FILM WITH ALTERNATING STRIPES AND STRANDS AND APPARATUS AND METHOD FOR MAKING THE SAME

• US 20140093716A1
• Filed: 10/02/2012
• Published: 04/03/2014
• Est. Priority Date: 10/02/2012
• Status: Active Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hanschen, Thomas P., Ausen, Ronald W., Wallis, Paul S., Kopecky, William J., Rajagopal, Vathsala, Sikorski, William H. Jr.
• Granted Patent: US 10,272,655 B2
• Time in Patent Office: Days
• US Class Current: 428/221
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/307 specially adapted for bringing together components, e.g. melts within the die
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/726 Permeability to liquids, absorption
• CPC Class Codes: B32B 2535/00 Medical equipment, e.g. bandage, prostheses, catheter medical patches B32B2556/00
• CPC Class Codes: B32B 2555/00 Personal care
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 2556/00 Patches, e.g. medical patches, repair patches
• 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 5/04 characterised by a layer being specifically extensible by reason of its structure or arrangement , e.g. by reason of the chemical nature of the fibres or filaments
• CPC Class Codes: B32B 7/02 Physical, chemical or physicochemical properties
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component

Abstract

A film comprising stripes alternating with strands is disclosed. In some embodiments, the strands have a core and a sheath. The core is more elastic than both the sheath and the strands. In some embodiments, the film has an elongation of at least 75 percent, the width of the strands is in a range from 100 micrometers to 750 micrometers, and a portion of each strand forms part of at least one major surface of the film. An extrusion die useful for making the film and a method for making the film using the extrusion die are also disclosed.

Claims

1. A film comprising stripes alternating with strands comprising a core and a sheath, wherein the core is more elastic than both the sheath and the stripes.

2. The film of claim 1, wherein the stripes are made from a first polymeric composition that is found throughout the thickness of the stripes.

3. The film of claim 1, wherein the sheath forms part of at least one major surface of the film.

4. The film of claim 1, wherein the stripes are made from a first polymeric composition, the core is made from a third polymeric composition, and the sheath is made from a second polymeric composition that is different from the first polymeric composition and the third polymeric composition.

5. The film of claim 1, wherein the stripes have stretch-induced molecular orientation in a direction transverse to their lengths.

6. The film of claim 1, wherein the stripes have stretch-induced molecular orientation and are shirred in a direction parallel to their lengths.

7. A film article comprising an extensible region alongside a ribbon region, wherein the extensible region comprises the film of claim 1, and wherein the ribbon region comprises a film of a first polymeric composition, from which the stripes are made.

8. A laminate comprising the film of claim 1 joined to a fibrous carrier.

9. The laminate of claim 8, wherein the fibrous carrier is an extensible fibrous carrier with a tensile elongation at maximum load of at least 50 percent.

10. The laminate of claim 8, wherein the film is discontinuously bonded to the fibrous carrier, and wherein the fibrous carrier is bonded to the film predominantly at one of the stripes or the strands.

11. An absorbent article comprising the laminate of claim 8.

12. A film comprising alternating stripes and strands, wherein at least portions of the strands are more elastic than the stripes, wherein the film has an elongation of at least 75 percent, wherein the width of the strands is in a range from 100 micrometers to 750 micrometers, and wherein a portion of each strand forms part of at least one major surface of the film.

13. An extrusion die comprising at least a first cavity, a second cavity, a third cavity, a dispensing surface having a dispensing slot, and fluid passageways between the first, second, and third cavities and the dispensing slot, wherein the fluid passageways comprise a first fluid passageway extending from the first cavity to the dispensing slot, a third fluid passageway extending from the third cavity to the dispensing slot, at least two second fluid passageways extending from the second cavity to the dispensing slot on either side of the third fluid passageway, and wherein each of the second passageways has a dimension larger than the third passageway at the point where the third passageway enters the dispensing slot.

14. The extrusion die of claim 13, wherein the fluid passageways are provided by a plurality of sequences of shims, wherein each sequence comprises at least one first shim that provides the first fluid passageway, at least one third shim that provides the third fluid passageway, and at least two second shims that provide the at least two second fluid passageways.

15. The extrusion die of claim 14, wherein each sequence of shims further comprises at least two spacer shims, each spacer shim being between the at least one third shim and one of the at least two second shims, wherein the spacer shim has a dispensing opening but lacks a passageway between the dispensing opening and any of the first, second, or third cavities.

16. A method of making a film, the method comprising:

providing the extrusion die of claim 13;

extruding polymeric compositions from the first, second, and third cavities so as to form the film, which comprises stripes alternating with strands comprising a core and a sheath.

17. The method of claim 16, wherein the core is more elastic than both the stripes and the sheath, and wherein the sheath forms part of at least one major surface of the film.

18. The extrusion die of claim 13, further comprising a fourth fluid passageway extending from the first cavity to the dispensing slot.

19. A method of making a film, the method comprising:

providing the extrusion die of claim 18, wherein the fourth fluid passageway is provided by a shim in a second sequence of shims, and wherein the second sequence of shims further includes a spacer shim with a dispensing opening but with no passageway between the dispensing opening and the first cavity; and

extruding polymeric compositions from the first, second, and third cavities so as to form the film comprising an extensible region alongside a ribbon region, wherein the extensible region comprises stripes alternating with strands comprising a core and a sheath, and wherein the ribbon region comprises a film of a first polymeric composition, from which the stripes are made, extruded through a plurality of the second sequence of shims.

20. A method of controlling the caliper in an extruded film, the method comprising:

providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining at least a first cavity and a die slot with a distal opening, wherein each of the plurality of shims defines a portion of the distal opening, wherein the plurality of shims includes first shims providing a passageway between the first cavity and the die slot with their distal openings together providing a dispensing opening in the die slot, and wherein the plurality of shims further includes spacer shims having a dispensing orifice but lacking a passageway between the dispensing orifice and the first cavity; and

extruding a polymeric composition from the first cavity to provide the extruded film;

wherein the caliper of the extruded film is controlled by adjusting the width of the dispensing opening between the spacer shims.