Patent ID: 8496774

Claim:
A method of preparing a filter construction for use in an air cleaner; the method comprising steps of: (a) providing a filter media construction comprising a fluted filter media sheet secured to a facing sheet of filter media with a first seal therebetween against a first side of the facing sheet; (b) forming a generally circular coiled configuration by coiling the filter media combination around itself with the facing sheet directed to the outside of the coiled configuration and with a second sealant strip, during the coiling, positioned between the fluted filter media sheet and a second side of the facing sheet; (i) the step of forming a coiled configuration comprising providing a resulting generally circular coiled configuration in the form of a coreless coil having a central open space; (c) distorting the generally circular coiled configuration having a central aperture to a media construction having a non-circular shape; (i) the step of distorting including closing the central open space with sealing of the fluted filter media to itself; and, (d) positioning a housing seal on the media construction.