ES2601844T3 - Procedure and device for optimizing the relative position of at least two printing group cylinders - Google Patents

Abstract

Method for optimizing the relative position of at least two printing group cylinders (21, 37, 40), in which the relative position of the at least two printing group cylinders is adjusted on the basis of measured values, in that the measurement values comprise first values relative to the size of the surface (9), with which at least one of the printing group cylinders touches an additional body (5, 25, 40), and that the measurement values comprise second values relative to at least one second physical magnitude, characterized in that the first values comprise measurement values, which are obtained on the basis of the electromagnetic radiation record (6, 13), in which the electromagnetic radiation (6, 13) is diffusely reflected by a printing form (1, 45) from an ink transfer surface of a printing group cylinder (21, 37, 40) or a body, which touches (3, 39) the printing form or the transfer surface d e ink from a cylinder (21, 37, 40) involved in the printing process, before radiation recording occurs.

Description

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DESCRIPTION

Procedure and device for the optimization of the relative position of at least two printing group cylinders

The present invention relates to a method according to the preamble of claim 1 and to a device according to the preamble of claim 6.

Procedures and devices of this type are used in printing machines and here especially in flexographic printing machines to adjust the distance between the cylinders involved in the printing process. Only when this distance is optimized, is it possible to apply a print image, for which the ink transfer is in the desired area.

EP 1249346 A1 proposes for this purpose to review the print image, which is generated after the juxtaposition between sf of the cylinders involved in the printing process, with an optical sensor. Based on the results, juxtaposition is optimized. This procedure leads to good juxtaposition results. However, at the beginning of the printing process, low quality print images are often printed until the juxtaposition has been optimized.

To avoid maculature, EP 1 916 102 A1 proposes to measure the topography of the printing form or of the printing cylinder with a laser or by mechanical scanning, and thus obtain values that can be used in the printing machine before undertaking the printing operation for juxtaposition of the printing cylinder. In this measurement of the surface of the printing plate cylinder, however, a whole series of factors, which affect the operation of printing to the transfer of ink, are not taken into account. Among these factors is among others the behavior of the printer form under the conditions existing in the printing slot as well as the variation of almost all physical parameters of the printing while the printing operation is underway.

In particular, to maintain proper juxtaposition, it has long been known to monitor the pressure in the printing slot during the printing process. EP 0 867 281 A1 proposes this for a flexographic printing machine. However, it has been observed that due to dynamic variations also of the printing plates, also in case of a constant pressure in the printing slot, undesired variations in the printing image can occur.

Document DE 10 2008 025 287 A1 presents a procedure for adjusting the pressure in a printing slot, in which the width of the printing area is measured. For this purpose, a flat sensor carrier is inserted into the printing slot. Two pressure sensors are mounted on this sensor carrier at a certain distance between them. With these pressure sensors the pressure in the printing groove can be measured and the width of the area can be determined, in which the pressure does not fall below a certain minimum pressure.

WO 2008/028516 A1 discloses a method and a device for determining the properties of a groove between rollers. With an optical measurement arrangement, the rotation speeds of both rollers can be determined. From these measurement values, certain properties of the printing slot can be determined.

Among the disadvantages of the procedure described above is that it cannot be used with the printing operation in progress and that with it only the width of the traction and compression area is measurable and not all its surface extension. Therefore, the task of the present invention is to remedy these disadvantages.

For this, the invention starts from document DE 10 2008 025 287 A1, according to whose teachings the optimization of the relative position is carried out on the basis of measurement values - before the printing operation -.

The task is solved by claims 1 and 6.

According to the present invention, the task is solved by means of the resource that measurement values are recorded, which comprise first values relative to the surface size, with which at least one of the cylinders involved in the printing process touches another body. This size can first be understood as the absolute size of this surface. From this magnitude, however, a part can also be derived on a possible contact surface. As already mentioned, the process according to the invention is employable under certain conditions also during the printing operation.

Here, the present invention takes advantage of the fact that in particular in the gravure printing or embossing process it is about which components of the printing form touch the material to be printed in the printing slot. In relief printing they print the embossed areas of the printing form, while in gravure printing ink is transported into the depressed areas by engraving and is also transferred to the material to be printed.

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As a consequence, it is important for the quality of the print image that all areas of the printer form, which must be printed, also come into contact with the material to be printed. The same is of course also valid for an ink transfer between cylinders established before the printing slot. This can be in flexographic printing machines the transfer of ink from an anilox roller to the shape cylinder. Also in offset printing machines ink and / or wetting agent is transferred between a whole series of rollers.

Therefore, in the context of the present invention the size of the areas that are in contact with another additional body is measured. This additional body may be an additional printing group cylinder, to which ink must be transferred. When the two cylinders of the printing group are the printing plate cylinder and the backpressure cylinder, the material to be printed acts as an intermediary in the contact. However, it is also possible to introduce an added measurement body as an additional body, which is otherwise not involved in the printing process.

