Pre-treatment device and inkjet digital printing press comprising said pre-treatment device

Abstract

The invention relates to a pre-treatment device (102) for pre-treating at least one container (5) having a longitudinal axis (C) with an outer surface to be subjected to inkjet digital printing, comprising a plasma emission device, a worktable (2) supporting at least one support spindle (6) supporting at least one container (5), wherein the worktable (2) has a rotation axis (L), wherein the spindle (6) has an axis (M) oriented radially with respect to the rotation axis (L) of the worktable (2), wherein the worktable (2) is configured to carry the spindle (6) and park it at an exposed position at which the outer surface of the container (5) is exposed to the plasma.

Description

Technical Field

[0001] This invention relates to a pretreatment apparatus for pretreating containers to be printed by inkjet digital printing. Background Technology

[0002] Among the solutions available on the market for printing on cylindrical or other shaped containers, a rotary table with a support mandrel for supporting the container is envisioned.

[0003] The rotary table rotates to position the mandrel at the next printing station, where a special print head applies ink of a different color between printing stations.

[0004] When the container is positioned at the printing station, the mandrel rotates on its own to expose the entire side surface of the container to the printing head.

[0005] Applying ink to various surfaces (such as the outer surface of containers used for packaging) requires that the substrate to be printed be completely clean, so that there are no oily residues that may have come from the container's manufacturing process.

[0006] Therefore, the containers must be washed with water and detergent before printing, and then dried.

[0007] These industrial processes preceding inkjet printing have a high ecological impact because they are highly energy-intensive and involve high water consumption.

[0008] In addition, to ensure the necessary printing quality, the container to be printed must have sufficient surface tension.

[0009] In fact, in order for the ink droplets applied to the container to have the correct shape behavior so as to form an image while controlling the size of the ink droplet shape on the container, the surface tension of the container must be at an appropriate value defined by the technical specifications of the ink used. Summary of the Invention

[0010] Therefore, the technical objective of this invention is to manufacture a pretreatment device for pre-treating containers to be printed by inkjet digital printing, thereby eliminating the technical defects of the cited prior art.

[0011] In the context of this technical task, one object of the present invention is to manufacture an ecologically sustainable and energy-efficient pretreatment device.

[0012] Another object of the present invention is to manufacture a pretreatment device that helps to improve printing quality.

[0013] Another object of the present invention is to manufacture a pretreatment device that helps improve printing production capacity and reduce waste in inkjet digital printing presses.

[0014] Another object of the present invention is to manufacture a pretreatment device that helps to achieve repeatable printing results.

[0015] The technical objective of the invention, and these and other objectives, are achieved by manufacturing a pretreatment apparatus for pretreatment of at least one container having a longitudinal axis and an outer surface to be inkjet digitally printed. The pretreatment apparatus is characterized by comprising a plasma emission device, a stage supporting at least one support mandrel that supports the at least one container, wherein the stage has a rotation axis, and wherein the at least one mandrel has an axis radially oriented relative to the rotation axis of the stage, wherein the stage is configured to carry the at least one mandrel and position it in an exposed position where the outer surface of the at least one container is exposed to plasma.

[0016] Plasma surface treatment is particularly beneficial for the following reasons.

[0017] The application generates a moderate amount of heat: this is very helpful for installations inside printing presses, where there are electronic and hydrodynamic components that may be affected by excessively high temperatures.

[0018] The use of a modular construction for the plasma emission device allows the installation to be adapted so that the generated plasma beam is coupled to the contour of the rotating solid (container) to be printed.

[0019] Therefore, pretreatment equipment enables efficient cleaning and preparation of surfaces for printing in a highly versatile manner.

[0020] Pretreatment can be performed during at least one full rotation of the surface to be printed, so as to expose each surface unit to the plasma source at least once.

[0021] If we envision several stages of plasma emitters surrounding the surface to be printed, pretreatment can be performed during the time it takes for the surface to be printed to rotate less than one full revolution.

[0022] The plasma emitter that activates the surface to be printed is preferably constructed and arranged to operate at a distance of 1 mm to 2 mm from the same surface.

[0023] The pretreatment speed is preferably the same as the linear ink application speed, for example, about 50 meters per minute.

[0024] Using this working mode, the surface tension can be increased by more than 12 mN / m, thus becoming suitable for receiving ink droplets that make up the image to be printed.

