EP2091735A2

EP2091735A2 - Printing machine and corresponding method

Info

Publication number: EP2091735A2
Application number: EP07870236A
Authority: EP
Inventors: Alain Blanchard; Roger Stanchina; Bernard Beranger; Antoine Chevalier; Pascal Ollivier
Original assignee: Goss International Montataire SA
Current assignee: Goss International Montataire SA
Priority date: 2006-11-24
Filing date: 2007-10-31
Publication date: 2009-08-26
Anticipated expiration: 2027-10-31
Also published as: JP2010510107A; FR2909031A1; CN101573236B; EP2091735B1; FR2909031B1; US20100064917A1; WO2008068399A3; WO2008068399A2; CN101573236A

Abstract

The invention relates to a rotary printing machine including: a continuous print tape (12) of material to be printed, at least one printing unit (6) designed to print on the print tape (12), and a cutting device (10) designed to cut the print tape (12) with the printing unit (6). The machine also includes a traction device (8) located downstream of the printing unit (6) that is located furthest downstream and upstream of the cutting device (10). The traction device (8) is designed to apply a pre-determined mechanical strain on the print tape (12) leaving the most downstream printing unit (6). The print tape (12) comprises a band of coated paper. The invention is suitable for magazine printing presses.

Description

Printing machine and corresponding method

The present invention relates to a rotary printing machine, of the type comprising:

a continuous printing tape of material to be printed, at least one printing unit adapted to print on the tape to be printed,

- A cutting device adapted to cut the printed tape by the printing unit.

Rotary printing machines are known in the state of the art, which comprise at least one printing unit provided with a pair of printing rolls, and a cutting device adapted to cut the printed tape by the printing unit.

Known printing machines further include a dryer disposed between the last printing unit and the cutting device. This dryer is used to dry the ink which is arranged on the printed web to avoid marking the sheets in the cutter.

The presence of a dryer leads to a large footprint of the printing machine, and increases the cost of the printing machine.

The present invention aims to overcome these disadvantages, and to provide a printing machine that has a small footprint.

In addition, known rotary printing machines are not able to print on high quality paper. Another object of the invention is to provide a printing press which enables the production of high quality printed products for given expenses. To this end, the invention relates to a printing machine of the type indicated, characterized in that it further comprises a traction device located downstream of the printing unit further downstream and upstream of the cutting device, in that the pulling device is adapted to apply a determined mechanical tension on the printed web coming out of the printing unit furthest downstream, and in that the printing tape is a strip of coated paper .

According to the particular embodiments, the printing machine has one or more of the following features: the machine is adapted to transport the printed web in free suspension and in ambient air all along the path between the printing unit furthest downstream and the traction device;

the machine is adapted to transport the printed band in the ambient air all the way between the traction device and the cutting device;

the machine comprises a device for drying the printed strip, in particular an infrared drying device, arranged downstream of the traction device and upstream of the cutting device;

the traction device comprises two traction elements, each having a traction surface adapted to come into contact with one face of the printed band in order to exert the determined mechanical traction on this printed band;

the machine comprises means for supplying an ink repellent liquid to at least one traction surface; the two traction elements comprise traction surfaces repelling the ink;

the two traction elements are traction rollers;

the two traction rollers are arranged apart from each other by defining a substantially S-shaped path of the printed band; the two traction rollers are arranged one behind the other in the path of the printed band, and the traction device comprises two clamping rolls, each of which is arranged opposite one of the rollers of pulling, the clamping rollers having a diameter different from the diameter of the pull rollers, and each time a clamping roll and a pulling roll being adapted to clamp the printed web therebetween;

the two traction rollers are arranged vis-à-vis;

each of the two traction elements is adapted to come into contact with one of the two opposite faces of the printed band;

at least one of the traction rollers has openings in its enveloping surface, and the traction device is provided with a vacuum device adapted to create a vacuum in these openings;

the traction device is provided with a device for cleaning the traction surface of at least one of the traction rollers; the cleaning device comprises a cleaning bar in contact with the traction surface;

