Ultrasonic bonding method for absorbent article, ultrasonic bonding device for absorbent article, and absorbent article

Patent metadata

Field	Value
Publication number	US-9517169-B2
Application number	US-201314407550-A
Country	US
Kind code	B2
Filing date	Jun 13, 2013
Priority date	Jul 4, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

An absorbent article having a plurality of granular particles placed between two liquid-permeable non-woven fabric sheets, the article including: a high-strength bonded portion formed in a loop-shaped pattern on the article such that the two non-woven fabric sheets are not separated even if the granular particles swell to thereby apply a separating force to a bonded position between the two non-woven fabric sheets; and a low-strength bonded portion formed in an inner area surrounded by the high-strength bonded portion such that the two non-woven fabric sheets are separated from each other at a bonded position when the granular particles swell to thereby apply a separating force to the bonded position between the two non-woven fabric sheets.

First claim

The invention claimed is:

1. An ultrasonic bonding device for use with an absorbent article having a plurality of granular particles, capable of absorbing a body fluid to swell, between two liquid-permeable non-woven fabric sheets facing each other, the device comprising:
an anvil roll for carrying the two non-woven fabric sheets while the two non-woven fabric sheets are laid on each other;
a plurality of protruding portions formed on the anvil roll so as to protrude outward in a radial direction of the anvil roll;
a placement device for preventing the granular particles from being placed on the non-woven fabric sheets over the protruding portions; and
a horn for ultrasonically vibrating so that the two non-woven fabric sheets are bonded together between the horn and the plurality of protruding portions, thereby forming bonded portions, the protruding portions comprising:
at least one first protruding portion, which is away from the horn by a first distance when the first protruding portion comes closest to the horn, for forming at least one high-strength bonded portion such that the non-woven fabric sheets are unseparated from each other at the bonded portion by a peeling force urging the non-woven fabric sheets to peel off each other; and
at least one second protruding portion, of which a second distance to the horn when the second protruding portion comes closest to the horn is greater than the first distance, for forming at least one low-strength bonded portion such that the non-woven fabric sheets are separatable from each other at the bonded portion by the peeling force urging the non-woven fabric sheets to peel off each other,
wherein a difference between the first distance and the second distance is 3 μm to 60 μm.

2. The ultrasonic bonding device according to claim 1 , wherein:
the first protruding portion is placed on the anvil roll so that the high-strength bonded portion is formed in a loop-shaped pattern on the article; and
the second protruding portion is placed on the anvil roll so that the low-strength bonded portion is formed in an inner area surrounded by the high-strength bonded portion.

3. The ultrasonic bonding device according to claim 2 , wherein the first protruding portion includes a first protruding portion placed on the anvil roll for forming another high-strength bonded portion different from the high-strength bonded portion formed in the loop-shaped pattern.

4. The ultrasonic bonding device according to claim 3 , wherein:
the first protruding portion and/or the second protruding portion are provided so that the low-strength bonded portion and/or the high-strength bonded portions define a plurality of placement areas partitioned from one another in a predetermined pattern; and
the placement device places a plurality of granular particles separately in the placement areas.

Assignees

• Nakakado Masaki
• Zuiko Corp

Inventors

• Nakakado Masaki

Classifications

• B29C66/7373

  Joining soiled or oxidised materials · CPC title

• B29C66/433

  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) · CPC title

• B29C66/7294

  Non woven mats, e.g. felt · CPC title

• B29C66/1122

  Single lap to lap joints, i.e. overlap joints (B29C66/45, B29C66/472, B29C66/52272 take precedence) · CPC title

• B29C66/81433

  being toothed, i.e. comprising several teeth or pins (comprising a single tooth B29C66/81429), or being patterned · CPC title