Fiber sheet

• US 10,441,978 B2
• Filed: 06/01/2015
• Issued: 10/15/2019
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: LEC Incorporated (Windstream Holdings II LLC)
• Original Assignee: Kikuo Yamada
• Inventors: Yamada, Kikuo
• Primary Examiner(s): Ferguson, Lawrence D
• Application Number:
  US15/308,007
• Publication Number:
  US 20170056933A1
• Time in Patent Office: 1,597 Days
• CPC Class Codes: A47K 10/16 Paper towels; Toilet paper; Holders therefor dispensers A47K10/32
• CPC Class Codes: A47K 7/00 Body washing or cleaning implements bathing devices for special therapeutic or hygienic purposes A61H33/00; baths for specific parts of the body A61H35/00
• CPC Class Codes: A47K 7/03 containing soap or other cleaning ingredients, e.g. impregnated
• CPC Class Codes: A47L 13/17 containing cleaning agents A47L13/19 takes precedence ; chemical compositions C11D17/049
• CPC Class Codes: B08B 1/00 Cleaning by methods involving the use of tools cleaning hollow articles by methods or apparatus specially adapted thereto B08B9/00
• CPC Class Codes: B08B 1/143 Wipes
• CPC Class Codes: B32B 2037/243 Coating
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 2555/00 Personal care
• CPC Class Codes: B32B 37/24 with at least one layer not being coherent before laminating, e.g. made up from granular material sprinkled onto a substrate B32B37/15 takes precedence
• CPC Class Codes: B32B 38/06 Embossing
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: D21H 27/002 Tissue paper; Absorbent paper D21H21/22, D21H27/02, D21H27/20 take precedence; toilet paper A47K10/00; absorbent pads for physiological fluids A61L15/16; making on paper-making machines D21F11/00
• CPC Class Codes: D21H 27/30 Multi-ply for surface covering D21H27/18; making on paper-making machines D21F9/00, D21F11/00
• CPC Class Codes: D21H 27/32 with materials applied between the sheets attaching together paper or cardboard sheets B31F5/00; adhesives C09J
• CPC Class Codes: D21H 27/38 at least one of the sheets having a fibrous composition differing from that of other sheets

Abstract

A fiber sheet having both a bulky feel and softness is provided. A fiber sheet (1) is provided with a surface sheet layer (5) and a softness imparting layer (6). The fiber sheet (1) is subjected to embossing and a binder is applied to the fiber sheet (1). The softness imparting layer (6) is constituted by a plurality of fibers; and the fibers exist densely in a compressed state in a region of a boundary face between the surface sheet layer (5) and the softness imparting layer (6). Additionally, the surface sheet layer (5) is a paper material formed from pulp paper or a material including pulp as a principal raw material; and the softness imparting layer (6) is formed from crushed pulp or a material including crushed pulp as a principal raw material. Furthermore, the surface sheet layer (5) is manufactured by a paper making process; and the softness imparting layer (6) is formed by laminating crushed pulp along a flow of an airflow on a surface of the surface sheet. Moreover, depressions are formed via the embossing and, thereafter, the binder is applied.

Claims

1. A fiber sheet, comprising:

a first surface sheet layer and a second surface sheet layer each comprising a paper material formed from pulp paper or from a material including pulp as a principal raw material; and

a softness imparting layer comprising a plurality of fibers of crushed pulp or a plurality of fibers of a material including crushed pulp as a principal raw material, and having a fiber density varying in a thickness direction of the fiber sheet such that the fibers are dense in a first side of the softness imparting layer and are sparse in a second side of the softness imparting layer opposite to the first side,

wherein the fiber sheet is embossed to have a plurality of depressions and is applied with a binder,

the binder is applied to the fiber sheet after the fiber sheet is embossed, and

a first joining strength joining the first surface sheet layer and the softness imparting layer at the first side of the softness imparting layer is stronger than a second joining strength joining the second surface sheet layer and the softness imparting layer at the second side of the softness imparting layer.

2. The fiber sheet according to claim 1,

wherein the softness imparting layer is formed by laminating crushed pulp on a surface of the first surface sheet layer while applying an airflow in the thickness direction of the fiber sheet.

