Latex-free and formaldehyde-free nonwoven fabrics

A multi-layer 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 multi-layer 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 multi-layer nonwoven fabric;
• wherein the fiber web comprises a first outer layer, a second outer layer, and optionally one or more intermediate layers, wherein the one or more intermediate layers are disposed between the first outer layer and the second outer layer;
• wherein the first outer layer, the second outer layer, or both the first outer layer and the second outer layer comprise the cured natural binder;
• wherein each layer of the fiber web comprises natural fibers and synthetic fibers;
• wherein the cured natural binder comprises modified cellulose and a strengthening agent, wherein the modified cellulose comprises CMC and/or 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.

A method of making a nonwoven fabric, the method comprising:

• (a) forming a plurality of fibers into a fiber web;
• wherein the fiber web comprises natural fibers and synthetic fibers;
• wherein the natural fibers are present in the fiber web in an amount of from about 70 wt. % to about 90 wt. %, based on the total weight of the fiber web;
• and wherein the synthetic fibers are present in the fiber web in an amount of from about 10 wt. % to about 30 wt. %, based on the total weight of the fiber web;
• (b) contacting at least a portion of the fiber web with an aqueous natural binder to form a binder impregnated fiber web, wherein the aqueous natural binder comprises modified cellulose, a strengthening agent, and water, wherein the modified cellulose comprises CMC and/or 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, and 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;
• and
• (c) curing the binder impregnated fiber web to form the nonwoven fabric;
• wherein the nonwoven fabric comprises the 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 wherein the nonwoven fabric comprises 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 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.

A multi-layer nonwoven fabric comprising a fiber web in an amount of about 98 wt. %, based on the total weight of the multi-layer nonwoven fabric;

• and a cured natural binder in an amount of about 2 wt. %, based on the total weight of the multi-layer nonwoven fabric;
• wherein the fiber web comprises a first outer layer, a second outer layer, and optionally one or more intermediate layers, wherein the one or more intermediate layers are disposed between the first outer layer and the second outer layer;
• wherein the first outer layer, the second outer layer, or both the first outer layer and the second outer layer comprise the cured natural binder;
• wherein each layer of the fiber web comprises natural fibers and synthetic fibers;
• wherein the natural fibers are present in the nonwoven fabric in an amount of about 80 wt. %, based on the total weight of the nonwoven fabric;
• wherein the synthetic fibers are present in the nonwoven fabric in an amount of about 18 wt. %, based on the total weight of the nonwoven fabric;
• wherein the cured natural binder comprises modified cellulose and a strengthening agent, wherein the cured natural binder is characterized by a weight ratio of strengthening agent to modified cellulose of from about 1:2 to about 1:1,000, wherein the modified cellulose comprises CMC and/or 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.

A single-layer 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 single-layer 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 single-layer nonwoven fabric;
• wherein the fiber web comprises natural fibers;
• wherein the natural fibers are present in the single-layer nonwoven fabric in an amount of from about 85 wt. % to about 99.99 wt. %, based on the total weight of the single-layer 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 CMC and/or 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.