WO2007096106A1

WO2007096106A1 - Printing press

Info

Publication number: WO2007096106A1
Application number: PCT/EP2007/001395
Authority: WO
Inventors: Uwe Rogge; Dietmar Pötter; Ulrich Harte; Andreas Ihme; Frank Gunschera
Original assignee: Windmöller & Hölscher Kg
Priority date: 2006-02-21
Filing date: 2007-02-19
Publication date: 2007-08-30
Also published as: DE102006008348A1; EP1989052A1; ES2333377T3; EP1989052B1; ATE447482T1; DE102006008348B4; DE502007001908D1

Abstract

The invention describes a printing press (1) having an engraved roll (7) which removes printing ink from an ink reservoir (8), an ink applicator roll (6) which removes printing ink from the engraved roll (7), an impression cylinder (5) removes printing ink from the ink transfer roll (6) with its printing regions and transfers it onto a web-shaped printing material (3), and a back-pressure cylinder (2), on which a web-shaped printing material (3) can be guided, onto which the printing ink can be applied in accordance with the printing regions of the impression cylinder (5). Here, the impression cylinder (5) is designed to print according to a planographic printing process. The outer circumference of the impression cylinder (5) is variable.

Description

press

The invention relates to a printing press.

In the past, numerous printing machines have become known which operate on different principles. Of particular note here are flexographic and gravure printing machines, which have a simple inking unit structure with only a few rollers involved in the printing process. A disadvantage of such printing machines is to mention that the production of the format images bearing the images (flexographic) and form cylinder (gravure) is expensive. In return, these on or in these rollers or cylinders on or incorporated motifs are very durable. Therefore, both printing methods, especially at high print runs are very economical and superior in this respect than other printing processes.

Recently, however, there has been a tendency for lower print runs. This means that after less production time the print motif should be changed. As a result, it is increasingly desired to change the format of the printed products as well. These requirements occur primarily in packaging printing.

Due to the associated with a motive and / or format change high production costs in flexographic and gravure printing, the above-mentioned requests are often not economically feasible. The smaller the print run, the greater the price per product. The invention is therefore based on the object to propose a printing machine, with which also printed products with small runs economically, so at a lower cost, can be produced.

This object is achieved by a printing machine with the features of claim 1.

According to the invention, this object is solved by the features of claim 1. Accordingly, the printing machine according to the invention comprises an anilox roller, with the ink from a paint reservoir can be removed, an inking roller, which decreases ink from the anilox roller, a printing cylinder, which decreases with its printing areas ink from the ink transfer roller and an impression cylinder, which leads a web-shaped substrate. On this substrate, the ink according to the printing areas of the printing cylinder can be applied. In addition, the printing cylinder operates according to the planographic printing method and it is in its outer periphery, for example by replacing at least parts of the printing cylinder, changeable, wherein the change of the outer circumference of the printing cylinder is the change in the printing length is meant and not the change in the circumference by Removal or assembly of a printing plate is caused.

The printing plates for a printing cylinder, which operates on the planographic printing method, are inexpensive to produce, since they can be produced by means of chemical processes. Under pressure forms for planographic printing processes are to be understood as those that have a height difference between printing and non-printing areas of up to about 5 microns (= 0.005mm), preferably of up to about 3 microns (= 0.003mm), wherein usually the non-printing areas are raised compared to the printing areas (so-called negative form). Of these, rotogravure and flexographic printing forms differ significantly. In gravure printing, this height difference is 10 to 50 microns, with the printing areas are lower than the non-printing areas. In flexographic printing, so-called positive forms are used in which the printing areas are raised in relation to the non-printing areas are. These surveys are usually between 600 microns to 3000 microns. However, in planographic printing, the areas of printing and non-printing are distinguished not only by the height difference but by the different adhesive properties of the printing and non-printing areas with respect to the printing ink. Thus, the ink does not adhere to non-printing areas, so that the inking roller can not deliver color to these areas. In contrast, the color adheres very well to the printing areas. In the printing machine according to the invention no use of fountain solutions is provided to influence the adhesive properties. It is rather a so-called waterless planographic printing process. The different adhesive properties are influenced by the choice of the materials of the printing plates, wherein the composition and other properties of the ink, in particular their viscosity, and the materials of the printing plates must be coordinated to achieve the best possible printing result.

