Stretchable structure for absorbent article and disposable diaper pants

Patent metadata

Field	Value
Publication number	US-10751228-B2
Application number	US-201615555854-A
Country	US
Kind code	B2
Filing date	Mar 25, 2016
Priority date	Mar 27, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

A stretchable structure of an absorbent article includes two sheet layers that extend in a stretchable direction and an orthogonal direction orthogonal to the stretchable direction; and elongated resilient and elastic members that are disposed between the sheet layers at predetermined intervals in the orthogonal direction and extend in the stretchable direction, wherein, the two ends in the stretchable direction of each of the resilient and elastic members comprise fixed ends fixed to the two sheet layers, and the section between the fixed ends comprises a free section unfixed to the two sheet layers, at least one sheet bonding section is disposed in at least one inter-free region defined between the free sections adjacent to each other in the orthogonal direction, the two sheet layers being bonded in the at least one inter-free region, and the two sheet layers in a contracted state conform with each other in a wave pattern in response to contraction of the resilient and elastic members.

First claim

The invention claimed is:

1. A stretchable structure of an absorbent article, comprising:
two sheet layers that extend in a stretchable direction and an orthogonal direction orthogonal to the stretchable direction; and
a plurality of elongated resilient and elastic members extending in the stretchable direction disposed at intervals in the orthogonal direction between the two sheet layers, wherein,
each of the resilient and elastic members comprises two fixed ends fixed to the two sheet layers in the stretchable direction, and a free section between the two fixed ends of each of the resilient and elastic members, wherein the free sections of the resilient and elastic members are unfixed to the two sheet layers,
two adjacent free sections of the resilient and elastic members in the orthogonal direction define an inter-free region including at least one sheet bonding section, the two sheet layers being bonded at the at least one sheet bonding section,
wherein the two sheet layers are in a contracted state accompanied by contraction of the resilient and elastic members and each of the two sheet layers are configured to conform to each other in a wave pattern, in which one of the two sheet layers follows corrugations formed by an other of the two sheet layers.

2. The stretchable structure of an absorbent article, according to claim 1 , wherein,
the at least one sheet bonding section comprises multiple sheet bonding sections disposed in the inter-free region at intervals in the stretchable direction and the orthogonal direction, and
the area rate of the sheet bonding sections gradually decreases toward the sides of the inter-free region in the orthogonal direction.

3. The stretchable structure of an absorbent article, according to claim 2 , wherein,
the inter-free region comprises three portions having equal widths in the orthogonal direction in an unfolded state, the three portions comprising a central portion and two side portions positioned on the two sides of the central portion in the orthogonal direction, and
the area rate of the sheet bonding sections in the side portions is 20% or less of the area rate of the sheet bonding sections in the central portion.

4. The stretchable structure of an absorbent article, according to claim 1 , wherein,
the resilient and elastic members comprise three or more resilient and elastic members disposed at intervals in the orthogonal direction, the resilient and elastic members defining multiple inter-free regions therebetween in the orthogonal direction, and
the inter-free regions each include the sheet bonding sections intermittently disposed in the stretchable direction, a partial or entire group of the sheet bonding sections disposed in two adjacent inter-free regions in the orthogonal direction is substantially continuous along the stretchable direction.

5. The stretchable structure of an absorbent article, according to claim 1 , wherein the two sheet layers have a bending resistance in the stretchable direction higher than the bending resistance in the orthogonal direction.

6. The stretchable structure of an absorbent article, according to claim 1 , wherein, in an unfolded state, unbonded regions free from the sheet bonding sections are continuously disposed in the width direction on at least the two sides of the respective inter-free regions in the orthogonal direction, the unbonded regions being disposed over the entire width of the respective inter-free regions.

7. The stretchable structure of an absorbent article, according to claim 6 , wherein each of the unbonded regions has a length within a range of 4 to 20 mm in the orthogonal direction.

8. The stretchable structure of an absorbent article, according to claim 1 , wherein
the resilient and elastic members comprises three or more resilient and elastic members disposed at intervals in the orthogonal direction, the resilient and elastic members defining multiple inter-free regions therebetween in the orthogonal direction, and
the inter-free regions each include the sheet bonding sections.

9. An underpants-type disposable diaper comprising:
an outer member having the stretchable structure of claim 1 comprising a front body and a back body; and
an inner member disposed on the inner face of the outer member and comprising an absorber, wherein,
side seal portions provided by bonding the two side edges of the outer member of the front body and the respective side edges of the outer member of the back body constitute an annular waist portion, a waist opening, and left and right leg openings, and
the stretchable structure is disposed in an area of the outer member including at least two exteriors of the inner member in the width direction, the stretchable direction of the stretchable structure is aligned with the width direction, by which the outer member is configured to be stretchable in the width direction.

10. An underpants-type disposable diaper comprising:
an outer member having the stretchable structure of claim 1 comprising a front body and a back body which are separated or integrated; and
an inner member comprising an absorber, the inner member disposed in a lateral intermediate portion extending from the inner face of the outer member of the front body to the inner face of the outer member of the back body, wherein,
the two side edges of the outer member of the front body is bonded to the respective side edges of the outer member of the back body, to constitute a waist opening and left and right leg openings,
the outer member comprises:
a non-stretchable region that is disposed in a lateral intermediate area and extends in the front-back direction including the absorber; and
intermittent stretchable regions disposed on the two exteriors of the non-stretchable region in the width direction,
the intermittent stretchable regions are disposed such that the stretchable direction of the stretchable structure of an absorbent article according to claim 1 aligns with the width direction, by which the outer member is configured to be stretchable in the width direction,
the non-stretchable region comprises two sheet layers continuing from the intermittent stretchable regions and residual resilient and elastic members, the residual resilient and elastic members comprising at least one of residual pieces remaining between the two sheet layers and continuing from resilient and elastic members in the intermittent stretchable regions and cut pieces of the resilient and elastic members discontinuous from the resilient and elastic members in the intermittent stretchable regions,
the residual resilient and elastic members are unfixed to the two sheet layers, and
in the non-stretchable region, the two sheet layers are bonded at the sheet bonding sections substantially continuous in the width direction on the two sides of the residual resilient and elastic members in the front-back direction.

11. The underpants-type disposable diaper according to claim 10 , wherein, the sheet bonding sections in the non-stretchable region are disposed at intervals to define multiple arrays extending in the width direction, the multiple arrays are disposed in the front-back direction, the sheet bonding sections in each first array of the multiple arrays overlap with the sheet bonding sections in the width direction in a second array adjacent to the first array in the front-back direction, and an overlapping width in the width direction of the sheet bonding sections in the first array and the sheet bonding sections in the second array adjacent to the first array in the front-back direction is larger than the interval between the first and second sheet bonding sections in the front-back direction.

Assignees

• Daio Seishi Kk

Inventors

• Kurohara Takeshi
• Obata Masayo
• Manabe Sadanao
• Hayashi Akifumi
• Mori Yosuke

Classifications

• A61F2013/15878

  by thermal bonding · CPC title

• A61F13/496

  in the form of pants or briefs · CPC title

• A61F13/49012

  the elastic means being elastic panels · CPC title

• A61F13/49009 Primary

  with elastic means · CPC title

• A61F13/15585

  of babies' napkins, e.g. diapers (A61F13/15617 - A61F13/15804 take precedence) · CPC title