3. The fiber sheet according to claim 1, wherein each of the first and second surface sheet layers has a thickness of from 0.003 cm to 0.050 cm.

4. The fiber sheet according to claim 1, wherein a density of each of the first and second surface sheet layers is from 0.05 g/cm³ to 0.5 g/cm³.

5. The fiber sheet according to claim 1, wherein an air permeability of each of the first and second surface sheet layers is from 500 mm³/(mm²×

sec) to 2000 mm³/(mm²×

sec).

6. The fiber sheet according to claim 1, wherein the softness imparting layer comprises a fiber having a length sufficient to bridge adjacent depressions.

7. The fiber sheet according to claim 1, wherein the binder is included in an amount of from 2 wt % to 9 wt %.

8. The fiber sheet according to claim 1, wherein the softness imparting layer includes 80% or more of pulp.

9. The fiber sheet according to claim 1, wherein the binder is applied to a surface of the first surface sheet layer opposite to a surface joined to the first side of the softness imparting layer and a surface of the second surface sheet layer opposite to a surface joined to the second side of the softness imparting layer.

10. The fiber sheet according to claim 1, wherein the fiber sheet is embossed in a dried state in atmosphere.

11. The fiber sheet according to claim 1, wherein the fiber sheet is embossed such that the first surface sheet layer has a flat shape and the second surface sheet layer has a depressed shape.

12. The fiber sheet according to claim 1, wherein the binder comprises at least one selected from the group consisting of carboxymethyl cellulose, polyvinyl alcohol, and ethylene-vinyl acetate copolymer resin.

13. The fiber sheet according to claim 1, wherein the first and second surface sheet layers of the surface sheet layer have a same thickness and composition.

14. The fiber sheet according to claim 1, wherein the fiber sheet is embossed to form the plurality of depressions uniformly throughout an entire surface of the fiber sheet.

15. The fiber sheet according to claim 1, wherein the fiber sheet does not comprise a releasing agent.

23. A method of making the fiber sheet of claim 15, comprising:

laminating the softness imparting layer to the surface sheet layer by using the airflow such that the softness imparting layer comprises the plurality of fibers of the material comprising 50% or more of pulp and that the surface sheet layer has the air permeability of from 500 to 2000 mm³/(mm²×

sec), thereby producing a laminated sheet;

compressing or pressing the laminated sheet in the non-wet state to process the at least one surface of the laminated sheet; and

applying at least one of the binder and the water-based composition to the laminated sheet.

16. A fiber sheet, comprising:

a surface sheet layer comprising a paper material formed from pulp paper or from a material including pulp as a principal raw material, the surface sheet layer having an air permeability of from 500 to 2000 mm³/(mm²×

sec); and

a softness imparting layer laminated on the surface sheet layer and comprising a plurality of fibers of crushed pulp or a plurality of fibers of a material including crushed pulp as a principal raw material,

wherein the fiber sheet is compressed or pressed in a non-wet state to process at least one surface of the fiber sheet, and then applied with at least one of a binder and a water-based composition, and

the softness imparting layer is laminated on the surface sheet layer by an airflow permeating the surface sheet layer.

17. The fiber sheet according to claim 16, wherein the fiber sheet has a bulk portion comprising depressions, protrusions, or both, such that the bulk portion increases a bulkiness of the fiber sheet.

18. The fiber sheet according to claim 16, wherein the fiber sheet is compressed or pressed by a roller.

19. The fiber sheet according to claim 16, wherein the softness imparting layer has a fiber density varying in a thickness direction of the fiber sheet such that the fibers are dense in a first side of the softness imparting layer and are sparse in a second side of the softness imparting layer opposite to the first side.

20. The fiber sheet according to claim 16, wherein the fiber sheet does not comprise a releasing agent.

21. The fiber sheet according to claim 16, wherein the softness imparting layer comprises a plurality of fibers of a material including crushed pulp as a principal raw material, and the material includes 50% or more of the crushed pulp.

22. The fiber sheet according to claim 16, wherein the crushed pulp in the softness imparting layer has a basis weight of 60 g/m² or less.

24. A cleaning article, comprising:

the fiber sheet according to claim 16.