Abstract: An air filter 100 includes a plurality of filter units 2 and an outer frame 10 surrounding the plurality of filter units 2. The filter units 2 each include a pleated filter medium 4 and a supporting frame 6 holding a peripheral portion 4e of the filter medium 4. Adjacent two filter units 2 and 2 form a V-shape. The plurality of filter units 2 are coupled to each other at the respective supporting frames 6 thereof. The plurality of filter units 2 are fitted in the outer frame 10 so that all of the filter units 2 are inclined with respect to in-plane directions of opening surfaces of the outer frame 10.

Abstract: Provided is a filter unit in which an increase in pressure loss is suppressed despite the use of an injection-molded resin as a frame. This filter unit includes a pleated filter medium 1 and a frame 2 for supporting the filter medium 1. The frame 2 has inner and outer peripheries, each of which is rectangular in shape when viewed along an air flow path through the filter medium 1. In this filter unit, the filter medium 1 is fixed to the frame 2 with a peripheral portion of the filter medium 1 being embedded inside the frame 2. The pleated filter medium 1 has a value DIP of 0.25 or less. This value DIP is obtained by dividing the distance D between adjacent ridges of the pleats of the filter medium 1 by the height P of the pleats. The distance D has a minimum value d of at least 1 mm. The frame 2 has a length La longer than a length Lm.

Abstract: The present invention provides filter units that, when joined together, allow joining portions thereof to be fixed together satisfactorily and can prevent air from leaking at the joining portions. A filter unit includes a filter medium that has been pleated and a frame that supports the circumference of the filter medium. The frame has a protruding part on at least one face selected from an upper face and a lower face thereof, with the protruding part being formed by allowing a part of the at least one face to protrude. The upper face is a surface of the frame that faces the upstream side relative to the flow of air that passes through the filter medium, and the lower face is a surface of the frame that faces the downstream side relative to the flow of air.

Abstract: The present invention provides a filter medium reducing an increase in pressure drop while in use even in an environment where ultrafine particles form a large proportion of the particles to be collected. The filter medium includes a porous polytetrafluoroethylene (PTFE) membrane, an air-permeable supporting member and a web layer made of polymeric fibers formed by electrospinning (charge induction spinning, electrostatic spinning). The filter medium of the present invention may include an air-permeable adhesive layer adjacent to the web layer.

Abstract: The present invention provides filter units that, when joined together, allow joining portions thereof to be fixed together satisfactorily and can prevent air from leaking at the joining portions. A filter unit includes a filter medium that has been pleated and a frame that supports the circumference of the filter medium. The frame has a protruding part on at least one face selected from an upper face and a lower face thereof, with the protruding part being formed by allowing a part of the at least one face to protrude. The upper face is a surface of the frame that faces the upstream side relative to the flow of air that passes through the filter medium, and the lower face is a surface of the frame that faces the downstream side relative to the flow of air.

Abstract: Polytetrafluoroethylene porous film is laminated with an ultra high molecular weight polyolefin porous film to realize excellent formability, dust collecting ability, and permeability that could not be attained by these porous films used alone. The laminate, which can be formed to prescribed shape if desired, is used to make a container for holding an adsorbent.

Abstract: An antibacterial air filter medium has at least one layer of a porous polytetrafluoroethylene film and at least one layer of an antibacterial reinforcing material which may be colored so as to make dirt inconspicuous; the antibacterial air filter medium retains its filtering performance even in an environment rich in water and can be inhibited from undergoing the growth of bacteria or mold fungi even in such an environment; and the antibacterial air filter medium, even when used after washing with water or in a high-humidity environment, does not undergo a decrease in filtering property such as particle collection efficiency and can be inhibited from undergoing the growth of bacteria or mold fungi thereon.

Abstract: Turbine air filter media include at least one porous film of polytetrafluoroethylene, and at least one air-permeable support member, wherein the turbine air filter media exhibit a pressure drop of from 100 Pa to 300 Pa, both inclusively, and a PF value of not smaller than 15. The porous film of polytetrafluoroethylene preferably exhibits a pressure drop of from 70 Pa to 250 Pa, both inclusively, and a PF value of not smaller than 18.

Abstract: A filtering medium for air filters, comprising a laminate including at least one porous polytetrafluoroethylene (PTFE) membrane and at least one air-permeable supporting member, the filtering medium having a surface potential of 0.3 kV or lower in terms of absolute value. By regulating the absolute value of surface potential so as to be within that range, the formation of a through-hole attributable to a discharge (spark) caused by, e.g., contact with a bare hand can be prevented. Thus, the leakage phenomenon observed in filtering media for air filter using a porous PTFE membrane can be inhibited.

Abstract: A filter medium for filters wherein the evolution of organic gases and dusting from a reinforcing member are depressed and thus the excellent characteristics inherent to a porous polytetrafluoroethylene membrane as a collection layer are fully achieved. The filter medium (1) for filters comprises a porous polytetrafluoroethylene membrane (2) and a porous ultrahigh-molecular weight polyolefin membrane (3) as a reinforcing member for the filter medium.

Abstract: A filter medium for air filters wherein the collection performance of polytetrafluoroethylene (PTFE) membranes is not damaged even after processing, for example, pleating and bonding to air-permeable supporting members. The filter medium containing a laminate (2) containing at least three layers of porous PTFE membranes wherein the pressure drop of a porous PTFE membrane (4) located as an outermost layer has a pressure drop of 1/2 times or less the pressure drop of porous PTFE membrane (5) located as at least one intermediate layer. Air-permeable supporting members (3) are bonded to both outermost layers of the laminate (4) to obtain a filter medium for air filters (1).

Abstract: A filtering medium for air filters wherein its surface conditions have been improved, whereby the porous PTFE membrane is not damaged even after pleating, thus appropriately meeting needs for clean space in clean rooms. The filtering medium comprises a porous polytetrafluoroethylene membrane (2) and an air-permeable supporting member (1) which are laminated such that at least one of exposed surfaces comprises a surface of the air-permeable supporting member (1) having a maximum frictional resistance of 25 gf or less. This filtering medium can be obtained by, for example, press bonding the air-permeable supporting member (1) to the porous membrane (2) under heating and then pressing the surface of the air-permeable supporting member (1) to a silicone roll (4) for smoothing.