[0025] Specific applications involve the pretreatment of the shoulder of beverage cans.

[0026] This part of the can is particularly critical because it shows traces of residual lubricating oil used in the mechanically deformed matrix that makes the cylinder taper.

[0027] Typically, food oils (colloidal dispersions) that can be removed by washing with hot water are used.

[0028] The effects of plasma produce similar results and allow for enhanced pretreatment without multiplying the heat transfer that could damage the inner walls of the can, impairing its resistance to attacks from the packaged product.

[0029] In fact, according to the present invention, plasma emitters circumferentially distributed around the surface of the can to be printed can be used.

[0030] In this way, the pretreatment intensity is divided and effective removal of lubricating oil is achieved simultaneously, because the pretreatment is repeated almost seamlessly.

[0031] Other features of the invention are further defined in the following claims. Attached Figure Description

[0032] Further features and advantages of the invention will become more fully apparent from the description of a preferred, but non-exclusive, embodiment of an inkjet digital printer according to the invention for printing on a substrate having a longitudinal axis, illustrated by non-limiting examples in the accompanying drawings, wherein:

[0033] Figure 1 A schematic side front view of the printing press is shown, with only two printing stations shown for clarity;

[0034] Figure 2 A floor plan is shown, viewed from below the printing station.

[0035] Figure 3 A view of the printing station in the radial direction relative to the axis of rotation of the worktable is shown;

[0036] Figure 4 It shows the relationship with Figure 3 The same view, but a vertical section, in which the axial generatrices of the printed substrate have been added schematically;

[0037] Figure 5 An isometric view of the printing station is shown;

[0038] Figure 6 A plan view is shown, viewed from below the printing press;

[0039] Figure 7 A side front view of the eccentricity profile detection station is shown;

[0040] Figure 8 The eccentricity profile of the container locked on the mandrel is shown;

[0041] Figure 9 The hourly motion patterns of the plasma emission module at the pretreatment station and the print head at the printing station are shown.

[0042] Figure 10 A side front view of the equipment present in the pretreatment station in a first configuration of the modular and combinable plasma emission device is shown;

[0043] Figure 11 A side front view of the equipment present in the pretreatment station in a second configuration of the modular and combinable plasma launcher is shown;

[0044] Figure 12 An isometric view of the pretreatment station is shown;

[0045] Figure 13 A side front view of the equipment present in the pretreatment station in another configuration of the modular and combinable plasma launcher is shown;

[0046] Figure 14 A variant of the printing press is shown, in which the cooling station is positioned immediately downstream of the plasma treatment station;

[0047] Figure 15 It shows Figure 14 A side front view of the cooling station in the middle; and

[0048] Figure 16 It shows Figure 14 Vertical cross-sectional view of the cooling station. Detailed Implementation

[0049] In all implementation schemes, the same reference numerals are used to denote equivalent components.

[0050] Referring to the accompanying drawings, a pretreatment device 102 is shown positioned in a pretreatment station 103.

[0051] The device 102 is designed to pre-treat at least one container 5 having a longitudinal axis C, particularly a container 5 having rotational symmetry about the longitudinal axis C, the at least one container having an outer surface to be printed by an inkjet digital printer 1.

[0052] Container 5 can be intended for various purposes, such as a food container or a container for deodorizing sprays, detergents, etc.

[0053] Advantageously, the pretreatment device 102 includes a frame supporting a plasma emission device for irradiating the outer surface of the container 5.

[0054] The pretreatment device 102 also includes a worktable 2, which is rotatable about axis L and supports at least one support mandrel 6, which supports container 5.

[0055] For reasons that will be explained more clearly below, the worktable 2 supports multiple mandrels 6 distributed at a constant angular pitch.

[0056] The worktable 2 preferably has a vertical axis of rotation L.

[0057] The spindle 6 can be activated to rotate on its own axis M and rigidly supports the rotation of the container 5.

[0058] In the case shown where container 5 is completely symmetrical and centered on the mandrel 6, axes C and M coincide.

[0059] The spindle 6 has an axis M that is radially oriented relative to the axis of rotation L of the worktable 2.

[0060] The workbench 2 is configured to carry the mandrel 6 and place it in an exposed position where the outer surface of the container 5 is exposed to plasma.

