# US 10,869,784 B2 · Method for manufacturing stretchable sheet

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- Number: US 10,869,784 B2
- Document ID: US10869784B2
- Status: Granted
- Kind: B2
- Application number: 16/324,287
- Filed: 2017-07-04
- Published: 2019-06-06
- Granted: 2020-12-22
- Earliest claimed: 2016-08-19
- Assignees: Daio Paper Corporation
- Applicants: Daio Paper Corporation
- Inventors: Tomonari Takeuchi
- Web page: https://patentgrep.com/patent/US10869784B2

## CPC

- A61F 13/15593: {having elastic ribbons fixed thereto; Devices for applying the ribbons}
- A61F 5/4404: {Details or parts}
- 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 13/15699: {Forming webs by bringing together several webs, e.g. by laminating or folding several webs, with or without additional treatment of the webs}
- A61F 13/15731: {Treating webs, e.g. for giving them a fibrelike appearance, e.g. by embossing}
- B29C 65/08: using ultrasonic vibrations {(non-plastics element to plastics elements B29C65/645)}
- 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 66/73921: {characterised by the materials of both parts being thermoplastics}
- B29C 66/81422: {being convex}
- 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 66/83413: {cooperating rollers, cylinders or drums}
- B29C 66/83511: {jaws mounted on rollers, cylinders or drums}
- B32B 7/04: Interconnection of layers
- B32B 37/06: characterised by the heating method
- A61F 2013/15552: {Air permeability}
- A61F 2013/15869: {with ultrasonic energy}
- B29C 66/71: {characterised by the composition of the plastics material of the parts to be joined (welding bar compositions B29C65/125)}
- B29C 66/7294: {Non woven mats, e.g. felt}
- B29C 66/73116: {of different melting point, i.e. the melting point of one of the parts to be joined being different from the melting point of the other part}
- 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)}
- B29K 2105/0088: {Blends of polymers}
- B29K 2995/0046: Elastic
- B29L 2031/4878: {Diapers, 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
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A stretchable elastic film is interposed in a stretched state between a first sheet layer having no elasticity and a second sheet layer having no elasticity. Heat melt energy is applied to a region of a large number of bonded portions spaced apart from each other by a heat melting apparatus from the outside of the first sheet layer and the second sheet layer to melt the elastic film. The first sheet layer and the second sheet layer are bonded directly or via an elastic film at the large number of bonded portions. The elastic film is caused to pass through the counter roll and the nip roll to pass along the counter roll and then pass along the anvil roll. The elastic film is stretched by making the circumferential speed of the anvil roll faster than the circumferential speed of the counter roll.

## Claims

### Claim 1

A method for manufacturing a stretchable sheet, comprising:
a supplying step in which a stretchable elastic film is interposed in a stretched state between a first sheet layer having no elasticity and a second sheet layer having no elasticity; and
a bonding step in which, in a state where the elastic film is interposed in a stretched state between the first sheet layer and the second sheet layer in the supplying step, the first sheet layer and the second sheet layer are bonded directly or via an elastic film at a plurality of bonded portions by applying heat melt energy to a region of the plurality of bonded portions spaced apart from each other by a heat melting apparatus from the outside of the first sheet layer and the second sheet layer to melt the elastic film;
wherein the heat melting apparatus has an anvil roll and an ultrasonic horn, the anvil roll has a plurality of protrusions spaced apart from each other in a roll length direction and an outer circumference direction on an outer surface of the anvil roll such that bonding is performed by the ultrasonic horn and a group of the protrusions of the anvil roll at a bonding position;
wherein a counter roll is disposed apart from the anvil roll, and the elastic film is not nipped between the anvil roll and the counter roll;
wherein a nip roll that nips the elastic film is disposed corresponding to the counter roll, and
the elastic film passes through a nip position between the counter roll and the nip roll, along the counter roll, and then along the anvil roll,
wherein a circumferential speed of the anvil roll is faster than a circumferential speed of the counter roll and the nip roll to stretch the elastic film;
wherein a holding angle α from the nip position to a position where the elastic film is separated from the counter roll is 300° to 30°, and a holding angle β from a position where the elastic film starts to be held by the anvil roll to the bonding position is 270° to 30°,
wherein a distance between the nip position and the bonding position is less than 250 mm; and
wherein a distance from a position where the elastic film is separated from the counter roll to the position where the elastic film starts to be held by the anvil roll is 50 mm or less.

### Claim 2 (depends on 1)

The method for manufacturing a stretchable sheet according to claim 1, wherein the anvil roll is a crown roll.

### Claim 3 (depends on 1)

The method for manufacturing a stretchable sheet according to claim 1, wherein the protrusions are disposed in a staggered shape.

### Claim 4 (depends on 1)

The method for manufacturing a stretchable sheet according to claim 1, wherein, a hole is not formed in the entire of the region of the bonded portions and the first sheet layer and the second sheet layer are allowed to remain in the bonding step, and
a through hole is formed at least in a boundary portion in the stretchable direction between the elastic film and the bonded portion.

### Claim 5 (depends on 1)

The method for manufacturing a stretchable sheet according to claim 1, wherein:
the elastic film is additionally nipped between a pre-roll and a pre-nip roll such that the elastic film is configured to pass through a nip position between the pre-roll and the pre-nip roll and then pass through the nip position between the counter roll and the nip roll; and
wherein a circumferential speed of the pre-roll and the pre-nip roll, the circumferential speed of the counter roll and the nip roll, and the circumferential speed of the anvil roll are gradually increased.