When an additional body thus is at the same distance from one cylinder of the printing group as the other one of the at least two cylinders of the printing group, the optimization of the relative position of the two cylinders between them can be produced without further assistance with the help of measurement values of the additional body. The additional body may, however, also be one of the at least two printing group cylinders. If the at least two cylinders of the printing group are the printing plate cylinder and the backpressure cylinder, these are often touched with the intermediation of the material to be printed. In particular when measurements are made in the printing plate cylinder, the so-called surface coverage can be determined, that is the part of the printing image that is actually transferred to the material to be printed, when the printing plate cylinder is at its totally inked part, by means of a measurement in the printing plate cylinder and not in the material to be printed as for example according to the teachings of EP 1249346 A1. This possibility is very advantageous, since the completeness of the image transfer is of course exactly the magnitude that is sought to be optimized by adjusting the relative position.

Within the framework of the invention, it is provided that, together with the first values relative to at least a first physical quantity, second values relative to a second quantity are also measured. Thus it is possible to measure the values relative to the magnitude of the contact surface with a pressure sheet, which has a multiplicity of pressure sensors, which can measure the juxtaposition pressure, which results respectively in a partial area of the surface. The second measurement values may be pressure values that are developed, for example, in two exposed areas of the groove between rollers. It is also possible to print with a flexible impression form impression marks on the material to be printed, and to use as a second value the increase in surface of the printing point as a result of an increase in the juxtaposition pressure. Alternatively, the positions of the roller supports can also be associated with the first measured values respectively determined as second values. Also a measure of the position of the respective roller envelope - which could be produced, for example, with optical measuring means - is presented as advantageous. It is important that first values determined in all these procedures, whose values refer to the contact surface, can be associated to the relative position of the rollers or to a pressure in the groove between rollers. Often, the determination of the second values will be limited to the front end areas of the rollers.

The determination of the second values in addition to the first values is particularly advantageous, when the determination of the first values occurs in an external device with respect to the printing group itself, whose device is often referred to as an external mount. In this case, it can be determined in the external mount so that relative position and / or so that juxtaposition pressure (second values) with respect to another body gives a satisfactory juxtaposition position (first values). The printing group cylinder, measured in this way, can then be placed in the printing group correspondingly thereto (ie correspondingly to the second values for first good values) with respect to the other, at least one, printing group cylinder. In this way, the devices, surely more expensive, can be dispensed with for the determination of the first values in the printing group. The measurement values for carrying out the process according to the invention can also be obtained by registering electromagnetic radiation. Often radiation will be recorded which is reflected by the surface of one of the inking group cylinders.

One possibility is to take advantage of the effect of total frustrated reflection. For this, a body that shines light can be approximated to the printing group cylinder. When a contact occurs between a surface, which produces total reflection, of the optical waveform or respectively radiation beam and the surface of the printing group cylinder, the effect of the total reflection is weakened as a rule (in particular, when the surface is optically denser (it has a higher refractive index) than the optical waveform and leads to diffuse reflection on the surface of the cylinder.

Print and use as a second value the increase in surface area of the impression point as a result of an increase in the juxtaposition pressure. Alternatively, the positions of the roller supports can also be associated with the first measured values respectively determined as second values.

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Also a measure of the position of the respective roller envelope - which could be produced, for example, with optical measuring means - is presented as advantageous. It is important that first values determined in all these procedures, whose values refer to the contact surface, can be associated to the relative position of the rollers or to a pressure in the groove between rollers. Often, the determination of the second values will be limited to the front end areas of the rollers.

The determination of the second values in addition to the first values is particularly advantageous, when the determination of the first values occurs in an external device with respect to the printing group itself, whose device is often referred to as an external mount. In this case, it can be determined in the external mount so that relative position and / or so that juxtaposition pressure (second values) with respect to another body gives a satisfactory juxtaposition position (first values). The printing group cylinder, measured in this way, can then be placed in the printing group correspondingly thereto (ie correspondingly to the second values for first good values) with respect to the other, at least one, printing group cylinder. In this way, the devices, surely more expensive, can be dispensed with for the determination of the first values in the printing group. The measurement values for carrying out the process according to the invention can also be obtained by registering electromagnetic radiation. Radiation will often be recorded here which is reflected by the surface of one of the inking group cylinders.

One possibility is to take advantage of the effect of total frustrated reflection. For this, a body that shines light can be approximated to the printing group cylinder. When a contact occurs between a surface, which produces total reflection, of the optical waveform or respectively radiation beam and the surface of the printing group cylinder, the effect of the total reflection is weakened as a rule (in particular, when the surface is optically denser (it has a higher refractive index) than the optical waveform and leads to diffuse reflection on the surface of the cylinder.

In this case, the light is diffusely reflected back towards the optical wave line, it crosses essentially in its transverse direction to its original propagation direction, therefore it affects an acute angle on the surface, away from the printing cylinder, of the optical wave line and leaves for it - in the absence of total reflection due to the acute angle - of the optical wave line. When diffused light is reflected by a sensor, which measures the intensity of the reflected light or electromagnetic radiation respectively, a measurement quantity is obtained, which depends on the size of the contact surface.

