FILTER CARTRIDGES WITH PLEATED FILTER MEDIA

摘要

Filter cartridges (10) include a pleated multi-layer filter media (16) having a filtration membrane layer (16a), and a structural support layer (16b) for the membrane layer (16a) which is in the form of an expanded polymeric film mesh. Most preferably, the membrane layer (16a) and the expanded polymeric film support layer (16b) are each formed of a fluoropolymer, most preferably PTFE. The preferred expanded polymeric film support layer (16b) is in the form of a relatively open mesh structure having generally diamond-shaped apertures (20). Improved flow rate characteristics through pleated filter media (16) ensue when diamond-shaped apertures (20) of the mesh (16b) are oriented such that the long dimensions (LD) thereof are substantially transverse to the elongate pleat axis of the pleated filter medium (16) in which the mesh (16b) is employed.