FI106941B - Rotary gravure printing machine and method - Google Patents

Abstract

In a rotogravure printing machine (1) having at least two printing units (24 to 27 and 30 to 33) and a drying device (34 to 36; 38 to 40) arranged between said printing units, through which a paper web (2) to be printed runs one after the other, to simplify the operation and to reduce the occurrence of waste, provision is made for the printing units to be aligned in such a way that the paper web runs in a straight line from the preceding printing unit through the drying device without contact to the subsequent printing unit, guided only by the forme cylinders (55, 55) and impression cylinders (56, 56) of these two printing units. <IMAGE>

Description

, 106941 ROTARY DEPRESSION EQUIPMENT AND METHOD

The invention relates to a rotogravure printing apparatus of the kind set forth in the preamble of claim 1 and to a method for operating such a device according to the preamble of claim 11.

Such devices and methods are well known and described, for example, in DE 3530561. In order to make the paper web 10 multicolored, there is a separate printing device for each ink, the inner part of which forms a rotatable roller sink which sinks into the color bath. In the "pressure gap" formed between the frame cylinder and the press 15, the paper web is guided from above, whereby a guide screw is provided for guiding and turning. After each pressure gap, the paper web must go through a drying apparatus, because in the rotogravure printing process, unlike in offset printing, the previously printed colors are hitherto dried immediately before the next color is printed. The drying devices may be formed either from drying cylinders as disclosed in DE-A-3530561, or from drying casings which, especially in modern high speed machines, are long enough to provide a sufficiently long residence time for each part of the paper web to be dried. inside the case. Regardless of the particular design of the dryer, the paper web is always guided in these areas by a plurality of guide or pivoting rollers, hereinafter referred to as guide screws. Because, for example, eight printing presses, each of which has a size of seven to ten guide screws, are required for two-color printing, there are a number of problems with known rotogravure printing machines: each of the numerous guide screws has its own drive; As a result, with every change of speed * · 2 106941, especially during start-up and shut-down, a large amount of wasted material becomes available. Namely, when accelerating the Pape web, the guide screws act brakingly, whereas when decelerating, they tend to continue to rotate 5 wheels at a previously higher speed so that they must first be braked by the paper web. Thus, it will take some time for the speed to change to provide a new, constant state, which can be used to adjust the positioning position with the necessary precision. 10 Both such in-transition and in-machine running paper will be printed with inadequate alignment accuracy and thus cannot be used.

Particular problems are when the machine must be stopped very quickly due to a break or ignition of the paper web. Not least because of the enormous size of the rotogravure printing equipment, especially for two-color printing on both sides, such damage cases are not uncommon, and for each printed product 20, a lost proportion of 6% to 10% has to be calculated.

Therefore, it is an object of the present invention to further develop the rotogravure printing apparatus and method as is known today to provide a substantially higher reliability and, in particular, to significantly reduce the amount of wasted material. In addition, the labor costs required to operate the machine are reduced.

In order to achieve the object of the invention, the invention is characterized by the features set forth in the claims. sa 1 and 11 respectively.

This solution is based on the knowledge that in current printing inks it is quite sufficient for the printing press used to desiccate the outer color of the ink applied to the surface of the paper web, as desired, so that the next ink can be printed without any problems. The hitherto required thorough drying of the used paint, which must be completely dry before applying the next paint, is no longer necessary. Thus, the drying devices arranged between the successive printing presses can be designed to be linear and so short that the guiding provided on the printable web by the first and second printing press rollers and presses is completely sufficient. No additional control between printing devices 10, which sequentially presses the paper web from one side, and especially control in imaging devices, is necessary so that most of the guide screws used so far can be removed. In fact, it is possible to equip the rotogravure printing apparatus according to the invention for eight printing presses for mutual four-color printing, with a total number of guide screws not used in a single printing press to date.

This provides a number of advantages: the distance traveled by the paper web to be printed inside the rotogravure printing machine will be considerably reduced. Thus, the reliability of travel is substantially increased. The risk of tearing of the paper web 25 has been greatly reduced. However, if such a malfunction occurs, the device can be stopped much quicker, since a very much smaller number of guide screws have been charged with much less rotational energy, which must be taken into account when stopping. Also, with the desired change in the web speed, the previously mentioned retardation effects caused by the guide screws are greatly reduced, so that the new printing speed is achieved substantially faster. Since the length of the paper web in the device at any given time is substantially shorter than in the prior art devices, the amount of wasted paper is thereby greatly reduced.