To improve the effect and to avoid fouling of the optical waveform, it will be provided between the surface of the cylinder and the surface, which produces total reflection, of the optical waveform an additional sheet-like body, which among other things has an optical density that weakens total reflection to an appropriate extent. The sheet can be applied to the cylinder or preferably to the surface that produces total reflection in a way that allows a closer contact of the sheet with the surface that produces total reflection as a result of the juxtaposition pressure of the cylinder.

When evaluating the first values (regardless of whether they have been measured with pressure sensors, optically or in any other way), a comparison with absolute nominal values can be carried out. Advantageously, however, a nominal image appears in view of a printing plate cylinder in embossing or gravure printing technique, in which the components, active with respect to pressure, of the printing plate are distinguished from the inactive. By comparing the measured contact image ("where the contact takes place") with the nominal image it is also clear where the juxtaposition must be modified. Another possibility, which shows good results in particular in the relief printing procedure consisting of flexographic printing, is the evaluation of the surface increase:

It has been observed that the surface with which a flexographic printing plate transfers ink, increases strongly depending on the juxtaposition after reaching a first point of contact (often referred to as a light contact point (kiss-print)), to then reach a saturation It is therefore possible to carry out an optimization of the relative position of the cylinders involved with the help of the evolution of the surface increase:

For this purpose, an overcompression of the cylinder to be measured can be carried out to reach the saturation zone. However, it is also possible to stop the juxtaposition process, in the case of a certain curve evolution, based on an analytical and / or empirical knowledge of the saturation behavior.

In this way, an optimized relative position of the at least two cylinders involved in the printing process can be assumed, when the first values are set aside a nominal value from the saturation point by juxtaposing the at least one cylinder to the additional cylinder.

What measurement values are generated with the various devices and what measures serve as a basis for the curves or graphs mentioned, is something that is deepened again in the specific description.

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A device for carrying out the process according to the invention has a measuring device, with which the size of the surface can be measured, with which at least one cylinder of printing group touches another body. As already mentioned, a measuring device can thus comprise a sheet, which has pressure sensors, which respectively measure the pressure in a surface section. When the resolution of this pressure sheet is therefore high enough - and thus the individual surface sections are small enough - even the contact of individual pressure points with the measuring device can be measured. When the number of pressure points, which come into contact with the measuring device upon juxtaposition of the printing group cylinder, stagnates after a phase of strong growth, one approaches the saturation mentioned above.

In a device, in which the frustrated total reflection is used and the luminous intensity of the diffusedly reflected radiation is measured, the measured light intensity reaches saturation when the contact surface between cylinder and measuring device no longer grows as in the growth phase by continuing juxtaposition.

Other examples of embodiment of the invention result from the specific description and the claims.

The different figures show:

1 shows an example of light intensity distribution, as is the case for camera 8 in

figure 2

2 shows a diagram of a device according to the invention with an optical waveform 5

Figure 3 a diagram of a second device according to the invention

Figure 4 a diagram of a third device according to the invention

Figure 5 a diagram of a fourth device according to the invention

figure 6 section A-A of figure 5

figure 7 a view of figure 6

Figure 8 a diagram of a fifth device according to the invention

Figure 9 a schematic of a sixth device according to the invention

10 shows a diagram of a device analogous to the third device according to the invention

Figure 11 a diagram of a printing group of a central cylinder flexographic machine

Figure 12 a printing plate cylinder with pressure sensors for the determination of second values

Figure 13 an outline of a measuring roller 49

Figure 14 a temporary chain of measurement values of the measuring roller 49

Figure 2 shows a device according to the invention, with which an optimized relative position is found between the at least two cylinders of the printing group by means of the electromagnetic radiation evaluation. This radiation is emitted by the radiation source 4. It affects the body 5 transparent for radiation 6 under an angle that leads to a total reflection of the radiation 6 on the walls 7 of the body 5. The angle of incidence a of the radiation 6 on the walls 7 must vary in a certain interval, to allow total reflection. Another condition for total reflection is that the refractive index n1 of the body 5 be greater than the refractive index n0 of the surrounding air. Due to these circumstances, the body 5 serves as a radiation target 6. In the case of light, precisely as an optical waveform.

The separators 11 distance the sheet 3 over the body 5 and can also fix this to the body 5. The sheet has three important properties in this context, and will be replaceable with any material that also has these properties:

It shows a certain flexibility with respect to a mechanical pressure. It can diffusely reflect radiation 6 and has a refractive index n2 higher than body 5.

The flexibility, possibility of shaping and depth of the sheet / separator unit are also interesting: depending on the roughness and hardness of the roller to be measured, these can be adjusted. If, for example, a printing plate cylinder with a flexible printing form and with a smaller distance between raised areas and deep areas of the printing form is to be examined, a relatively hard "design" of the separator unit 11 / sheet 3 is recommended and a small distance from sheet 3 to body 5. If the roller to be examined is facing a

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Anilox roller 37 with a hard surface, which has large distances between raised areas and deep areas, a relatively "soft" design of the separator unit 11 / sheet 3 and a small distance of the sheet 3 from the body 5 are recommended.

