Machine for the ink-jet printing of three-dimensional objects, tubular objects in particular

A machine for ink-jet printing of three-dimensional objects, comprising:

• a plurality of spindles individually configured and operable to carry and drive an object to be printed in rotation around a pre-set rotational axis of the spindle, and
• a first support and displacement system configured and operable to move the plurality of spindles in succession along a pre-set loop path, stopping the plurality spindles one after another in a plurality of operating stations,
• wherein each of said plurality of operating stations comprise:
• at least one input station wherein a respective one the plurality of spindles receives an object to be printed,
• a plurality of printing stations wherein the object is ink-jet printed, and
• at least one output station wherein the printed object is removed from the respective one of the plurality of spindles,
• wherein each of the plurality of printing stations comprises:
• a printing unit configured for ink-jet printing the object carried by the respective one of the plurality of spindles found in the printing station, and
• a second support and displacement system configured and operable to vary a relative position of the printing unit with respect to the respective one of the plurality of spindles found in the printing station, and
• wherein each of said printing units comprises at least:
• one or more ink-jet printer heads,
• one ink tank,
• one ink pump configured and operable to transfer ink from a tank to the one or more ink-jet printer heads,
• one vacuum pump configured and operable to create depression in the one or more ink-jet printer heads, and
• one electronic apparatus for controlling and commanding the ink pump, the vacuum pump and the one or more ink-jet printer heads.