Porous laminate and method of manufacture

Abstract

A porous laminate is disclosed consisting of a plurality of lamina each having a parallel slot series formed therein, stacked with the respective adjacent slot series overlapping and extending transversely to each other and bonded to each other to form the porous laminate. Variations disclosed include tapering the slots in one or more of the lamina to create a variable porosity and the inclusion of tying sections at intermediate points along the slots for reinforcement purposes. The disclosed process includes the steps of photoetching metal sheets to create the slot pattern, stacking a plurality of the sheets together with the slots in adjacent sheets extending transversely to each other, diffusion bonding the stacked sheets to form a porous laminate, and calendering the finished sheet to modify or adjust permeability.

What is claimed is: .[.1. A porous laminate comprising: 
     
        .[.6.  The laminate of claim 1 wherein said slots in alternate lamina in said stack extend parallel to each other but are at least partially offset from each other to form lateral flow passages in said laminate..]. .[.7. A method of manufacturing a porous material comprising: forming a slot pattern in a plurality of lamina;   stacking said lamina in intimate contact with each other with said slot patterns of adjacent lamina overlapping and extending transversely to each other; and   
     
     
       bonding said lamina to each other to form a porous laminate..]. .Iadd. 8. A multilayer porous laminate comprising a plurality of lamina, each lamina having a slot pattern formed therein, wherein each slot pattern comprises a series of slots formed in the corresponding lamina, said slots in a lamina defining axes of orientation parallel therebetween, said lamina being stacked in intimate contact with each other, with said slots of adjacent lamina overlaying in abutting relationship and extending with their respective axes of orientation at an angle to each other to provide intersecting slot patterns, the slots in alternate lamina in said stack having parallel axes of orientation to each other which are at least partially and laterally offset from each other to form lateral flow passages in said laminate, and means bonding said lamina to each other to form said laminate, whereby said intersecting slot patterns form fluid flow passages through said laminate. .Iaddend. .Iadd. 9. The laminate of claim 8 wherein said slots in said slot patterns have spaced tie sections formed along their lengths. .Iaddend..Iadd. 10. The laminate of claim 8 wherein each of said lamina have solid areas formed extending around said slot patterns and wherein said solid areas as aligned in said stack, whereby said laminate is formed with a solid peripheral border. .Iaddend. .Iadd. 11. A porous filter laminate comprising: a plurality of lamina having slot patterns formed therein, said lamina stacked in intimate contact with each other with said slot patterns of adjacent lamina overlapping and extending transversely to each other to provide intersecting slot patterns, said slots formed in said lamina being tapered in the plane of the lamina and said lamina being stacked with the larger end of said slots overlapping, whereby a variable porosity laminate is provided, the slots in alternate lamina in said stack having parallel axes of orientation to each other which are at least partially and laterally offset from each other, said stacked lamina being bonded to each other to form said laminate, whereby said intersecting slot patterns form fluid passages through said laminate. .Iaddend..Iadd. 12. A method of manufacturing a porous material, characterized by the steps of forming a series of slots in a plurality of lamina, said slots in a lamina defining axes of orientation parallel therebetween, stacking said lamina in intimate contact with each other with said slots of adjacent lamina overlaying and extending at an angle to each other, stacking said lamina with slots of alternate lamina having parallel axes of orientation which are laterally offset from each other, and bonding said lamina to each other to form a multilayer porous laminate. .Iaddend. .Iadd. 13. The method of claim 12 wherein said forming step comprises photoetching said slot pattern in said lamina. .Iaddend..Iadd. 14. The method of claim 12 wherein said bonding step comprises diffusion bonding said lamina together to form said laminate. .Iaddend..Iadd. 15. The method of claim 14 wherein said forming step comprises photoetching said slot pattern in said lamina. .Iaddend.