PRINTING ON FIBROUS MATERIAL

• US 20180361759A1
• Filed: 12/01/2016
• Published: 12/20/2018
• Est. Priority Date: 12/11/2015
• Status: Active Grant

• Current Assignee: Dover Europe Sarl (Dover Corporation)
• Original Assignee: MS Printing Solutions S.r.l. (Dover Corporation)
• Inventors: Milini, Luigi
• Granted Patent: US 10,639,913 B2
• Time in Patent Office: Days
• CPC Class Codes: B41J 11/0015 for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing selective coating B41J2/2114
• CPC Class Codes: B41J 11/007 Conveyor belts or like feeding devices
• CPC Class Codes: B41J 3/4078 Printing on textile
• CPC Class Codes: B41M 5/0011 Pre-treatment or treatment during printing of the recording material, e.g. heating, irradiating after-treatment of prints B41M7/00; printers for treating or overcoating copy materials before, during or after printing B41J11/0015
• CPC Class Codes: B41M 5/0047 by ink-jet printing
• CPC Class Codes: B41M 5/0064 on plastics, horn, rubber, or other organic polymers
• CPC Class Codes: D06P 1/6491 (Thio)urea or (cyclic) derivatives
• CPC Class Codes: D06P 1/653 Nitrogen-free carboxylic acids or their salts sulfocarboxylic acids D06P1/626
• CPC Class Codes: D06P 1/673 Inorganic compounds
• CPC Class Codes: D06P 5/2011 Application of vibrations, pulses or waves for non-thermic purposes
• CPC Class Codes: D06P 5/30 Ink jet printing

Abstract

The present invention refers to a plant (1) for printing, particularly for digitally printing, a sheet fibrous material (T), said printing plant (1) comprising: a conveyor belt (2) configured for receiving the sheet fibrous material (T) and guiding it in the movement along an advancement direction (A); a printing station (6) adapted to ink-print at least part of a second side (T2) of the sheet fibrous material (T); one preparing station (4) configured for modifying the surface hydrophobicity of at least part of the sheet fibrous material (T). The preparing station (4) comprises at least a plasma treating device (11) configured for define a treatment environment where at least a portion of the fibrous material is received and wherein ionized gas is present. The plant (1) comprises a control unit (9) actives on the conveyor belt (2) and on the plasma treating device (11); the control unit (9) being configured for: commanding the movement of the conveyor belt (2), controlling at least an operative parameter of the plasma treating device (11) as function of the movement of the conveyor belt (2). The present invention further refers to a process of printing of sheet fibrous material.

Claims

1. A printing plant for printing a sheet fibrous material, said printing plant comprising:

at least one conveyor belt exhibiting an exposed surface configured to receive the sheet fibrous material (T), the exposed surface defining an operative tract configured to for temporarily receive in contact a first side of the sheet fibrous material and to guide the sheet fibrous material in moving along an advancement direction,

at least one printing station configured to ink-print at least part of a second side of the sheet fibrous material opposite the first side, said printing station operating at the conveyor belt and being configured to print the sheet fibrous material placed on the operative tract of the conveyor belt, and

at least one material preparing station disposed upstream of the printing station with respect to the advancement direction of the sheet fibrous material, said preparing station being configured to modify a surface hydrophobicity of at least part of the sheet fibrous material,

wherein the preparing station comprises at least one plasma treater configured to produce a treatment environment in which at least one portion of the fibrous material is received and in which an ionized gas is present,

and wherein the printing plant further comprises at least one control unit active on the conveyor belt, and on the plasma treater, said control unit being configured to;

command movement of the conveyor belt, and

control at least one operative parameter of the plasma treater as a function of the movement of the conveyor belt.

2. The printing plant of claim 1, comprising at least one sensor adapted to emit a signal related to the motion of the conveyor belt, said control unit being active on the conveyor belt and on the plasma treater, said control unit being configured to:

receive from said sensor the emitted signal related to the movement of the conveyor belt,

determine, as a function of said signal, a movement speed of the sheet fibrous material along the advancement direction, and to

as a function of the determined movement speed of the fibrous material, command a value of at least one operative parameter of the plasma treater selected from among;

a potential difference between two electrodes connected to an electric field generator of the plasma treater,

an intensity of a current flowing in a circuit connecting the generator with the electrodes;

a current frequency of the electric field generator;

a distance between the electrodes of the sheet fibrous material;

a treatment dose defined by a power transmitted by an electric discharge dispensed by the plasma treater per surface unit of the sheet fibrous material within the preparing station.

3. The printing plant of claim 1, wherein the control unit is configured to command the movement of the conveyor belt to define an operative condition, wherein said conveyor belt continuously moves, along the advancement direction, the sheet fibrous material at a constant speed of between 20 and 100 m/min,

and wherein the printing station comprises a printing module configured to:

define a print on all a width of the sheet fibrous material, said width being measured normal to the advancement direction, and

remain in a fixed position while printing the second side of the sheet fibrous material placed on the operative tract.