When - as shown in Figure 2 - the plot point 2 is pressed in the direction of the arrow 12 against the sheet 3, the sheet 3 comes into contact with the body 5. The total reflection is eliminated in the area of the contact surface between body 5 and sheet 3, the sheet 3 reflects the diffuse radiation back to the body 5. Those parts of the diffuse radiation 13, which fall under a suitable acute angle p on the wall 7, cross this way practically total.

Consequently, the camera 8 registers an increase in light intensity, which is related to the contact surface between the plot point 2 and the body 5 (even though the sheet 3 is intermediate).

The camera (more properly the sensor for electromagnetic radiation) forms an image, as outlined in Figure 1. By 9 the contact surface of a frame point on the body is indicated. The camera receives a clear imprint of the size of the contact surface. The contact surface 9 is located in the contact area 10, which develops, for example, between two cylinders as a groove between cylinders. The contact zone 10 is therefore the surface area where the cylinders could really come into contact. The contact surface 9 is a partial zone of the contact zone 10, in which in 9 true contact occurs.

When the transparent body 5 and the printer-shaped carrier 1 are developed as cylinders that roll over each other, during the rolling process various contact areas 10 ', 10' 'are formed, which consecutively sweep the field of vision of the camera 8. When the printer-shaped carrier 1 carries a complete print image, the camera can compose the contact image of this print image on the body 5 or respective on the sheet 3 from contact areas 10, 10 ', 10 '' captured successively.

In the following contact zones 10 ', 10' 'the following contact surfaces 9' and 9 '' are outlined in Figure 1. If the camera 8 records the intensity of the diffusedly reflected light in the manner described by the sheet 3 due to the contact through the printing form, the light intensity is - as mentioned - a measure for the contact surface. It can be measured for various parts of the contact area. Comparisons with absolute nominal values are possible. It is also possible to check to what extent the light intensity values approximate a saturation point throughout the contact area and advantageously in different parts thereof. Based on calculations and / or values derived from experience, it is possible to determine how far from this saturation point an optimized juxtaposition is achieved.

Figure 3 shows an alternative device. Again, electromagnetic radiation 6 is emitted by the radiation source 4. The angle and, under which the radiation 6 affects the body 5, leads to the radiation penetrating widely into the body and only experiencing a total reflection on the limit surface 17 (transition to an optically less dense medium) when the body 5 is not - as shown - in contact with the plot point 2. As a consequence of the total reflection on the boundary surface 17, a large part of the emitted radiation 6 by the radiation source 4 it reaches the chamber 8. If the plot point 2 - which here, unlike figure 2 is in direct contact with the body 5 - comes into contact with the body 5, the total reflection is weakened , since the plot point has a higher refractive index than the body 5.

Consequently, a diffuse reflection is reached again at frame point 2 (diffusely reflected radiation 13) as well as a transmission into the frame point (radiation 16).

Contact by the frame point therefore leads to a reduction in the light intensity to be measured by the camera. This reduction is a function of the contact surface 9 between frame point 2 and body 5. (This will also be so, if there were again a sheet of refractive index higher than body 5 between body 5 and the frame point 2). Also, Figure 4 shows a device in which the light source 4, the transparent body 5, the frame point 2 and the camera 8 are arranged or respectively shaped such that as a consequence of a contact between frame point 2 and body 5, and as a consequence of the weakening, coupled with it, of the total reflection it is necessary to notify a reduction of the light intensity to be measured by the camera 8. This intensity is again a function of the contact surface 9 and can be used for a measurement of it.

Figures 5 to 7 show a device that operates according to the principle set forth in relation to Figure 2. However, here the transparent body 5 is already made as a transparent roller 25. The printing plate holder 1 shown in Figure 2 is here a printing plate cylinder 21. The placement between rollers of the transparent roller 25 and of the printing plate cylinder 21 can be carried out in the manner outlined in an external mount 22. As already indicated above, such an arrangement can be carried out also in a printing group. Then, either the additional function of a roller normally arranged in the printing group must be assigned to the transparent roller or the roller 25 must be additionally placed in the printing group in question.

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In both cases, the two rollers or cylinders 21, 25 must be juxtaposed between them, which is indicated in Figure 5 by arrow 26, which indicates the direction of movement of the roller stand 18. This moves with the support of roller 19 and with the transparent roller 25 in the direction of the printing plate cylinder 21. This movement of the easel 18 should generally be carried out with rails of rails, linear motors and spindle drives on the basic frame of the mount 23. The representation of all these individual components is not necessary in the present context. In all cases, it is possible for the person skilled in the art to monitor the position of the stand 18 with position detectors as well as rotary transducers (especially for spindle drive). In this position or respectively the positions of the two roller supports 19 and 20 on the front sides of the transparent roller 25, second values can be found in the sense of the present invention. Additionally or alternatively it is possible to apply pressure sensors to at least one of the two cylinders 21, 25. In this way, the pressure produced in the groove between rollers can be measured and used as a second value. Also with a view to these second pressure values it is advantageous that at least two values are available respectively from the area of a front end of the groove between rollers. Here, the obtaining of the second measurement values can also be limited to partial zones or respectively smaller partial surfaces. Against this, it is advantageous that the first values are obtained at least from the zones in which a contact between cylinders can take place (for the cylinder of the printing form, for example the extension of the printing form).

