Pleated air filters and methods of making the pleated air filters. The pleated air filter includes an air filter media sheet which is folded along a longitudinal centerline. The air filter media sheet is separated into a plurality of sections by hinges formed out of the air filter media sheet, with each section forming a pocket. The pleated air filter further includes a plurality of spacer elements, each spacer element positioned on an outer surface of a section or within a pocket. The pleated air filter includes a polyurethane seal. The air filter media sheet is alternately folded along the hinges to form a pleat block. The polyurethane seal is positioned on a side of the pleat block such that the polyurethane seal seals the side.