# US 12,004,927 B2 · Method for forming elastic film stretchable structure and absorbent article

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,004,927 B2
- Document ID: US12004927B2
- Status: Granted
- Kind: B2
- Application number: 17/717,837
- Filed: 2022-04-11
- Published: 2022-10-06
- Granted: 2024-06-11
- Earliest claimed: 2016-03-24
- Assignees: Daio Paper Corporation
- Applicants: Daio Paper Corporation
- Inventors: Syunsuke Sakai
- Web page: https://patentgrep.com/patent/US12004927B2

## CPC

- A61F 13/15617: {Making absorbent pads from fibres or pulverulent material with or without treatment of the fibres}
- A61F 13/15: Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F 13/15593: {having elastic ribbons fixed thereto; Devices for applying the ribbons}
- A61F 13/15699: {Forming webs by bringing together several webs, e.g. by laminating or folding several webs, with or without additional treatment of the webs}
- A61F 13/15739: {Sealing, e.g. involving cutting}
- A61F 13/49: specially adapted to be worn around the waist, e.g. diapers or nappies
- A61F 13/49012: {the elastic means being elastic panels}
- A61F 13/4902: {characterised by the elastic material}
- A61F 13/496: in the form of pants or briefs
- B29C 65/086: {using a rotary anvil}
- B29C 66/1122: {Single lap to lap joints, i.e. overlap joints (B29C66/45, B29C66/472, B29C66/52272 take precedence)}
- B29C 66/21: {said joint lines being formed by a single dot or dash or by several dots or dashes, i.e. spot joining or spot welding}
- B29C 66/344: {Stretching or tensioning the joint area during joining}
- B29C 66/41: {Joining substantially flat articles (B29C66/47 and subgroups take precedence); Making flat seams in tubular or hollow articles (B29C66/51 and subgroups take precedence)}
- B29C 66/433: {Casing-in, i.e. enclosing an element between two sheets by an outlined seam (for bookbinding B42C11/06; for packaging B65B; by laminating B32B37/00; enclosing tubular articles between substantially flat elements B29C66/53261)}
- B29C 66/7294: {Non woven mats, e.g. felt}
- B29C 66/81429: {comprising a single tooth}
- B29C 66/81433: {being toothed, i.e. comprising several teeth or pins (comprising a single tooth B29C66/81429), or being patterned}
- B29C 66/83511: {jaws mounted on rollers, cylinders or drums}
- B32B 37/04: characterised by the partial melting of at least one layer
- B32B 37/14: characterised by the properties of the layers
- A61F 2013/15869: {with ultrasonic energy}
- A61F 2013/1591: {via adhesive}
- A61F 2013/15934: {for making non-woven}
- A61F 2013/49022: {being elastomeric sheet}
- B29C 66/83415: {the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle (B29C66/83433 takes precedence)}
- B29L 2031/4878: {Diapers, napkins}
- B32B 5/022: {Non-woven fabric}
- B32B 5/08: the fibres or filaments of a layer being of different substances {, e.g. conjugate fibres, mixture of different fibres}
- B32B 27/08: of synthetic resin
- B32B 27/12: next to a fibrous or filamentary layer
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 37/144: {using layers with different mechanical or chemical conditions or properties, e.g. layers with different thermal shrinkage, layers under tension during bonding (constructional features for tensioning B32B38/1825)}
- B32B 2307/51: Elastic
- B32B 2307/7265: Non-permeable
- B32B 2555/02: Diapers or napkins
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

Ultrasonic welding is performed by passing a first sheet layer, a second sheet layer, and an elastic film interposed therebetween in a stretched state in a machine direction between an anvil roll having a large number of protrusions and an ultrasonic horn. The anvil roll includes a region having the protrusions and in the region. A site, in which welding is performed by one ultrasonic horn, has a portion in which an area rate of the protrusions changes in a roll circumferential direction and a roll length direction. A difference between a maximum value and a minimum value in a change of the area rate of the protrusions in the roll circumferential direction is 4.5% or less, and a difference between a maximum value and a minimum value in a change of the area rate of the protrusions in the roll length direction is 1.5% or less.

## Claims

### Claim 1

An absorbent article comprising
an absorber that absorbs excrement, wherein:
the absorbent article has an elastic film stretchable structure in which an elastic film is stacked between a first sheet layer and a second sheet layer and the first sheet layer and the second sheet layer are bonded via through-holes penetrating the elastic film at a plurality of sheet bonded portions arranged at intervals, and
the elastic film stretchable structure has a portion in which an area rate of a subset of the plurality of sheet bonded portions changes in a stretchable direction of the elastic film stretchable structure, and a difference between a maximum value and a minimum value in a change of the area rate of the subset of the plurality of sheet bonded portions in the stretchable direction is 4.5% or less.