With the help of the second values, as a general rule obtainable more easily, the relative position can then be found again, in which the first values relative to the size of the contact surface are located in a desired range.

This is particularly advantageous when the first values relative to the contact surface are obtained in an external mount 22, and then in the printing group simply the same optimized juxtaposition situation as in the external mount 22 must be achieved.

Figure 6 shows even more in detail the transparent roller 25 of Figure 5 from the angle of view of the arrows 29 along the section A-A:

On the front sides of the roller 25 are placed radiation support fasteners 24, which support the radiation sources 4. The radiation sources 4 are positioned in such a way with respect to the roller 25 that the radiation, analogously to the case of Figure 2, it remains in the transparent body, since it experiences a total reflection on its outer walls. Total reflection is however impeded when the sheet 3 is pressed by elements of the printing plate cylinder against the walls of the transparent roller. Consequently, for the chamber 8, the contact surfaces 9 are visible within the roller 25 analogously to the situation represented in Figures 2 and 1. If the rollers 25 and 21 roll on each other during their contact, it is possible to compose various zones of contact 10 and thus obtain an imprint of the ink transmission of the entire printing plate of the printing plate cylinder 21 (ie of the entire printing image of the printing group). Note that this possibility exists according to the present invention without having to apply ink on the material to be printed and without having to produce maculature by an impression.

Of course, the teachings of the invention can also be applied with simultaneous ink transfer, as shown even later.

Figure 7 shows the roller 25 from the point of view of the arrows 20, in which among other things the roller support 19 ', the carrier of the radiation sources 24 and the sheet 3 have been dispensed with for reasons of clarity in the representation.

Figure 8 corresponds broadly to Figure 5, in which the function of the transparent roller 25 is again adopted by a transparent body 5. Towards this radiation emits the radiation source 4. The transparent body 5 for this radiation can be juxtaposed to the 21 cylinder with easel. The body hangs on it from the support arm of the stand 34 and can be moved along the rail 33 in a vertical direction in one direction and in another, as indicated by the arrows 32. The body 5 and the cylinder 21 can thus roll one over another (rotating movement of the cylinder outlined by arrows 31). Thus, also with the device shown in Figure 8, a larger perimeter zone of the cylinder 21 can be brought into a rolling contact with the body. The representation of any actuators for body movement 5 has been renounced.

In figure 9 a device is outlined, which works from the point of view of the optical principle as the device according to figure 3: if the body 5 touches the cylinder 21, due to the weakening of the total reflection on the contact surfaces it arrives less radiation 6 to the chamber 8.

The body 5 is juxtaposed to the cylinder 21 according to Figure 9 as a punch along the rail 33. By means of a plurality of such juxtaposition processes the entire surface of the cylinder 21 can be explored, which can be rotated for this purpose successively in certain angles

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Figure 10 shows a device with a structure, which from the point of view of the lightning paths reminds of Figure 4. Also here the light intensity decreases as a result of the contact between the body 5 and the cylinder 21. If the body is moved with the aid of a rail 33 along the surface of the cylinder (which is represented by the double arrow 35), various contact areas 10 between the body 5 and the cylinder 21 can be covered again at different times.

In the figures a multiplicity of devices have been represented, for which a determination of the contact surface 9 has been carried out with the help of optical methods. If this effort is carried out with the aid of a pressure plate (pressure sensor in the form of a sheet), the pressure plate takes the place of the surface of the body 5 or respectively of the roller 25, which touches the cylinder 21. It is not A sheet 3 advantageous in part for optical methods is generally necessary for this. Nor is a description of a lightning path or similar necessary in this context. Therefore, there is no need to describe at this point any additional figure, showing a pressure plate instead of the described surface of body 5 or roller 25.

In Fig. 11, two printing groups 36 and 38 of a central cylinder flexographic printing machine with a central cylinder 40 are outlined in a simple manner. For these inking or printing groups, it is shown how procedures can also be found according to the invention. In a central cylinder flexographic printing machine of the type shown, a band of material to be printed 39 is added to the central cylinder 40 and is pressed there with the aid of an application roller 41. The material to be printed 39 is transported by rotating the cylinder. backpressure through grooves between rollers 42, which develop the backpressure cylinder 40 with the printing plate cylinders 21 (referred to as flexographic printing form cylinders). In these grooves between rollers, the material 39 is printed with the ink of the respective printing group, so that a multicolored printing group is generated. In the meantime there are flexographic central cylinder printing machines that have a two-digit number of such inking groups 36, 38. The direction of rotation of the cylinders 21, 40 and 37 is indicated by the arrows A, B and C.

Printing in the flexographic printing process is then produced by the embossed components of asf called cliches 45 - that is flexible forms of printing - which are often structured as weft points 2. The cliches are often inked by means of so-called rollers. anilox 37 - that is also printing group rollers within the meaning of this document -.

Other elements of the printing groups such as scraper chambers or roller stands for juxtaposing the cylinders and rollers 40, 21, 37 are not shown in Figure 11.

