Filter and method for manufacturing filters

Abstract

A filter element is assembled by first fixturing the parts together so that the assembly may be manipulated by automated assembly equipment before the end cap sealant is fully cured in an oven which is off-line from the automated assembly equipment. In one embodiment, a plastisol sealant is used, which is 'kiss-gelled' by rapidly increasing the temperature of the sealant for a few seconds to cure the sealant sufficiently to permit the assembly to be handled but without fully curing the sealant. The end cap on the other end of the assembly is then installed and kiss-gelled before the completed (but uncured) assembly is transferred to a curing oven where the plastisol at both ends of the assembly is fully cured at the same time. In another embodiment of invention, a small bead or band of an ultravioletly cured polymer sealant is dispensed against adjacent the centertube of the assembly and the ends of the inner tips of the pleats, and a band of conventional plastisol sealant is dispensed on the rest of the end cap. The ultravioletly cured polymer is then cured by ultraviolet light to permit the partially completed assembly to be inverted and a similar end cap installed on the opposite end, before the completed (but uncured) assembly is transferred to an off-line curing oven where the plastisol is fully cured.