US 11,993,877 B2
Latex-free and formaldehyde-free nonwoven fabrics
Abdus Salam, Harrisburg, NC (US); and Timothy Kistemaker, Mooresville, NC (US)
Assigned to Glatfelter Corporation, Charlotte, NC (US)
Appl. No. 17/280,778
Filed by Glatfelter Corporation, Charlotte, NC (US)
PCT Filed Jan. 31, 2019, PCT No. PCT/US2019/016041
§ 371(c)(1), (2) Date Mar. 26, 2021,
PCT Pub. No. WO2020/068151, PCT Pub. Date Apr. 2, 2020.
Claims priority of provisional application 62/736,760, filed on Sep. 26, 2018.
Prior Publication US 2022/0002921 A1, Jan. 6, 2022
Int. Cl. D04H 1/425 (2012.01); D04H 1/587 (2012.01); D04H 1/593 (2012.01)
CPC D04H 1/425 (2013.01) [D04H 1/587 (2013.01); D04H 1/593 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A nonwoven fabric comprising a fiber web in an amount of from about 85 wt. % to about 99.99 wt. %, based on the total weight of the nonwoven fabric; and a cured natural binder in an amount of from about 0.01 wt. % to about 15 wt. %, based on the total weight of the nonwoven fabric; wherein the fiber web comprises natural fibers and synthetic fibers; wherein the natural fibers are present in the nonwoven fabric in an amount of from about 70 wt. % to about 90 wt. %, based on the total weight of the nonwoven fabric; wherein the synthetic fibers are present in the nonwoven fabric in an amount of from about 10 wt. % to about 30 wt. %, based on the total weight of the nonwoven fabric; wherein the cured natural binder comprises modified cellulose and a strengthening agent in a weight ratio of strengthening agent to modified cellulose of from about 1:2 to about 1:1,000, wherein the modified cellulose comprises carboxymethylcellulose (CMC) and/or sodium carboxymethylcellulose (sodium CMC), wherein the strengthening agent comprises a crosslinking agent and a wet strength agent, wherein the crosslinking agent comprises a carboxylic acid having two or more carboxyl groups, wherein the wet strength agent comprises at least one reactive functional group selected from the group consisting of a halide group, a chloride group, a fluoride group, a hydroxyl group, and combinations thereof,
wherein the natural fibers comprise cellulose fibers, wherein the synthetic fibers comprise biodegradable synthetic fibers, and wherein the nonwoven fabric is characterized by a degree of biodegradability of equal to or greater than about 99%, wherein the degree of biodegradability refers to aerobic biodegradability in soil as determined in accordance with ISO 17556:2003 E, and wherein the nonwoven fabric excludes latex and formaldehyde.