### Claim 2

An absorbent article comprising
an absorber that absorbs excrement, wherein:
the absorbent article has an elastic film stretchable structure in which an elastic film is stacked between a first sheet layer and a second sheet layer and the first sheet layer and the second sheet layer are bonded via through-holes penetrating the elastic film at a plurality of sheet bonded portions arranged at intervals, and
the elastic film stretchable structure has a portion in which an area rate of a subset of the plurality of sheet bonded portions changes in a direction orthogonal to a stretchable direction of the elastic film stretchable structure, and a difference between a maximum value and a minimum value in a change of the area rate of the subset of the plurality of sheet bonded portions in the direction orthogonal to the stretchable direction is 1.5% or less.

### Claim 3

An absorbent article comprising
an absorber that absorbs excrement, wherein:
the absorbent article has an elastic film stretchable structure in which an elastic film is stacked between a first sheet layer and a second sheet layer and the first sheet layer and the second sheet layer are bonded via through-holes penetrating the elastic film at a plurality of sheet bonded portions arranged at intervals, and
the elastic film stretchable structure has a portion in which an area rate of a subset of the plurality of sheet bonded portions changes in a stretchable direction of the elastic film stretchable structure and a direction orthogonal to the stretchable direction, a difference between a maximum value and a minimum value in a change of the area rate of the subset of the plurality of sheet bonded portions in the stretchable direction is 4.5% or less, and a difference between a maximum value and a minimum value in a change of the area rate of the subset of the plurality of sheet bonded portions in the direction orthogonal to the stretchable direction is 1.5% or less.

### Claim 4 (depends on 1)

The absorbent article according to claim 1, wherein:
the elastic film stretchable structure includes:
a non-stretchable region, and
either one of or both of:
a stretchable region adjacent to at least one side of the non-stretchable region in the stretchable direction, and
a stretchable region adjacent to at least one side of the non-stretchable region in the direction orthogonal to the stretchable direction, and
an area rate of the plurality of sheet bonded portions is higher in the non-stretchable region than in the stretchable region.

### Claim 5 (depends on 1)

The absorbent article according to claim 1, wherein:
the absorbent article is an underpants-type disposable diaper including an outer member disposed in a front body and a back body provided individually or as one unit, and an inner member including the absorber and attached to the outer member, both side portions of the outer member in the front body and both side portions of the outer member in the back body being bonded, respectively, and having a waist opening and a pair of left and right leg openings, and
the outer member in at least one of the front body and the back body has the elastic film stretchable structure throughout a range including a whole of a width direction thereof such that a stretchable direction thereof is the width direction.

### Claim 6 (depends on 2)

The absorbent article according to claim 2, wherein:
the elastic film stretchable structure includes:
a non-stretchable region, and
either one of or both of:
a stretchable region adjacent to at least one side of the non-stretchable region in the stretchable direction, and
a stretchable region adjacent to at least one side of the non-stretchable region in the direction orthogonal to the stretchable direction, and
an area rate of the plurality of sheet bonded portions is higher in the non-stretchable region than in the stretchable region.

### Claim 7 (depends on 3)

The absorbent article according to claim 3, wherein:
the elastic film stretchable structure includes:
a non-stretchable region, and
either one of or both of:
a stretchable region adjacent to at least one side of the non-stretchable region in the stretchable direction, and
a stretchable region adjacent to at least one side of the non-stretchable region in the direction orthogonal to the stretchable direction, and
an area rate of the plurality of sheet bonded portions is higher in the non-stretchable region than in the stretchable region.

### Claim 8 (depends on 2)

The absorbent article according to claim 2, wherein:
the absorbent article is an underpants-type disposable diaper including an outer member disposed in a front body and a back body provided individually or as one unit, and an inner member including the absorber and attached to the outer member, both side portions of the outer member in the front body and both side portions of the outer member in the back body being bonded, respectively, and having a waist opening and a pair of left and right leg openings, and
the outer member in at least one of the front body and the back body has the elastic film stretchable structure throughout a range including a whole of a width direction thereof such that a stretchable direction thereof is the width direction.

### Claim 9 (depends on 3)

The absorbent article according to claim 3, wherein:
the absorbent article is an underpants-type disposable diaper including an outer member disposed in a front body and a back body provided individually or as one unit, and an inner member including the absorber and attached to the outer member, both side portions of the outer member in the front body and both side portions of the outer member in the back body being bonded, respectively, and having a waist opening and a pair of left and right leg openings, and
the outer member in at least one of the front body and the back body has the elastic film stretchable structure throughout a range including a whole of a width direction thereof such that a stretchable direction thereof is the width direction.

### Claim 10 (depends on 4)

The absorbent article according to claim 4, wherein:
the absorbent article is an underpants-type disposable diaper including an outer member disposed in a front body and a back body provided individually or as one unit, and an inner member including the absorber and attached to the outer member, both side portions of the outer member in the front body and both side portions of the outer member in the back body being bonded, respectively, and having a waist opening and a pair of left and right leg openings, and
the outer member in at least one of the front body and the back body has the elastic film stretchable structure throughout a range including a whole of a width direction thereof such that a stretchable direction thereof is the width direction.