having a width that is less than or equal to 2.5 mm;
wherein refining the pulp fibers is performed such that the refiner(s) consume at least 300 kilowatt-hours (kWh) per ton.
13 . The method of claim 12 , wherein the pulp fibers are softwood pulp fibers.
14 . The method of claim 13 , wherein refining the pulp fibers is performed such that the refiner(s) consume at least 650 kWh per ton.
15 . The method of claim 14 , wherein refining the pulp fibers is performed such that the refiner(s) consume at least 1,000 kWh per ton.
16 . The method of claim 12 , wherein refining the pulp fibers is performed such that at least one of the refiner(s) operates at a specific edge load that is between 0.1 and 0.3 Watt-seconds per meter.
17 . The method of claim 12 , wherein for each of the refining elements of at least one of the refiner(s), each of the grooves has a width that is less than or equal to 2.0 mm.
18 . The method of claim 12 , wherein for each of the refining elements of at least one of the refiner(s), each of the bars has a width that is less than or equal to 1.0 mm and each of the grooves has a width that is less than or equal to 1.6 mm.
19 . The method of claim 12 , wherein:
the one or more refiners comprise two or more refiners; and
refining the pulp fibers includes:
transporting the fibers from a first one of the refiners to a second one of the refiners after the pulp fibers are refined with the first refiner, wherein:
for each of the refining elements of the first refiner, each of the bars has a width that is greater than 1.0 mm and a groove width that is greater than 2.0 mm; and
for each of the refining elements of the second refiner, each of the bars has a width that is less than or equal to 1.0 mm and each of the grooves has a width that is less than or equal to 1.6 mm; and
operating the second refiner at a specific edge load that is between 0.1 and 0.3 Watt-seconds per meter.
20 . The method of claim 12 , wherein each of the refiner(s) is a double disk refiner, a conical refiner, a single disk refiner, or a multi-disk refiner.