the cleaning device comprises a first cleaning roller whose surface is adapted to come into rolling contact with a traction roller, the surface of the first cleaning roller attracts the ink, and the cleaning device comprises means of removal. ink from the surface of the cleaning roll;

the cleaning roller is movable between a cleaning position in which it is in contact with the associated traction roller and a washing position in which it is in contact with a washing device of the cleaning roller;

the cleaning device comprises a second cleaning roller adapted to come into contact with the same traction roller as the first cleaning roller, and these two cleaning rollers are adapted to alternately come into contact with the traction roller;

the pull rollers and the clamping rollers are movable between a drawing position of the printed web and a cleaning position, and the machine is adapted to feed a pair of draw rolls and a pick roller to its cleaning position while the other pair of pull roller and clamp roller is in its pulling position;

the traction elements comprise tensile bars extending through the printed band;

the machine further comprises an accompanying device arranged between the printing unit furthest downstream and the cutting device, this accompanying device comprises at least one support roll provided with a support surface of the printed web, and the accompanying device comprises means for creating an air cushion between the support surface and the printed web,

the printing unit comprises an ink tank containing ink suitable for printing on the strip to be printed;

the ink is ink without water;

the ink is secative ink or two-component ink; and

- the coated paper of the tape to be printed is coated paper having a layer of kaoline or chalk. The invention further relates to a printing method of the type comprising the following steps: a) printing on a tape to be printed by forming a printed tape, b) cutting the printed tape printed sheets, characterized by the following steps c) generating a predetermined mechanical tension in the printed web prior to cutting by means of a printing machine according to any one of the preceding claims, and in that d) the web to be printed is a web of paper coated, especially comprising a layer of kaoline or chalk.

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the appended drawings, in which: FIG. 1 is a diagrammatic side view of a machine for printing according to the invention;

FIG. 2 is a view corresponding to the view of FIG. 1 of a variant of a printing machine according to the invention;

FIG. 3 is a perspective view of a detail of a traction device according to a first embodiment of the invention;

- Figures 4 and 5 are detail views corresponding to the view of Figure 3, the second and third embodiments of a traction device according to the invention;

FIGS. 6 and 7 are side views of the fourth and fifth embodiments of a traction module according to the invention;

FIGS. 8A to 8C are side views of a detail of a traction module according to a sixth embodiment of the invention, during different stages of operation;

FIG. 9 is a sectional view of a traction roller of a traction module according to a seventh embodiment of the invention;

FIG. 10 is a schematic side view of a detail of a traction module according to an eighth embodiment;

- Figure 11 is a top view of the detail of Figure 10; FIG. 12 is a schematic side view of a printing machine according to a second variant, comprising a device for accompanying the printed band; and

- Figures 13 and 14 are side views of the first and second embodiments of the accompanying device.

In Figure 1 is shown a rotary printing machine according to the invention, designated by the general reference 2.

The printing machine 2 comprises a unwinder 4, four printing units 6, a traction device 8 and a cutting device 10. The printing machine 2 could comprise any number of printing units 6, theory, from one to n.

Each printing unit 6 comprises an inking device 6A which is provided with an ink tank 7 comprising ink 7 A intended for printing on the strip 12. The ink 7A used in the context of the invention will be explained below. Each ink device 6A further comprises an ink transfer roller 7B for transferring ink 7A to printing rolls 15 (see below).

The unwinder 4 is adapted to unroll a continuous printing tape 12. According to the invention, the print tape 12 is a coated paper web.

Coated paper is a paper that includes a coating layer, for example, kaolin or chalk, improving the mechanical or optical properties of the paper. This paper makes it possible to obtain a printed product of high quality.

The printing machine 2 defines a print path of the web 12 between the unwinder 4, through the printing units 6 and the pulling device 8, to the cutting device 10.

The printing units 6 comprise printing rollers 15 which are adapted to print on the web 12.

