Abstract:
Apparatus for the production of a paper web, comprising: a first embossing unit (1) with a first embossing cylinder (2) and a corresponding counter-cylinder (3) for embossing a first paper ply (4); a second embossing unit (5) with a second embossing cylinder (6) and a corresponding counter-cylinder (7) for embossing a second paper ply (8), such that, once embossed, the said plies have a series of oppositely oriented reliefs (R4, R8), said embossing units (1, 5) being synchronized so that the said reliefs are nested into each other; a sizing unit (1C, 2C, 3C) associated with said first embossing cylinder (2) to distribute a predetermined amount of glue on the side of the second ply (8) opposed to that from which the respective reliefs (R8) emerge; means (11) for joining to each other the plies (4, 8) exiting from the apparatus. The apparatus comprises means (12) to form, on said second ply (8), a series of further reliefs (RC) oppositely oriented with respect to those (R8) previously formed by the second embossing unit (5), creating, on the same second ply (8), a step (S) between each further relief (RC) and the corresponding relief (R8) produced by means of the second embossing unit.