[0061] Advantageously, at this exposure position, the mandrel 6 can be activated to rotate about its own axis M to gradually expose the outer surface of the container 5 to the plasma.

[0062] Advantageously, the plasma emission device is modularly combinable.

[0063] Specifically, the emitting device includes first plasma emitting modules 105i and 105ii, which are arranged at a first corner position around the axis of the mandrel 6 placed at the exposed position.

[0064] The first modules 105i and 105ii are aligned to illuminate the axial section of the outer surface of the container 5.

[0065] In practice, the first adjacent emitting modules 105i and 105ii irradiate adjacent and partially overlapping regions of the axial segments of the outer surface of the container 5.

[0066] As the spindle 6 rotates around its own axis M, continuous axial sections of the outer surface of the container 5 are exposed to plasma, and when the spindle 6 completes a 360° rotation around its own axis M, all outer surfaces of the container 5 are exposed to plasma irradiated by the first emission modules 105i and 105ii.

[0067] The framework independently supports the first modules 105i and 105ii, which can be removed and repositioned independently of each other.

[0068] Device 102 provides a device for changing the emission direction of the first modules 105i and 105ii.

[0069] The device for changing the launch direction includes a pin 106, which is used to hinge the first modules 105i and 105ii to the frame.

[0070] The hinge pins 106 are parallel to each other and orthogonal to the axis M of the spindle 6, which is parked in the exposed position.

[0071] The first modules 105i and 105ii can be locked within a range of angular positions around the corresponding hinge pin 106 by a special locking device (not shown).

[0072] In practice, the orientation of each of the first emission modules 105i and 105ii can be set such that the incident angle θ of the plasma is substantially orthogonal to the corresponding irradiation area of ​​the axial segment of the outer surface of the container 5.

[0073] If the axial section of the outer surface of the container 5 exposed to plasma is perfectly cylindrical, then all first modules 105i and 105ii will have emission surfaces with the same orientation; on the other hand, if the axial section of the outer surface of the container 5 exposed to plasma is located in different regions, then correspondingly, the first modules 105i and 105ii will also have emission surfaces with different orientations to maintain the basic orthogonality of the incident angle of the plasma.

[0074] This concept is Figure 10 and Figure 11 This is well explained in the text.

[0075] exist Figure 10 In the container 5, the irradiated axial section of the outer surface includes a first region 5a of cylindrical section and a second region 5b of truncated conical section that converges toward the axis C of container 5.

[0076] The first module 105i that irradiates the first region 5a of the cylindrical section has an emitting surface with the same orientation, while the first module 105ii that irradiates the second region 5b of the truncated cone section has an emitting surface with an orientation different from all other first modules 105i.

[0077] exist Figure 11 In the container 5, the axial section of the outer surface includes a first region 5a of cylindrical section, a second region 5b of truncated conical section converging toward the axis C of container 5, a third region 5c of truncated conical section diverging from the axis C of container 5, a fourth region 5d of cylindrical section, and a fifth region 5e of truncated conical section converging toward the axis C of container 5.

[0078] The first module 105i that irradiates the first region 5a and the third region 5d of the cylindrical section has an emitting surface with the same orientation, while the first module 105ii that irradiates the different regions 5b, 5c, and 5e of the truncated cone section has an emitting surface with a different orientation.

[0079] Preferably, the device 102 also provides a special variation device for changing the radial distance between the first launch modules 105i, 105ii and the axis of the mandrel 6 parked in the exposed position.

[0080] The device for changing the radial distance of the first launch modules 105i and 105ii is used to maintain the distance between the first launch modules 105i and 105ii and the outer surface of the container 5 when the specifications of the container 5 itself change.

[0081] The means for changing the radial distance between the first launch modules 105i and 105ii includes, for example, a translational rod 107 for jointly supporting the first launch modules 105i and 105ii.

[0082] Therefore, the frame supports the translational rod 107, and the first modules 105i and 105ii can be individually removed from the translational rod and repositioned independently of each other.

[0083] To improve the flexibility of radial adjustment, the hinge pin 106 can also be configured to be supported individually by corresponding blocks, which can then be adjusted in the appropriate position in the sliding seat provided in the translational rod 107.

[0084] Preferably, as shown in the figure, one or more second plasma emission modules 105j, 105jj are provided, and these second plasma emission modules are arranged at the second corner position around the axis of the mandrel 6 placed at the exposed position.

