Vacuum system for securing items in printing machines

A vacuum system for securing items in printing machines, comprising a printing table having a perforated surface, in relation to which there is arranged a vacuum system for securing on said printing table the items to be printed, wherein the vacuum system comprises a box structure connected through nozzles with a suction system from the intermediate area of its transversal width, said box structure having an upper perforated wall opposite the perforated surface of the printing table, whereas in the interior thereof there are arranged lateral panels that vertically close in a sealed manner said interior of the box structure, which lateral panels can be moved transversally to move them closer to and farther away from one another inside the box structure, an actuation system being linked to said panels in order to move them,

• wherein a longitudinal extension of the box structure is divided into a plurality of independent successive chambers in which different vacuum pressures are applied for securing items to be printed, a first force being applied in an inlet area where the items are positioned on the printing table, a second force weaker than the first force being applied in a printing area where the items are printed, and a third force weaker than the second force being applied in a removal area where the items that are removed after having been printed.