Abstract: A filtration material having a second fibrous layer (downstream drainage layer) with a length that is shorter than the length of the first fibrous material (upstream drainage layer) is provided. At least the first fibrous material is meltable. In forming the filtration material, the second fibrous layer may be cut to a predetermined length while the porous membrane and the first fibrous layer maintain their length. The length of the second fibrous layer may be substantially the same as the length of the outer cage. The filtration material is disposed within the outer cage such that the first fibrous layer and the porous membrane protrude from the cage member. When positioning an end cap onto the filtration material, heat is applied and the first fibrous layer melts and bonds to the end cap at a melt interface. The filtration material is free from thermoplastic strips and imbibed thermoplastic material(s).

Abstract: A filtration material having a second fibrous layer (downstream drainage layer) with a length that is shorter than the length of the first fibrous material (upstream drainage layer) is provided. At least the first fibrous material is meltable. In forming the filtration material, the second fibrous layer may be cut to a predetermined length while the porous membrane and the first fibrous layer maintain their length. The length of the second fibrous layer may be substantially the same as the length of the outer cage. The filtration material is disposed within the outer cage such that the first fibrous layer and the porous membrane protrude from the cage member. When positioning an end cap onto the filtration material, heat is applied and the first fibrous layer melts and bonds to the end cap at a melt interface. The filtration material is free from thermoplastic strips and imbibed thermoplastic material(s).

Abstract: A filtration device having therein a pleated, twisted filtration material is provided. The filtration material has a generally cylindrical shape and includes a first end, a second end opposing the first end, and outwardly projecting pleats. The pleats have a non-linear orientation within the filtration device. The twisting of the filtration material moves the ends of the pleats a distance around the circumference of the filtration material from a first position (P1) to a second position (P2). The angle of rotation may range from about 5 degrees to about 1440 degrees. Twisting the filtration material increases the effective amount of filtration material in the filtration device, which in turn, corresponds to an increase in the Effective Filtration Area (EFA). The intentional misalignment of the pleat ends in the filtration material improves the cutting ability of the material, removes buckling of the material, and improves the quality of the trim cut.