Ionomeric sheeting in roll form and process for producing same

Abstract

Provided herein is relatively thick ionomeric sheeting that can be taken up into a roll and supplied in continuous form. Also provided herein are methods of manufacturing rolls of relatively thick, continuous ionomeric sheeting. Further provided herein are methods of producing glass laminates, wherein the relatively thick ionomeric sheeting is not conditioned to reduce curvature prior to stacking the pre-press assembly. These continuous rolls eliminate costly cutting and stacking steps in ionomeric sheeting that is intended for use as interlayers in laminated structures, for example safety glass and photovoltaic cells.

What is claimed is:  
     
       1. A process for producing a glass laminate, said process comprising the steps of:
 (a) unwinding a roll of thick continuous ionomeric sheeting, said ionomeric sheeting having a thickness of at least 20 mils, a length of at least 10 feet, and an aspect ratio of at least 10;  
 (b) cutting a sheet of a desired size from the ionomeric sheeting;  
 (c) preparing a pre-press assembly by stacking the sheet with at least one lite of glass; and  
 (d) subjecting the pre-press assembly to heat, to pressure, or to both heat and pressure to produce the glass laminate;  
 
       wherein the ionomeric sheeting and the sheet are not conditioned to reduce curvature prior to stacking the pre-press assembly. 
     
     
       2. The process of  claim 1 , wherein the wound-up roll is self- supporting. 
     
     
       3. The process of  claim 1 , wherein the wound-up roll further comprises a core, and wherein the ionomeric sheeting is wound around the core. 
     
     
       4. The process of  claim 3 , wherein the core has an outer diameter of up to about 1.0 meter. 
     
     
       5. The process of  claim 3 , wherein the core has an outer diameter of about 2 inches (5.1 cm) to about 24 inches (61.0 cm). 
     
     
       6. The process of  claim 3 , wherein the core has an outer diameter of about 3 inches (7.6 cm) to about 8 inches (20.3 cm). 
     
     
       7. The process of  claim 1 , wherein the thickness is up to 20 mm. 
     
     
       8. The process of  claim 7 , wherein the thickness is 25 mils (635 micrometers) to 1.0 mm. 
     
     
       9. The process of  claim 7 , wherein the thickness is 25 mils (635 micrometers) to 0.50 mm. 
     
     
       10. The process of  claim 7 , wherein the thickness is 30 to 70 mils (762 to 1778 micrometers). 
     
     
       11. The process of  claim 1 , wherein the aspect ratio is at least 25. 
     
     
       12. The process of  claim 11 , wherein the aspect ratio is at least 50. 
     
     
       13. The process of  claim 11 , wherein the aspect ratio is at least 100. 
     
     
       14. The process of  claim 1 , wherein the glass laminate is a solar cell module, said process further comprising the step of:
 including a solar cell and, optionally, an associated electrical connection in the pre-press assembly.  
 
     
     
       15. A continuous roll-to-roll process for producing a wound-up roll of a multilayer structure; said multilayer structure selected from the group consisting of a prelaminate assembly and a multilayer laminate; and said process comprising the steps of:
 providing a wound-up roll of thick continuous ionomeric sheeting, said ionomeric sheeting having a thickness of greater than 20 mils (508 micrometers), a length of at least 3 m, and an aspect ratio of at least 10;  
 providing at least one other wound-up roll of a first other film;  
 unwinding the ionomeric sheeting and the other film;  
 aligning the ionomeric sheeting and the first other film to form a prelaminate assembly;  
 optionally adhering or laminating the prelaminate assembly to form a multilayer laminate; and  
 winding the prelaminate assembly or the multilayer laminate to form the wound-up roll of the multilayer structure.  
 
     
     
       16. The process of  claim 15 , further comprising the steps of:
 providing a second other film;  
 unwinding the second other film; and  
 aligning the ionomeric sheeting and the first and second other films to form a prelaminate assembly.  
 
     
     
       17. The process of  claim 16 , wherein the first other film and the second other films are in contact with opposite sides of the thick ionomeric sheeting in the prelaminate assembly. 
     
     
       18. The process of  claim 16 , wherein at least one of the first other film and the second other film comprises biaxially oriented PET. 
     
     
       19. The process of  claim 16 , wherein at least one of the first other film and the second other film comprises a flexible thin film solar cell or an associated electrical connection. 
     
     
       20. An extrusion process for producing a wound-up roll; said wound-up roll comprising relatively thick, continuous ionomeric sheeting, said ionomeric sheeting having a thickness of greater than 20 mils (508 micrometers), a length of at least 3 m, and an aspect ratio of at least 10; wherein the improvement comprises increasing the rate at which heat is removed from the as-extruded sheeting to reduce or eliminate the heat-setting of the curvature of the ionomeric sheeting, and wherein the rate is increased by one or more steps selected from the group consisting of passing the as-extruded sheeting over a chilled water roll before taking up the sheeting into the wound-up roll; decreasing the temperature of the chilled water roll; increasing air flow across the as-extruded sheeting; altering the placement of one or more stations, including a tension control station, a tentering station, a calendering station, and an embossing station, so that the station is closer to a winding apparatus; and slowing the extrusion rate.