Apparatus and Methods for Processing Exfoliated Graphite Materials

Abstract

Methods and apparatus for processing flexible graphite sheet material involve patterning the material, on at least one major surface, prior to further processing of the material such as densification, lamination, folding or shaping into three-dimensional structures. For densification and lamination, the patterning is selected to facilitate the removal of air from the flexible graphite sheet material during the densification and lamination process. For folding or shaping, the patterning is selected to render the graphite sheet material more flexible. In some embodiments, methods for increasing the through-plane conductivity of flexible graphite sheet material are employed. Integrated heat removal devices include sheets of graphite material that have been selectively patterned in different regions to impart desirable localized properties to the material prior to it being shaped or formed into an integrated heat removal device. Coatings and/or resin impregnation can also be used to impart desirable properties to the material or device.

1 . (canceled) 
     
     
         2 . (canceled) 
     
     
         3 . A method for making a graphite sheet material comprising:
 blending an exfoliated graphite material to reduce the particle size thereof and form a graphite particulate material; and   compacting said graphite particulate material to make a compacted graphite material.   
     
     
         4 . The method of  claim 3  wherein said exfoliated graphite material comprises exfoliated graphite flakes. 
     
     
         5 . The method of  claim 3  wherein said graphite particulate material is a powder. 
     
     
         6 . The method of  claim 3  wherein blending said exfoliated graphite material comprises chopping up said exfoliated graphite material using an industrial blender. 
     
     
         7 . The method of  claim 3  wherein said exfoliated graphite material comprises exfoliated graphite flakes, said graphite particulate material is a powder, and blending said exfoliated graphite material comprises chopping up said exfoliated graphite material using an industrial blender. 
     
     
         8 . The method of  claim 3  wherein compacting said graphite particulate material to make said compacted graphite material comprises compressing said graphite particulate material in a die cavity. 
     
     
         9 . The method of  claim 3  wherein said method further comprises embossing an at least one major surface of said compacted graphite material to form a patterned compacted graphite material. 
     
     
         10 . The method of  claim 9  wherein embossing said at least one major surface of said compacted graphite material increases the through-plane thermal conductivity of said compacted graphite material. 
     
     
         11 . The method of  claim 9  wherein embossing said at least one major surface of said compacted graphite material comprises using at least one patterned reciprocating platen press or die press to emboss said at least one major surface of said compacted graphite material to form said patterned compacted graphite material. 
     
     
         12 . The method of  claim 9  wherein embossing said at least one major surface of said compacted graphite material comprises using roller embossing apparatus to emboss said at least one major surface of said compacted graphite material to form said patterned compacted graphite material. 
     
     
         13 . The method of  claim 9  further comprising compressing said patterned compacted graphite material to flatten said at least one major surface. 
     
     
         14 . The method of  claim 3  wherein compacting said graphite particulate material to make said compacted graphite material comprises simultaneously embossing said graphite particulate material so an at least one major surface of said compacted graphite material is patterned. 
     
     
         15 . The method of  claim 14  further comprising compressing said compacted graphite material to flatten said at least one major surface. 
     
     
         16 . The method of  claim 8  wherein compacting said graphite particulate material in said die cavity to make said compacted graphite material comprises using a patterned die press so that an at least one major surface of said compacted graphite material is patterned. 
     
     
         17 . The method of  claim 3  wherein said exfoliated graphite material comprises flexible graphite sheet, and wherein the through-plane to in-plane thermal conductivity ratio of said graphite sheet material is lower than the through-plane to in-plane thermal conductivity ratio of said flexible graphite sheet. 
     
     
         18 . The method of  claim 3  wherein the through-plane thermal conductivity of said graphite sheet material exceeds 20 W/mK. 
     
     
         19 . The method of  claim 3  wherein the through-plane thermal conductivity of said graphite sheet material is in the range of 20 W/mK to 30 W/mK. 
     
     
         20 . The method of  claim 3  wherein the through-plane thermal conductivity of said graphite sheet material exceeds 40 W/mK. 
     
     
         21 . The method of  claim 3  wherein the thickness of said graphite sheet material is in the range of 100-200 microns. 
     
     
         22 . The method of  claim 3  wherein the thickness of said graphite sheet material is in the range of 100-200 microns and the through-plane thermal conductivity of said graphite sheet material exceeds 20 W/mK.