[0085] Preferably, the first transmitting modules 105i and 105ii are located relative to the axis M of the mandrel 6 in a position that is diametrically opposite to the second transmitting modules 105j and 105jj.

[0086] The second modules 105j and 105jj are aligned to irradiate an axial section of the outer surface of the container 5, which is diametrically opposite to the axial section irradiated by the first emitting modules 105i and 105ii.

[0087] The framework independently supports the second modules 105j and 105jj, which can be removed and repositioned independently of each other.

[0088] Device 102 also envisions a change device for changing the launch direction for the second modules 105j and 105jj, which is similar to the change device provided for the first modules 105i and 105ii, in particular pin 106, by which the second modules 105j and 105jj are hinged to the frame.

[0089] Device 102 also envisions a device for changing the radial distance of the second modules 105j and 105jj from the axis of the mandrel 6 parked in the exposed position, similar to the device provided for the first modules 105i and 105ii, particularly for the translational rod 107 that jointly supports the second launch modules 105j and 105jj.

[0090] As the example illustrates, in the case of a non-cylindrical rotationally symmetric solid, maintaining the orthogonality of the incident plasma beam may require tilting one or more first emission modules or employing a shaped emission surface (such as...). Figure 11 (as shown in module 105ii). In some cases, to avoid mechanical interference between two adjacent first firing modules at different inclinations, one of the two first firing modules can be eliminated and a second firing module can be provided at a diametrically opposed position relative to the axis M of the mandrel 6, the second firing module being designed to irradiate the same segment of the axial section intended to be irradiated by the removed first firing module. Utilizing Figure 10 The architecture of the first implementation scheme can be easily achieved by changing the tilt angle of the head module to completely illuminate both the cylindrical portion and the shoulder of the container 5 twice within one revolution of the mandrel 6, while utilizing... Figure 11 The architecture of the second embodiment can completely irradiate both the cylindrical and truncated conical portions of the container 5 twice in one revolution of the mandrel 6 by providing a special module with a shaped irradiation surface (such as an irradiation surface having two segments that are mirror-inclined relative to the axis of the module).

[0091] In some applications, if it is desired, for example, to selectively enhance pretreatment at the shoulder of a beverage can, then... Figure 10 Compared to the architecture shown, it is sufficient to disable (or remove) the second module 105j which is orthogonal to the axis M of the mandrel and keep only the module with the emitting surface tilted relative to the axis M of the mandrel 6 active.

[0092] Figure 13A variant is shown in which the continuous plasma emission modules 105i, 105j in the direction of the axis M of the mandrel 6 have overlapping segments Ts in the direction of the axis M of the mandrel 6.

[0093] In this way, when the consecutive modules 105i and 105j irradiate the same axial segment of container 5 in their overlapping segment TS, all areas of container 5 are plasma-treated: thus, the surface of container 5, which is uniformly treated with plasma, reacts uniformly to the subsequent deposition of ink with uniform color and uniform adhesion on the uniformly treated plasma surface.

[0094] In the case shown, the consecutive modules 105i and 105j in the direction of the axis M of the mandrel 6 are located on opposite sides of the mandrel 6 in diameter, but in a solution not shown, they may be positioned on the same side of the mandrel 6.

[0095] Pre-processing station 103 is integrated into inkjet digital machine 1.

[0096] The inkjet digital machine 1 includes a printing unit 3, which includes one or more longitudinally extending printing stations 4, and each printing station is provided with one or more printheads 8.

[0097] The printhead 8 has a main flat plane S, which, in the case of a roughly parallelepiped shape, corresponds to a central plane that is parallel to the two transverse longitudinal surfaces.

[0098] In this type of printing head 8, one or more rows of parallel longitudinal jet nozzles are provided on the lower longitudinal surface.

[0099] The worktable 2 is configured to sequentially carry the mandrel 6 and place it at the printing station 4, where the mandrel 6 can be activated to rotate about its own axis M.

[0100] The mandrel 6, placed at the printing station, has its axis M parallel to the longitudinal axis P of the printing head 8 and is equidistant from it.

[0101] Workbench 2 is configured to carry spindle 6 and place it at pretreatment station 103 before carrying spindle 6 and placing it at printing station.

