Absorbent material and method for making same

• US 5,879,487 A
• Filed: 07/17/1997
• Issued: 03/09/1999
• Est. Priority Date: 04/09/1996
• Status: Expired due to Fees

• Current Assignee: Finova Mezzanine Capital, Inc.
• Original Assignee: Wearco, LLC
• Inventors: Ravella, Joseph A.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): YAO, SAMCHUAN CUA
• Application Number:
  US08/896,185
• Time in Patent Office: 600 Days
• Field of Search: 28/106, 28/107, 28/112, 442/403, 442/164, 442/408, 156/148, 156/62.8, 156/199, 156/219, 427/331, 427/371, 427/444
• US Class Current: 156/62.8
• CPC Class Codes: B32B 2323/04 Polyethylene
• CPC Class Codes: B32B 2323/10 Polypropylene
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• 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 5/022 Non-woven fabric
• CPC Class Codes: B32B 5/24 one layer being a fibrous or filamentary layer
• CPC Class Codes: D04H 1/46 by needling or like operations to cause entanglement of fibres D04H1/45 takes precedence; needling machines D04H18/00
• CPC Class Codes: Y10T 156/1039 Surface deformation only of sandwich or lamina [e.g., embossed panels]
• CPC Class Codes: Y10T 428/24033 including stitching and discrete fastener[s], coating or bond
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 442/2484 Coating or impregnation is water absorbency-increasing or hydrophilicity-increasing or hydrophilicity-imparting
• CPC Class Codes: Y10T 442/2525 Coating or impregnation functions biologically [e.g., insect repellent, antiseptic, insecticide, bactericide, etc.]
• CPC Class Codes: Y10T 442/2861 Coated or impregnated synthetic organic fiber fabric
• CPC Class Codes: Y10T 442/667 Needled
• CPC Class Codes: Y10T 442/684 Containing at least two chemically different strand or fiber materials
• CPC Class Codes: Y10T 442/689 Hydroentangled nonwoven fabric

Abstract

An absorbent material and method for making same comprising a fiber web, including a fiber blend comprising from about 50 to about 75 weight percent of a fiber having fineness less than about 3 denier and from about 25 to about 50 weight percent of a fiber having fineness ranging from about 3 to about 5 denier wherein the fiber web is bound together by fiber bundles transverse to the plane of the web. The fiber blend may further comprise from about 3 to about 7 percent by weight of a fiber having fineness greater than about 5 denier. The fibers comprising the fiber blend may be entirely hydrophobic, or the about 3 to about 5 denier fiber may be hydrophilic. The absorbent material exhibits a high degree of absorption and fluid retention and does not wet back even under compression. The transverse fiber bundles formed during the mechanical bonding of the web function as wicks for transferring fluid from the surface of the material to the inner portion of the material. The fiber bundles also act as support structures resisting compression and maintaining void space and absorbent surface area within the material, even when wet. The material is reusable and is strong enough to withstand numerous washings. The material is useful as a component of reusable absorbent products further comprising an outer layer or body-side layer. The outer layer may be fluid impermeable, gas permeable or both.

Claims

1. A method for making an absorbent material, the method comprising the steps of:

forming a fiber web, the fiber web comprising from about 50 to about 75 percent by weight of a fiber having fineness less than about 3 denier, from about 25 to about 50 percent by weight of a fiber having fineness ranging from about 3 to about 5 denier, and from about 3 to about 7 percent by weight of a fiber having fineness greater than about 5 denier, based on a total weight of the blend, and

mechanically bonding the web providing fiber bundles transverse to the plane of the web.

2. A method for making an absorbent material as recited in claim 1, wherein the web forming step comprises providing a carded non-woven fiber web.

3. A method for making an absorbent material as recited in claim 1, further comprising the step of rolling the material over a hot can.

4. A method for making an absorbent material as recited in claim 1, wherein the mechanical bonding step comprises needle punching.

5. A method for making an absorbent material as recited in claim 4, wherein the needle punching step comprises using a needle punch density ranging from about 700 to about 900 penetrations per square inch.

6. A method for making an absorbent material as recited in claim 1, further comprising the step of cross-lapping the web to from a layered batt.

7. A method for making an absorbent material as recited in claim 6, wherein the cross-lapping step comprises forming a batt having at least about 8 layers.

8. A method for making an absorbent material as recited in claim 1, further comprising the step of applying a fluid impermeable coating to a surface of the web.

9. A method for making an absorbent material as recited in claim 1, further comprising the step of embossing a surface of the web.