Kärcher has filter bags made of a fleece material for its professional range of dry vacuum cleaners. They accommodate up to three times as much dust as conventional paper filter bags­ of the same size. This results in longer periods of uninterrupted operation and, therefore, a higher area coverage. In this way the costs for filter bags can be reduced noticeably and to make the use of the vacuum more economical than previously possible.

The high capacity is due to the three-dimensional structure of the filter material. It consists of a coarse inner layer, a very fine intermediate layer and a tear-resistant outer layer. The pores of the new fleece material do not clog up as quickly as two-ply paper, suction power remains practically constant over a longer period. Up to 99.9% of standard soil (particle size of 2 µm) is retained (this is equivalent to dust class M). The tear resistance of the material is so good that the bag is not damaged by paper clips, sand and gravel, when used as directed.

 An indicator shows the user when the filter bag needs to be changed. The filter bag can be easily removed from the front of the machine without creating any dust.