Process for making an embossed web
A process for making an embossed web. A precursor web is provided between a forming structure and a compliant substrate. The forming structure has a plurality of discrete protruded elements and lands completely surrounding them. Pressure is provided between the compliant substrate and the forming structure to conform the precursor web to the forming structure to form the embossed web. The resulting embossed web has a plurality of discrete extended elements completely surrounded by land areas.
1. A process for making an embossed polymeric film web comprising a plurality of discrete extended elements formed integrally with said embossed web, said extended elements having open proximal portions, closed or open distal ends, and sidewalls, said extended elements being thinned at said distal ends and/or along said sidewalls, said process comprising the steps of:
providing a forming structure comprising a plurality of discrete protruded elements and lands completely surrounding said discrete protruded elements, wherein said discrete protruded elements each have a diameter of less than about 500 microns;
providing a compliant substrate;
providing a precursor polymeric film web between said compliant substrate and said forming structure; wherein said precursor web has a melting point and comprises synthetic material, metallic material, biological material, or combinations thereof; and
providing pressure between said compliant substrate and said forming structure sufficient to conform said precursor web to said discrete protruded elements of said forming structure to form said embossed polymeric film web;
wherein said process is carried out at a temperature less than said melting point of said precursor web.
2. A process for making an embossed polymeric film web comprising a plurality of discrete extended elements formed integrally with said embossed web, said extended elements having open proximal portions, closed or open distal ends, and sidewalls, said extended elements being thinned at said distal ends and/or along said sidewalls, said process comprising the steps of:
providing a forming structure comprising a plurality of discrete protruded elements and lands completely surrounding said discrete protruded elements, wherein said forming structure comprises at least about 95 discrete protruded elements per square centimeter;
providing a compliant substrate;
providing a precursor polymeric film web between said compliant substrate and said forming structure; wherein said precursor web has a melting point and comprises synthetic material, metallic material, biological material, or combinations thereof; and
providing pressure between said compliant substrate and said forming structure sufficient to conform said precursor web to said discrete protruded elements of said forming structure to form said embossed polymeric film web;
wherein said process is carried out at a temperature less than said melting point of said precursor web.
3. A process for making an embossed polymeric film web comprising a plurality of discrete extended elements formed integrally with said embossed web, said extended elements having open proximal portions, closed or open distal ends, and sidewalls, said extended elements being thinned at said distal ends and/or along said sidewalls, said process comprising the steps of:
providing a dimensionally stable forming structure comprising a plurality of discrete protruded elements and lands completely surrounding said discrete protruded elements, wherein said discrete protruded elements each have a non-columnar shape;
providing a compliant substrate;
providing a precursor polymeric film web between said compliant substrate and said forming structure; wherein said precursor web has a melting point and comprises synthetic material, metallic material, biological material, or combinations thereof; and
providing pressure between said compliant substrate and said forming structure sufficient to conform said precursor web to said discrete protruded elements of said forming structure to form said embossed polymeric film web;
wherein said process is carried out at a temperature less than said melting point of said precursor web.
4. A process for making an embossed polymeric film web comprising a plurality of discrete extended elements formed integrally with said embossed web, said extended elements having open proximal portions, closed or open distal ends, and sidewalls, said extended elements being thinned at said distal ends and/or along said sidewalls, said process comprising the steps of:
providing a dimensionally stable forming structure comprising a plurality of discrete protruded elements and lands completely surrounding said discrete protruded elements, wherein said discrete protruded elements have an average height;
providing a compliant substrate having a Shore A hardness of from about 30 to about 80 durometer;
providing a precursor polymeric film web between said compliant substrate and said forming structure; wherein said precursor web has a melting point and comprises synthetic material, metallic material, biological material, or combinations thereof; and wherein said precursor web has a thickness; and
providing pressure between said compliant substrate and said forming structure sufficient to conform said precursor web to said discrete protruded elements of said forming structure to form said embossed polymeric film web;
wherein said process is carried out at a temperature less than said melting point of said precursor web; and wherein a ratio of said average height of said protruded elements to said thickness of said precursor web is at least about 2:1.
5. The process of claim 1 , wherein said precursor web is fed between said compliant substrate and said forming structure at a rate of at least about 0.01 meters per second.
6. The process of claim 5 , wherein said precursor web is fed between said compliant substrate and said forming structure at a rate of at least about 5 meters per second.
7. The process of claim 1 , wherein said pressure is applied to a given portion of said precursor web for a dwell time of about 0.5 milliseconds to about 5 seconds.
8. The process of claim 1 , wherein said pressure is applied to a given portion of said precursor web for a dwell time of about 0.5 milliseconds to about 0.01 seconds.
9. The process of claim 1 , wherein said process is carried out at a temperature of from about 10° C. to about 40° C.
10. The process of claim 1 , wherein said precursor web is a thermoplastic film comprising polyethylene, polypropylene, or mixtures thereof.
11. The process of claim 1 , wherein said compliant substrate comprises rubber having a Shore A hardness of from about 30 to about 80 durometer.
12. The process of claim 1 , wherein said compliant substrate is in the form of a roll and said forming structure is in the form of a roll.
13. The process of claim 1 , wherein said discrete extended elements each have a generally columnar shape and an aspect ratio of at least about 0.2.
14. The process of claim 1 , wherein said discrete protruded elements each have a generally columnar shape and an aspect ratio of at least about 0.5.
15. The process of claim 1 , wherein said discrete protruded elements have an average edge-to-edge spacing of from about 30 microns to about 650 microns.
16. The process of claim 1 , wherein said pressure between said compliant substrate and said forming structure is from about 100 to about 5000 pounds per square inch.
17. The process of claim 16 , wherein said pressure between said compliant substrate and said forming structure is from about 100 to about 3500 pounds per square inch.
18. The process of claim 1 , wherein said precursor web has a thickness of from about 5 microns to about 150 microns.
19. The process of claim 1 , wherein said extended elements are thinned relative to said thickness of said precursor web.
20. The process of claim 1 , wherein said extended elements are thinned relative to said land areas of said embossed web.
21. The process of claim 20 , wherein said extended elements are thinned by at least 25% relative to said land areas of said embossed web.
22. The process of claim 21 , wherein said extended elements are thinned by at least 50% relative to said land areas of said embossed web.
23. The process of claim 1 , wherein said extended elements are thinned at said distal ends.
24. The process of claim 1 , wherein at least some said extended elements have a height of at least about 1.5 times the thickness of said precursor web.
25. The process of claim 1 , wherein said distal ends of said extended elements are closed.
26. The process of claim 1 , wherein said distal ends of said extended elements are open.
27. The process of claim 1 , wherein said precursor web has a yield point, wherein said precursor web is stretched beyond said yield point by said process.
28. The process of claim 4 , wherein said discrete extended elements each have a generally columnar shape and an aspect ratio of at least about 0.2.
29. The process of claim 4 , wherein said discrete protruded elements each have a generally columnar shape and an aspect ratio of at least about 0.5.
30. The process of claim 4 , wherein said extended elements are thinned by at least 25% relative to said land areas of said embossed web.
31. The process of claim 1 , wherein the precursor web is not heated before being provided between the forming structure and the compliant substrate.
32. The process of claim 31 , wherein the forming structure and the compliant substrate are not heated before providing the precursor web between the forming structure and the compliant substrate.