In Fig. 11, the backpressure cylinder 40 is equipped with a transparent body 5 and a chamber 8. The transparent body 5 somewhat forms a window on the enveloping surface of the back pressure cylinder 40 (the back pressure cylinder is therefore partially transparent). The chamber 8 is dragged in the rotation by the counterpressure cylinder and thus remains during the rotation of the counterpressure cylinder 40 in a position, in which it, 8, can capture diffuse radiation 13, which leaves the body 5. The operating principle of the measuring device 47 composed of chamber 8 and body 5 in figure 11 corresponds to the operating principle that has already been explained with the help of figures 3 as well as 5 to 7:

At least one front end of the backpressure cylinder 40 is emitted radiation by radiation sources 4 into the transparent body 5 (which is shown for example in Figure 6). This experiences a total reflection on the surfaces of the body 5, which is weakened when contacts between parts of the click 45 and the body 5 take place. These contacts can also be mediated by a sheet 3. The web of material to be printed 39 can assume the role of the sheet 3. It is advantageous that between the sheet 3 or respectively the strip of material to be printed 39 and the body 5 are provided with dividers 11.

When, when starting the printing machine, the printing plate cylinders 21 are juxtaposed for the first time using the measuring device 47 of the backpressure cylinder 40 (for the first time adjusting the relative position between these two printing group cylinders 40, 21) and the backpressure cylinder 40 carries in this process material to be printed 39, the production of maculature should not be avoided.

However, it is possible that the measuring device 47, during a rotation of the backpressure cylinder, obtains data regarding the contact of the backpressure cylinder 40 with several or even all of the printing plate cylinders 21. Thus, the relative positions can be optimized clearly faster than in juxtaposition procedures that carry out the optimization, inking group 36, 38 to inking group, of the relative positions at the beginning of printing. Another advantage of the procedure that has just been explained is that it can work without second values within the meaning of this document. In addition, a long-lasting dynamic monitoring of the contact surface 9 during the printing operation in the manner explained above seems particularly advantageous.

Another measuring device 48, which is shown in Figure 11, consists of a cylinder 25, which is analogously structured to the cylinder 25 in Figures 5 to 7. This, 25, has a juxtaposition device 43, which is articulated to the articulation point 44 in a fixed position for example in the machine frame. The cylinder 25 can

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be juxtaposed to the printing group cylinders 21 and 37 of the inking groups 36 and 38 and thus measure the contact surface 9 (first values).

In Fig. 12 a printing plate cylinder 21 is shown, such as the one that frequently finds application when performing the flexographic printing procedure. He, 21, has a flexible click. Additionally, the cylinder 21 shown in Figure 12 is equipped with two pressure sensors 46, which are located in the vicinity of the front ends of the cylinder 21. These pressure sensors 46 can determine the juxtaposition pressure in the groove between rollers 42 and determine with them second values within the meaning of this document.

These can be used among other things as follows:

With the measuring device 48 shown in Figure 11, first values have been obtained, by means of the resource that the transparent roller 25 is juxtaposed by the juxtaposition device 43 to the printing plate cylinder 21 which is located in the printing group 38. Added to the first optimized values relative to the size of the contact surface 9 between the cylinders 21 and 25 are measured with the sensors 46 second values (tightening pressure).

These are stored as a rule. They express that for optimum pressure conditions (second values) at both ends of the groove between rollers there has been an optimal surface coverage, which has been determined with the help of transparent rollers. Before the start of printing, the printing plate cylinder 21 is juxtaposed to the backpressure cylinder 40. In the first approximation it is necessary to start from the fact that for the same pressure values in the groove between rollers 42 (second values) the same optimized surface coverage is also obtained, so that an impression can be carried out with the same pressure values. Advantageously, however, correction factors for the tightening pressure will be introduced over time, taking into account that the cylinders 25 and 40 have different diameters and that the material to be printed 39 has a certain elasticity.

In principle, with the procedure just explained, a first impression is possible without maculature. It is also possible to check from time to time the variation of the surface coverage with the cylinder 25, in which it is necessary to take into account of course the fouling thereof, 25, with ink.

Instead of applying the pressure sensors 46, when performing the procedure explained, to the printing plate cylinder 21, these, 46, can also be applied to both the backpressure cylinder 40 and the transparent cylinder 25. This is also valid for others. means, with which second values can be obtained within the meaning of this request. As already explained, second values can be obtained within the meaning of this document also by means of position detectors, which reproduce the position of the respective cylinder in its juxtaposition device 43. In particular, in the case of using linear motors, the juxtaposition force. As the cylinders are held by front supports and these respectively have a juxtaposition device, it is advantageous to collect at least two second values with respect to the juxtaposition situation at respectively a front end of the cylinder.

The procedure explained lastly, with the aid of the measuring device 48, which also uses second values, is also advantageous when the first values are obtained with an external mount 22.

Figures 13 and 14 again clarify the obtaining of first and second measurement values. A measuring roller 49 is shown in Figure 13, which also has pressure sensors 46 for obtaining second values. The aqrn pressure sensors shown sweep a rectangular measuring zone. It is convenient that these pressure sensors can measure a certain pressure increase continuously, so that it can be determined exactly at what pressures at both front ends of the roller 49 that first values have been obtained.

