Method of imparting a three-dimensional fiber-like appearance and tactile impression to a running ribbon of thermoplastic film

• US 4,601,868 A
• Filed: 12/20/1983
• Issued: 07/22/1986
• Est. Priority Date: 04/21/1982
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Thompson, Hugh A., Radel, Clifford J.
• Primary Examiner(s): Silbaugh, Jan
• Application Number:
  US06/563,724
• Time in Patent Office: 945 Days
• Field of Search: 264/504, 264/154, 264/156, 264/555, 264/556, 264/280, 264/288.8, 425/290, 425/326.1, 425/387.1, 425/388
• US Class Current: 264/504
• CPC Class Codes: A61F 13/51104 the top sheet having a three-dimensional cross-section, e.g. corrugations, embossments, recesses or projections
• CPC Class Codes: A61F 13/512 characterised by its apertures, e.g. perforations
• CPC Class Codes: B26F 1/26 Perforating by non-mechanical means, e.g. by fluid jet
• CPC Class Codes: B29C 59/06 using vacuum drums for thermoforming B29C51/225

Abstract

A resilient plastic web exhibiting a fiber-like appearance and tactile impression and method and apparatus for its manufacture. In a preferred embodiment, the web exhibits a three-dimensional microstructure comprising a regulated continuum of debossed areas of non-uniform cross-section along their length. In a particularly preferred embodiment, the debossed areas comprise capillary networks interconnecting the first and second surfaces of the web, said networks being of decreasing size in the direction of said second surface to promote fluid transport from the first surface of the web to the second surface and inhibit the flow of fluid in the reverse direction. Forming surfaces utilized to produce said webs are constructed by laminating a multiplicity of thin plates having patterns of apertures therein to form an integral structure exhibiting properties and characteristics unachievable by prior art machining and weaving techniques. In a particularly preferred embodiment, the individual lamina from which the laminate forming structure is comprised are produced utilizing photoetching techniques, thus making it feasible to produce nearly any desired level of intricacy in the resultant laminate structure. Preferred means for interconnecting said laminate structures with one another without disrupting the three-dimensional pattern in the area of joinder are also disclosed.

Claims

1. A method of continuously debossing a running ribbon of substantially planar thermoplastic film to produce a resilient three-dimensional web having first and second surfaces and containing a multiplicity of capillary networks, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially uniform U-shaped cross-section along its length, said method comprising the steps of :

(a) continuously bringing said film in contacting relation with a tubular-shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks originating in and extending continuously from the film contacting surface to the non-film contacting surface thereof, each of said capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(b) heating a portion of said film in contact with said forming surface above its thermoplastic temperature;

(c) applying a sufficiently great pressure to said heated thermoplastic film to cause those portions of said film which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said capillary networks and imparting a three-dimensional fiber-like appearance and tactile impression to said film; and

(d) cooling the debossed film below its thermoplastic temperature to form said resilient web before removing said web from said forming structure.

3. The method of claim 1 or claim 2, wherein said pressure applied to said heated thermoplastic film comprises pneumatic differential pressure, said pneumatic differential pressure being sufficient to cause said film to be debossed and perforated in the image of said perforate laminate forming structure.

4. The method of claim 1 or claim 2, wherein said tubular-shaped perforate laminate forming surface is preheated prior to bringing said film in contacting relation therewith to facilitate better conformance of said film to said forming surface.

2. A method of continuously debossing a running ribbon of substantially planar thermoplastic film to produce a resilient three-dimensional web having first and second surfaces and containing a multiplicity of capillary networks of non-uniform cross-section along their length, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially uniform U-shaped cross-section along its length, said method comprising the steps of:

(a) continuously bringing said film in contacting relation with a tubular-shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks of non-uniform cross-section along their length originating in and extending continuously from the film contacting surface to the non-film contacting surface thereof, each of said non-uniform cross-section capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(b) heating a portion of said film in contact with said forming surface above its thermoplastic temperature;

(c) applying a sufficiently great pressure to said heated thermoplastic film to cause those portions of said film which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said non-uniform cross-section capillary networks and imparting a three-dimensional fiber-like appearance and tactile impression to said film; and

(d) cooling the debossed film below its thermoplastic temperature to form said resilient web before removing said web from said forming structure.

