Disposable nonwoven wiping fabric and method of production
AssigneeAhlstrom Nonwovens LLC
InventorsVaughan R Annis, Margaret Anne McDade
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Abstract
Disclosed is a fibrous nonwoven web material and a method of manufacture thereof. The fibrous nonwoven web material includes natural cellulose fibers, manmade cellulose fibers and synthetic fibers. The manmade cellulose fibers are preferably high crystallinity cellulose fibers. The fibrous nonwoven web material has appreciable wet strength yet is capable of dispersing in most aqueous environments with only mild agitation. The fibrous nonwoven web material can be wet laid from an aqueous dispersion of fibers.
Claims21
A fibrous nonwoven web material comprising at least about 50 percent by weight natural cellulose fibers, at least about 5 percent by weight manmade high crystallinity cellulose fibers having a crystallinity of at least about 40 percent and a binder component comprising 0.5 percent to less than 2 percent by weight of binder fibers;
- wherein the web material is entangled, has a dried basis weight in the range of about 30 to about 90 grams per square meter, has a wet tensile strength (for a 55 gsm basis weight) in the machine direction of at least about 160 gms/25 mm, and has a maximum flush break up time (B) of 45 seconds, and wherein the binder fibers consist of bicomponent fibers, each of the bicomponent fibers having a sheath consisting of at least one of polyethylene and polypropylene.
A method for making a nonwoven fibrous sheet comprising:
- dispersing a major amount of natural cellulose fibers, a lesser amount of manmade high crystallinity cellulose fibers having a crystallinity of at least about 40 percent and a binder component comprising 0.5 percent to less than 2 percent by weight of synthetic binder fibers in a liquid dispersing media to form a furnish, the binder fibers consisting of bicomponent fibers, each of the bicomponent fibers having a sheath consisting of at least one of polyethylene and polypropylene;
- wet laying the furnish over a foraminous member to form a nonwoven web;
- hydroentangling the nonwoven web;
- and
- heating and drying the hydroentangled nonwoven web to form the sheet,
- wherein the sheet has a Flush Index to a state of substantially individual fibers of less than about 20 rotations and the sheet has a machine direction wet tensile strength (for a 55 gsm basis weight) of at least about 160 grams/25 mm.
A nonwoven sheet material, wet laid from an aqueous mixture and subsequently hydroentangled, the sheet material comprising about 50 percent to about 97 percent by weight natural cellulose pulp fibers, about 5 percent to about 40 percent by weight manmade cellulose fibers having a crystallinity of at least about 40 percent and a binder component consisting of 0.5 percent to less than 2 percent by weight of synthetic binder fibers and optionally 0.1 percent by weight to 2.0 percent by weight of a non-fiber binder, wherein the binder fibers consist of bicomponent fibers, each of the bicomponent fibers having a sheath consisting of at least one of polyethylene and polypropylene, and a portion of the binder fibers in the sheet material is at least partially bonded to some of the natural cellulose pulp fibers and manmade cellulose fibers so that the sheet material is suitable for use as a premoistened wipe and has a flush break up time to fibers of less than 300 seconds.
A premoistened wipe, comprising a nonwoven, hydroentangled sheet material comprised of about 50 percent to about 97 percent by weight natural cellulose pulp fibers, about 5 percent to about 40 percent by weight manmade cellulose fibers having a crystallinity of at least about 40 percent and a binder component comprising 0.5 percent to less than 2 percent by weight of synthetic binder fibers, wherein the binder fibers consist of bicomponent fibers, each of the bicomponent fibers having a sheath consisting of at least one of polyethylene and polypropylene, a portion of the binder fibers in the sheet material is at least partially bonded to some of the natural cellulose pulp fibers and manmade cellulose fibers and the wipe has a maximum flush break up time (B) of 45 seconds in water at most pH ranges.
Dependencies are inferred from the claim text.