The present invention relates to a method to make polymeric membranes that are preferably useful in dialysis, wherein the method conducts at least one membrane-forming step and/or post-forming processing step with the use of sonication. Polymeric membrane, such as polymeric hollow fiber membrane, having improved one or properties are further described.

The present disclosure relates to a spinneret for producing hollow fiber membranes in a phase inversion process.

A hollow fibre membrane having a coiled, a hemihelix, a helical or an undulated native form, in which the membrane can be stretched by up to 4-times its original length with no plastic deformation, and wherein the native form of the membrane is produced by the asymmetric flow of liquid polymer through an opening of a die or nozzle.

There is provided a thin film composite (TFC) hollow fibre membrane comprising a porous hollow fibre support layer formed of a polymer and a selective layer, formed of a cross-linked polyamide, on an inner circumferential surface of the hollow fibre support layer, wherein the TFC hollow fibre membrane has a power density of 25-50 W/m.sup.2 at a pressure of 30 bar. There is also provided a method of forming the TFC hollow fibre membrane.

A method for manufacturing a hollow fiber membrane has a spinning step of applying a first membrane forming stock solution and a second membrane forming stock solution for forming a porous membrane layer to the outer peripheral surface of a hollow porous base material using a nozzle for hollow fiber membrane spinning and solidifying these membrane forming stock solutions, wherein a draft ratio (V.sub.B/V.sub.A), which is the ratio of feed velocity V.sub.B for hollow porous base material fed out from a base material feed opening to linear velocity V.sub.A for the first membrane forming stock solution and the second membrane forming stock solution discharged from a membrane forming stock solution discharge opening of the nozzle for hollow fiber membrane spinning, is set to 1-6.

Systems and methods can be used to produce fibers with external corrugations, internal corrugations, or both. These fibers can be used, for example, in hollow fiber membrane modules.

Methods of producing a deformed porous hollow fiber membrane by thermally induced phase separation, particularly by discharging a fusion kneaded product containing a thermoplastic resin and an organic liquid through an orifice of a hollow fiber-forming deformed nozzle; cooling and solidifying the fusion kneaded product discharged through the deformed nozzle to form the product into a hollow fiber-like material having a deformed cross section at a cross section vertical to a discharging direction; and extracting away the organic liquid from the hollow fiber-like material to obtain the deformed porous hollow fiber membrane, wherein an inorganic fine powder is kneaded in the fusion kneaded product.

The present invention is related to a method for fabricating multilayer singlebore membranes (10) or multilayer multibore membranes (20) for ultrafiltration applications including the following method steps: (a) feeding at least a material of a substrate (12), at least one material of a functional layer (14, 15) and a bore fluid (36) to a spinneret (30) simultaneously; (b) forming said membranes (10, 20) as a tube-like string (54) in a one-step process in said spinneret (30); (c) thereby assigning a functionality to said functional layer (14, 15) applied on at least one surface (13, 17) of said substrate (12). The invention is also related to a spinneret (30) for fabricating multilayer singlebore membranes (10) or multilayer multibore membranes (20), using the inventive method, and to a system comprising such a spinneret (30).

The present invention relates to high performance, crosslinked hollow-fibre membranes and a new process for manufacturing the same.

A filament production device, in particular a filament reaction-spinning production device, comprising at least one spinning nozzle unit, which is provided for producing at least one filament formed as a hollow fibre membrane from at least one polymer solution, and comprising a polymerisation unit, which is provided for initiating a polymerisation of the polymer solution, wherein the polymerisation unit is provided for initiating the polymerisation at least partially within the spinning nozzle unit.