Abstract: Process for producing a filtering structure, in particular for cigarette filters from a fibrous mass comprising a homogeneous mixture of fibres of different types. Some of the fibres are necessarily thermofusible synthetic fibres having a low melting point and adhesive properties in the molten state, and the others are absorbent with respect to harmful products of tobacco smoke and stable at the melting temperature of the thermofusible fibres. The fibrous mixture is shaped into a cylindrical rod which is in state which is not yet coherent but homogeneous and comprises fibrous networks which are closely imbricated relative to each other.

Abstract: The device permits the application in the form of a mist on a sheet wholly or partly consisting of artificial or synthetic short fibres, such as cellulose acetate fibres, a liquid chemical agent for binding the fibres together, for example a specific plasticizer of the constituent material of the fibres. The sheet may be produced by a conventional paper-making method or a non-woven method and is intended for the production of cigarette filters. The device comprises a rotary support roller with which one face of the fibrous sheet is in contact in the zone of the spraying of the binding agent, the spraying being carried out on the other face of the sheet.