In the central zone, in the axial direction of the roller, is the measurement zone 50 for the first measured values. It is convenient to divide it into partial zones 51.

If this measuring zone 50 is represented by a pressure sheet, the size of the partial zones 51 is often obtained by resolution of the pressure sheet (resolution = in which surface units pressure can be measured). For many of these sheets it is only possible to make binary statements about the existing pressure (a certain pressure threshold has been exceeded or not). However, the use of an ast sheet may also be sufficient

It is also possible to form the measuring zone 50 of the measuring roller 49 essentially in the same way as the light-grinding bodies 5, mentioned above, or that the transparent roller 25. Also in this case partial zones 51 of the area of measure 50. This can occur, inter alia, by the recourse that the chamber 8 associates the radiation leaving the optical waveform 5 or the transparent roller 25 to the partial zones. For this purpose, the chamber 8 may consist among others things of a diode array, which is arranged very close to the optical waveform.

5

10

fifteen

twenty

25

30

35

40

Figure 14 shows a chain of measurement values of the measuring roller 49, which occurs in a time interval T, while the measuring roller 49 is juxtaposed to a click roller 21.

In the time interval T represented, precisely the click 45 begins to roll on the measuring roller. The contact zone, that is to say the entire area where a contact between the measuring roller and the cliche is possible, is outlined - for reasons of clarity in the representation - by rectangles 45 ', 45' 'and 45' ' '.

At the beginning of the time interval T (above) there is absolutely no contact (rectangle 45 '), and no first measurement value is determined in the partial zones 51 of the measurement zone 50. Only the pressure sensors 46, which they have measuring probes that protrude above the surface of the roller 49, are already in contact with the click roller 21 and provide respectively a measurement value 46 '(The measured values, captured at a certain moment, of the two sensors 46 will often be different, for the adjustment of an optimized roller position it may even be necessary to adjust to different measurement values at the two front ends). After another rotation of the roller, as a result of an additional juxtaposition of the rollers 21, 49 between them, a partial zone 51 of the measuring zone 50 has been formed, which is located within the possible contact surface 49 '', a contact surface 9. This, 9, is represented as a black square in a partial zone 51. In this way it becomes clear that in this partial zone a contact of the cylinders 21, 49 with a certain intensity has taken place. If, for example, simple pressure plates are used for the determination of the second values, the corresponding statement is that there has been a contact with a certain minimum pressure in a certain partial area.

When the contact surface 9 is captured, the pressure sensors 46 also communicate second modified values 46 '', which are characteristic for the relative position, adjusted at that moment, of the rollers 21, 49 between themselves. and second values 46 '', previously cited, thereby form a pair of values, which can characterize the surface extension of a pressure for a certain relative position of the rollers between sf

After another rotation of the roller - and after the corresponding additional juxtaposition of the rollers 21, 49 between sf - they have formed within the possible contact surfaces 45 '' 'and four contact surfaces 9.

As mentioned above, it is among other things possible to determine the optimized roller position by juxtaposing the rollers 21, 49,

- until a nominal surface has been reached (for example partial zones 51 of the measuring surface 50, which communicate contact) and / or

- until the contact surfaces 9 constitute a certain percentage of the possible contact area and / or

- until the contact surface 9 corresponds to its extension and forms a nominal image and / or

- until the increase in contact surface 9, which results from continuing juxtaposition of the rollers

between yes, show a saturation behavior or show a certain behavior (often

determined emphatically or analytically), which allows to expect a rapid saturation ("evolution of curve").

In particular, the alternative set forth in the last preceding script can be practiced particularly well with the optical procedures disclosed in this document. Here the evolution of the light intensity recorded by the camera 8 can be recorded depending on the second values, such as juxtaposition of rollers or pressure in the printing slot (for which the sensors 46 offer representative values). In this case, the evolution of the light intensity in the entire measurement area for the first measurement values and / or the evolution of the light intensity in a possible contact zone 19 and / can be used as the basis for optimized relative position. or the evolution of light intensity in partial areas 51.

 List of reference symbols

 one

 Printer form carrier

 2

 Plot point

 3

 Sheet

 4

 Source of electromagnetic radiation (for example of light)

 5

 Transparent body / optical wave gma

 List of reference symbols

 6

 Wave field (as a rule electromagnetic waves)

 7

 Surface, which produces total reflection, of the body 5

 8

 Camera

 9

 Contact surface

 10

 Contact area

 eleven

 Separators

 12

 Arrow in the “tightening direction” of the plot point 2 of figure 2

 13

 Diffuse radiation (retrodifusion)

 14

 Measuring area of camera 8

 fifteen

 Tooth of the body 5

 16

 Radiation

 17

 Surface, which produces total reflection, of body 5 (figure 3)

 18

 Roller stand

 19, 19 '

