A method for producing a cellulose nanofiber-containing polyolefin microporous stretched film according to the invention includes: a first step of obtaining a cellulose powder dispersion mixture by uniformly dispersing a cellulose which has a powder particle shape and whose hydroxyl groups have been subjected to a lipophilizing treatment using a dibasic acid anhydride, in a plasticizer; a second step of melt-kneading the cellulose powder dispersion mixture and a polyolefin to obtain a polyolefin resin composition; a third step of extrusion-molding the polyolefin resin composition to obtain an extrudate; a fourth step of stretching the extrudate with a film stretcher to obtain a film; a fifth step of extracting out the plasticizer from the film; and a sixth step of thermally fixing the film from which the plasticizer has been extracted out for inhibiting contraction, while stretching the film at a temperature not higher than a melting point of the polyolefin, in which a twin-screw kneading extruder is used only once throughout the second and third steps.

A process for welding porous membranes, the process containing i) providing first and second porous membranes; ii) at least partially superimposing the first and second porous membranes to obtain an at least partial superimposition region; iii) welding the first and second porous membranes at least in a portion of the at least one superimposition region at a temperature in the range from 100 to 300 C. to obtain an at least partially welded composite of the first and second porous membranes, wherein the first and second porous membranes are made of at least one thermoplastic elastomer selected from the group consisting of a polyurethane elastomer, a polyester elastomer, a polyetherester elastomer, a polyesterester elastomer, a polyamide elastomer, a polyetheramide elastomer, a polystyrene elastomer, and an ethylene-vinyl acetate elastomer, and wherein the first and second porous membranes have pores having an average pore diameter of less than 2000 nm.

The invention discloses a diaphragm including a polymer material layer made of polymer material and a porous damping material layer made of porous damping material. The polymer material layer is stacked and fixed onto the porous damping material layer. The beneficial effects of the present invention are: (1) the porous damping material has high structural strength, and can restrain the contractility of polymer material; therefore, it can be ensured that the dimensions of products made of the diaphragm substrate material of the present invention remain consistent. (2) The diaphragm substrate material of the present invention can restrain and improve the variation of the properties of polymer materials under high temperature conditions.

A semipermeable ultrathin polymer membrane comprises a substantially optically transparent polymer film having a surface area to thickness ratio of at least 1,000,000:1, and an array of precisely spatially ordered pores of a user-selected diameter defined therethrough. Such membranes can be fabricated by providing a mold having a patterned array of nanoholes femtosecond laser ablated in a surface thereof; applying a first polymer solution onto the mold surface so that the first polymer solution infiltrates the nanoholes; allowing the first polymer solution to dry and form a replica of the mold having a plurality of freestanding nanoneedles extending from a surface of the replica; removing the replica from the mold; coating the replica surface with a second polymer solution; drying the second polymer solution to form a porous polymer film; and dissolving the replica in a solvent to release the film from the replica as a semipermeable ultrathin polymer membrane.

A reinforced oil-absorptive membrane material, includes: a tubular support (101) and an oil absorbing layer (102) provided on a surface of the tubular support (101), wherein a plurality of holes are provided on the tubular support (101); and the oil absorbing layer (102) is a piece of nonwoven fabric with a polymer layer provided thereon. The reinforced oil-absorptive membrane material has an excellent oil-absorbing and supportive performance, and is capable of being utilized continuously in a negative pressure suction manner and thus shows high oil absorption efficiency. A method for manufacturing the reinforced oil-absorptive membrane material including pre-treating the nonwoven fabrics by aqueous alkali, covering a membrane casting solution including a solvent, a graphene, polyvinylidene fluoride, pore-forming agent and inorganic particle, and then solidifying and extracting to obtain the oil-absorbing layer.

The present invention relates to a folded side-leakage-proof arc-shaped elastic sanitary product wainscot and a production line therefor. After two sides of an elastic membrane under a tensile state are compounded with nonwoven fabric strips by hot pressing respectively, the elastic membrane rebounds and resets to impel the nonwoven fabric strips located on two sides of the elastic membrane to form a folded side-leakage-proof side wall. The elastic membrane is in the shape of a concave arc. The present invention has the following advantages: 1, the nonwoven fabric strips may be compounded with two sides of the elastic air-permeable membrane without a hot melt adhesive so as to ensure that the air permeability of the elastic air-permeable membrane and the nonwoven fabric strips is not affected by the hot melt adhesive; and 2, after two sides of the elastic air-permeable membrane under a tensile state are compounded with the nonwoven fabric strips, the elastic air-permeable membrane rebounds to impel the nonwoven fabric strips to form a required elastic folded side-leakage-proof side wall with the rebound and reset of the elastic air-permeable membrane. This side wall not only has a function of preventing liquid from flowing, but also greatly reduces a contact area between a sanitary napkin or a panty-shape diaper and a human body, such that the comfort level of the human body is greatly improved.

A porous polytetrafluoroethylene (PTFE) membrane of the present disclosure has a water vapor permeability, as measured according to Japanese Industrial Standard (JIS) L 1099 (method B-1), of 150000 g/(m.sup.2.Math.day) or more in a thickness direction of the membrane. The porous PTFE membrane of the present disclosure, when attached as a waterproof air-permeable membrane to a housing of an electrical component or electrical device, allows water vapor residing inside the housing to be quickly discharged out of the housing.

A porous polytetrafluoroethylene (PTFE) membrane of the present disclosure is a membrane having an average fibril length of 50 m or more, having an average node length 5 or more times larger than the average fibril length, and having an average node area ratio of 5% or less. The porous PTFE membrane of the present disclosure, when attached as a waterproof air-permeable membrane to a housing of an electrical component or electrical device, allows water vapor residing inside the housing to be quickly discharged out of the housing.

An orifice plate having orifice openings is interposed between a roller body and a side plate. In a closed region of an outer peripheral surface of the roller body which is covered with a base material, the base material is held on the outer peripheral surface of the roller body under suction by a negative pressure developed in suction holes. In an open region of the outer peripheral surface which is not covered with the base material, the sucking of a gas from an exterior space into the roller body is suppressed because it is difficult for the gas to pass through the orifice openings. This suppresses a reduction in sucking force in the closed region due to the entry of the gas from the open region. The roller body, the orifice plate and the side plate rotate as a unit. This suppresses deterioration of the members due to the slidable movement thereof.

A piece of substrate material is formed under heat and pressure against a cavity into a shaped substrate sheet having one or more depressions. Two substrate sheets are bonded together to form a substrate wherein the one or more depressions form one or more interior channels. The substrate, if not formed with pre-coated substrate material, is coated with a dope and quenched to form a filtering membrane. A plurality of membranes may be placed side by side to form a bundle with permeating ends of the membrane, which are open to the one or more interior channels, separated by gaps or spacers. The bundle is connected to a header to produce a module. The module can be assembled into a cassette.