[0102] The pre-processing station 102 and the printing station 4 are therefore positioned above the table 2 along the circular trajectory of the mandrel 6 with an angular pitch defined about the axis of rotation L of the rotary table 2, specifically equal to or a multiple of the angular pitch of the mandrel 6.

[0103] The digital printing press 1 envisions servo-assisted motorization for bidirectional linear movement of the plasma emission device and the print head 8 of each printing station 4 in a direction parallel to the rotation axis L of the worktable 2.

[0104] In particular, the servo-assisted motorization for bidirectional linear movement of the plasma emission device can be activated synchronously by lever 107.

[0105] Furthermore, advantageously, the printing press 1 includes a detection station 100 for detecting the eccentricity profile of the container 5, which is located upstream of the pretreatment station 102.

[0106] The inspection station 100 includes a distance sensor device for the container locked onto a corresponding spindle 6 that rotates on its own.

[0107] The inspection station 100 also includes an actuation controller for actuating servo-assisted motorization present in the preprocessing station 102 and each printing station 4.

[0108] The controller is configured to activate servo-assisted motorization during the self-rotation of the mandrel 6 at the pre-processing station 102 and the printing station 4, wherein the hourly regular s = s(t) is explicitly determined by the detected eccentricity profile.

[0109] The hourly rate s = s(t) is defined starting from the detected eccentricity profile in order to maintain a constant distance between the plasma emission module and the printhead 8 and the containers 5 in the pretreatment station 102 and in each print station 4.

[0110] The sensor device 101 includes one or more non-contact distance sensors, such as optical sensors.

[0111] The distance sensor 101 is installed at a fixed position in the detection station 100 and is orthogonal to the axis M of the mandrel 6.

[0112] As the spindle 6 rotates 360°, the sensor 101 acquires the eccentricity profile of the container 5 locked on the spindle 6.

[0113] During the rotation of container 5, the sensor device detects the eccentricity of the container by measuring the distance between them, thereby acquiring a series of points along the outer periphery of container 5.

[0114] In practice, the electronic controller acquires distance measurement results and constructs the eccentricity curve of the workpiece, using this eccentricity curve to illustrate the hourly law s = s(t). This curve is then sent to the moving plasma emission module and the motorized actuator of the printing head 8.

[0115] The motorized generation generates movement according to an hourly regularity s = s(t), such that during the rotation of the container 5 at the pre-processing station 102 and at each printing station 4, the distance between the launching module and the container 5, and the distance between the printing head 8 and the container 5, are constant.

[0116] The plasma emission module and printhead 8 of the subsequent printing station move sequentially according to the same hourly pattern during the parking of the same container 5. In fact, once the container 5 is locked by the mandrel 6, the container maintains its eccentric position and angular position so that it remains entirely within the printing press 1.

[0117] Machine 1 specifically provides initial settings for the plasma emission device and the print head 8 of the printing station 4.

[0118] Machine 1 specifically provides initial settings for the initial distance between the launching module and the axis M of the spindle 6, the initial distance d between the axis M of the spindle 6 and the printing head 8 of the printing station 4, and the initial orientation of the main flat plane S of the printing head 8.

[0119] The initial settings depend on the form of the container 5 to be printed.

[0120] In the initial setting, the print head 8 is tilted so that the axis M of the mandrel 6, which is placed at the printing station 4, belongs to the center plane S of the print head 8.

[0121] The longitudinal dimension of printing station 4 must match the axial length of the cylindrical printing substrate 5.

[0122] Therefore, although the solution shown by way of example only includes three print heads 8 for each printing station 4, the number of print heads 8 for each printing station 4 can vary.

[0123] If printing station 4 is designed with multiple print heads 8, then these print heads must have overlapping segments F in the direction of their longitudinal axis P.

[0124] To ensure partial overlap and simultaneously ensure the required tilt of their main flat planes S, adjacent printheads 8 have an offset angle α of their main flat planes S relative to the axis M of the mandrel 6.

[0125] Therefore, two rows of printheads 8 are depicted, with each row of printheads 8 sharing the main flat plane S.

[0126] The printing station 4 has frames 30 and 36 for supporting two rows of printing heads 8.

[0127] Each row of printing heads 8 is supported by corresponding support structures 13, 23, and 31.

[0128] Each support structure 13, 23, 31 includes a longitudinal plate 13 and corner supports 31a, 31b for each printhead 8, which in turn support a bracket 23 for accommodating the printhead 8.

