Composite nonwoven and process for producing a composite nonwoven

Patent metadata

Field	Value
Publication number	US-2023083348-A1
Application number	US-202117801607-A
Country	US
Kind code	A1
Filing date	Feb 24, 2021
Priority date	Feb 24, 2020
Publication date	Mar 16, 2023
Grant date	—

Abstract

A composite nonwoven fabric (1, 51, 61) and a process (100, 101, 102) for the production of the composite nonwoven fabric (1, 51, 61) are shown, wherein the composite nonwoven fabric (1, 51, 61) comprises at least one spunbonded nonwoven (8, 54, 64), which exhibits essentially continuous regenerated cellulosic filaments (4, 55, 65) deposited in a random orientation, and at least one layer (52, 62) of biobased biodegradable short fibers (14, 53, 63). So as to provide a fully biodegradable composite nonwoven fabric of the initially mentioned type, which exhibits a high stability and tensile strength as well as good absorption properties and haptic properties and, in addition, can be produced in a cost-efficient way, it is suggested that the composite nonwoven fabric (1, 51, 61) has at least one mixing area (56, 66) in which the filaments (4, 55, 65) of the spunbonded nonwoven (8, 54, 64) and the short fibers (14, 53, 63) are present in a state of physical interconnection.

First claim

1 . A composite nonwoven fabric comprising;
at least one spunbonded nonwoven which exhibits essentially continuous regenerated cellulosic filaments deposited in a random orientation; and at least one layer of biobased biodegradable short fibers, wherein the composite nonwoven fabric has at least one mixing area in which the continuous regenerated cellulosic filaments of the at least one spunbonded nonwoven and the biobased biodegradable short fibers are present in a state of physical interconnection.

2 . The A composite nonwoven fabric according to claim 1 , wherein the biobased biodegradable short fibers are cellulosic short fibers and the composite nonwoven fabric in an absolutely dry state has a cellulose content of at least 93 wt.-%, optionally at least 95 wt.-%, or optionally at least 97 wt.-%.

3 . The composite nonwoven fabric according to claim 1 , wherein the composite nonwoven fabric comprises between 10 wt.-% and 99 wt.-%, optionally between 15 wt.-% and 95 wt.-%, or optionally between 20 wt.-% and 90 wt.-%, of the continuous regenerated cellulosic filaments of the at least one spunbonded nonwoven and between 1 wt.-% and 90 wt.-%, optionally between 5 wt.-% and 85 wt.-%, or optionally between 10 wt.-% and 80 wt.-%, of the biobased biodegradable short fibers.

4 . The composite nonwoven fabric according to claim 1 , wherein the composite non woven fabric is essentially free from binders that do not occur naturally in wood.

5 . The composite nonwoven fabric according to claim 1 , wherein the biobased biodegradable short fibers are selected from the group comprising: natural cellulose fibers, pulp fibers, Viscose, Modal, Cupro and Lyocell fibers, chemically modified cellulose fibers, recycled cellulosic fibers, starch fibers, and combinations thereof.

6 . The composite nonwoven fabric according to claim 1 , wherein the biobased biodegradable short fibers have a length of between 0.5 mm and 15 mm, optionally between 1 and 12 mm.

7 . The composite nonwoven fabric according to claim 1 , wherein the composite nonwoven fabric is obtainable by a process according to claim 8 .

8 . A process for producing a composite nonwoven fabric according to claim 1 , comprising
extruding a spinning mass containing cellulose through a plurality of nozzle holes of at least one spinneret to form filaments, and drawing the filaments, in each case, in an extrusion direction, wherein the filaments are deposited in a random orientation on a perforated conveying device to form a spunbonded nonwoven and wherein short fibers are added to the spunbonded non woven to form the composite non woven fabric, wherein the filaments of the spunbonded nonwoven are charged with the short fibers in a never-dried state.

9 . The process according to claim 8 , wherein the filaments of the spunbonded nonwoven are charged with a suspension of the short fibers in the never-dried state.

10 . The process according to claim 9 , wherein the suspension comprises between 0.01 wt.-% and 2.00 wt.-% of the short fibers.

11 . The process according to claim 9 , wherein the filaments of the spunbonded nonwoven are charged with the suspension during washing.

12 . The process according to claim 9 , wherein the filaments of the spunbonded nonwoven are charged with the suspension during formation of the spunbonded nonwoven.

13 . The process according to claim 8 , wherein the filaments of the spunbonded nonwoven are charged with an air stream comprising the short fibers in the never-dried state.

14 . The process according to claim 13 , wherein the filaments are charged with a drawing air stream for drawing and the short fibers are added to the drawing air stream in order to charge the filaments of the spunbonded nonwoven with the short fibers in the never-dried state.

15 . The process according to claim 8 , wherein after the filaments have been charged with the short fibers, the composite nonwoven fabric is subjected to at least one treatment step, the at least one treatment step being selected from the group comprising: hydroentanglement, water jet embossing, water jet perforation, washing, drying and combinations thereof.

16 . The process according to claim 8 , wherein the spinning mass is a solution of cellulose in a direct solvent, optionally a tertiary amine oxide.

17 . The process according to claim 8 , wherein, after extrusion from the at least one spinneret, the filaments are coagulated at least partly.

Assignees

• Chemiefaser Lenzing Ag

Inventors

• Sagerer-Foric Ibrahim
• Einzmann Mirko
• Gregorich Katharina
• Goldhalm Gisela

Classifications

• B32B2555/00

  Personal care · CPC title

• B32B2250/20

  All layers being fibrous or filamentary · CPC title

• B32B2307/732

  Dimensional properties · CPC title

• B32B2262/04

  Cellulosic plastic fibres, e.g. rayon · CPC title

• B32B2307/7163

  Biodegradable · CPC title