Filter material construction and method

Abstract

A preferred filter media is provided. The media includes a fine fiber web secured to the surface of a coarse fiber support. A preferred filter media, comprising multiple layers of fine fiber media separated by coarse fiber support, is provided. Advantageous filter constructions result and are provided. Also according to the disclosure, methods for using such arrangements to filter are provided.

1 - 18 . (canceled)  
   
   
       19 - 33 . (canceled)  
   
   
       34 . A filter element comprising: 
 (a) a first extension of media; and,    (b) a second media construction; the second media construction comprising a multilayer media composite including a plurality of layers of fine fiber material each having an average fiber diameter of no greater than 5 microns and each having an efficiency, on its own, for 0.78 micron monodispersed polystyrene particles at 20 fpm, of at least 10% and no greater than 70%: 
 (i) each one of the layers of fine fiber material in the multilayer media composite being separated from a next adjacent one of the layers of fine fiber material by a fibrous spacing layer comprising fibers having an average diameter of at least 10 microns and having an efficiency, on its own, of no more than 10% for 0.78 micron monodispersed polystyrene particles at 20 fpm; 
 (A) more than one of the layers of fine fiber material having a first efficiency; and  
 (B) more than one of the layers of fine fiber material having a second efficiency greater than the first efficiency; and,  
 
 (ii) the multilayer media composite having an overall efficiency of at least 97% for 0.78 micron monodispersed polystyrene particles at 20 fpm.  
   
   
   
       35 . A filter element according to  claim 34  wherein: 
 (a) the second media construction is positioned around the first extension of media.    
   
   
       36 . A filter element according to  claim 34  wherein: 
 (a) the multilayer media composite is located downstream of the first extension of media.    
   
   
       37 . A filter element according to  claim 34  wherein: 
 (a) the multilayer media composite is unpleated.    
   
   
       38 . A filter element according to  claim 34  wherein: 
 (a) the multilayer media composite has an overall efficiency of at least 99% for 0.78 micron monodispersed polystyrene particles at 20 fpm.    
   
   
       39 . A filter cartridge according to  claim 34  wherein: 
 (a) each one of the layers of fine fiber material in the multilayer media composite has an efficiency, on its own, for 0.78 micron monodispersed polystyrene particles at 20 fpm, within the range of 20-60%.    
   
   
       40 . A filter element according to  claim 34  wherein: 
 (a) each fibrous spacing layer in the multilayer media composite has a thickness of at least 12 microns.    
   
   
       41 . A filter element according to  claim 34  wherein: 
 (a) each fibrous spacing layer in the multilayer media composite has a thickness within the range of 25-254 microns.    
   
   
       42 . A filter element according to  claim 34  wherein: 
 (a) each layer of the fine fiber material in the multilayer media composite has a depth of no greater than 15 microns.    
   
   
       43 . A filter element comprising: 
 (a) a first extension of media; 
 (i) the first extension of media being cylindrical; and,  
   (b) a second media construction surrounding the first extension of media; the second media construction comprising a multilayer media composite including at least three layers of fine fiber material each layer having an average fiber diameter of no greater than 5 microns and being separated from a next adjacent one of the at least three layers of fine fiber material by a fibrous spacing layer having an average fiber diameter of at least 10 microns; 
 (i) at least two of the at least three layers of fine fiber material differing in efficiency.  
   
   
   
       44 . A filter element according to  claim 43  wherein: 
 (a) the multilayer media composite is located downstream of the first extension of media.    
   
   
       45 . A filter element according to  claim 43  wherein: 
 (a) the multilayer media composite is unpleated.    
   
   
       46 . A filter element according to  claim 45  wherein: 
 (a) the multilayer media composite has an overall efficiency of at least 99% for 0.78 micron monodispersed polystyrene particles at 20 fpm.    
   
   
       47 . A filter cartridge according to  claim 46  wherein: 
 (a) each one of the layers of fine fiber material in the multilayer media composite has an efficiency, on its own, for 0.78 micron monodispersed polystyrene particles at 20 fpm, within the range of 20-60%.    
   
   
       48 . A filter element according to  claim 47  wherein: 
 (a) each fibrous spacing layer in the multilayer media composite has a thickness of at least 12 microns.    
   
   
       49 . A filter element according to  claim 43  wherein: 
 (a) each fibrous spacing layer in the multilayer media composite has a thickness within the range of 25-254 microns.    
   
   
       50 . A filter element according to  claim 43  wherein: 
 (a) each layer of the fine fiber material in the multilayer media composite has a depth of no greater than 15 microns.    
   
   
       51 . A filter element according to  claim 43  wherein: 
 (a) the multilayer media composite has an overall efficiency of at least 99% for 0.78 micron monodispersed polystyrene particles at 20 fpm.    
   
   
       52 . A filter cartridge according to  claim 43  wherein: 
 (a) each one of the layers of fine fiber material in the multilayer media composite has an efficiency, on its own, for 0.78 micron monodispersed polystyrene particles at 20 fpm, within the range of 20-60%.    
   
   
       53 . A filter element according to  claim 43  wherein: 
 (a) each fibrous spacing layer in the multilayer media composite has a thickness of at least 12 microns.