The collection and cleaning cycles of the filter media used in industrial air cleaning were analysed experimentally. Examination of the simultaneous pressure drop and filtration efficiency changes established that the efficiency of filters increases sharply during the collection phase only to fall back during cleaning. The amplitude of this reduction of efficiency is attained as the cycles progress. In contrast, the residual pressure drop rises. Our study has shown that treating the surface with thermobonding or covering the surface with a fine layer of submicronic fibres promotes detachment of the dust cake and prevents particle penetration inside the initial porous media.