The cutting device 10 is adapted to cut the print tape 12 into individual sheets.

The traction device 8 is located downstream of the printing unit 6 furthest downstream and upstream of the cutting device 10. This traction device 8 is adapted to apply a determined mechanical tension on the strip 12 coming out of the printing unit 6 furthest downstream.

As can be seen in FIG. 1, the printing machine 2 can transport the printed strip 12 in free suspension and in ambient air all the way between the printing unit 6 furthest downstream and the printing device. In addition, the printing machine 2 is also adapted to transport the printed tape 12 to the ambient air all the way between the traction device 8 and the cutting device 10. Thus, the printing machine 2 does not have a dryer and has a small footprint. The printing machine 2 according to the variant shown in Figure 2 differs from the printing machine 2 shown in Figure 1 in that between the traction device 8 and the cutting device 10 is disposed a dryer 14 to Infrared rays through which the printed strip 12 is conducted. The dryer 14 has reduced dimensions compared with the prior art driers. In Figure 3 is shown in perspective a detail of the traction device 8 according to the invention. We see the printed tape. The printed strip 12 consists of a succession of strip sections 16, each of which is the length of a sheet cut by the cutting device 10. Each section 16 furthermore comprises an image 18 printed on both sides by the rolls of printing printing units 6. Moreover, each section 16 comprises an unprinted area, which does not contain ink.

The traction device 8 comprises two traction rollers 20, 22 which are rotated about their respective axes X-X, Y-Y. Each of the pull rollers 20, 22 comes into contact with one of the surfaces of the printed web 12. The pull rollers 20, 22 are driven in opposite directions, and their traction surface moves, at the location of contact with the strip 12, in the same direction S as the printed strip 12. Each of the traction rollers 20, 22 has an outer surface whose circumference is identical to the length of the strip section 16, which reduces the marking. In a variant, the circumference is identical to an integer multiple of the length of the section 16.

The outer surface of each pull roller 20, 22 is made of an ink repellent material used to print the images 18. The pull rollers 20, 22 include, for example, a surface hydrophilic. One of the two rolls is coated with an elastomer. The generatrix of contact of the two rollers makes it possible to pinch to pull the paper strip 12. The surfaces of the two traction rollers 20, 22 may for example comprise a coating of a silicone-based compound. The two traction rollers 20, 22 are arranged facing each other, so that the contact line of the traction roller 20 with the belt 12 and the line of contact of the traction roller 22 with the belt 12 are located in vis-à-vis.

Advantageously, the circumferential speed of the traction rollers 20, 22 is slightly greater than the circumferential speed of the printing rollers of the printing unit 6 furthest downstream, so that the printed band 12 is maintained under a traction and therefore a predetermined mechanical tension between the printing unit 6 and the traction device 8.

The traction device 8 makes it possible to print a strip of paper and to receive it in a cutting device 10, such as a flat exit, without drying the paper strip 12 by evaporation of the ink solvents.

The image 18 is printed by the ink 7A contained in the ink tank 7. Advantageously, the ink 7A is a secative ink, or a waterless ink ("waterless"), or a two-component ink . The drying of the secant inks is the combination of a first phenomenon called "penetration into the support" and a second phenomenon called "the oxidation polymerization of varnishes consisting of oils and resins".

The heat-set inks dry by evaporation of the mineral solvents mixed with the resin. The UV inks dry by polymerization of the resin under the effect of ultraviolet radiation.

The waterless inks are used with specific printing plates to define non-printing areas without using the conventional lithographic process based on the rejection of the greasy ink by a previously moistened hydrophilic surface. The use of these inks can be considered in the same way as the conventional secundant inks previously seen and can dispense with a dryer, or design less cumbersome.

In Figure 4 is shown a detail of a second embodiment of a traction device 8, which differs from Figure 3 by what follows. Similar elements bear the same references.

