Process and materials for coiling z-filter media, and/or closing flutes of filter media; and, products

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 at least 10 times around with the facing sheet directed to the outside of the coiled configuration and with a 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 a coreless coil having:
• a central open space;
• and, an outside perimeter of at least 60 cm;
• (c) distorting the generally circular coiled configuration having a central aperture to a media construction having a shape with two generally parallel sides joined at their ends by curved portions;
• (i) the step of distorting including closing the central open space with sealing of the fluted filter media to itself, by a sealant, to provide a media construction having a shape with no center core;
• and,
• (ii) the step of distorting comprising forming an inner sealant strip in a center of the resulting media construction that is at least 12 cm long;
• and,
• (d) positioning a housing seal on the media construction.