CARTRIDGE FILTER AND MANUFACTURE THEREOF

A filter cartridge is provided comprising, in combination: (1) a filter sheet material formed in a tube open at at least one end; (2) a support such as an internal core or external sheath disposed in supporting relation to and substantially coextensive with the tube and supporting the filter sheet material of the tube; (3) the support having one end at the open end of the tube formed in a castellated configuration in which at least some of the castellations define grooves therebetween, preferably having reentrant sides; and (4) at least one end cap attached to and extending across the open end of the tube of filter sheet material, and having embedded therein at least the castellated end of the support, with end cap material extending into and substantially filling the grooves, thereby fixedly attaching the end cap to the support in a leak-tight seal.