Abstract: A fluid filtration unit having two or more filter medium layers and/or zones, at least one of the layers/zones having a different particle retention capability disposed on each side of a non-filtering separator element. The filter medium are presently preferably positioned such that each succeedingly distal filter layer or zone from the separator has a decreased particle retention capability than each proceeding filter layer or zone. The filter medium layer most proximal to the separator element may be separated from the separator by a support material for supporting such filter medium element and preventing collapsing of the medium into any separator conduit. At least one of the medium elements is formed from a material which swells in size due to fluid absorption with the various zones and the separator being operatively connected by a new and innovative edge seal.

Abstract: A fluid filtration unit having two or more filter medium layers and/or zones, at least one of the layers/zones having a different particle retention capability disposed on each side of a non-filtering separator element. The filter medium are presently preferably positioned such that each succeedingly distal filter layer or zone from the separator has a decreased particle retention capability than each proceeding filter layer or zone. The filter medium layer most proximal to the separator element may be separated from the separator by a support material for supporting such filter medium element and preventing collapsing of the medium into any separator conduit. At least one of the medium elements is formed from a material which swells in size due to fluid absorption with the various zones and the separator being operatively connected by a new and innovative edge seal.

Abstract: A fluid filtration unit having two or more filter medium layers and/or zones, at least one of the layers/zones having a different particle retention capability disposed on each side of a non-filtering separator element. The filter medium are presently preferably positioned such that each succeedingly distal filter layer or zone from the separator has a decreased particle retention capability than each proceeding filter layer or zone. The filter medium layer most proximal to the separator element may be separated from the separator by a support material for supporting such filter medium element and preventing collapsing of the medium into any separator conduit. At least one of the medium elements is formed from a material which swells in size due to fluid absorption with the various zones and the separator being operatively connected by a new and innovative edge seal.

Abstract: Phase inversion microporous membranes including at least two different pore size regions are provided, wherein two membrane sheets are placed, back-to-back, such that the qualifying pore zones are positioned internally within the structure. Exemplary membranes according to the present disclosure provide excellent thermal stability and retention characteristics. Methods for fabricating and using the disclosed membrane structures are also provided according to the present disclosure.

Abstract: A filter element is disclosed that includes a filtration media, an upstream pleat support and a multi-layer downstream pleat support. The multi-layer downstream support includes a first downstream support layer and a second downstream support layer. The first downstream support layer is in contact with the filtration media and is interposed between the filtration media and the second downstream layer. The first downstream support layer is fabricated so as to minimize points of surface contact with the filtration media, thereby enhancing fluid flow away from the filtration media. The second downstream support layer is in contact with the first downstream support layer and is fabricated so as to facilitate lateral fluid flow relative to the multi-layer downstream pleat support. The disclosed filter element may be utilized in filter cartridges of various designs to provide enhanced filtration performance, e.g., by way of increased media area and improved flow/throughput.

Abstract: A fluid filtration unit having two or more filter medium layers and/or zones, at least one of the layers/zones having a different particle retention capability disposed on each side of a non-filtering separator element. The filter medium are presently preferably positioned such that each succeedingly distal filter layer or zone from the separator has a decreased particle retention capability than each proceeding filter layer or zone. The filter medium layer most proximal to the separator element may be separated from the separator by a support material for supporting such filter medium element and preventing collapsing of the medium into any separator conduit. At least one of the medium elements is formed from a material which swells in size due to fluid absorption with the various zones and the separator being operatively connected by a new and innovative edge seal.

Abstract: A filter is disclosed that includes a cylindrical filter element having a longitudinal axis, an outer periphery, an inner periphery, and a plurality of longitudinal pleats arranged in a spiral configuration in close proximity to one another. Each of the pleats has a pair of legs, and the legs of each pleat are joined to one another at a root. The roots of adjacent pleats are radially spaced from one another about the inner periphery of the filter element.

Abstract: A spiral wound filter element is disclosed which includes at least three radially successive prequalifying sections of filter medium commencing with a radially outer prequalifying section of filter medium and concluding with a radially inner prequalifying section of filter medium, each prequalifying section of filter medium having a number of perforation formed therein, wherein the number of perforations in the filter medium of each radially successive prequalifying sections is less than the number of perforations in the filter medium of a radially preceding prequalifying section, and further including a radially inner qualifying section of filter medium succeeding the radially inner prequalifying section, the radially inner qualifying section of filter medium having imperforate filtering layers.

