The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material and a preparation method and uses thereof. The polytetrafluoroethylene composite filter material comprises a support layer and a polytetrafluoroethylene microporous membrane layer, and the support layer and the polytetrafluoroethylene microporous membrane layer are compounded by an adhesive, wherein the adhesive comprises a two-component polyurethane adhesive, a pore forming agent and an inorganic filler. The present invention adopts a two-component solvent-free polyurethane adhesive, and by adding a low-temperature pore forming agent and an inorganic filler, the pore forming agent forms an irregular pore channel structure at the bonding interface during curing, and the inorganic filler prevents the adhesive from entering the micropores of the polytetrafluoroethylene membrane, so that the air permeability and filtration efficiency of the polytetrafluoroethylene microporous membrane are not affected after compounding; and the prepared polytetrafluoroethylene composite filter material has good air permeability, high peel strength, good filtration efficiency and good barrier effect.

A provided stretched porous polytetrafluoroethylene membrane has an air permeability of 4 cm.sup.3/(sec.Math.cm.sup.2) or more, as expressed in terms of Frazier air permeability, in a thickness direction, and has a total cohesion of 1.9 (N/20 mm).sup.2 or more, the total cohesion being expressed by a product of a peel cohesion in a first in-plane direction and a peel cohesion in a second in-plane direction perpendicular to the first direction. The above stretched porous membrane is highly air-permeable and, for example, when included in a filter member, being less likely to suffer breakage at the time of handling the member or placing the member on a housing or the like.

A spunbond non-woven fabric includes a nonbonded projected part and a bonded recessed part. Bending resistance in a machine direction of the spunbond non-woven fabric is 20 mN or more and 40 mN or less, and in a non-woven fabric cross-section, a thickness from one surface to another surface of the projected part is determined to be t.sub.A, a thickness from one surface to another surface of the recessed part is determined to be t.sub.B, and respective distances from one surface of the projected part to one surface of the recessed part are determined to be t.sub.C and to (t.sub.C<t.sub.D), and the spunbond non-woven fabric has a relation represented by formulas (1) and (2) below:

0.5≤1−t.sub.B/t.sub.A<1.0  (1)

0.35<t.sub.C/t.sub.D<0.65  (2).

A method of cleaning a complex powder transfer system including providing a powder transfer system having a washing fluid source, a spray device valve in fluid communication with the washing fluid source, a backflush valve in fluid communication with the washing fluid source, a receiving device having an upper chamber, a lower chamber, and a membrane filter disposed between the upper and lower chambers. The method includes opening the backflush valve to initiate a backflush cycle, running the backflush cycle to wash the upper chamber with a fluid, and closing the backflush valve after the backflush cycle completes. The method includes opening the spray device valve to initiate a spray device cycle, running the spray device cycle to wash the lower chamber with fluid, and closing the spray device valve after the spray device cycle completes. The method includes opening a pressure valve to provide PCA to the receiving container.

Provided is a porous polytetrafluoroethylene membrane in which an absolute value of a difference in lightness between one principal surface and the other principal surface is 1.0 or more, where the lightness is lightness L* of CIE 1976 (L*, a*, b*) color space specified in JIS Z8781-4: 2013. The porous polytetrafluoroethylene membrane may be colored black or gray. The porous polytetrafluoroethylene membrane provided can have properties with a reduced coloring-induced deterioration.

Disclosed herein are phase separator devices, and related methods of fabrication and use. The disclosure provides improved phase separator devices for phase separation of input feeds, and systems/methods for utilizing and fabricating the devices. The disclosure provides phase separator devices utilizing inertial separation and porous media extraction for the phase separation of two-phase input feeds (e.g., to separate an input feed of a two-phase mixture to a first phase output (e.g., to a liquid output flow) and to a second phase output (e.g., to a gas output flow)). The device can separate a mixed fluid flow of both liquid and gases. The liquid and gas can include liquid and vapor phases of the same chemical/constituent (e.g., ammonia), or may include liquid and gases of two different constituents (e.g., liquid water and air). The phase separator devices can be utilized at standard gravity to micro-gravity to zero gravity environments.

Devices, systems and methods are disclosed which relate to using a wet foam elution method for removal of particles from a flat filter. Particles are captured from the atmosphere onto the flat filter. The flat filter is then placed into an extractor which passes a stream of wet foam through the flat filter. Expansion of the foam works to efficiently remove captured particles. The foam flows from the filter along with the captured particles into a sample container. Once in the sample container, the foam quickly breaks down leaving an analysis ready liquid sample.

A device for preventing contamination of a positive-pressure connector (6) of an indwelling needle and a method based on same. The device comprises a shell (1), a connecting port (3) fixedly connected to the shell (1) and used for connecting to the positive-pressure connector (6), an air pressure balance hole (5) disposed opposite to the connecting port (3) and provided on the shell (1), and a filtering membrane (2) provided between the air pressure balance hole (5) and the connecting port (3). The device is simple in structure, adopts a structural design of the filtering membrane (2), can filter microorganisms, bacteria, viruses, dusts, and particulate pollution sources, and is used during indwelling of infusion intervals to prevent the positive-pressure connector (6) from being exposed to the air and maintain the aseptic state and positive-pressure condition of the positive-pressure connector (6) during indwelling.

The invention relates to a modular, portable, air purifier device capable of supplying filtered or otherwise conditioned airflow to an individual. More specifically, the present invention provides an air purification system that allows for the remote detection and analysis of local ambient air quality and transmit that information to wirelessly connected devices.

A smoke and dust treatment apparatus for welding, said apparatus comprising a polishing and dust extraction module and a smoke and dust purification module. The polishing and dust extraction module comprises a double-layer dust extraction cover (3), a protective cover (2), an industrial brush (4), a first air guide portion, a second air guide portion (24) and a drive motor (22), the drive motor (22) driving the industrial brush (4) to rotate at high speed to perform polishing. During welding and polishing, a mechanical arm (6) drives the double-layer dust extraction cover (3), and a suction hole (20) of the double-layer dust extraction cover (3) and a suction guide hole (19) on the industrial brush (4) simultaneously take in toxic gas and debris such as iron filings.