The two traction rollers 20, 22 are arranged apart from each other, so that they define a substantially S-shaped path of the printed strip 12. The S-shaped arrangement makes it possible to increase the winding arc of the band on the driven rollers and thus to promote the efficiency of the traction module by capstan effect. Another device must then be associated with this traction module. This device must make it possible to create a low but sufficient downstream voltage to induce an upstream voltage sufficiently high to pull the band at the output of the last printing unit. Figure 5 shows a detail of a third embodiment of a traction device 8 according to the invention, which differs from the embodiment of Figure 3 by the following. Similar elements bear the same references.

The traction module 8 further comprises two cleaning devices 30, 32. Thus, the quality of the image 18 on the printed tape 12 is further improved.

The cleaning devices 30, 32 comprise cleaning bars 34, 36 in permanent contact with the traction surface of the rollers 20, 22. By way of example, the cleaning bars 34, 36 may comprise a rotating brush placed in contact with each other. the surface to be cleaned or a strip of tissue contacted by a mechanical member. In both cases, the cleaning is facilitated by the action of a solvent. These techniques are used in particular for washing blankets on offset presses.

In Figure 6 is shown a fourth embodiment of the traction device 8, in side view. This embodiment differs from the third embodiment by the following.

Both pull rollers 20, 22 have ink-repelling surfaces, such as a coating of a silicone-based compound.

The cleaning device 30 comprises a cleaning roller 38 comprising a surface of an ink-attracting material which is in contact with the surface of the traction roller 20. The cleaning roller 38 is, for example, coated with a porous ceramic intended for cleaning. to be impregnated with ink and thus has surface properties favorable to the transfer of the ink. This technique is used in particular to make inkwell rolls. The cleaning device 30 further comprises a doctor blade 42 which is in permanent contact with the surface of the cleaning roller 38 and which conveys the ink taken by the roller 38 to a recovery tank 46.

The cleaning device 32 further comprises a cleaning roll 40 comprising a surface of an ink attracting material, such as a coating of a porous ceramic to be impregnated with ink and thus having favorable surface properties to the ink. ink transfer. The surface of the roller 40 is in contact with the surface of the traction roller 22.

The cleaning device 32 further comprises a doctor blade 44 which is in permanent contact with the surface of the cleaning roller 40 and which conveys the ink collected by the rollers 40 to a collection tank 48.

FIG. 7 shows a fifth embodiment of the traction device 8, which comprises a variant of the cleaning devices 30,

32. Each cleaning device 30, 32 has two cleaning rollers

38, 40 attracting the ink, as well as for each of the cleaning rollers 38, 40, a washing device 50, 52.

The washing device 50, 52 is disposed at a distance a from the surface of the associated pulling roll 20, 22 which is larger than the diameter of the corresponding cleaning roll 38, 40. Each cleaning roll 38, 40 is movable between a position cleaning device in which it is in contact with the associated traction roller 20, 22 and a washing position in which it is in contact with the washing device 50, 52 associated. The two cleaning rollers 38, 40 of each cleaning device 30, 32 are controlled in such a way as to come into alternate contact with the associated pulling roll 20, 22. In other words, while one of the rolls of cleaning 38 is in contact with the traction roller 20, the other cleaning roller 38 is in contact with the washing device 50. Similarly, while one of the cleaning rollers 40 is in contact with the traction roller 22, the other cleaning roll 40 is in contact with the washing device 52. The device described in Fig.7 has an advantage over the device described in fig. 6. Indeed, assuming that the cleaning can, by contamination with the washing solvent, temporarily modify the properties of the surfaces of the rollers 20 and 22 (ink rejection), this operation is carried out, in the case of the device of Figure 7, on rollers 38 and 40 which are not in contact with the traction rollers 20 and 22.

FIGS. 8A to 8C show a sixth embodiment of a traction module 8 according to the invention. This traction device comprises two traction rollers 20, 22 which are arranged on one side of the printed strip 12 one behind the other. The traction device 8 further comprises two clamping rollers 54, 56 which are arranged on the other side of the printing band 12 and which have a smaller diameter than the diameter of the traction rollers 20, 22. Each of the clamping rollers 54, 56 is adapted to apply to the printed tape 12.

