Plasma is a unique technology to deposit ultra-thin coatings on all exposed surfaces of a material or product. It is increasingly used in the manufacturing of filtration media and elements to achieve functionalities such as hydrophilic, hydrophobic, oleophobic, or dielectric.

Improvements in process and machine design allow the deposition of these coatings in a very cost-effective way, with a process that is completely dry and clean. The technology is giving an increasing number of producers of technical nonwovens, membranes, mesh, nanofibers or film a clear competitive edge.

The paper will start with a short introduction to plasma technology.

Then it will review industrial concepts for both batch and roll-to-roll treatment. It will also compare industrial equipment for atmospheric and low-pressure plasma deposition.

Next, an overview will be given of typical coating chemistries used for such coatings. The paper will discuss challenges in liquid-repellent coatings, more specifically the market need for halogen-free solutions. Several approaches will be presented to induce surface roughness and combine it with halogen-free plasma coatings to achieve a hydrophobic, even oleophobic effect. Case studies of these halogen-free coated materials will be presented both for gas and liquid filtration...