A film-stretching apparatus in accordance with an embodiment of the present invention includes a stretching furnace which is divided into a plurality of air amount control zones. In a case where the number of the plurality of air amount control zones is seven, a total amount of air to be discharged from, out of the plurality of air amount control zones, three air amount control zones which are located on an entrance side of the stretching furnace is controlled so as to be larger than a total amount of air to be discharged from, out of the plurality of air amount control zones, three air amount control zones which are located on an exit side of the stretching furnace.

A method for manufacturing a hollow fiber membrane module, the hollow fiber membrane module including: a hollow fiber membrane bundle including a plurality of hollow fiber membranes; a housing configured to contain the hollow fiber membrane bundle; and a potting part in which a potting agent is added between an outer surface of the hollow fiber membranes and an inner surface of the housing at both end regions or at one end region of the hollow fiber membrane bundle, wherein the method including: providing a sheet-shaped spacer in a space between the hollow fiber membranes at the both end regions or at the one end region of the hollow fiber membrane bundle; and adding a potting agent between the outer surface of the hollow fiber membranes and the inner surface of the housing at the both end regions or at the one end region of the hollow fiber membrane bundle such that the provided spacer is embedded, wherein the potting agent includes resin, rubber, or elastomer, as a main ingredient, and wherein the spacer is a net, a non-woven fabric, a porous sheet, or a film.

The present invention relates to a micro-porous filtration membrane with performance enhancing projections as well as a method for producing the same.

A membrane filter 26 is disclosed comprising cellulous material 23 allowing the transition of fluid therethrough, and, in a substantially dry state, said membrane comprising also a salt of deoxycholic acid. Optionally, the air side of the membrane (the side facing away from the screen or belt used to manufacture the membrane) faces the sample fluid during use of the membrane. A method of manufacture of the membrane material is disclosed also, employing deoxycholic acid as a surfactant, to improve the recovery rate of the membrane filter in use.

The present invention relates to a micro-porous filtration membrane with performance enhancing multi-level macro-scopic cavities as well as a method for producing the same.

A hollow fiber membrane module according to an aspect of the present disclosure comprises: a hollow fiber membrane bundle that has a plurality of hollow fiber membranes aligned in one direction; a housing that accommodates the hollow fiber membrane bundle; and a potting portion provided around both ends or one end of the hollow fiber membrane bundle, in which space between an outer surface of the hollow fiber membranes and an inner surface of the housing is filled with a potting agent, wherein each of the hollow fiber membranes has a body portion, and an enlarged-diameter portion provided at both ends or one end of the body portion and having an inner diameter enlarged as compared to the body portion, and the enlarged-diameter portion is buried in the potting portion.

Asymmetric articles are described including a porous substrate with two opposing major surfaces and a porous structure extending between the surfaces, and a polymeric coating on one of the major surfaces and extending into the porous structure to a depth of the porous structure. Methods for making an asymmetric composite article are also provided, including providing a porous substrate, treating the porous substrate with a plasma treatment or a corona treatment from one major surface to a depth of the porous structure between the two major surfaces. The method further includes applying a coating solution to the treated porous substrate and drying the coating solution to form a composite asymmetric composite article having a polymeric coating on one major surface and extending into the porous structure to the depth of the treated porous structure.

A method for use in the manufacture of a filtration article includes providing a porous, fluoropolymer membrane, and applying a force to at least a portion of a first side surface of the membrane to modify the first side surface. The applied force may have a non-normal directional component relative to the first side surface. The surface modification may increase the density of the modified surface and/or reduce the porosity of the modified surface. Particle retention capabilities are thereby enhanced across the modified surface while maintaining permeability across the volume of the membrane.

Forward osmosis membranes include an active layer and a thin support layer. A bilayer substrate including a removable backing layer may allow forward osmosis membranes with reduced supporting layer thickness to be processed on existing manufacturing lines.

Provided is a compression bar apparatus for applying pressure to desired areas of a thin film composite (TFC) membrane, such as spiral wound TFC membranes and elements, including membranes and elements used for nanofiltration, reverse osmosis or forward osmosis to purify water, such as tap water, seawater, and brackish water. Application of pressure to a spiral wound element by the apparatus produces a membrane with increased sealant penetration, reduced osmotic blistering, and minimal damage to the active area of the membrane. Also provided are methods of using the apparatus.