High strength nonwoven fabric and process for making

• US 6,537,935 B1
• Filed: 01/29/1999
• Issued: 03/25/2003
• Est. Priority Date: 01/29/1999
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Melbye, William, Seth, Jayshree
• Primary Examiner(s): Morris, Terrel
• Assistant Examiner(s): Guarriello, John J.
• Application Number:
  US09/240,452
• Time in Patent Office: 1,516 Days
• Field of Search: 442/328, 442/333, 442/366, 604/373, 604/385.2, 428/198, 428/298.1, 428/92, 428/152, 428/195, 428/196
• US Class Current: 442/366
• CPC Class Codes: D04H 1/559 the fibres being within layered webs
• CPC Class Codes: D04H 1/593 to layered webs
• CPC Class Codes: D04H 11/04 formed by zig-zag folding of a fleece or layer of staple fibres, filaments, or yarns, strengthened or consolidated at the folds
• CPC Class Codes: D04H 3/04 in rectilinear paths, e.g. crossing at right angles
• CPC Class Codes: D04H 3/14 with bonds between thermoplastic yarns or filaments produced by welding
• CPC Class Codes: Y10T 428/23957 Particular shape or structure of pile
• CPC Class Codes: Y10T 428/24446 Wrinkled, creased, crinkled or creped
• CPC Class Codes: Y10T 428/2481 including layer of mechanically interengaged strands, strand-portions or strand-like strips
• CPC Class Codes: Y10T 428/24826 Spot bonds connect components
• CPC Class Codes: Y10T 428/249942 Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 442/601 Nonwoven fabric has an elastic quality
• CPC Class Codes: Y10T 442/607 Strand or fiber material is synthetic polymer
• CPC Class Codes: Y10T 442/643 Including parallel strand or fiber material within the nonwoven fabric

Abstract

A nonwoven fabric sheet comprising a multiplicity of generally parallel elongate strands of inelastic thermoplastic material extending in a first direction in spaced relationship, each of said strands having opposite elongate side surface portions that are spaced from and are adjacent elongate side surface portions of adjacent strands, and each of said strands also having corresponding opposite first and second elongate surface portions extending between said opposite elongate side surface portions, and a first sheet of flexible nonwoven material having spaced anchor portions bonded at first bond sites of the strands along said first elongate surface portions wherein the elongate strands thermoplastic material is oriented at least between adjacent bond sites along the length of the strands.

Claims

1. A nonwoven fabric sheet comprising:

a multiplicity of generally parallel elongate strands of inelastic thermoplastic material extending in a first direction in spaced relationship, each of said strands having opposite elongate side surface portions that are spaced from and are adjacent elongate side surface portions of adjacent strands, and each of said strands also having corresponding opposite first and second elongate surface portions extending between said opposite elongate side surface portions; and

a first sheet of flexible nonwoven material formed of fibers, having spaced anchor portions bonded at first bond sites of the strands along said first elongate surface portions wherein the thermoplastic material forming the strands is oriented by stretching the strands at least between adjacent bond sites along the length of the strands.

2. The nonwoven fabric sheet of claim 1 where the nonwoven fabric sheet has a tensile yield strength in the first direction of at least 2000 grams/2.54 cm-width.

3. The nonwoven fabric sheet of claim 1 wherein the nonwoven fabric sheet has a second web attached to the second elongate surface portion.

4. The nonwoven fabric sheet of claim 1 wherein the nonwoven fabric sheet has a tensile yield strength in the first direction of at least 4000 g/2.54 cm-width.

5. The nonwoven fabric sheet of claim 1 wherein the strands at the bond sites are less oriented than the strands between the bond sites.

6. The nonwoven fabric sheet of claim 1 wherein the bond sites are from 2 to 70 percent of the nonwoven fabric sheet cross sectional area.

7. The nonwoven fabric sheet of claim 1 wherein the strands at the bond sites are oriented by less than 100 percent.

8. The nonwoven fabric sheet of claim 7 wherein strands at the bond sites are oriented by less than 5 percent.

9. The nonwoven fabric sheet according to claim 1 having regions with oriented strand and adjacent regions without oriented strands.

10. The nonwoven fabric sheet according to claim 1 wherein the strand length between the bond sites is greater than the length of the flexible nonwoven material between the bond sites creating upstanding strand loop portions.

11. The nonwoven fabric sheet according to claim 8 wherein said strands have a greater width between said opposite elongate side surface portions at said first sheet bond sites.

12. The nonwoven fabric sheet according to claim 1 wherein the strands and at least some of the fibers forming the flexible nonwoven material are formed of a polyolefin.

13. A disposable diaper or other garment including a nonwoven fabric sheet, the nonwoven fabric sheet comprising:

a multiplicity of generally parallel elongate strands of inelastic thermoplastic material extending in spaced relationship, each of said strands having opposite elongate side surface portions that are spaced from and are adjacent elongate side surface portions of adjacent strands, and each of said strands also having corresponding opposite first and second elongate surface portions extending between said opposite elongate side surface portions; and

a first sheet of flexible nonwoven material having anchor portions thermally bonded at first sheet bond sites of the strands along said first elongate surface portions wherein thermoplastic material forming the elongate strands is oriented at least between adjacent bond sites along the length of the strands.