Abstract: The present invention is a filter that includes a length of filter media and a continuous, substantially nonlinear adhesive strand. The filter media has a front face and a rear face. The filter media has a plurality of pleats defined by a plurality of fold lines, each fold line being intermediate oppositely sloping first and second wall surfaces. The plurality of fold lines comprise a first plurality of pleat tips and a second plurality of pleat valleys. The adhesive strand is provided on the front face of the filter media in discontinuous contact with the filter media. The adhesive strand contacts the filter media at a pleat tip and contacts the filter media at a portion of a first wall surface and contacts the filter media at a portion of a second wall surface.

Abstract: The method of forming pleated filter media includes providing a generally planar web of filter material, folding the web to form a pleated web having a plurality of fold lines, arranging the plurality of pleats in a first spaced configuration defined by a first distance between adjacent pleat tips, applying a continuous strand of adhesive to the web, and adjusting the arrangement of the plurality of pleats into a second spaced configuration defined by a second distance between adjacent pleat tips. The web has a front face and a rear face. Each fold line is intermediate oppositely sloping first and second wall surfaces. The plurality of fold lines form a plurality of pleats having a first plurality of pleat tips and a second plurality of pleat valleys. The second distance is different from the first distance.