Abstract: Expansion resistant filter cartridge assemblies are provided that facilitate filtering of strong solvent solutions. The filter cartridge assemblies generally include a cylindrical filter element defining an outer periphery, an inner periphery and opposed end surfaces, a perforated cage operatively associated with the outer periphery of the filter element, a perforated core operatively associated with the inner periphery of the filter element and having opposed ends and a predetermined length, and an end cap operatively associated with each of the opposed end surfaces of the filter element and bonded to each end of the core. The perforated cage generally includes an expansion region of about 2.5% to about 4% of the total length of the filter cartridge, e.g., a region of axial discontinuity or a plurality of angular struts, to accommodate swelling and/or dimensional expansion of the cage without adversely affecting the integrity of the filter cartridge assembly.

Abstract: A filter cartridge is provided having a filter element including media preferably constructed from continuous, reinforced, geometrically symmetrical, microporous membranes having three distinct pore zones. Preferred filter elements are assembled with high and/or increased filtration area to yield increased throughput cartridge elements. Preferred filter elements are constructed from reinforced microporous membranes that include a scrim having two sides at least substantially encapsulated within a first dope and at least one additional dope coated onto each side of the encapsulated scrim prior to the first dope being quenched.

Abstract: A filter is disclosed that includes a cylindrical filter element having a longitudinal axis, an outer periphery, an inner periphery, and a plurality of longitudinal pleats arranged in a spiral configuration in close proximity to one another. Each of the pleats has a pair of legs, and the legs of each pleat are joined to one another at a root. The roots of adjacent pleats are radially spaced from one another about the inner periphery of the filter element.

Abstract: A spiral wound filter element is disclosed which includes alternating layers of filter medium and diffusion medium wrapped about a cylindrical core defining a central axis of the filter element. The alternating layers extend from a radially innermost layer of the filter element to a radially outermost layer of the filter element, the diffusion medium is defined by a continuous lengthwise sheet of mesh material, and the filter medium is defined by at least one sheet of filter material arranged along the length of the continuous sheet of mesh material. The alternating layers of filter medium and diffusion medium define three distinct radially disposed layered filtering sections surrounding the cylindrical core, and include a first filtering section having radially outer prequalifying layers, a second filtering section having middle prequalifying layers and a third filtering section having radially inner qualifying layers.

Abstract: Expansion resistant filter cartridge assemblies are provided that facilitate filtering of strong solvent solutions. The filter cartridge assemblies generally include a cylindrical filter element defining an outer periphery, an inner periphery and opposed end surfaces, a perforated cage operatively associated with the outer periphery of the filter element, a perforated core operatively associated with the inner periphery of the filter element and having opposed ends and a predetermined length, and an end cap operatively associated with each of the opposed end surfaces of the filter element and bonded to each end of the core. The perforated cage generally includes an expansion region of about 2.5% to about 4% of the total length of the filter cartridge, e.g., a region of axial discontinuity or a plurality of angular struts, to accommodate swelling and/or dimensional expansion of the cage without adversely affecting the integrity of the filter cartridge assembly.

Abstract: A filter including alternating layers of filter medium and diffusion medium. The filter provides optimum distribution of fluid over the filtering medium, a reduced pressure drop and an increased filter life, without a reduction in filter rating. The diffusion medium has a first plane of spaced-apart, substantially parallel strands defining first longitudinal passages having a first height dimension and a first width dimension, and a second plane of spaced-apart, substantially parallel strands defining second longitudinal passages having a second height dimension and a second width dimension. The strands of the second plane of the diffusion medium are oriented in a non-parallel manner with respect to the strands of the first plane, such that the first and the second planes define lateral openings having side dimensions. The first and the second longitudinal passages include at least one dimension that is smaller than any of the side dimensions of the lateral openings.

Abstract: A method is disclosed for forming a filter cartridge which includes the steps of providing a cylindrical filter element having a plurality of radially extending longitudinal pleats, engaging an outer periphery of the cylindrical filter element along a substantial portion of the length thereof, and simultaneously moving the plurality of radially extending longitudinal pleats into a laid-over spiraled configuration along the entire length of the cylindrical filter element to form a spiral pleated filter element. An apparatus is also disclosed for effectuating the disclosed method.

Abstract: A method is disclosed for forming a filter cartridge which includes the steps of providing a cylindrical filter element having a plurality of radially extending longitudinal pleats, engaging an outer periphery of the cylindrical filter element along a substantial portion of the length thereof, and simultaneously moving the plurality of radially extending longitudinal pleats into a laid-over spiraled configuration along the entire length of the cylindrical filter element to form a spiral pleated filter element. An apparatus is also disclosed for effectuating the disclosed method.