A filtration medium including a polymeric netting of polymeric ribbons and polymeric strands. Each of the polymeric ribbons and strands has a length and width, with the length being the longest dimension and the width being the shortest dimension. The polymeric ribbons have a height-to-width aspect ratio of at least three to one or five to one a major surface that is intermittently bonded to a polymeric strand, and a height typically greater than the height of the one polymeric strand. A filter including the filtration medium and a method useful for making the polymeric netting are also disclosed.

A cylindrical or tubular filter insert (10) of a filter material (2) for liquid media (7) is disclosed. A filtration arrangement (30) serves to receive the cylindrical or tubular filter insert (10). The filtration arrangement (30) comprises a filter housing (31) with an inlet (32) for the medium (7) to be filtered and an outlet (34) for the filtered medium (7).

A method for removing retroviruses from liquid samples and a nanofiber containing liquid filtration medium that simultaneously exhibits high liquid permeability and high microorganism retention is disclosed. Retroviruses are removed from a liquid by passing the liquid through a porous nanofiber containing filtration medium having a retrovirus LRV greater than about 6, and the nanofiber(s) has a diameter from about 10 nm to about 100 nm. The filtration medium can be in the form of a fibrous electrospun polymeric nanofiber liquid filtration medium mat.

A filter medium includes first and second porous films mainly containing fluororesin, and a pre-collection member upstream of the first film. The second film is downstream of the first film. The pre-collection member has a pressure drop when air is passed through at a flow rate of 5.3 cm/s of between 15 Pa and 55 Pa, a collection efficiency of NaCl particles having a particle diameter of 0.3 ?m when air containing the particles is passed hrough at a flow rate of 5.3 cm/s of between 25% and 80%, a thickness of 0.4 mm or less, and a PF value between 7 and 15. The PF value={?log((100?collection efficiency (%))/100)}/(pressure drop (Pa)/1000). A ratio of the PF value of the pre-collection member to the PF value when the first and second films are overlapped, is between 0.20 and 0.45. The filter medium can be used in a filter pack or filter unit, and may be produced by integrating the first and second films and the pre-collection member using heat lamination.

A filter includes an electrode; a base layer coupled with the electrode; and a nanofiber layer spun on one side of the base layer and coupled, in which the coupling between the nanofiber layer and the base layer is performed as the nanofiber layer is adsorbed on the base layer by an electric field generated by supplying power to the electrode.

A filtration media with improved filtration, strength, tear resistance and air permeability in the form of a relatively thin and lightweight wet-laid fibrous web that has a wet Mullen ratio of 60% to 80% to ensure that the media is flexible enough to be formed into a fluted structure, and strong enough to retain the fluted structure when wound into a roll and to permit further processing without the media becoming too brittle. The filtration media comprises a blend of cellulose and synthetic fibers having a weight percent of 81 wt % to 87 wt % of a weight of the media and a resin binder having a weight of 13 wt % to 19 wt % (preferably about 16 wt %) of the weight of the media.

A polymeric netting including polymeric ribbons and polymeric strands. Each of the polymeric ribbons and strands has a length and width, with the length being the longest dimension and the width being the shortest dimension. The polymeric ribbons have a height-to-width aspect ratio of at least five to one, a major surface that is intermittently bonded to only one polymeric strand, and a height greater than the height of the one polymeric strand. An extrusion die and method useful for making the polymeric netting are also disclosed.

Fiber webs that may be used as filter media are provided. In some embodiments, the filter media may include multiple layers. Each layer may be designed to have separate functions in the filter media. For example, a first layer may be provided for improving dust holding capacity, a second layer for improving efficiency, and a third layer for providing support and strength to the media. By designing the layers to have separate functions, each layer may be optimized to enhance its function without negatively impacting the performance of another layer of the media.

Provided herein is a filter medium comprising a first nonwoven melt-blown layer, the meltblown nonwoven comprising a) at least one styrenic thermoplastic elastomer and b) at least one polyolefin. Also provided herein is the use of the filter medium for coffee filters, compressed air filters and face masks.

Fiber webs that may be used as filter media are provided. In some embodiments, the filter media may include multiple layers. Each layer may be designed to have separate functions in the filter media. For example, a first layer may be provided for improving dust holding capacity, a second layer for improving efficiency, and a third layer for providing support and strength to the media. By designing the layers to have separate functions, each layer may be optimized to enhance its function without negatively impacting the performance of another layer of the media.