Method and apparatus for packaging glass substrates

Abstract

Packages ( 11 ) of glass substrates ( 13 ) are provided in which the surfaces of the substrates are coated with a water-removable protective coating and then sealed in an air-sealing container ( 19 ), e.g., a polymer bag or a polymer wrapping, having an internal volume which is vacuumed, filled with an inert atmosphere, or filled with humidity-controlled air prior to sealing. In this way, the substrates can be stored for at least 6 months in an ambient environment having a relative humidity of 90 percent at 50° C. without substantial degradation of the protective coating.

1 . A method for packaging glass substrates for storage and/or transportation, each substrate having two substantially flat surfaces which are coated with a water-removable protective coating, said method comprising in order: 
 (A) stacking the coated glass substrates to form a block; and    (B) packaging the block in a container having a sealed internal environment which protects the water-removable protective coating from humidity-based degradation.    
   
   
       2 . The method of  claim 1  wherein said substrates when stacked have exposed corners and edges and said method comprises protecting the exposed corners and/or at least some of the exposed edges of the substrates using cushioning material prior to step (B).  
   
   
       3 . The method of  claim 2  wherein both the exposed corners and at least some of the exposed edges of the substrates are protected using cushioning material.  
   
   
       4 . The method of  claim 1  wherein the container is an air-sealing polymer bag or polymer wrapping.  
   
   
       5 . The method of  claim 1  wherein the coated glass substrates are stacked together using separators between the substrates.  
   
   
       6 . The method of  claim 1  wherein the internal volume within the container is vacuumed prior to sealing.  
   
   
       7 . The method of  claim 1  wherein the internal volume within the container is filled with an inert gas or an inert gas mixture prior to sealing.  
   
   
       8 . The method of  claim 1  wherein the internal volume within the bag or wrapping is sealed in a controlled humidity environment.  
   
   
       9 . The method of  claim 8  wherein the controlled humidity environment has a relative humidity of less than 50% at a temperature less than 50° C.  
   
   
       10 . The method of  claim 1  wherein the water-removable protective coating is protected from degradation for at least 6 months in an ambient environment having a relative humidity of 90 percent at 50° C.  
   
   
       11 . The method of  claim 1  comprising the additional steps of: 
 removing the glass substrates from the container; and    removing the water-removable protective coating from the glass substrates using an aqueous cleaning method.    
   
   
       12 . The method of  claim 11  wherein the aqueous cleaning method includes washing the glass substrates in an aqueous solution of an alkaline detergent whose temperature is between 25° C. and 80° C.  
   
   
       13 . A package of glass substrates comprising: 
 (A) a plurality of glass substrates arranged in a block, each of said substrates having two substantially flat surfaces which are coated with a water-removable protective coating; and    (B) an air-sealing container surrounding the block, said container forming a sealed internal environment which protects the water-removable protective coating from humidity-based degradation.    
   
   
       14 . The package of glass substrates of  claim 13  wherein the substrates when stacked have exposed corners and edges and said package further comprises cushioning material applied to the exposed corners and/or at least some of the exposed edges of the substrates.  
   
   
       15 . The package of  claim 14  wherein cushioning material is applied to both the exposed corners of the substrates and at least some of the exposed edges.  
   
   
       16 . The package of  claim 13  wherein the container is an air-sealing polymer bag or polymer wrapping.  
   
   
       17 . The package of  claim 13  further comprising separators between the substrates.  
   
   
       18 . The package of  claim 13  wherein the sealed internal environment is at a pressure below atmospheric pressure.  
   
   
       19 . The package of  claim 13  wherein the sealed internal environment contains an inert gas or an inert gas mixture.  
   
   
       20 . The package of  claim 13  wherein the sealed internal environment contains air which has a relative humidity of less than 50% at a temperature less than 50° C.  
   
   
       21 . The package of  claim 13  wherein the water-removable protective coating is protected from degradation for at least 6 months in an ambient environment having a relative humidity of 90 percent at 50° C.  
   
   
       22 . The package of  claim 13  wherein the glass substrates are LCD glass substrates.