Method of manufacturing multilayer nonwoven fabric

• US 7,955,549 B2
• Filed: 07/29/2009
• Issued: 06/07/2011
• Est. Priority Date: 06/23/2006
• Status: Expired due to Fees

• Current Assignee: Unicharm Corporation
• Original Assignee: Unicharm Corporation
• Inventors: Kimura, Akihiro, Noda, Yuki, Ishikawa, Hideyuki, Mizutani, Satoshi
• Primary Examiner(s): Huson; Monica A
• Application Number:
  US12/511,115
• Publication Number:
  US 20090282660A1
• Time in Patent Office: 678 Days
• Field of Search: None
• US Class Current: 264/510
• CPC Class Codes: B32B 27/02 in the form of fibres or filaments not used
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 3/30 characterised by a layer formed with recesses or projections, e.g. hollows, grooves, protuberances, ribs apertured layer B32B3/266; layer with cavities or internal voids B32B3/26
• 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: D04H 1/492 by fluid jet D04H1/49 takes precedence
• CPC Class Codes: D04H 1/495 for formation of patterns, e.g. drilling or rearrangement
• CPC Class Codes: D04H 1/498 entanglement of layered webs
• CPC Class Codes: D04H 1/559 the fibres being within layered webs
• CPC Class Codes: D04H 13/006 strengthened or consolidated by the use of bonding agents in solid or liquid form
• CPC Class Codes: D04H 13/007 strengthened or consolidated by welding together the various components
• CPC Class Codes: Y10T 428/2457 Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/24603 Fiber containing component

Abstract

A method of manufacturing a multilayer nonwoven fabric includes a supporting step of arranging on a predetermined surface of a permeable supporting member a multilayer fiber aggregate, a moving step of moving the multilayer fiber aggregate supported on the permeable supporting member in a prescribed direction by a predetermined moving device, and a spraying step of spraying a fluid onto the multilayer fiber aggregate moved in the prescribed direction in the moving step from the second surface by a predetermined spraying device.

Claims

1. A method of manufacturing a multilayer nonwoven fabric, said method comprising:

a supporting step of arranging on a side of a permeable supporting member a multilayer fiber aggregate having,

a first fiber aggregate having opposite first and second surfaces and arranged as a first fibrous sheet in a state where fibers composing the first fiber aggregate have a degree of freedom, and

a second fiber aggregate arranged as a second fibrous sheet facing the first surface of the first fiber aggregate and being in a state where fibers composing the second fiber aggregate have a degree of freedom, said second fiber aggregate being positioned between the first fiber aggregate and the permeable supporting member to support the first fiber aggregate on the permeable supporting member;

a moving step of moving the multilayer fiber aggregate supported on the permeable supporting member in a first direction by a moving device; and

a spraying step of spraying a fluid composed of gas onto the multilayer fiber aggregate moved in the first direction in the moving step from the second surface of the first fiber aggregate by a spraying device to form in said multilayer fiber aggregate a plurality of raised ridge portions and a plurality of groove portions on both sides of each of the raised ridge portions, thereby obtaining the multilayer nonwoven fabric.

2. The method according to claim 1, wherein the permeable supporting member comprises a plurality of permeable portions and a plurality of impermeable portions arranged alternatingly in the first direction,

each permeable portion permits the fluid sprayed onto the multilayer fiber aggregate to permeate to a side opposite to the side on which the multilayer fiber aggregate is arranged, and

each impermeable portion does not permit the fluid, sprayed on the multilayer fiber aggregate to permeate to the opposite side,

in the spraying step, the fluid is sprayed on a plurality of first regions of the multilayer fiber aggregate to form the groove portions, and to move the fibers from the first regions to a plurality of second regions of the multilayer fiber aggregate to form the raised ridge portions, wherein the first and second regions are alternatingly arranged in a second direction substantially perpendicular to the first direction.

3. The method according to claim 2, wherein

each of the groove portions has a plurality of low basis weight portions and a plurality of high basis weight portions alternatingly arranged in the first direction,

in the spraying step, the fluid is sprayed on a plurality of first areas of each said first region, which are supported on the permeable portions of the permeable supporting member to form the low basis weight portions, respectively, and

in the spraying step, the fluid is sprayed on a plurality of second areas of each said first region, which are supported on the impermeable portion of the permeable supporting member to form the high basis weight portions.

4. The method according to claim 3, wherein

in the spraying step, the fibers composing the multilayer fiber aggregate are displaced by (i) the fluid sprayed on the multilayer fiber aggregate from the second surface of the first fiber aggregate, and (ii) the fluid which, after permeating the multilayer fiber aggregate, has a direction of flow modified by the impermeable portions.

5. The method according to claim 3, wherein each said low basis weight portion is an opening.

6. The method according to claim 1, wherein the spraying step forms in each said raised ridge portion an apex of a curved surface between the adjacent groove portions.

7. The method according to claim 1, wherein the fluid consists of gas.

8. The method according to claim 1, wherein the fluid is mainly gas and includes solid or liquid particles.

9. The method according to claim 2, wherein the permeable portions of the permeable supporting member are defined by a meshed supporting member.

10. The method according to claim 2, wherein

the permeable portions of the permeable supporting member are defined by a meshed supporting member though which the fibers composing the multilayer fiber aggregate are displaceable during the spraying step;

and

the impermeable portions of the permeable supporting member are defined by a plurality of elongated members arranged on the meshed supporting member and through which the fibers composing the multilayer fiber aggregate are not displaceable during the spraying step.

11. The method according to claim 10, wherein

the elongated members arranged on the meshed supporting member longitudinally extend in the second direction.

12. The method according to claim 9, wherein said meshed supporting member has a plurality of raised portions and groove portions arranged alternatingly in the first direction.

13. The method according to claim 2, wherein

the permeable supporting member is defined by a plate member which is substantially flat and includes a plurality of holes and solid flat regions around the holes, said holes and solid flat regions defining the permeable portion and the impermeable portion of the permeable supporting member, respectively.