A cleaning roller to be brought into contact with a medium includes a rotary shaft having a first end portion and a second end portion, and a sticky roller attached to the rotary shaft. A cleaning roller holder includes a first bearing portion configured to restrict a movement range of the first end portion and a second bearing portion configured to restrict a movement range of the second end portion. In a state where the first end portion is disposed at the first bearing portion and the second end portion is disposed at the second bearing portion, the cleaning roller holder positions the cleaning roller in a detachable manner. The center of gravity of the cleaning roller is shifted from the center of the cleaning roller in the longitudinal direction toward the first end portion, and is in a range where the sticky roller exists in the longitudinal direction.

An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

A ductor roll assembly for use in an ink station assembly of a can decorator for communicating ink from a fountain roll to a distributor roll. The ductor roll assembly having a roll portion including an elongated axial member and a plurality of segments selectively disposed on and around the axial member axially adjacent each other for rotation about a rotation axis. The plurality of segments includes: a number of ink transfer segments, each ink transfer segment having an ink transfer surface disposed at a first radial distance from the rotation axis and structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll; and a number of spacer segments having a second outer diameter less than the first outer diameter.

A ductor roll assembly for use in an ink station assembly of a can decorator for communicating ink from a fountain roll to a distributor roll. The ductor roll assembly having a roll portion including an elongated axial member and a plurality of segments selectively disposed on and around the axial member axially adjacent each other for rotation about a rotation axis. The plurality of segments includes: a number of ink transfer segments, each ink transfer segment having an ink transfer surface disposed at a first radial distance from the rotation axis and structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll; and a number of spacer segments having a second outer diameter less than the first outer diameter.

A ductor roll assembly for use in an ink station assembly of a can decorator for communicating ink from a fountain roll to a distributor roll. The ductor roll assembly having a roll portion including an elongated axial member and a plurality of segments selectively disposed on and around the axial member axially adjacent each other for rotation about a rotation axis. The plurality of segments includes: a number of ink transfer segments, each ink transfer segment having an ink transfer surface disposed at a first radial distance from the rotation axis and structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll; and a number of spacer segments having a second outer diameter less than the first outer diameter.

A ductor roll assembly for use in an ink station assembly of a can decorator for communicating ink from a fountain roll to a distributor roll. The ductor roll assembly having a roll portion including an elongated axial member and a plurality of segments selectively disposed on and around the axial member axially adjacent each other for rotation about a rotation axis. The plurality of segments includes: a number of ink transfer segments, each ink transfer segment having an ink transfer surface disposed at a first radial distance from the rotation axis and structured to transfer ink between a corresponding axial portion of a fountain roll and a corresponding axial portion of a distributor roll; and a number of spacer segments having a second outer diameter less than the first outer diameter.

An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

An ink recovery pipe comprises: an inflow port for receiving ink from an ink reservoir, and disposed at a position close to a first machine frame; and an outflow port for discharging ink into an ink container, and disposed at a position close to a second machine frame. A first restriction device is disposed at a position downstream of the inflow por. A first coupling part is configured to couple a high-pressure air generation part with the ink recovery pipe at a position downstream of the first restriction device. A first high-pressure air control device is configured to stop supply of high-pressure air to the ink recovery pipe, while ink is supplied to the ink reservoir, and supply the high-pressure air to the ink recovery pipe, after start of an ink recovery operation of recovering ink from the ink reservoir after completion of supply of ink.

An ink feeding device of a printing machine advances and retracts individual ductor rollers pneumatically between an ink fountain roller and an ink transfer roller. Along a fixed shaft, the individual ductor rollers are aligned, and the fixed shaft is provided with an air feeding pipe; electromagnetic valves for advancing the individual ductor rollers toward the ink fountain roller by the air from the air feeding pipe; and springs for retracting the individual ductor rollers toward the ink transfer roller. The controller makes the electromagnetic valves on in the order from a deep position to an inlet position along the air feeding pipe and advances the individual ductor rollers toward the ink fountain roller in this order.