Nonwoven thermoplastic fabric

• US 4,041,203 A
• Filed: 10/04/1976
• Issued: 08/09/1977
• Est. Priority Date: 09/06/1972
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Corporation
• Original Assignee: Kimberly-Clark Corporation
• Inventors: Meitner, Gary H., Brock, Robert J.
• Primary Examiner(s): Bell, James J.
• Application Number:
  US05/729,356
• Time in Patent Office: 309 Days
• Field of Search: 428/195, 428/198, 428/286, 428/288, 428/296, 428/297, 428/298, 428/302, 428/332, 428/515, 428/903, 428/910, 156/219, 156/220, 156/291, 156/309
• US Class Current: 428/157
• CPC Class Codes: A61B 42/40 Packages or dispensers
• CPC Class Codes: A61B 46/10 specially adapted for instruments, e.g. microscopes
• CPC Class Codes: A61M 5/002 Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres
• CPC Class Codes: B32B 2262/0261 Polyamide fibres
• CPC Class Codes: B32B 2262/14 Mixture of at least two fibres made of different materials
• CPC Class Codes: B32B 2307/718 Weight, e.g. weight per square meter
• CPC Class Codes: B32B 2309/02 Temperature
• CPC Class Codes: B32B 2309/12 Pressure
• CPC Class Codes: B32B 2309/14 Velocity, e.g. feed speeds
• CPC Class Codes: B32B 37/15 with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
• CPC Class Codes: B32B 37/206 Laminating a continuous layer between two continuous plastic layers
• CPC Class Codes: B32B 38/06 Embossing
• CPC Class Codes: B32B 5/022 Non-woven fabric
• CPC Class Codes: B32B 5/08 the fibres or filaments of a layer being of different substances , e.g. conjugate fibres, mixture of different fibres
• 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 1/559 the fibres being within layered webs
• CPC Class Codes: D04H 1/56 in association with fibre formation, e.g. immediately following extrusion of staple fibres
• CPC Class Codes: D04H 3/14 with bonds between thermoplastic yarns or filaments produced by welding
• CPC Class Codes: Y10S 428/903 Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10S 428/91 : Product with molecular orientation
• CPC Class Codes: Y10T 428/24488 : Differential nonuniformity at margin
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/27 : Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
• CPC Class Codes: Y10T 442/626 : Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric
• CPC Class Codes: Y10T 442/69 : Autogenously bonded nonwoven fabric

Abstract

A non-woven fabric-like material comprising an integrated mat of generally discontinuous, thermoplastic polymeric microfibers and a web of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer. The polymeric microfibers have an average fiber diameter of up to about 10 microns while the average diameter of filaments in the continuous filament web is in excess of about 12 microns. Attachment between the microfiber mat and continuous filament web is achieved at intermittent discrete regions in a manner so as to integrate the continuous filament web into an effective load bearing constituent of the material. The material has desirable strength characteristics and possesses a textile-like appearance, drape and hand. By autogenously bonding the mat and web together in a manner so as to provide substantially uniform discrete bond regions, particularly outstanding strength characteristics with respect to energy absorption, tensile strength, and tear resistance can be achieved.

Claims

1. A nonwoven fabric-like material comprising a web of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer having an average filament diameter in excess of about 12 microns and an integrated mat of generally discontinuous, thermoplastic polymeric microfibers having an average fiber diameter of up to about 10 microns and a softening temperature of about 10°

-40°

C. less than the softening temperature of the continuous filaments;

said web and mat being positioned in laminar surface-to-surface relationship and united together at intermittent discrete bond regions formed by the application of heat and pressure to thereby provide a unitary structure having desirable textile-like appearance and drape characteristics and to integrate the web of substantially continuous filaments so that said web can function as an effective load bearing constituent of the material during straining thereof.

2. The nonwoven fabric-like material of claim 1 wherein the discrete bond regions are present in a density of about 50-1,000/in.² and occupy about 5-50% of the surface area of the material.

3. The nonwoven fabric-like material of claim 1 wherein the discrete bond regions are present in a density of about 100-500/in.² and occupy about 10-30% of the surface area of the material.