4, 106941

The paper web is subjected to substantially less resistance and thus less stretch. In this way, the targeting accuracy is greatly increased.

5 The need for energy due to lower frictional losses and reduced 'damped' rotational energy, which becomes the released heat when stopped, is greatly reduced. The essential benefit of moving the paper web in a straight line and contactless manner from one web to another is that arranged immediately before or after the weight slot, parallel to the rack cylinders, so that the uppermost paper web, when passing through the weight gap, pivots substantially horizontally and then back up again, since at least one of these two guide screws is necessarily within the range of movement. pass through the rack cylinder when, for example, the sy-20 cylinder is being replaced for the second printed product.

Namely, according to the prior art, each of the two shaft pins extending over the ends of the rack cylinders is mounted on a peripheral bearing, which in turn is secured to the machine frame. When changing the racking cylinder, this is lifted by a special lifting device, together with both peripheral bearings, upwardly from the machine frame and then displaced parallel to itself and transverse to its longitudinal axis in a clearance between it and the adjacent printing device. The circumferential bearings are then removed in the axial direction and the rack cylinder is moved. by pulling longitudinally from the space between the printers.

Conversely, in this state, the reassembly rack cylinder is moved longitudinally and, after the runner bearings are attached to their shaft pins, is displaced transversely to its longitudinal axis to a position above which it is finally lowered.

5 In order for these movements to take place, according to the state of the art, not only the press in question must be raised a considerable distance, but also the two latter guide screws on the side of the printing device must be moved out of the way so that the rack cylinders can be dismantled. In this case, it is necessary to use a mechanism which can be omitted in the rotogravure printing machine according to the invention with its said guide screws. Thus, in the device according to the invention, both the disassembly and assembly of the racking cylinder becomes considerably simpler and the automation is further facilitated.

Advantageously, the printing devices necessary for printing one side of the paper web can be placed vertically over one another in the tower device so that the web of material to be printed through them 20 runs perpendicularly.

This device results in a drastic reduction in the bottom area required by such a machine.

25 An additional benefit of this tower device is that virtually every clamp is no longer exactly above the corresponding rack cylinder and press this from above. In addition, it is possible to place the clamp substantially laterally and with only a slight amount of axis above the operating axis of the rack cylinder. Thus, when changing the rack cylinder, it is not necessary to raise the press forcefully from its operating position; in this case, it is sufficient to move it to a small extent from the cradle cylinder, whereby a substantially simpler mechanism can be used. Thus, the tower device of the weight-35 device also provides for a simplified removal and installation of the rack cylinder.

«6 106941

In order to keep the height at which the racking cylinder must be lifted during removal and lowered during installation respectively, according to a particularly preferred embodiment of the invention, each shaft pin is provided with a lower bearing having one, two, or three support rolls , that the rack cylinder with its shaft pins can simply be replaced from near the top and lifted respectively from the top. These auxiliary bearings 10 may be attached to the machine frame in such a way that they can be adjusted to a variety of diameters of the rack cylinder. This also provides for the removal of the circumferential bearings from the dismountable rack cylinders, and in particular their connection to the shaft pins of the rebuilt rack cylinders.

The latter has often become difficult in practice due to the fact that the shaft pins must fit very precisely into the inner bearing ring so that no swinging or carrying occurs. If the racking cylinder to be assembled is only a few ° C too warm, which is easily possible due to the prior galvanic treatment, due to the temperature radial expansion of the shaft pins, bearings can often not be retained until such cooling has been used. By using auxiliary bearings according to the invention, all these difficulties are eliminated. Because the auxiliary bearings require smaller bearings to be applied over a longer period of time than the peripheral bearings used to date, it was previously assumed that the auxiliary bearings, particularly those used in high-speed rotary printing machines today bearings 35, which require a certain stability. In practice, however, these fears have surprisingly proved to be useless. Thus, it is possible to provide sufficient cooling of the auxiliary bearing, and the specific gravity of the cradle cylinder and the gravity of the press are sufficient to maintain a constant level bearing.

