Abstract: The pretreatment device for pretreating at least one container with a longitudinal axis having an outer surface to be subjected to ink jet digital printing, comprises plasma emitting means, a table supporting at least one support spindle supporting the at least one container, wherein the table has an axis of rotation, wherein the spindle has an axis oriented radially with respect to the rotation axis of the table, wherein the table is configured to carry and park the spindle at an exposure position in which the outer surface of the container is exposed to the plasma.

Abstract: An ink jet digital printing machine configured to detect an eccentricity profile of the containers to be printed and to move the printing heads with an hourly law that is univocally determined by the eccentricity profile so as to maintain the distance of the printing heads from the containers to be printed constant during the rotation of the containers on themselves.

Abstract: Digital inkjet printing machine printing on cylindrical substrates, comprising a conveyor table conveying a cylindrical substrate and a printing station equipped with printheads having a parallel longitudinal axis. The table has a vertical rotation axis and supports a spindle supporting the cylindrical substrate. The spindle has an axis radially oriented with respect to the vertical rotation axis, and is actuatable in rotation about its axis. The conveyor table is configured to stop the spindle below the printheads, so the printheads have its axis parallel to the longitudinal axis of the printheads. The spindle axis stopped below the printheads belongs to main planes in which the printheads lie. The printheads are equidistant from the axis of the spindle. A first adjustment means adjusts the distance between the axis of the spindle and the printheads and a second adjustment means adjusts the orientation of the main planes in which the printheads lie.