Airlaid nonwoven

1 . An absorbent core for an absorbent article, the core comprising 2 to 10 separately formed airlaid layers consisting of staple fibers in which 50 to 100 percent of the staple fibers, based on the total weight of the absorbent core, are bamboo derived staple fibers, and wherein the absorbent core exhibits the following:

a decrease in thickness from 10 to 60% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers;

a decrease in machine direction (MD) stiffness from 10 to 50% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers; and

an increase in wicking rate that is from 40 to 120% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers.

2 . The absorbent core of claim 1 , wherein the airlaid layers comprise a blend of bamboo derived staple fibers and non-cellulose staple fibers.

3 . The absorbent core of claim 2 , wherein the non-cellulose staple fibers comprises fibers derived from synthetic polymers, fibers derived from bio-based polymers, combinations of fibers derived from synthetic polymers and bio-based polymers, and blends of polymers derived from synthetic polymers and bio-based polymers.

4 . The absorbent core of claim 2 , wherein the non-cellulose staple fibers are bicomponent staple fibers having a polyethylene sheath and a polypropylene or polyethylene terephthalate core, and mixtures thereof.

5 . The absorbent core of claim 2 , wherein the absorbent core comprises three airlaid layers.

6 . The absorbent core of claim 2 , wherein the bamboo derived staple fibers have an average length from about 0.8 to 4.5 mm, and an average width from about 12 to 22 microns.

7 . The absorbent core of claim 2 , wherein the bamboo derived staple fibers have a length to width ratio that is from about 60 to 120.

8 . The absorbent core of claim 2 , wherein the absorbent core has a basis weight ranging from about 25 to 400 gsm and a thickness ranging from about 0.4 to 4 mm.

9 . The absorbent core of claim 1 , wherein the absorbent core comprises a tissue layer.

10 . The absorbent core of claim 9 , wherein the airlaid layers of the absorbent core are sandwiched between a pair of tissue layers.

11 . The absorbent core of claim 1 , wherein the absorbent core further comprises:

a first layer of fibers bonded together to form a coherent web; and

an airlaid nonwoven layer overlying the first layer, the airlaid nonwoven layer comprising a blend of bamboo derived staple fibers, the airlaid nonwoven layer comprising a first surface disposed towards, and thermally bonded, to a surface of the first layer, and a second surface defining an outer surface of the absorbent core.

12 . The absorbent core of claim 11 , wherein the first layer is selected from the group consisting of spunbond nonwoven, meltblown nonwoven, spunlace nonwoven, carded nonwoven, airlaid nonwoven, a spunbond-meltblown-spunbond composite (SMS), cellulosic tissue paper, film, and combinations thereof.

13 . The absorbent core of claim 10 , wherein the tissue layers comprise tissue derived from bamboo fibers, conventional wood pulp fibers, and mixtures thereof.

14 . The absorbent core of claim 1 , wherein the absorbent core comprises a bio-based polymer layer comprising carboxy methyl cellulose.

15 . An absorbent core for an absorbent article, the absorbent core comprising two or more separately formed airlaid layers consisting of staple fibers and optionally a latex material, wherein the staple fibers include bamboo derived staple fibers, the bamboo derived staple fibers being present in an amount from 75 to 100 weight percent, based on the total weight of the absorbent core, and wherein the bamboo derived staple fibers are bonded to each other via a latex material or via hydrogen bonding, and wherein the absorbent core exhibits the following:

a decrease in thickness from 10 to 60% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers;

a decrease in machine direction (MD) stiffness from 10 to 50% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers; and

an increase in wicking rate that is from 40 to 120% in comparison to a similar absorbent core in which the similar absorbent core comprises staple fibers derived from conventional wood pulp fibers in lieu of the bamboo derived staple fibers.

16 . The absorbent core of claim 15 , wherein the absorbent core comprises substantially no non-cellulose staple fibers.

17 . The absorbent core of claim 15 , wherein the absorbent core comprises a tissue layer.

18 . The absorbent core of claim 15 , wherein said two or more separately formed airlaid layers are sandwiched between a pair of tissue layers.

19 . The absorbent core of claim 18 , wherein the tissue layers comprise tissue derived from bamboo fibers, conventional wood pulp fibers, and mixtures thereof.

20 . The absorbent core of claim 15 , wherein the bamboo derived staple fibers have an average length from about 0.8 to 4.5 mm, and an average width from about 12 to 22 microns.

21 . The absorbent core of claim 15 , wherein the bamboo derived staple fibers having a length to width ratio that is from about 60 to 120.