5. A method of continuously debossing and perforating a running ribbon of planar thermoplastic film to produce a resilient three-dimensional web having first and second surfaces and containing a multiplicity of capillary networks, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially uniform U-shaped cross-section along its length, said method comprising the steps of:

(a) establishing and maintaining control of said film by establishing and maintaining constant tension therein;

(b) isolating a portion of said film from said constant tension while it is in contacting relation with a tubular shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks originating in and extending continuously from the film contacting surface to the non-film contacting surface thereof, each of said capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(c) heating the tension isolated portion of said film above its thermoplastic temperature;

(d) applying a sufficiently great pressure to said heated, tension isolated portion of said thermoplastic film to cause those portions of said film which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said capillary networks and imparting a three-dimensional fiber-like appearance and tactile impression to said film; and

(e) cooling the debossed and perforated film below its thermoplastic temperature to form said resilient web before subjecting said web to downstream tension.

7. The method of claim 5 or claim 6, wherein said tubular-shaped perforate laminate forming surface is preheated prior to bringing said film in contacting relation therewith to facilitate better conformance of said film to said forming surface.

6. A method of continuously debossing and perforating a running ribbon of planar thermoplastic film to produce a resilient three-dimensional web having first and second surfaces and containing a multiplicity of capillary networks of non-uniform cross-section along their length, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially uniform U-shaped cross-section along its length, said method comprising the steps of:

(a) establishing and maintaining control of said film by establishing and maintaining constant tension therein;

(b) isolating a portion of said film from said constant tension while it is in contacting relation with a tubular shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks of non-uniform cross-section along their length originating in and extending continuously from the film contacting surface to the non-film contacting surface thereof, each of said non-uniform cross-section capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(c) heating the tension isolated portion of said film above its thermoplastic temperature;

(d) applying a sufficiently great pressure to said heated, tension isolated portion of said thermoplastic film to cause those portions of said film which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said capillary networks and imparting a three-dimensional fiber-like appearance and tactile impression to said film; and

(e) cooling the debossed and perforated film below its thermoplastic temperature to form said resilient web before subjecting said web to downstream tension.

8. A method of continuously forming a resilient three-dimensional thermoplastic web having first and second surfaces and containing a multiplicity of capillary networks, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially non-uniform U-shaped cross-section along its length, said method comprising the steps of:

(a) continuously extruding a melt of thermoplastic resin onto the periphery of a tubular-shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks originating in and extending continuously from the resin contacting surface to the non-resin contacting surface thereof, each of said capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(b) applying a sufficiently great pressure to said heated thermoplastic resin to cause those portions of said resin which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said capillary networks and imparting a fiber-like appearance and tactile impression to said film; and

(c) cooling the three-dimensional film thus formed below its thermoplastic temperature to form said resilient web before removing said web from said forming structure.

10. The method of claim 8 or claim 9, wherein said pressure applied to said heated thermoplastic resin comprises pneumatic differential pressure, said pneumatic differential pressure being sufficient to provide perforations corresponding to those in said perforate laminate forming structure in the resultant web.

11. The method of claim 8 or claim 9, wherein said tubular shaped perforate laminate forming surface is preheated prior to bringing said resin in contacting relation therewith to facilitate better conformance of said resin to said forming surface.

9. A method of continuously forming a resilient three-dimensional thermoplastic web having first and second surfaces and containing a multiplicity of capillary networks of non-uniform cross-section along their length, said first surface having a multiplicity of apertures in which said capillary networks originate, each of said apertures being defined by a multiplicity of intersecting fiber-like elements, each of said fiber-like elements exhibiting a substantially non-uniform U-shaped cross-section along its length, said method comprising the steps of:

(a) continuously extruding a melt of thermoplastic resin onto the periphery of a tubular-shaped perforate laminate forming structure exhibiting a three-dimensional microstructure comprising a regulated continuum of capillary networks of non-uniform cross-section along their length originating in and extending continuously from the resin contacting surface to the non-resin contacting surface thereof, each of said non-uniform cross-section capillary networks in said forming structure being defined by a multiplicity of intersecting fiber-like elements interconnected to one another, each of said fiber-like elements further exhibiting a substantially uniform cross-section along its length, said cross-section comprising a base portion and a sidewall portion joined to each edge of said base portion, said intersecting sidewall portions of said interconnected fiber-like elements being interconnected to one another intermediate said film-contacting and said non-film contacting surfaces of said forming structure;

(b) applying a sufficiently great pressure to said heated thermoplastic resin to cause those portions of said resin which do not coincide with the base portions of said fiber-like elements in said forming structure to substantially conform with each of the intersecting sidewall portions of each of said interconnected fiber-like elements in said forming structure without causing rupture of said film at the points of intersection between said sidewall portions, thereby forming said capillary networks and imparting a fiber-like appearance and tactile impression to said film; and

(c) cooling the three-dimensional film to thus formed below its thermoplastic temperature to form said resilient web before removing said web from said forming structure.