US 9,315,931 B2Granted

Production process of a nonwoven fabric sheet

AssigneeUnicharm Corporation

InventorsKatsuhiro Uematsu, Toru Oba, Satoshi Mizutani

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Abstract

A sheet of nonwoven fabric which has surface irregularities, the shape of the surface irregularities being less apt to be changed by external pressure, etc. The sheet has a machine, cross and thickness directions which are perpendicular to one another. The upper surface has a plurality of protrusions continuously extending, in parallel, in the cross direction and further has a plurality of recesses that are located between the adjacent protrusions and extend in the cross direction. The sheet includes first and second fibrous layers located on the upper-surface side and the lower-surface side, respectively. The first fibrous layer comprises heat-fusible fibers, and the second fibrous layer comprises coil-shaped three-dimensional crimp fibers that are oriented mainly in the machine direction and form a network by entanglement thereof without having been fused at the sites where the crimp fibers cross one another.

Claims20

Dependent claims

A method of processing a non-woven fabric sheet, comprising the steps of:

a) opening a first fiber assembly containing heat-fusible fibers by passing the first fiber assembly through a carding machine to form a web containing heat-fusible fibers,
b) opening a second fiber assembly containing latent crimpable fibers by passing the second fiber assembly through a carding machine to form a web containing latent crimpable fibers,
c) superimposing the web containing heat-fusible fibers and the web containing latent crimpable fibers to form a laminated web,
d) creating a difference in shrinkage force in the machine direction in the laminated web by causing crimping of the latent crimpable fibers during a heat treatment step over a prescribed width in the machine direction,
f) heating the laminated web to a temperature that:
i) is lower than the fusing temperature of the heat-fusible fibers;
and ii) causes crimping of the latent crimpable fibers by lowering resistance to crimping of the latent crimpable fibers, and
g) fusing the web obtained in step f at sites where the heat-fusible fibers mutually intersect by heating to a temperature equal to or higher than the fusing temperature of the heat-fusible fibers.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/193,904Filed 28 Feb 2014 · division
Priority: JP 2010-07597629 Mar 2010
Published: US 2014/0174628 A126 Jun 2014
Granted: 19 Apr 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification29 codes

D04H 13/007
Making non-woven fabrics from staple fibres, filaments or yarns, bonded to at least one web-like material, e.g. woven, knitted non-woven fabric,…:…
A61F 13/15699
Apparatus or processes for manufacturing: forming webs by bringing together several webs, e.g. by laminating or folding several webs, with or…
A61F 13/51104
Topsheet, i.e. the permeable cover or layer facing the skin: the top sheet having a three-dimensional cross-section, e.g. corrugations,…
B29C 61/02
Shaping by liberation of internal stresses; Making preforms having internal stresses; Apparatus therefor: thermal shrinking

Family

PCT/JP2011/057511Parent of this division · filed 22 Mar 2011
US 2014/0174628 A1Pre-grant publication · published 26 Jun 2014
Application13/637,889Parent of this division
US 2013/0022784 A1Published application
US 9,315,931 B2This patent

From the US filing history. Foreign family members aren’t listed.