Each clamping roll 54, 56 is, in combination with the associated pulling roller 20, 22 adapted to clamp the printed web 12.

The traction rollers 20, 22 are adapted to alternatively come into contact with the printed tape 12. The traction device further comprises, for each traction roller 20, 22 a washing device 50, 52. Each washing device 50, 52 is located at a distance a from the surface of the printed web 12 which is greater than the diameter of the associated pulling roll 20, 22. When the pulling roller 20, 22 is out of contact with the printed web 12, these washing devices 52, 52 wash the surface of the traction roller 20, 22.

Figure 8A shows the step in which the pull roller 20 is being cleaned by the washing device 50. The clamping roller 54 is away from the surface of the belt 12. The pull roller 22 is away from the washing device 52 and is applied to the surface of the printed web 12. The clamping roller 56 also applies to the web 12, so that the web 12 is clamped between the web clamping device 56 and pulling roller 22.

FIG. 8B shows an intermediate step, after the end of the cleaning of the traction roller 20. During this step, the two traction rollers 20, 22 are in contact with the band 12, and the clamping rollers 54, 56 apply also on the tape.

During a subsequent step, illustrated in FIG. 8C, it is only the pull roller 20 and the clamping roll 54 that clamp the web 12 between them, while the pull and clamp rollers 56 are out of contact with the band 12, the traction roller 22 being cleaned by the cleaning device 52.

The device described in FIGS. 8A, 8B, 8C has an advantage over the device described in FIG. 6. Indeed, assuming that the cleaning can, by contamination with the washing solvent, temporarily modify the properties of the surfaces of the rollers 20 and 22 (ink rejection), this operation is carried out with the cleaning devices 50 and 52 while the traction rollers 20 and 22 are not in contact with the band.

Figure 9 shows a cross-section of a traction roller of a seventh embodiment of a traction module 8 according to the invention. This traction module 8 comprises a traction roller 22 which is provided with a porous wall 60 so as to define a porous traction surface. The pores of the wall 60 are open cells, so that a liquid 62 disposed inside the roller 22 can pass through the wall 60 and come into contact with the printed tape 12. The liquid 62 is for example a mixture of water and silicone.

Furthermore, the traction roller 22 further comprises a rotary joint 63 comprising a central liquid feed 64 which opens into the interior of the traction roller 22. The feed 64 is arranged coaxially with the axis YY of the roller traction 22.

In Figures 10 and 11 is shown an eighth embodiment of a traction device 8 according to the invention.

This traction device 8 comprises two blanket rollers 70 which are applied on both sides of the printed band 12 and which are offset from one another in the direction of travel of the band 12.

The traction device 8 further comprises eight toothed rollers 72 connected in pairs by an axis 73. The traction device 8 is provided with four belts or chains 74, each of which is guided around two toothed rollers 72 arranged on one side only. The two belts 74 on one side of the printed web 12 are connected by pull bars 76, which are arranged at a mutual distance on the belt 74 which corresponds to the length of the strip section 16. The traction bars 76 are adapted to apply on both sides on the strip 12, facing each other and to tighten the strip between them. Thus they are adapted to exert traction on the band 12.

Preferably, the bars 76 are driven in synchronism with the strip 12 so that they only apply to the unprinted area of the strip 12. In addition, the surface coming into contact with the strip 12 of the strip 76 is preferably elastomeric.

FIG. 12 shows a part of a variant of a printing machine, comprising an accompanying device 80 disposed between the printing unit 6 furthest downstream and the cutting device 10. In this case, the accompanying device 80 is arranged upstream of the traction device 8. This accompanying device 80 comprises two support rollers 82 arranged on one side and the other of the band 12.