To change the print format, parts of the impression cylinder that define the format must be exchanged or edited. For this purpose, the outer circumference can be covered with adapter pieces or the impression cylinder can be completely replaced. However, in order to change the format, in particular the printing length, all rollers must be positionally variable relative to the machine frame, but a single roller, preferably the impression cylinder, can remain stationary. In order to keep these changes in location simple, in the printing unit according to the invention, either only the rollers described for ink guide are provided from the ink reservoir to the impression cylinder, or a color transfer cylinder is additionally provided between impression cylinder and impression cylinder. The provision of further rollers, such as a Verreibewalze for trimming the ink on the inking roller, this is not excluded, however, such a further roller is not involved in the color guide and therefore not to be understood as a "roller for color guide" in the context of the invention. All rollers except the impression cylinder belong to an inking unit, to which reference is made below. The combination of only a few existing in the printing unit rollers, the format variability of the printing cylinder and printing by a planographic printing process, which is preferably a waterless planographic printing process, leads to the printing machine according to the invention, with the production of printed products with a small number of copies is particularly economical and the case additionally comparatively compact. Said combination is not known from printing machines of the prior art.

In order to apply printing ink on the web-shaped substrate, it is necessary to make the printing cylinder, which is acted upon on its outer periphery with a substantially unyielding pressure plate, to a cylinder with an elastic surface. In a preferred embodiment, therefore, the counter-pressure cylinder, which leads the web-shaped printing material, provided with an elastic surface coating, such as a rubber layer, which is compliant. Thus, in a format change only the replacement of at least parts of the printing cylinder is necessary, while all other cylinders and rollers can remain unchanged.

Alternatively it can be provided between the printing cylinder and the impression cylinder nor a color transfer cylinder, which decreases the printed image of the printing cylinder and transmits to the substrate. In this case, the ink transfer cylinder must be provided with an elastic surface, while the printing material leading impression cylinder has an unyielding surface. This configuration is advantageous if a particularly stretchable printing material, such as certain plastic films, to be printed. On an unyielding surface even a stretchable substrate experiences no longitudinal forces that can cause a change in length.

However, it may also be advantageous to provide the inking roller formatvariabel, for example, the effect of stenciling, so the negative image of a printed image part at another location on the substrate, to avoid.

In a further advantageous development of the invention, the ink-carrying cylinders are displaceable along parallel planes. For example, all of these cylinders can be moved in a plane which is spanned by the axis of the impression cylinder and the connecting line between the axis of the impression cylinder and the axis of the impression cylinder. However, the ink-guiding cylinders can also be moved in a single plane in which the axis of the impression cylinder is not. This is especially to be provided when several inking units are employed on a common counter-pressure cylinder in order not to let the overall height of such a printing press become too large.

In a concrete embodiment, the printing cylinder, the inking roller and the anilox roller are rotatably mounted in bearing blocks arranged at both ends of the respective rollers, wherein these bearing blocks are displaceable on preferably common rails along a plane. The latter two rolls can, if the inking roller is not made variable in size, are stored in common storage blocks, so that the arrival and Abstellprozess is simplified, since now only two bearing blocks are to be moved per page. Of course, the ink transfer cylinder, if this is provided in a printing press according to the invention, stored in its own, independently of the bearing blocks of the pressure roller bearing blocks.

The two bearing blocks arranged at each end of a roller or a cylinder can be displaceable relative to one another in order to make one end of the cylinder accessible by exposing, while the other end is held in the respective bearing block. However, the relative displaceability is also necessary for a precise adjustment of a roller to another roller. In order to easily and quickly perform the format and / or the motif change on the printing cylinder, but also the format change to the ink transfer cylinder and optionally to the inking roller, it is intended to perform this each in the form of a pressure roller on the respective sleeves with different Außendurchmessem , can be applied with different widths and / or with different motives. In this case, sleeves can be applied to other sleeves that have been applied to the Druckwalzendom. The sleeves are thereby advantageously pushed over an exposed end of the Druckwalzendom. The sleeves may be processed outside the printing press while the printing roll dome may remain in the printing press. In this way, the printing plates, which are usually present as a plate during the Bebilderungsprozesses, outside of the printing press, for example, in an auxiliary frame, mounted on a sleeve and firmly connected or braced with this.