4. The nonwoven fabric-like material of claim 3 wherein the intermittent discrete bond regions are uniformly bonded without a substantial degree of fusion of the continuous filament occurring therein.

5. The nonwoven fabric-like material of claim 4 having a basis weight of up to about 4 oz./yd.².

6. The nonwoven fabric-like material of claim 5 wherein the average filament diameter of the filaments of the continuous filament web is about 12-55 microns.

7. The nonwoven fabric-like material of claim 6 wherein the average filament diameter of the filaments of the continuous filament web is about 15-25 microns.

8. The nonwoven fabric-like material of claim 7 wherein the ratio of the mat to the web is about 0.2:

1 to 4;

1 by weight.

9. The nonwoven fabric-like material of claim 8 having a basis weight of about 0.75-2.5 oz./yd.².

10. The nonwoven fabric-like material of claim 9 wherein the thermoplastic polymer filaments and the thermoplastic polymeric microfibers are of polypropylene.

11. The nonwoven fabric-like material of claim 1 wherein a second polymeric microfiber mat is united to the web on the other surface thereof to provide a material which is highly suitable for decorative or informative printing.

26. The nonwoven fabric-like material of claim 1 wherein a second web of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer is united to the mat on the other surface thereof.

12. A sterile wrap for wrapping about items to be sterilized for subsequent use in surgical procedures, said sterile wrap having a surface resistivity of less than 1 ×

10.sup. 12 ohms/square and comprising a web, having a basis weight of at least about 0.5 oz./yd.² of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer having an average filament diameter in excess of about 12 microns and, to provide bacterial barrier properities and yet allow sterilant penetration, an integrated mat, having a basis weight of at least about 0.3 oz./yd.², of generally discontinuous, thermoplastic polymeric microfibers having an average fiber diameter of up to about 10 microns, said web and mat being positioned in laminar surface-to-surface relationship and united together at intermittent discrete bond regions formed by the application of heat and pressure to thereby provide a unitary structure having a desirable textile-like appearance and drape characteristics and to integrate the web of substantially continuous filaments and the microfiber mat so that said web can function as an effective load bearing constituent of the material while said mat retains said sterilant penetration and bacterial barrier properties in said material.

13. The sterile wrap of claim 12 wherein the thermoplastic polymer filaments and the thermoplastic polymeric microfibers are of polypropylene.

14. The sterile wrap of claim 13 having a basis weight of about 0.8 oz./yd.² - 2 oz./yd.².

15. The sterile wrap of claim 14 having a surface resistivity of less than 1 ×

10¹¹ ohms/square.

16. The sterile wrap of claim 15 wherein the ratio of the mat to the web is less than about 1:

1 by weight.

17. The sterile wrap of claim 16 wherein the ratio of the mat to the web is about 0.7:

1-0.9;

1 by weight.

18. The sterile wrap of claim 17 having a basis weight of about 1.1-1.5 oz./yd.².

19. The sterile wrap of claim 12 wherein a second web having a basis weight of at least about 0.5 oz./yd.² of substantially continuous and randomly deposited, molecularly oriented filaments of a thermoplastic polymer is united to the mat on the other surface thereof.

20. The sterile wrap of claim 12 wherein the discrete bond regions are present in a density of about 50-1,000/in.² and occupy about 5-50% of the surface area of the material.

21. The sterile wrap of claim 12 wherein the discrete bond regions are present in a density of about 100-500/in.² and occupy about 10-30% of the surface area of the material.

22. The sterile wrap of claim 21 wherein the intermittent discrete bond regions are uniformly bonded without a substantial degree of fusion of the continuous filaments occurring therein.

23. The sterile wrap of claim 12 wherein the average filament diameter of the filaments of the continuous filament web is about 12-55 microns.

25. The sterile wrap of claim 12 wherein a second polymeric microfiber mat is united to the web on the other surface thereof to provide a material which is highly suitable for decorative or informative printing.

24. The sterile wrap of claim 24 wherein the average filament diameter of the filaments of the continuous filament web is about 15-25 microns.