[0129] Each corner support 31a, 31b is independently supported by the longitudinal plate 13 at a linearly adjustable position along the longitudinal plate 13 itself.

[0130] Each corner support 31a, 31b then supports the bracket 23 and the print head 8 fixed therein in an angle-adjustable position around the pin 32.

[0131] Each corner support 31a, 31b has a base 31a and a shoulder 31b.

[0132] More precisely, bracket 23 is fixed to base 33, which abuts against base 31a of corner supports 31a and 31b.

[0133] The device for setting the orientation of the print head 8 includes a toggle system 9.

[0134] The toggle system 9 can be activated to cause the two rows of printheads 8 to rotate in coordination about their respective pivots 10.

[0135] For each row of printheads 8, the corresponding pivot 10 is located at the lower end 11 of the printhead 8 and defines a rotation axis Q parallel to the axis M of the spindle 6.

[0136] The end block 36 of the longitudinal plate 13 is engaged with a pivot 10 consisting of a pin having a crescent-shaped cross-section.

[0137] In particular, the end block 36 has a special engagement seat 36 on its outer peripheral edge that is conjugate to the pivot 10.

[0138] The toggle system 9 has symmetrical connecting rods 12, the lower end of which is hinged to the longitudinal plate 13 of the corresponding support structure 13, 23, 31a, 31b.

[0139] The upper end of each connecting rod 12 is operatively connected to a nut 15, which is engaged to slide along a screw 16 having a vertical axis V that intersects the axis M of the spindle 6.

[0140] More precisely, a longitudinal rod 37 with a hinge at the opposite end to the connecting rod 12 is centrally fixed to a nut 15.

[0141] The lower hinge axis H and the upper hinge axis I of the connecting rod 12 are then parallel to the axis M of the spindle 6.

[0142] The screw 16 is supported in a special housing 19 of the longitudinal rod 36 fixed to the frames 30 and 36.

[0143] In practice, the screw 16 can rotate on its own without translation, so as to drag the nut 15 up and down and thus activate the toggle 9.

[0144] The elastic actuation device is configured to maintain the rotation of the two rows of printheads 8 around their respective pivots 10 when the toggle 9 is activated.

[0145] The elastic actuation device includes a symmetrical spring 17, which is configured and arranged to apply a downward thrust at the lower hinge of the connecting rod 12.

[0146] Each printing station 4 also includes a fine-tuning device for adjusting the relative positions of the print heads 8.

[0147] The fine-tuning device includes a first fine-tuning device for the overlapping segment F between the printheads 8.

[0148] For each printhead 8, the first fine-tuning device includes a micrometer screw 20, which is counteracted by a spring 21 to eliminate the thread backlash of the micrometer screw 20.

[0149] The micrometer screw 20 is supported in the housing 22 fixed to the longitudinal plate 13 and engages with the threaded hole 24 present in the flange 25 of the base 31a fixed to the corner plates 31a, 31b.

[0150] For adjustment, the angle plates 31a, 31b and the bracket 23 that houses the printing head 8 are moved along the longitudinal plate 13 by activating the micrometer screw 20.

[0151] The fine-tuning device also includes a second fine-tuning device for adjusting the mutual alignment between the longitudinal axes P of the printhead 8.

[0152] In the same case, for each printhead 8, the second adjustment device includes a micrometer screw 26, which is counteracted by a spring 40 to eliminate the thread backlash of the micrometer screw 26.

[0153] The micrometer screw 26 is supported in the housing 38 of the base 31a fixed to the corner plates 31a, 31b, and engages with the threaded hole 39 in the base 33 of the bracket 23.

[0154] The micrometer screw 26 causes the bracket 23 to rotate about the pin 32, and the rotation of the bracket 23 is counteracted by the spring 41, which is supported by the shoulder 31b of the corner supports 31a, 31b and abuts against the bracket 23.

[0155] Spring 41 slides on bracket 23, thereby allowing the bracket to rotate but remaining under tension so that the resistance is achieved by the bracket 23 at the rotation angle after the micrometer screw 26 is activated.

[0156] Each printing station 4 is arranged to dispense single-color ink.

[0157] The printing process is as follows.

[0158] Before the printing process begins, initial settings related to the form of the container 5 to be printed are performed.

