| abstract |
The present invention relates to a filter medium based on activated carbon which is characterized in that it comprises three superimposed layers which are respectively an inner layer and two outer layers. The inner layer contains 80 to 95% by weight in the dry state of activated carbon, the rest, up to 100%, consisting of organic and / or inorganic chemical fibers, the first outer layer being formed from 45 to 95 % by weight in the dry state of organic and / or inorganic chemical fibers, the rest, up to 100% consisting of activated carbon and / or a material having a density of less than 0.9, the second outer layer being formed from 5 to 25% by weight in the dry state of activated carbon, the rest, up to 100% consisting of organic and / or inorganic chemical fibers. The filter medium is also characterized in that the weight of the inner layer is between 40 and 200 g / m2 and in that the weight of the outer layers is between 10 and 100 g / m2. |