 Roller support for transparent roller 25

 twenty

 Roller support for impression plate cylinder 21

 twenty-one

 Printing plate cylinder

 22

 Mount

 2. 3

 Basic Frame Frame

 24

 Support of radiation sources

 25

 Transparent roller

 26

 Arrow in the direction of movement of the roller stand 18

 27

 Arrow in the direction of rotation of the roller 21

 28

 Arrow in the direction of rotation of the roller 25

 29

 Arrow in the direction of view of Figure 6

 30

 Arrow in the direction of view of Figure 7

 31

 Arrow in the direction of the roller

 32

 Arrow in the direction of body movement 5

 33

 Rail

 3. 4

 Support arm

 35

 Double arrow figure 10

 List of reference symbols

 36

 Printing group / inking group

 37

 Anilox roller

 38

 Printing group / inking group

 39

 Band of material to print

 40

 Groove between rollers

 41

 Application roller

 42

 Groove between rollers

 43

 Juxtaposition device

 44

 Joint point of the juxtaposition device

 Four. Five

 Cliche

 46

 Pressure sensor for the determination of second values

 47

 Measuring device

 48

 Measuring device

 49

 Measuring roller

 fifty

 Measurement zone for first values

 51

 Partial zones of measurement zone 50 for first values

 52

 A, B, C

 Arrow in the direction of movement of a cylinder

 to

 Acute angle, appropriate for total reflection

 p

 Obtuse angle, the radiation crosses the surface 7

 Y

 Radiation entry angle in the body 5

 t

 Weather

 T

 Time interval

 45 ', 45' ', 45' ''

 Possible contact area for measuring roller / click

 46 ', 46' ', 46' ''

 Measuring values of pressure sensors 46

 fifty'

 Timing of the measured values 51 '

 51 '

 Measurement values in partial areas

Claims (9)

5 10 fifteen twenty 25 30 35 40 1. Procedure for optimizing the relative position of at least two printing group cylinders (21, 37, 40), in which the relative position of the at least two printing group cylinders is adjusted based on measurement values , in which the measurement values comprise first values relative to the size of the surface (9), with which at least one of the printing group cylinders touches an additional body (5, 25, 40), and in that the measurement values comprise second values relative to at least a second physical quantity, characterized because the first values include measurement values, which are obtained on the basis of the electromagnetic radiation register (6, 13), in which the electromagnetic radiation (6, 13) is diffusely reflected by a printing form (1, 45) of an ink transfer surface of a printing group cylinder (21, 37, 40) or of a body, which touches ( 3, 39) the printing form or the ink transfer surface of a cylinder (21, 37, 40) involved in the printing process, before the registration of the radiation occurs. 2. Procedure according to claim 1, characterized in that The second values include the juxtaposition pressure between the printing group cylinders (21, 37, 40) and / or the relative position of the printing group cylinder supports. 3. Method according to one of the preceding claims, characterized in that The first values include pressure values, which refer to the pressure that is established upon contact between at least one cylinder of the printing group (21, 37, 40) and the at least one body (5, 25, 40) additional in surface units of the contact zone (10) possible between the at least one printing group cylinder (21, 37, 40) and the at least one additional body (5, 25, 40). 4. Method according to one of the preceding claims, characterized in that Electromagnetic radiation (6, 13) is recorded, which, (6, 13), has been decoupled from a radiation beam (5, 25) previously due to a frustrated total reflection. 5. Method according to one of the preceding claims, characterized in that an optimized relative position of the at least two cylinders of the printing group (21, 37, 40) is assumed when the first values are a nominal value away from the saturation point by juxtaposing the at least one printing plate cylinder (21, 37, 40) to the additional cylinder (5, 25, 40). 6. Device for optimizing the relative position of at least two printing group cylinders (21, 37, 40), with which device an optimized relative position of the at least two printing group cylinders (21, 37, 40 can be determined ), based on measurement values, with a measuring device (47, 48), with which measurement values are measurable, comprising first values relative to the size of the surface, with which at least one printing group cylinder (21, 37, 40) touches an additional body (5, 25, 40), and second values relative to at least a second physical quantity, characterized because the measuring device comprises sensors (8) for recording electromagnetic radiation (6, 13), in which the measuring device has sources (4) of electromagnetic radiation (16, 13), and because the electromagnetic radiation (6, 13) emitted by the sources (4) of electromagnetic radiation is diffusely reflective by a printing form (1, 45), by an ink transfer surface of a printing group cylinder (21, 37, 40) or of a body, which touches the printing form or the ink transfer surface of a cylinder (21, 37, 40) involved in the printing process, and is recordable by sensors (8). 5 7. Device according to the preceding claim, characterized because The measuring device is arranged in or on the at least one printing group cylinder (21, 37, 40) and / or in or on said additional body (5, 25). 8. Device according to one of the two preceding claims, 10 characterized in that The measuring device comprises a pressure measuring unit, with which the pressure distribution can be measured, which occurs in at least a part of the contact surface between the printing group cylinder and the additional body. 9. Device according to one of the three preceding claims, 15 characterized in that The measuring device comprises the additional body and the additional body (5, 25, 40) has areas that are transparent to electromagnetic radiation (6, 13). 10. Device according to one of the four preceding claims, characterized in that 20 the sources (4) of electromagnetic radiation are arranged in such a way with respect to the zones (5, 25), which are transparent for the electromagnetic radiation (6, 13), which the zones serve as radiation rods (5, 25) .