[0159] Specifically, depending on the form of container 5, in the pretreatment station 103, a specific distribution of the first plasma emission module and the second plasma emission module is selected, for example, by setting their linear initial positions through the initial position of adjusting rod 107, and setting the angle of the emission module around pin 106.

[0160] The linear and angular positions of the print head 8 are also set in the printing station 4.

[0161] Specifically, at each printing station 4, the elbow 9 is activated to reorient the flat plane S of the print head 8, so that printing can be carried out substantially with the axis of the container 5 belonging to the main flat plane S of the print head 8.

[0162] Before the printing process begins, the print head 8 of each printing station 4 is also adjusted by micrometer screws 20 and 26. These micrometer screws adjust the alignment of the overlapping segments F between the print heads 8 and their longitudinal axes P in the direction parallel to the axis M of the mandrel 6.

[0163] In particular, the overlapping segment F must overlap with one or more of the jet nozzles included in the adjacent printhead 8.

[0164] Once the initial adjustment is complete, workbench 2 is activated, and container 5 is supplied to the spindle 6 of the workbench by a loader (not shown).

[0165] The workbench 2 is activated by rotating in a progressive manner, and in each forward step, the workbench sequentially positions each first container 5 first below the inspection station 100, then below the pre-processing station 103, and finally below the subsequent printing station 4.

[0166] Each time the worktable 2 stops, the spindle 6 rotates on its axis M.

[0167] During the rotation of container 5 below the detection station 100, its eccentricity profile is acquired. This eccentricity profile is processed by an electronic controller to establish an hourly motion law s = s(t). This hourly motion law is executed by the plasma emission module and the printhead 8 to maintain a constant distance between them and container 5.

[0168] Ink is distributed at each printing station 4 using a single channel, wherein the print head 8 moves in a manner synchronized with the rotation of the container 5 according to the hourly motion law s = s(t).

[0169] Each printing station 4 is dedicated to applying a single ink with a different color than the colors used in other printing stations 4.

[0170] Figures 14 to 16 The cooling station of container 5 is shown, which can be located immediately downstream of the plasma station.

[0171] The cooling station includes at least one cooling module 120, which includes a cooling compressed air discharge pipe 121 and a heating air intake pipe 122.

[0172] The spindle 6 can be placed at the cooling station, where the axis M is parallel to the axis of the discharge pipe 121 and parallel to the axis of the suction pipe 122.

[0173] Pipes 121 and 122 are configured such that one is for radially discharging air and the other is for radially drawing in air.

[0174] The discharge pipe 121 has discharge holes 123 distributed over at least a majority of its length, while the suction pipe 122 has suction grooves 124 extending over at least a majority of its length.

[0175] Compressed air is distributed by discharge pipe 121 in the direction toward container 5, and the airflow heated by contact with the surface of container 5 is drawn in by suction pipe 122.

[0176] The rotation direction of the spindle 6 itself, and thus the rotation direction of the container 5 placed therein, which presses the cooling station, facilitates the transfer of the cooling air layer toward the suction tank 124.

[0177] Preferably, a cooling module 120 above the spindle 6 and a cooling module 120 below the spindle are envisioned.

[0178] Of course, the discharge pipe 121 and the intake pipe 122 are respectively connected to appropriate compressed air distribution and smoke inhalation devices.

[0179] The cooling station can reduce the surface temperature of container 5 to the optimal level for printing using inkjet technology.

[0180] The pretreatment equipment and inkjet digital printing presses envisioned herein are readily subject to numerous modifications and variations, all of which fall within the scope of the inventive concept; furthermore, all details can be replaced with technically equivalent elements.

[0181] In practice, the materials and dimensions used can be determined according to needs and existing technology.

