# US 4,392,908 A · Process for making absorbent articles

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- Number: US 4,392,908 A
- Document ID: US4392908A
- Status: Granted
- Kind: A
- Application number: 06/223,864
- Filed: 1981-01-09
- Granted: 1983-07-12
- Earliest claimed: 1980-01-25
- Assignees: Lever Brothers Company
- Inventors: Roger B. Dehnel
- Web page: https://patentgrep.com/patent/US4392908A

## CPC

- A61L 15/60: Liquid-swellable gel-forming materials, e.g. super-absorbents
- A61F 13/00991: {for treating webs, e.g. for moisturising, coating, impregnating or applying powder}
- A61F 13/202: {Catamenial tampons (A61F13/2022-A61F13/34 take precedence)}
- A61F 2013/530481: {having superabsorbent materials, i.e. highly absorbent polymer gel materials}
- A61F 2013/530489: {being randomly mixed in with other material}
- A61F 2013/530496: {being fixed to fibres}
- Y10T 428/249962: Void-containing component has a continuous matrix of fibers only [e.g., porous paper, etc.]
- Y10T 428/2998: including synthetic resin or polymer
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention concerns a process for manufacturing a water-absorbent article in which particles of a water-swellable polymer are fixed to a water-absorbent substrate. The process includes the steps of forming on the surface of the water-swellable particles a coating of a thermoplastic adhesive resin; locating the coated particles in their unswollen and dry state on or within the water-absorbent substrate also in the dry state; and applying heat to soften the thermoplastic coating of the particles and pressing the particles and substrate to cause the particles to be bound to the substrate.

## Claims

### Claim 1

A process for manufacturing a water-absorbent article in which particles of a water-swellable polymer are fixed to a water-absorbent substrate, which process comprises:
1. forming on the surface of the water-swellable particles a coating of a thermoplastic adhesive resin to form coated particles;
2. locating the coated particles in their unswollen and dry state on or within the water-absorbent substrate also in the dry state; and
3. applying heat to soften the thermoplastic coating of the particles and pressing the particles and substrate to cause the particles to be bound to the substrate.

### Claim 2 (depends on 1)

A process as claimed in claim 1, wherein the thermoplastic coated absorbent particles have an absorbency efficiency of at least 75%.

### Claim 3 (depends on 1)

A process as claimed in claim 1, wherein the weight ratio of the thermoplastic resin to the water-swellable polymer is from 1:20 to 1:1.

### Claim 4 (depends on 2)

A process as claimed in claim 2, wherein the weight ratio of the thermoplastic resin to the water-swellable polymer is from 1:20 to 1:1.

### Claim 5 (depends on 1)

A process as claimed in claim 1, wherein the coated particles are bound to the substrate by passing the water-absorbent substrate on or within which the coated particles have been located through the nip of pair of rollers at least one of which is heated.