It may also be advantageous to design the rollers and cylinders, which are not designed to be variable in terms of format and / or motive, in the described manner, ie in sleeve / mandrel combination, in order to renew them simply and cost-effectively after wear of the surfaces can. This relates to the screen and optionally the inking roller, but in particular also the impression cylinder when it is provided with an elastic coating. Especially an elastic coating can be subject to high wear.

In a further advantageous embodiment of the invention, a counter-pressure cylinder is assigned a plurality of inking units. The impression cylinder is then centrally located while the individual inking units are arranged around it. The inking units may extend substantially radially. However, they can also be arranged at an angle to the vertical of the counterpressure cylinder circumference. The latter is particularly advantageous to limit the height of the printing press. This measure leads to a compact printing press. Also avoided with such a printing press, the substrate over stretching without Support to lead, as it is the case with series printing machines, each with only one inking unit per impression cylinder. This measure should be provided especially if an elastic substrate is to be printed. This printing material lies immovably on the peripheral surface of the impression cylinder, so that it does not expand, for example, by the action of heat.

Regardless of the number of inking units, it is particularly advantageous to guide the printing material over a larger angular range of the impression cylinder on it. In the case of different printing units, the printing material nominally touches the impression cylinder only along one line, the so-called printing line. In practice, however, this line expands to an area due to the existing softness of the system, so that the substrate de facto wraps around the impression cylinder over a small angular range. However, a "larger angle range" is not to be understood as meaning an angular range which results from the flexibility of the components of the printing press and which is usually less than 10 °.

Thus, in a particularly advantageous embodiment, a wrapping angle of at least 90 °, preferably at least 180 ° provided. At these wrap angles, it is possible in

Transport direction of the printing material behind the inking one more

Provide fixing that the substrate on the way between the inking unit and the fixing device and also behind the fixing device is guided by the impression cylinder. In this way, a linear expansion of the printing material is avoided. This is particularly advantageous if the fixing device is a

Drying device acts, with which the substrate is subjected to heat.

In an advantageous embodiment of the invention, each cylinder and each roller can be assigned its own drive, for example an electric motor, in order to be able to adapt the peripheral speeds to each other again after a format change. The anilox roller and the inking roller may also be powered by a common motor in an alternative. Also, raster and inking rollers may be operated at slightly different peripheral speeds to achieve rubbing of the ink on the inking roller. Trituration or leveling of the ink film on the ink transfer roller, however, can also be done with a rubbing roller or a doctor blade, the latter measure is particularly easy to implement. The inking roller, the impression cylinder, the impression cylinder and optionally the ink transfer cylinder, however, in each case run at the same peripheral speeds.

In order to ensure the desired ink transport, which depends strongly on the viscosity of the printing ink and thus on its temperature, between the rollers, cylinders and the printing material, it is intended to temper all areas which are in thermal contact with the ink. In addition to the cylindrical and cylindrical bodies and the squeegee chamber, these also include their surrounding spaces, but also the elements that are in direct or indirect contact with these bodies. In order to achieve an effective tempering effect, it is provided to temper such components, in particular to cool, which, for example due to friction, produce heat. These include bearings, gears and drive motors. Advantageously, such components are flowed around or flowed through with a fluid, for example water or oil, in order to be able to temper these components quickly and precisely. For this purpose, the fluid is appropriately tempered, which can be done outside the printing press.