Claims

1. A pretreatment apparatus (102) for pretreating at least one container (5) having a longitudinal axis (C), said at least one container having an outer surface to be inkjet digitally printed, characterized in that, The pretreatment equipment includes a plasma emitting device and a worktable (2) supporting at least one support mandrel (6), the at least one support mandrel supporting the at least one container (5), wherein the worktable (2) has a rotation axis (L), wherein the at least one support mandrel (6) has an axis (M) radially oriented relative to the rotation axis (L) of the worktable (2), wherein the worktable (2) is configured to carry the at least one support mandrel (6) and park it in an exposed position, wherein the outer surface of the at least one container (5) is exposed to plasma, wherein the plasma emitting device is a modular assembly comprising plasma emitting modules arranged sequentially in the direction of the axis (M) of the support mandrel (6), wherein the consecutive plasma emitting modules in the direction of the axis (M) of the support mandrel (6) have overlapping segments (Ts) in the direction of the axis (M) of the support mandrel (6), and wherein the plasma emitting module includes a first plasma emitting module (105i,) arranged at a first corner position around the axis (M) of the support mandrel (6) parked in the exposed position. 105ii), and one or more second plasma emission modules (105j, 105jj) arranged at a second corner position around the axis (M) of the support mandrel (6) parked at the exposed position.

2. The pretreatment equipment (102) according to claim 1, characterized in that, At the exposure position, the at least one support mandrel (6) is rotatable about its axis (M) to gradually expose the outer surface of the at least one container (5) to the plasma.

3. The pretreatment apparatus (102) according to claim 1 or 2, characterized in that, The pretreatment equipment has a device for changing the emission direction of the first plasma emission module (105i, 105ii).

4. The pretreatment apparatus (102) according to claim 1 or 2, characterized in that, The pretreatment equipment has a means for changing the radial distance of at least the first plasma emission module (105i, 105ii) from the axis (M) of the support mandrel (6) parked at the exposed position.

5. The pretreatment apparatus (102) according to claim 1 or 2, characterized in that, The first plasma emission module (105i, 105ii) is located diametrically opposite to the axis (M) of the support mandrel (6) to the one or more second plasma emission modules (105j, 105jj).

6. An inkjet digital printing press (1) for printing on at least one container (5), characterized in that, The inkjet digital printer includes the pretreatment equipment (102) according to claim 1.

7. The inkjet digital printing press (1) according to claim 6, characterized in that, The inkjet digital printer includes at least one printing station (4) with at least one printhead (8), wherein the worktable (2) is configured to carry and park the at least one support spindle (6) at the at least one printing station (4), wherein the at least one support spindle (6) is rotatable about its axis (M), wherein the at least one support spindle (6) parked at the at least one printing station (4) has its axis (M) parallel to the longitudinal axis (P) of the at least one printhead (8), and the inkjet digital printer includes a pre-processing station (103), wherein a pre-processing device (102) is positioned in the pre-processing station, and wherein the worktable (2) is configured to carry the at least one support spindle (6) and park it at the at least one printing station (4) before carrying and parking it at the at least one printing station (4).

8. The inkjet digital printing press (1) according to claim 7, characterized in that, The inkjet digital printer includes a detection station (100) for detecting the eccentricity profile of the at least one container (5), the detection station including a distance sensor device (101) of the at least one container (5) supported by the at least one self-rotating support mandrel (6), and wherein the worktable (2) is configured to carry the at least one support mandrel (6) and park it at the at least one detection station (100) for detecting the eccentricity profile before carrying the at least one support mandrel (6) and parking it at the at least one pre-processing station (103).

9. The inkjet digital printing press (1) according to claim 8, characterized in that, The pretreatment equipment has a means for changing the radial distance of at least the first plasma emission modules (105i, 105ii) from the axis (M) of the support mandrel (6) parked at the exposed position. The inkjet digital printer includes an actuation controller for controlling the actuation of the means to change the radial distance of at least the first plasma emission modules (105i, 105ii). The actuation controller is configured to move at least the first plasma emission modules (105i, 105ii) using a motion pattern determined by the detected eccentricity profile during the rotation of the at least one support mandrel (6) at the at least one pretreatment station (103) to maintain a constant distance of at least the first plasma emission modules (105i, 105ii) from the at least one container (5).

10. The inkjet digital printing press (1) according to any one of claims 6 to 9, characterized in that, The worktable (2) has a vertical axis of rotation.

11. The inkjet digital printing press (1) according to any one of claims 7 to 9, characterized in that, The inkjet digital printer includes a container cooling station (5) immediately downstream of the pretreatment station (103). The container cooling station includes at least one cooling module (120), which includes a cooling compressed air exhaust pipe (121) and a heating air intake pipe (122). A support mandrel (6) is positioned at the cooling station, wherein the axis (M) of the support mandrel (6) is parallel to the axis of the cooling compressed air exhaust pipe (121) and the axis of the heating air intake pipe (122).

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