The pre-filter consists of polypropylene cord, which filters the finest particles from the water, such as sand, dirt, suspended matter, limescale flakes, rust and discolouration. This sediment filter is primarily used as a pre-filter, e.g. for water filter devices or treatment systems. It has a good flow rate for osmosis systems and therefore produces clean water. Due to the special manufacturing process (yarn winding process), the yarn-wound filters are extremely robust, very dirt-absorbent and prove themselves with a low differential pressure and a high flow rate. Thanks to its pore size, the yarn wrap filter does not allow any particles larger than the specified µ-quantity to pass through.

The water flows through the filter cartridges from the outer surface to the core. The winding density of the cartridges increases towards the core, whereby the pores become finer and finer and the coarser dirt particles are trapped on the surface of the filter cartridge, while the smaller particles are trapped inside the core.