Also, the printing unit can be tempered in total by being enclosed by a housing or the like and the interior is tempered by supplying appropriately pre-tempered fluid, such as air. The rollers and cylinders can also fluid lines, which are traversed by a preheated fluid include, as well as heating elements. Other means for temperature control may be provided, such as a nozzle which gives a tempered gas to the ink-carrying rollers. Further embodiments of the invention will become apparent from the description and the claims. The individual figures show:

Fig. 1 Schematic side view of an embodiment of a printing press according to the invention. Fig. 2 Schematic side view of another embodiment of a printing press according to the invention

Fig. 3 side view as in Fig. 2, but with further components Fig. 4 View IV - IV of Fig. 3rd

Fig. 1 shows - in a schematic way - a printing machine 1 according to the invention. This comprises a counter-pressure cylinder 2, on the outer surface of which a printing substrate 3 rests in regions. On this substrate, the printed image is applied by means of a color transfer cylinder 4. This print image is applied by the pressure roller 5 to the ink transfer cylinder 4. In order for the printed image originating from the printing cylinder 5 to always hit the same points of the ink transfer cylinder, these two cylinders have the same outer circumference, which is not shown in FIG. The printing cylinder 5 is covered with a printing form not shown in detail, comprising printing and non-printing areas. The printing areas are suitable for receiving ink, while the non-printing areas do not accept printing ink. The ink is provided by the inking roller 6, which is coated with ink on its entire outer surface. However, as described, only the printing areas of the printing cylinder 5 remove ink from the inking roller 6. The parts of the ink that hit the non-printing areas, however, adhere to the inking roller 6. The anilox roller 7 carries the printing ink, which removes it from a doctoring chamber 8, onto the inking roller 6. The squeegee chamber 8 is of a generally known type and comprises two roof-shaped inclined doctor blades, which are engageable with the anilox roller, so that the squeegee chamber 8, doctor blade and anilox roller delimit a paint channel, which is completed and almost completely filled with ink 10. In the embodiment shown, ink transfer cylinders 4 and Printing cylinder 5 format variable executed. The inking roller may be fixed format in one variant, or format variable in another variant.

The embodiment of the invention shown schematically in Fig. 2 differs from the embodiment shown in Fig. 1 by the

Lack of the ink transfer cylinder. The printing ink, which is guided by the printing areas of the printing cylinder 5, directly to the

Substrate 3 delivered. In order to ensure a complete transfer of color, the impression cylinder 2 is coated with an elastic coating, for example with a rubber coating 11. Der

Color transport from the doctoring chamber 8 to the printing cylinder 5 does not differ from the embodiment shown in FIG.

Fig. 3 shows the embodiment shown in Fig. 2 with further elements of the printing machine according to the invention 1. The impression cylinder 2 is mounted in a manner not shown with the two ends of its axis in a machine frame, not shown. At least one printing unit console 12 is attached to this machine frame. On this printing unit console 12, a rail 13 is fixed, on which the bearing blocks 14 and 15 are slidably mounted. In order to move the bearing blocks 14, 15 relative to each other and / or relative to the machine frame and thus relative to the impression cylinder 2, known per se spindle drives are provided, of which the spindles 16, 17 and the spindle drives 18, 19 are shown. The printing cylinder 5 is mounted in a separate bearing block 14, while the inking roller 6 and the anilox roller 7 are mounted together in the bearing block 15. A further, not shown device for turning on and off the screen and the inking roller 7, 6 may be provided. This can be eccentric, in which bearing one of these two or both rollers can be stored.

If a color transfer cylinder is provided in a further embodiment of the invention, it is to be stored in a further bearing block, which would be displaced independently of the bearing block 14 which supports the printing cylinder. Of the color transfer cylinder bearing For example, the bearing block could be "piggybacked" relative to rails mounted on or on the bearing block 14. However, the rails on which the bearing block carrying the ink transfer cylinder is slidable may also include the rails 13 or other on the printing unit console 12 or on the machine frame In the same way, the inking roller 6 and the anilox roller 7 can be displaceable relative to one another if it is provided to make the inking roller 6 variable in terms of format.