Figure 13 shows an enlarged cross-section of the support rollers 82. The support rollers 82 are hollow and have a cylindrical wall 83 with an annular section. The wall 83 forms an outer support surface 84. The accompanying device 80 comprises means for creating an air cushion between the support surface 84 and the printed strip 12. These air cushion creation means comprise on the one hand, openings 86 passing through the wall 83 of the roller 82. These openings 86 are arranged, in cross-section, in a secant manner with respect to the own axis AA, BB of the roller 82. Moreover, the location close to the band 12, the openings 86 have a component directed in the direction of displacement S of the band 12, and this in the direction radially outwards with respect to the own axis AA, BB of the roller 82 considered. Moreover, the means for creating an airbag comprise two sealing walls 88 disposed inside each support roller 82, these walls 88 applying on the one hand in an airtight manner against the inner surface 89 of the wall 83, and secondly to the central axis of the support roller 82. In addition, a pressurized air inlet 90 is connected to the chamber 92 defined by the walls 83 and 88.

In operation of this accompanying device 80, the support rollers 82 are rotated so that their circumference at the location near the printed band moves in the S direction of the printed web path 12. The opening 86, which is at a given instant in communication with the chamber 92 defined by the walls 83 and

88, allows the air in the chamber 92 to escape, and create an air cushion between the outer surface 84 and the printed web 12, which guides the printed web 12. In FIG. 14 is shown a variant of the accompanying device 80, which differs from the device of Figure 13 by the following. Similar elements bear the same references.

This accompanying device 80 has a single sealing wall 88 per roll 82 which extends around the support roll 82 over substantially its entire circumference, with the exception of a portion facing the printed web 12. No wall sealing does not extend inside the roller

82. This embodiment is easy to manufacture.

In variant not shown, at least one of the traction rollers

20, 22 has openings in its enveloping surface, and the traction device 8 is provided with a vacuum device adapted to create a vacuum in these openings. This helps guide the band 12.

In general, the traction elements comprise traction surfaces which come into contact only with the unprinted zone of the strip 12. For this purpose, the traction elements may comprise a traction roller which applies on an unprinted side area of the strip.

Claims

1. Rotary printing machine, of the type comprising

a printing tape (12) continues with material to be printed,

at least one printing unit (6) adapted to print on the print tape (12),

- a cutting device (10) adapted to cut the printed web (12) by the printing unit (6), characterized in that it further comprises a traction device (8) located downstream of the printing unit (6) furthest upstream and upstream of the cutting device (10), in that the pulling device (8) is adapted to apply a determined mechanical tension to the printed web (12) emerging from the printing unit (6) furthest downstream, and in that the printing tape (12) is a coated paper web.

Printing machine according to claim 1, characterized in that the machine is adapted to transport the printed web (12) freely and in the ambient air all the way between the printing unit (6). the most downstream and the traction device (8).

Printing machine according to Claim 1 or 2, characterized in that the machine is adapted to transport the printed web (12) to the ambient air all the way between the pulling device (8) and the printing device. cutting (10).

4. Printing machine according to any one of claims 1 to 3, characterized in that the machine comprises a drying device (14) of the printed strip (12), in particular an infrared drying device, disposed in downstream of the traction device (8) and upstream of the cutting device (10).

5. Printing machine according to any one of claims 1 to 4, characterized in that the traction device (8) comprises two traction elements (20, 22; 76), each having a traction surface adapted to come in contact with one side of the printed web (12) to exert the determined mechanical traction on said printed web (12).

6. Printing machine according to claim 5, characterized in that the machine comprises means (60, 63, 64) for supplying a liquid (62) pushing the ink on at least one traction surface.

7. Printing machine according to claim 5 or 6, characterized in that the two traction elements (20, 22; 76) comprise traction surfaces repelling the ink.

8. Printing machine according to one of claims 5 to 7, characterized in that the two traction elements are traction rollers (20,22).

9. Printing machine according to claim 8, characterized in that the two traction rollers (20,22) are arranged apart from each other by defining a substantially S-shaped path of the printed strip ( 12).

