Media, filter element using corrugated media sheet, corrugated sheet, and methods

Abstract

A corrugated web having tapered flutes is usable in straight-through flow filter elements. The corrugated web can be made by passage between a pair of corrugated rollers having tapered teeth. Methods of making usable corrugated rollers include methods for generating the tapered teeth at the end points and the extension between the end points. Corrugated webs may be made from a variety of media, including certain media that stretches in the machine direction. Methods of forming the corrugated web into filter elements (e.g., air filter elements) includes forming filter media by securing a flat sheet to the corrugated web. The filter media may then be wound into a filter element, including application of sealant during the winding process to close selected flutes.

1 - 20 . (canceled) 
   
   
       21 . A corrugation roller arrangement comprising:
 (a) a cylindrical roller having opposite ends, a geometric center, a longitudinal axis passing through the geometric center; and a plurality of externally directed teeth projecting radially therefrom;
 (i) each of the teeth having an adjacent gullet; 
 (ii) the externally directed teeth being formed by an end point tooth cutting definition to generate the alternating teeth and gullets extending at least partially between first and second ends of the cylindrical roller; 
 (iii) each of the teeth decreasing in width between adjacent gullets from the first end to the second end; and 
 (iv) each of the gullets increasing in width between adjacent teeth from the first end to the second end. 
   
   
   
       22 . A corrugation roller arrangement according to  claim 21  wherein:
 (a) said roller includes at least 80 teeth formed by the end point tooth cutting definition by maintaining a cutting line an equal radial distance to the longitudinal axis for:
 (i) any given point on the cutting line spaced a first distance from a plane passing through a midpoint of the teeth in a direction toward the first end of the cylindrical roller as 
 (ii) a point along the cutting line spaced that first distance from the plane passing through a midpoint of the teeth in the direction toward the second end of the cylindrical roller. 
   
   
   
       23 . A corrugation roller arrangement according to  claim 21  wherein:
 (a) said roller further includes at least one web-peeling groove extending transverse to the longitudinal axis;   (b) each of the teeth at the second end includes a tip joining a pair of side flanks;
 (i) the side flanks defining an angle of 5-15° therebetween; 
   (c) each of the teeth has a uniform height between the first end and the second end of 0.1-0.2 inch;   (d) the teeth have a pitch at the second end of 0.25-0.5 inch;   (e) each of the teeth at the first end includes a tip and first and second side flanks;
 (i) the first end tip includes a first fillet, a middle section adjacent to the first fillet, and a second fillet adjacent to the middle section; 
 (ii) the first fillet extending between the first side flank and the middle section; 
 (iii) the second fillet extending between the middle section and the second side flank; 
 (iv) the middle section having a length of 0.07-0.15 inch; 
 (v) the first side flank and the second side flank defining an angle of 5-15° therebetween; 
   (f) the teeth have a pitch at the first end of 0.25-0.5 inch.   
   
   
       24 . A process for making a corrugated web comprising:
 (a) using a pair of corrugation rollers; each of the rollers comprising:
 (i) a cylindrical roller having opposite ends, a geometric center, a longitudinal axis passing through the geometric center; and a plurality of externally directed teeth projecting radially therefrom;
 (A) each of the teeth having an adjacent gullet; 
 (B) the externally directed teeth being formed by an end point tooth cutting definition to generate the alternating teeth and gullets extending at least partially between first and second ends of the cylindrical roller; 
 (C) each of the teeth decreasing in width between adjacent gullets from the first end to the second end; and 
 (D) each of the gullets increasing in width between adjacent teeth from the first end to the second end; and 
 
   (b) corrugating a web by passing the web between the pair of corrugation rollers; each of which has tapering teeth with the taper of the teeth of a first one of the pair of corrugation rollers tapering in a direction opposite to a direction of taper of the teeth of a second one of the pair of corrugation rollers.