In the transverse longitudinal direction of the barrier, the work of removing and installing the cage cylinder is previously caused by the squeegee devices, which according to the prior art are mounted so that the jacket line along which the squeeze presses the cage cylinder is as close as possible This is considered necessary to prevent drying of the ink in the recesses of the racking cylinder between the Rake and the upper surface of the paper to be printed. Not least because of the high printing speeds, this danger does not exist in modern rotogravure printing machines.

According to the invention, the squeegee device is therefore arranged in such a way that the sheath line along which the squeegee is located on the rack cylinder is not higher and preferably deeper than the rotational axis l1 of the rack cylinder in its position of use. Thus, the squeegee device is disposed outside the area through which the rack cylinder is moved during disassembly and assembly respectively. Previously, the conventional, used mechanics for lowering and raising the squeegee device can thus be omitted, and only the possibility of adjusting the squeegee position due to various pile cylinder diameters has to be taken care of. Thus, also this detail provides a very much simpler and thus easier to automate removal and assembly of the rack cylinder. 30

A particular advantage of the tower device is that the structure surrounding the machine can be formed into a housing in which the paper web to be printed comes from a narrow slot and further exits the opposite narrow slot 35 after printing and drying.

This type of enclosure provides the largest, most effective - · 8 106941 exterior sound insulation and allows virtually complete recovery of the solvent released when the paint dries. Since no one can be inside the enclosure during operation of the machine, the maximum solvent concentration values in the workplace are thus reduced to a minimum so that they can be well below the allowable values.

In the event that a fire 10 occurs inside the housing, which is very easily detected due to the tightly sealed device, it is possible to stop the flowing paper web in the inlet and outlet slots to close these slots in as short a time as possible. gas. In this way, the safety and environmental safety of such devices is substantially increased.

The printing device on the sides of the towers may be provided with a lifting device inside or outside the frame housing, thereby preventing unnecessary racking cylinders from being moved from the printing presses of the tower and, in the next step, transferring new shape cylinders.

Other preferred embodiments of the rotogravure printing apparatus of the invention are set forth in the subclaims.

The invention will now be described with reference to a preferred embodiment of the invention according to the accompanying drawings. Figures 1 shows a highly schematic side elevational view of a rotogravure printing apparatus for two-color printing according to the invention, Figure 2 shows a greatly enlarged detail of the device of Figure 1, 35 Figure 3 shows schematically the bearing of an aperture of the pivot cylinder.

I · »<· 9 106941

The rotogravure printing apparatus 1 shown in the figures serves to reciprocally press the paper web 2, which is fed to the roll support 4 from a paper roll 5 mounted thereon, from which it passes vertically upwardly to three guide screws 6, 7, 8, 7 acts as a tension guide to adjust the paper tension from the roll support 4 to the first printing device 24.

The horizontal portion of the paper web 2 following the guide screws 6, 7, 8 passes through a narrow inlet slot 10 inside the body region which surrounds the entire rotogravure printing device 1 in the form of a casing 12 with the exception of said inlet slot 10 and 13 through which the pre-printed paper web 2 exits the housing 12.

After the gap 13, the printed paper web 2 on both sides passes again from three guide screws 20 systems 14 for adjusting the position of alignment to the next superstructure 15, shown only in the drawing, where it is longitudinally into a product and assembled.

Inside the housing 12, two sets of printing devices 24, 25, 26, 27 and 30, 31, 32, 33 are disposed four over one another on top of the base 18 and the three adjustable mids 19, 20, 21, 24-27 the first group is the primary-side printing in four colors, yellow, red, blue and black, and a second group of 30-33 is toisiopinnan for printing these colors. '

There is a short drying distance 34, 35, 36 and 38, 39, 40, respectively, between each of the two successive printing apparatuses of each of these tower-like printing presses, each of which has an outlet dome 42, 43, 44 and 46, 47, 48 respectively.

