Hollow fiber membrane having improved diffusion properties
AssigneeFresenius Medical Care Deutschland GmbH
InventorsTorsten Keller, Roland Sander, Igor Raiko, Christian Finkler
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Abstract
The invention relates to an undulated thermostable hollow fiber membrane of reduced wall thickness, wherein the wall thickness amounts to 20 μm or greater and 30 μm 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.
Claims15
An undulated hollow fiber membrane, comprising at least one first hydrophobic polymer and at least one second hydrophilic polymer, having a wall thickness of 20 μm or greater and 30 μm or less, wherein the at least one first hydrophobic polymer is a polyarylether, polyamide, polyester, polycarbonate, polyacrylate and methacrylate, polymethacrylimide, polyvinylidenfluoride, polyimide, polyacrylnitrile group, or any copolymer thereof, and the at least one second hydrophilic polymer is a polyvinylpyrrolidone or polyethylene glycol group, and a waveform of the hollow fiber membrane exhibits a wavelength in a range of from greater than 1 mm and less than 4 mm and wherein a porosity of the hollow fiber membrane is 65% to less than 78%, and a drop in sodium clearance of the hollow fiber membrane is less than 13 ml/min after a heat sterilization process of above 100° C.
A method for producing an undulated hollow fiber membrane containing at least one first hydrophobic polymer, comprising the steps:
- producing a hollow fiber membrane having a wall thickness of 20 μm or greater and 30 μm or less and having a porosity of 65% to less than 78% from a spinning material in a spinning and phase inversion process;
- producing a waveform of predetermined wavelength and amplitude with at least one undulating tool;
- and
- processing the hollow fiber membrane with the at least one undulating tool so as to yield an undulation wavelength of more than 1 mm and less than 4 mm, wherein a drop in sodium clearance of the hollow fiber membrane is less than 13 ml/min after a heat sterilization process of above 100° C.
Dependencies are inferred from the claim text.