Manufacture of a filtration membrane

Abstract

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.

1 . A flat filtration membrane, comprising:
 a first protective support film and a second protective support film, and   a plurality of hollow fibers having an inner skin delimiting respectively a plurality of parallel filtration channels, the hollow fibers being formed by an organic polymer,   wherein the first and second protective support films are applied on outer walls of the hollow fibers.   
     
     
         2 . The filtration membrane according to  claim 1 , wherein at least one of the first and second protective support film is a nonwoven support. 
     
     
         3 . The filtration membrane according to  claim 1 , wherein at least one of the first and second protective support film is of a porous nature. 
     
     
         4 . The filtration membrane according to  claim 1 , wherein at least one of the first and second protective support film are polypropylene-based. 
     
     
         5 . The filtration membrane according to  claim 1 , wherein the inner skin includes a small width area without channels, so as to ease a folding of the filtration membrane. 
     
     
         6 . The filtration membrane according to  claim 1 , wherein each filtration channel has a diameter comprised between 0.2 and 3 mm. 
     
     
         7 . The filtration membrane according to  claim 1 , having a ratio of the total thickness of the membrane and the channel diameter comprised between 1.6 and 1.8. 
     
     
         8 . A flat filtration membrane, comprising:
 a first protective support film and a second protective support film,   a plurality of hollow fibers having an inner skin delimiting respectively a plurality of parallel filtration channels, the hollow fibers being formed by an organic polymer, wherein the plurality of hollow fibers are positioned between the first and second protective support films.   
     
     
         9 . A filtration membrane that includes a plurality of channels and is made a method comprising:
 a) selecting and preparing a collodion,   b) injecting the collodion into at least one channel of an extrusion spinneret that further comprises a core and an outlet,   c) injecting an internal liquid into a plurality of hollow centering needles, wherein each centering needle comprises a channel positioned at the core of the extrusion spinneret,   d) applying a first protective support film at the outlet of the extrusion spinneret, unrolling the first protective support film onto a first face of a flat filtration membrane emerging from the outlet of the extrusion spinneret, the filtration membrane having a plurality of filtration channels,   e) applying a second protective support film at the outlet of the extrusion spinneret, unrolling the second protective support film onto a second face of the filtration membrane emerging from the outlet of the extrusion spinneret,   f) immersing the filtration membrane with the first and second support films in a rinsing solution,   g) ending the rinsing of the filtration membrane.