4 shows the view IV - IV shown in FIG. 3. From this figure it can be seen that each roller and each cylinder is mounted at both ends in bearing blocks. In Fig. 3, the corresponding bearing blocks 14, 15 were shown on the operating side BS. These bearing blocks 14, 15 have shown in Fig. 4 counterparts on the drive side of the printing press, which are referred to as bearing blocks 14 'and 15'. On the drive side, of course, rails 13 ', spindles 16', 17 'and spindle drives 18', 19 'are provided.

In Fig. 4, the drives of the cylinders or rollers are further shown. The counter-pressure cylinder 2 can be set in rotation by its own drive 20. The printing cylinder 5 is also associated with its own drive 21. Above all, the own drive 21 of the printing cylinder 5 is important to continue to operate after changing the outer periphery of the pressure cylinder 5 this at the same peripheral speed can. The drive 22 drives the inking roller 6 and via the gears 23, 24 and the anilox roller 7 at. However, if the inking roller 6 provided variable in size, so preferably the inking roller 6 and the anilox roller 7 is assigned a separate drive.

Fig. 5 shows an example of a printing machine according to the invention, in which more than one inking unit is arranged around the impression cylinder. In this example, two identically constructed inking units are shown. The individual components of the inking units correspond to those shown in FIG. 2 Embodiment. Of course, additional color transfer cylinder according to the embodiment of FIG. 1 can also be provided here.

FIG. 5 additionally shows that the printing material wraps around the impression cylinder at a relatively large angle. This embodiment is also shown by way of example in FIG. 3 and is not limited to printing presses having a plurality of inking units. The illustrated wrap angle is more than 180 °.

Claims

claims

1st printing press (1) with

- An anilox roller (7), which takes ink from a color reservoir (8),

- An inking roller (6), which decreases ink from the anilox roller (7),

- A printing cylinder (5), which decreases with its printing areas ink from the ink transfer roller (6) and transfers to a web-shaped substrate (3),

- An impression cylinder (2) on which a web-shaped substrate (3) is feasible, on which the ink according to the printing areas of the printing cylinder (5) can be applied, wherein the printing cylinder (5) is designed for printing according to a planographic printing method, and wherein the outer circumference of the printing cylinder (5) is variable.

2. Printing machine (1) according to claim 1, characterized in that the impression cylinder (2) comprises an elastic surface on which the web-shaped substrate (3) is feasible.

3. Printing machine (1) according to claim 1, characterized in that a transfer cylinder (4) is provided, which decreases ink from the printing cylinder (5) according to the motif to be printed and transfers to the web-shaped printing material (3), wherein the transfer cylinder (4) is also variable in format.

4. Printing machine (1) according to the preceding claim, characterized in that the transfer cylinder (4) has an elastic surface.

5. Printing machine (1) according to one of the preceding claims, characterized in that the inking roller (6) is format variable.

6. Printing machine (1) according to any one of the preceding claims, characterized in that at least one of the aforementioned cylinders (2,4,5,6,7) or one of the aforementioned rollers (2,4,5,6,7) a roller mandrel comprising, which has a fixed diameter and on which sleeves with variable outer diameters are pushed.

7. Printing machine (1) according to any one of the preceding claims, characterized in that at least two printing cylinders (5) are provided, with which printing ink in the direction of the web-shaped substrate (3) is transferable, while this guided over a single impression cylinder (2) becomes.

8. Printing machine (1) according to one of the preceding claims, characterized in that the printing material (3) wraps around the impression cylinder (2) at least at an angle of 90 °, preferably at least 180 °.

9. A method for printing a web-shaped printing substrate (3), in which - Printing ink is removed by means of an anilox roller (7) from a paint reservoir (8),

- Ink is removed with an inking roller (6) from the anilox roller (7),

- ink is removed from a printing cylinder (5) with its printing areas of the ink transfer roller (6) and transferred to the web-shaped substrate (3),

- The substrate (3) on which the ink is applied according to the printing areas of the printing cylinder (5) is guided on a counter-pressure cylinder (2), wherein the printing cylinder (5) prints according to a planographic printing method and wherein when changing the printing length of the Outside circumference of the impression cylinder (5) is changed.