Embossed monolithic polymer film and process of forming the same

Abstract

A thermoplastic film formed of a monolithic polymer and which is embossed. The film has an embossed height of h, a material thickness of t1 at the apex of the embossed height h, and a material thickness of t2 at the base of the film. The film also has a concave cavity below the apex of the embossed height h. The monolithic polymer film is formed using a screen with a perforated pattern. A monolithic polymer is extruded onto the screen in semi-molten film. The screen is rotated such that the film passes over a vacuum slot behind the screen. A vacuum in the vacuum slot pulls the monolithic polymer into the perforated pattern of the screen without perforating the film. The perforated pattern of the screen is transferred to the monolithic polymer film as the film passes over the vacuum slot.

What is claimed is: 
     
       1. A thermoplastic film comprising a monolithic polymer sheet being embossed with apex sections disposed within base sections, said film having first side and a raised side, and said film having an embossed height between the first side of the film at the base sections and the raised side of the film at the base sections. 
     
     
       2. The thermoplastic film according to claim 1, wherein said embossed height is at least about 10 milinches. 
     
     
       3. The thermoplastic film according to claim 1, wherein said embossed height is at least about 14 milinches. 
     
     
       4. The thermoplastic film according to claim 1, wherein said embossed height is from about 7 milinches to about 18 milinches. 
     
     
       5. The thermoplastic film according to claim 4, wherein said film further includes a concave cavity disposed on the first side of said film below each of said apex sections. 
     
     
       6. The thermoplastic film according to claim 5, wherein the base sections have a base thickness t 1  between the first side and the raised side of the film, and wherein the apex sections of said film have an apex thickness t 2  between the first side and the raised side of the film, and wherein the base thickness t 1  of the base sections is greater than the apex thickness t 2  of the apex sections. 
     
     
       7. The thermoplastic film according to claim 6, wherein said apex thickness t 2  is from about ten percent (10%) of the base thickness t 1  to about sixty percent (60%) of the base thickness t 1 . 
     
     
       8. The thermoplastic film according to claim 6, wherein said apex thickness t 2  is less than about ten percent (10%) of the base thickness t 1 . 
     
     
       9. The thermoplastic film according to claim 6, wherein said apex thickness t 2  is less than about sixty percent (60%) of the base thickness t 1 . 
     
     
       10. The thermoplastic film according to claim 1, wherein said film further includes a concave cavity disposed on the first side of said film below each of said apex sections. 
     
     
       11. The thermoplastic film according to claim 10, wherein the base sections have a base thickness t 1  between the first side and the raised side of the film, and wherein the apex sections of said film have an apex thickness t 2  between the first side and the raised side of the film, and wherein the base thickness t 1  of the base sections is greater than the apex thickness t 2  of the apex sections. 
     
     
       12. The thermoplastic film according to claim 11, wherein said apex thickness t 2  is from about ten percent (10%) of the base thickness t 1  to about sixty percent (60%) of the base thickness t 1 . 
     
     
       13. The thermoplastic film according to claim 11, wherein said apex thickness t 2  is less than about ten percent (10%) of the base thickness t 1 . 
     
     
       14. The thermoplastic film according to claim 11, wherein said apex thickness t 2  is less than about sixty percent (60%) of the base thickness t 1 .