Membranes

Membrane filtration is a modern filtration method. In particular, it is used in gas and liquid processing. The mass flow, running across the filter, is typical for membrane filtration.

It means that a composite structure that enables good mass transfer through a corresponding layer (usually non-woven) is required. The required separation of substances can then take place on a large-scale through the actual membrane.

This technology enables the selective restriction of the particle size to the separated. The separation of particles sized from 0.5 – 0.1 µm is called microfiltration; the separation of particles from 0.1 – 0.01 µm is ultrafiltration and the separation of particles from 0.01 – 0.001 µm (10 – 1 nm) is nanofiltration.

The separation of particles sized between 1 and 0.1 is called reverse osmosis. In this case, there is no longer any separation of undissolved particles, since molecular dimensions have already been reached and only dissolved particles are retained.

The application areas for membranes are extremely varied. Many production plants for membrane production delivered by Coatema are used in the fields of reverse osmosis, nanofiltration and proton conductive membranes.

Special developments for gas filtration and fuel cell membranes also form part of Coatema's core business. In particular, this includes the casting of membranes onto carrier films and the capillary coating of metal foams.

The cleaning of water to produce drinking water is becoming increasingly important due to a rising population. Reverse osmosis is used here. The only way to manufacture the filter membranes required for this with large enough surfaces, sufficient productivity and reasonable costs is using a Roll-to-Roll method. Coatema supplies the complex production plants for this, which include the conditioning of surface/pore structures using a dip bath and the casting of polymer solutions onto surfaces using slot dies. These plants use multiple process steps to create composite materials that are normally multi-layered and that have the required structural accuracy.

To receive detailed quotations, please contact our project planning team at This email address is being protected from spambots. You need JavaScript enabled to view it. or your local Coatema agent.

Scale-up process

Coatema has various pilot plants that are suitable for membrane production, including with functions for the post-treatment or surface modification of membranes. In addition, a range of cooperative partners from universities and research institutions use Coatema's laboratory and pilot plants. Coatema has a global network in this area.