Printing machine according to one of Claims 8 or 9, characterized in that the two pulling rollers (20, 22) are arranged one behind the other in the path of the printed web (12). , and in that the pulling device comprises two clamping rollers (54, 56) each of which is arranged opposite one of the pulling rollers (20, 22), the clamping rollers (54, 56) having a diameter different from the diameter of the pull rollers (20,22), and that each time a clamping roll (54,56) and a pulling roll (20,22) are adapted to clamp the printed tape (12) between them.

11. Printing machine according to claim 8, characterized in that the two traction rollers are arranged vis-à-vis.

12. Printing machine according to any one of claims 5 to 11, characterized in that each of the two traction elements (20, 22) is adapted to come into contact with one of the two opposite faces of the printed tape. (12).

Printing machine according to one of Claims 8 to 12, characterized in that at least one of the pulling rollers (20, 22) has openings in its enveloping surface, and in that the device traction device (8) is provided with a vacuum device adapted to create a vacuum in these openings.

Printing machine according to one of claims 8 to 13, characterized in that the traction device is provided with a device (30, 32) for cleaning the traction surface of at least one pull rollers (20, 22).

15. Printing machine according to claim 14, characterized in that the cleaning device (30, 32) comprises a cleaning bar (34, 36) in contact with the traction surface.

Printing machine according to claim 14 or 15, characterized in that the cleaning device (30, 32) comprises a first cleaning roller (38, 40) whose surface is adapted to come into rolling contact with a roller. in that the surface of the first cleaning roller (38, 40) attracts the ink, and in that the cleaning device comprises means (42, 44) for removing the ink (20, 22); ink from the surface of the cleaning roll (38, 40).

Printing machine according to claim 16, characterized in that the cleaning roller (38, 40) is movable between a cleaning position in which it is in contact with the associated traction roller (20, 22) and a washing position (50,52) in which it is in contact with a washing device of the cleaning roller.

Printing machine according to claim 16 or 17, characterized in that the cleaning device comprises a second cleaning roller (38, 40) adapted to come into contact with the same traction roller (20, 22) as the first cleaning roll (38, 40), and in that these two cleaning rollers (38, 40) are adapted to alternately come into contact with the pull roll (20, 22).

Printing machine according to claims 9 and 14 taken together, characterized in that the traction rollers (20, 22) and the clamping rollers (51, 52) are movable between a drawing position of the printed web ( 12) and a cleaning position, and in that the machine is adapted to feed a pair of draw rollers (20, 22) and a pick roll (54, 56) to its cleaning position while the other pair traction roller (20, 22) and clamping roller (54, 56) is in its traction position.

Printing machine according to one of claims 1 to 5, characterized in that the pulling elements comprise pull rods (76) extending through the printed web.

Printing machine according to one of the preceding claims, characterized in that the machine further comprises a device (80) disposed between the further downstream printing unit (6) and the cutting device (10), in that said accompanying device (80) comprises at least one support roll (82). ) provided with a support surface (84) of the printed web (12), and in that the accompanying device (80) comprises means for creating an air cushion between the support surface (84) and the printed tape (12).

Printing machine according to one of Claims 1 to 21, characterized in that the printing unit (6) comprises an ink reservoir (7) containing ink (7A) suitable for print on the tape to be printed.

23. Printing machine according to claim 22, characterized in that the ink (7A) is ink without water.

24. Printing machine according to claim 22, characterized in that the ink (7A) is secative ink or two-component ink.

25. Printing machine according to any one of claims 1 to 24, characterized in that the coated paper of the printing tape (12) is coated paper having a layer of kaoline or chalk.

26. A printing method of the type comprising the following steps: a) printing on a tape to be printed by forming a printed tape, b) cutting the printed printed sheet strip, characterized by the following steps: c) generating a predetermined mechanical tension in the printed web before cutting by means of a printing machine according to any one of the preceding claims, and in that d) the printing tape (12) is a coated paper web, in particular comprising a layer of kaoline or chalk.