4. The printing plant of claim 1, wherein the preparing station is configured to increase surface hydrophobicity of at least part of the sheet fibrous material passing through said preparing station.

5. The printing plant of claim 1, wherein the control unit is configured to control said at least one operative parameter of the plasma treater in order to control an increase of the hydrophobicity of the sheet fibrous material.

6. The printing plant of claim 1, wherein the plasma treater comprises at least two electrodes spaced from and facing one another, said electrodes being configured to receive, through said treatment environment, the sheet fibrous material moving between the electrodes, and

wherein the plasma treater comprises an electric field generator connected to said two electrodes by a circuit, said generator being configured to generate between said two electrodes a predetermined potential difference adapted to enable formation of said ionized gas.

7. The printing plant of claim 1, wherein the plasma treater is configured to generate plasma in said treatment environment, by using one or more of the following gases:

air, nitrogen, nitrogen oxide (NO), ammonia, inert gases, oxygen, hydrogen, carbon dioxide (CO₂), fluorinated gases, hydrocarbon gases, and fluorocarbon gases.

8. The printing plant of claim 1, comprising at least one material treating station distinct and separated from the preparing station and disposed downstream of the preparing station with respect to the advancement direction of the sheet fibrous material, said treating station being configured to place, on at least part of a side of the sheet fibrous material, a treatment composition comprising at least one of:

a pH control agent and a hydrotropic agent.

9. The printing plant of claim 8, wherein the treating station is configured to treat at least part of the second side of the sheet fibrous material opposite the first side, said treating station being configured to effect one of:

a direct deposition of the predetermined quantity of the treatment composition on the second side, and

a deposition of the treatment composition on the first side, and a migration of the treatment composition through the sheet fibrous material in order to cause an indirect deposition of the predetermined quantity of the treatment composition on the second side.

10. The printing plant of claim 8, wherein the treating station is configured to place, during a predetermined operative condition, the treatment composition on the sheet fibrous material placed on the operative tract.

11. The printing plant of claim 8, wherein the treating station comprises at least one applicator configured to place, on the second side of the sheet fibrous material, the treatment composition, said applicator comprising at least one of:

a spreading doctor blade arranged transverse to the motion of the conveyor belt and spaced above the operative tract,

a spray dispenser spaced above the operative tract,

an applicator roll with an associated respective doctor blade for adjusting a thickness of the treatment composition deposited on a lateral surface of the applicator roll, the applicator roll disposed with a rotation axis transverse to the motion of the conveyor belt and with the lateral surface spaced above the operative tract of the conveyor belt,

a drum positioned with a rotation axis transverse to the motion of the conveyor belt and with a lateral surface spaced above the operative tract of the conveyor belt, the drum exhibiting a hollow interior configured to receive a predetermined quantity of the treatment composition and to be provided with a predetermined number of nozzles or slits for dispensing the same, and

a distributor comprising a reservoir configured to receive the treatment composition, the reservoir having at least one dispensing nozzle defining an outlet of the reservoir, the nozzle extending transverse to the motion of the conveyor belt across a width of the conveyor belt, the distributor comprising one or more pushers placed inside the reservoir, and configured to dispense the treatment composition from the nozzle.

12. The printing plant of claim 8, wherein the treatment composition comprises at least one of:

a treatment liquid and a treatment foam, said treatment composition comprising;

a pH control agent, and

a hydrotropic agent.

13. The printing plant of claim 8, wherein the preparing station is disposed upstream the conveyor belt with respect to the advancement direction of the sheet fibrous material, and wherein the treating station operates downstream of said printing station.

14. The printing plant of claim 8, wherein the control unit is active on the treating station, said control unit being configured to:

receive a desired value of at least one operative parameter representative of a quantity of the treatment material applied on the sheet fibrous material by said treating station said at least one operative parameter comprising at least one of the following;

a weight percentage per square meter variation of the sheet fibrous material between a section immediately upstream a second treating station in which the fibrous material has not received the treatment composition, and a section immediately downstream the treating station in which the fibrous material has received the treatment composition,

a volume flow rate of the treatment composition exiting said treating station, and

a mass flow rate of the treatment composition exiting said treating station, and

command second treating station to manage the application of the treatment composition on the sheet fibrous material, as a function of the desired value of the operative parameter and of the movement imparted to said conveyor belt.

15. The printing plant of claim 14, wherein the treatment composition comprises a treatment foam, the printing plant comprising at least one sensor capable of emitting a signal related to the motion of the conveyor belt, said control unit being configured to:

receive from said sensor, a signal related to the movement of the conveyor belt,

determine, as a function of said signal, a movement speed of the sheet fibrous material along the advancement direction,

command, as a function of the determined movement speed of the fibrous material, a dispensing of the treatment foam to satisfy the desired value of said at least one operative parameter.

