The present disclosure relates to a device and a process for cutting hollow fiber membranes having a large inner diameter.

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.

System, devices, and method for the production of thin film composite hollow fiber membranes on a hollow fiber support structure. The system includes a comb and roller device, or comb and dual roller device, which can be used to define a submerged travel path in a first solution bath for a hollow fiber. The combs and rollers control the amount of time the hollow fiber spends in the first solution. The first solution contains a first monomer, and the hollow fiber is impregnated with the first monomer. The amount of impregnation depends on the time spent in the first solution. Subsequent immersion in a second solution containing a second monomer results in the formation of a thin film composite hollow fiber membrane.

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 are herein provided for preparing a material for casting a flat-sheet, extruding a solid-fiber, and/or extruding a hollow-fiber utilizing a chlorinated aqueous amine solution as an effective solvent to form a crystalline polymorph structure of the material. This material in the form of, for example, an effective vapor permeable membrane can be used in membrane distillation to desalinate saline streams.

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.

Described are hollow fiber porous polymeric filter membranes and methods for preparing these membranes. The methods including extruding and shaping a polymer solution that includes polymer and solvent, and reducing the temperature of the extruded polymer by contacting the extruded polymer with liquid metal.

The present invention relates to a variable-diameter spinning nozzle, processing devices for hollow fiber membrane bundle and membrane module. The variable-diameter spinning nozzle comprises a center round tube, a middle round tube and an external chamber which are sequentially nested, and a first drive mechanism for driving the middle round tube to move vertically upwards and downwards. The bottoms of the center round tube, the middle round tube and the external chamber are leveled. The variable-diameter spinning nozzle provided by present invention obtains membrane fiber by adjusting the location of the middle round tube, and this membrane fiber involves membrane fiber heads with relatively large diameter on both ends and a membrane fiber middle section with relatively small diameter. In the subsequent process of binding and assembly of membrane module, porosity of the membrane fiber middle section can be adjusted by controlling a diameter ratio of the membrane fiber head to the membrane fiber middle section, and thus arbitrary fill density and regular arrangement of membrane module are achieved.

The invention relates to an undulated thermostable hollow fiber membrane of reduced wall thickness, wherein the wall thickness amounts to 20 m or greater and 30 m or less and the waveform of the hollow fiber membrane exhibits a wavelength in the range of from more than 1 mm and less than 5 mm. In particular, the invention relates to a method for producing an undulated thermostable hollow fiber membrane of lower wall thickness.

A filtration membrane made by a method that includes: a) selecting and preparing an organic polymer, such as a collodion; b) injecting a collodion into at least one channel of an extrusion die that also comprises an extrusion die core and at least one outlet; c) injecting an internal liquid into a hollow centering pin, the hollow centering pin comprising a channel positioned on the core of the extrusion die and also positioned at an axis of the outlet of the extrusion die; d) applying a holding film to the outlet of the extrusion die; e) unrolling the holding film onto a surface of at least one hollow fiber emerging from the outlet of the extrusion die; f) immersing the hollow fiber with the first holding film in a rinsing solution so as to obtain a flat hollow fiber filtration membrane; and ending the rinsing of the filtration membrane.