Wet-spinning of hollow fiber membranes

Wet spinning of hollow fiber membranes
© Fraunhofer IGB
Wet spinning of hollow fiber membranes

The big advantage of hollow fiber membranes is their large specific separation range. For their production, we have spinnerets that allow fibers with outer diameters in the range of 0.5 to 4 millimeters and wall thicknesses of 50 to 500 µm.

We succeed in producing such fibers from laboratory scale to pilot scale, where the fibers are continuously taken up by a reel. 

We have extensive experience with various polymers, for example polysulfone, polyethersulfone, polyacrylonitrile, polyvinylidene fluoride, polylactide as well as self-produced polymers. In addition, we have special knowledge about the further processing of dispersions to mixed-matrix membranes. Here we can use polymer particles as well as ceramic or even metallic powders. These particles are homogeneously dispersed into the polymer matrix during the phase inversion process.

In this way, mixed-matrix membranes can be equipped with special functionalities. In addition, we can produce full-ceramic and metal membranes by sintering.

Our research

Membrane adsorbers

Combined filtration and adsoption for downstream processing in biotechnology and for water treatment.

Ceramic hollow fiber membranes

Ceramic capillaries are used for liquid filtration in the food, chemical or pharmaceutical industry. For these applications Fraunhofer IGB develops ceramic hollow fibers with high packing densities.


Perovskite O2 conducting capillary membranes

Mixed conductive perovskites have increasingly come into focus as membrane materials for the selective separation of oxygen from air-gas mixtures.

Reference projects

March 2021 - February 2024


NEXT GENERATION PLASMA CONVERSION: Integration of green hydrogen into the plasma conversion of CO2

The NexPlas project aims at the innovative combination of a plasma process with a membrane process for the synthesis of higher-value basic chemicals from CO2 and "green hydrogen". The focus of the work at the IGB is on the upscaling of the individual process areas. In addition to membrane production, work is being carried out in particular on the integration of multi-fiber module systems in a plasma torch.

February 2017 – February 2020


Plasma-induced CO2 conversion

The Kopernikus satellite project PiCK is developing a novel process employing implementing regenerative electrical energy to utilize climate-damaging CO2 as a carbon source. A combination of plasma and membrane processes  will be used to break down CO2 into O2 and CO, which serves as the starting product for the synthesis of platform chemicals and chemical energy stores such as methanol. Within the framework of the project, gas-tight ceramic capillaries were produced at IGB for the first time. These capillaries are both CO2-stable and suitable for the separation of oxygen from a plasma.

March 2017 – February 2020


Polyvalent separations by flexible integration of active surfaces in membranes

In this project, new coating materials and particulate additives for filtration membranes are developed with the aim to generate membranes which – in addition to their filtration function – can adsorptively bind dissolved substances in water.

May 2021 - October 2023


Sulfate depletion by forward osmosis and hollow fiber immersion modules

One of the late effects of opencast lignite mining in Germany is the large-scale iron and sulfate contamination of ground and surface waters. Therefore, the aim of the SULFAMOS project is to develop and demonstrate a process based on forward osmosis to remove sulfate from surface and ground waters so that they can be used as irrigation and drinking water. For this purpose, hollow fibers based on celluslose acetate were developed at the IGB, which carry the separation layer on the outside and were processed from a green solvent.