16. The printing plant of claim 1, wherein the control unit is configured to command the movement of the conveyor belt to define an operative condition with which said conveyor belt continuously moves, along the advancement direction, the sheet fibrous material at a constant speed of between 20 and 100 m/min,

and wherein the printing station comprises a printing module configured to:

define a print across an entire width of the sheet fibrous material, said width being measured normal to the advancement direction,

remain in a fixed position while printing the second side of the sheet fibrous material positioned on the operative tract.

17. A process of printing a sheet fibrous material, comprising the following steps:

moving the sheet fibrous material along an advancement direction,

placing a first side of the sheet fibrous material in contact with an exposed surface of a conveyor belt so that the conveyor belt can define an operative tract in which the conveyor belt supports the fibrous material, and then

ink-printing a second side, opposite the first side, of the sheet fibrous material that is in contact with the conveyor belt,

wherein said process further comprises, before the ink-printing step, at least one step of preparing the sheet fibrous material in a plasma treater defining a treatment environment in which at least one portion of the sheet fibrous material is received and in which an ionized gas is present.

18. The process of claim 17, wherein the plasma treater generates plasma in said treating environment by using one or more of the following gases:

air, nitrogen, nitrogen oxide (NO);

ammonia, inert gases, oxygen, hydrogen, carbon dioxide (CO₂), fluorinated gases, hydrocarbon gases, and fluorocarbon gases.

19. The process of claim 17, further comprising:

commanding movement of the conveyor belt, and

controlling at least one operative parameter of the plasma treatment as a function of the movement of the conveyor belt.

20. The process of claim 17, further comprising the following steps:

receiving, from a sensor, a signal related to movement of the conveyor belt,

determining, as a function of said received signal, a movement speed of the sheet fibrous material along the advancement direction, and

as a function of the determined movement speed of the sheet fibrous material, commanding a value of at least one operative parameter of the plasma treater selected from among;

a potential difference between two electrodes connected to an electric field generator;

a current intensity in a circuit connecting the generator with the electrodes;

a current frequency of the electric field generator;

a distance between the electrodes and the sheet fibrous material; and

a treatment dose defined by a power transmitted by an electric discharge dispensed during plasma treatment per surface unit of the sheet fibrous material within the preparing station.

21. The process of claim 17, wherein the preparing step is configured to modify the surface hydrophobicity of at least part of the sheet fibrous material.

22. The process of claim 17, further comprising a treating step distinct and separated from the preparing step, the treating step being executed after said preparing step,

wherein said treating step provides the application of a predetermined quantity of the treatment composition on at least part of a side of the sheet fibrous material, said treatment composition comprising at least one of:

a pH control agent and a hydrotropic agent.

23. The process of claim 22, wherein the treating step comprises depositing the predetermined quantity of the treatment composition on the second side of the fibrous material opposite the first side, said depositing step providing one of:

direct deposition of the predetermined quantity of the treatment composition on the second side, and

deposition of the treatment composition on the first side and the migration of the treatment composition through the sheet fibrous material for determining an indirect deposition of the predetermined quantity of the treatment composition on the second side.

24. The process of claim 23, wherein the treatment composition dispensed during the treating step, comprises at least one of:

a treatment liquid and a treatment foam,

said treatment composition comprising at least one of;

a pH control agent, and

a hydrotropic agent.

25. The process of claim 24, further comprising the following steps:

detecting a desired value of at least one operative parameter representative of a quantity of the treatment material, applied on the sheet fibrous material during the treating step, said at least one operative parameter comprising at least one of the following;

a weight percentage per square unit variation of the sheet fibrous material immediately before a second treating, in which the fibrous material has not received the treatment composition, and immediately after the second treating step in which the sheet fibrous material has received the treatment composition,

a volume flow rate of the treatment composition immediately after the second treating step, and

a mass flow rate of the treatment composition immediately after the second treating step, and

managing the application of the treatment composition on the sheet fibrous material, as a function of the desired value of the operative parameter and of the movement imparted to said conveyor belt.

26. The process of claim 25, wherein the treatment composition comprises a treatment foam, the process comprising the following steps:

receiving, from a sensor, a signal related to the movement of the conveyor belt,

determining, as a function of said signal, a movement speed of the sheet fibrous material along the advancement direction,

as a function of the determined movement speed of the fibrous material, commanding a dispensing of the treatment foam to satisfy the desired value of said at least one operative parameter.

27. The process of claim 17, wherein the sheet fibrous material moves, along the advancement direction, at a constant speed of between 20 and 100 m/min.