The paper web 2 entering through the inlet slot 10 and subsequently horizontally extending is guided down by the guide screw 50 so as to be perpendicular from above to the top printing apparatus 24 of the first light tower, i.e. through all of the printing apparatuses 24-27 herein. through the drying apparatuses 34, 35 and 36 disposed therebetween, vertically downwards so that it is in contact only with the four rack cylinders 55 and associated presses 56. The short drying apparatuses 37-36 are sufficient to dry at least the upper surface of the color used in each printing apparatus 24-26. frustrated in the following printing equipment 25-27.

Also, downstream of the tower's lowest printing device 27, a drying device 58 with its associated exhaust hoods 59 is disposed. These two units are housed in a recess 60 below the housing 18, the interior of which is within the interior of the housing 12. In order to save space, the dryer 58 is disposed horizontally with a guide screw 61 between it and the previous printing device 27, which, as well as the guide screw 62 following the imaging device 58, is on the side of the paper web 2 not yet printed.

With the help of the guide screw 62, the paper web 2 is again turned into a vertical direction. It passes upwardly through a long drying apparatus 65 which extends above the printing apparatus 24, 30 on the upper intermediate plane 21. The paper web exiting the long dryer 65 is pivoted twice by means of three guide screws 67, 68, 69, of which the middle one is movable to adjust the position of alignment, and is moved from above to a secondary printing machine having printing means 30-33 and spaced between them. the short drying apparatuses 38-40 through which it runs in the same manner as previously described in connection with the primary tower, except that the secondary side is now printed in four colors.

5

The first guide screws that are in contact with the primary surface after printing are the lead screws 67 and 68. Since the paper web has then passed through a long drying device 65, this contact is perfectly acceptable since the printed colors on this side have permanently dried.

Below this lowest printing device 33 of the tower is a conductive short drying device 70 of the recess 60 and an associated outlet dome 71. The paper strip 2 is still vertically flowing through this drying device, since the next horizontal rotation guide screw 72 contacts the newly printed secondary surface. After a short horizontal portion, the paper web 2 is again turned by means of a guide screw 74, where it runs vertically 20 upwardly through another long drying device 75 extending approximately to the height of the upper intermediate floor 21. There is an auxiliary guide screw 77 by means of which the paper web 2 is pivoted again in a horizontal direction so that it is led out of the housing 12 through the outlet slot 13.

This description shows that in a single rotogravure printing machine 1 for two-color printing, only nine guide screws are needed between the inlet slot 10 and the outlet slot 13, which corresponds approximately to the number of guide screws required for this rotogravure printing machine in one single printing machine. The total length of the paper at each time in the rotogravure printing apparatus of the invention, i.e. inside the housing 12, is approximately four times the height of the entire apparatus 10, i.e., the distance traveled between the inlet slot 10 and outlet slot 13. Taking into account that the current rotogravure printing machine having eight printing machines requires about twice the length and the paper web has to travel half the height of the machine shown in Fig. 1 to two 5 times the height of the printing machine shown in Figure 1, device at each time to halve the length of the paper in the device.

As shown in Figures 1 and 2, the printing means on the other longitudinal side 10 are "open", whereby the side cylinder can be changed from this side. Figure 1 shows these "open" sides of the weight tower printers 24-27 to the left and the "open" sides of the other weight tower printers 30-33 to the right. In addition, there is a lifting device 80 and 81, respectively, formed from the primary weight 15 tower to the right and the secondary weighting tower, which is here configured to be patranosteroidal, thereby simultaneously removing all unnecessary development cylinders 55 and 20 in the next step. new rack cylinders can be moved simultaneously. This is symbolically marked in Fig. 1 for the upper printing apparatuses 24 and 30 of each of the printing apparatus towers on both bobbin cylinders 55 'which are fed by means 82 and 83 respectively of the lifting device 80 and 81 to the printing apparatus 24 and 25 respectively. 80 and 81 also include two rack cylinders 55 'pre-

V

to indicate their attachment to paternostereleroenters.

30

Fig. 2 shows once again on a heavily enlarged scale the upper printing apparatus 24 of the primary weight tower. This shows very clearly how the rack cylinder 55 sinks into the color basin 85 and on its outward side 35 the blade blade 86 removes excess color. As an exception to the prior art, this squeegee is arranged so down that the envelope line along which the weight of the squeegee is V · 13 106941 over the shape cylinder 55 during the event is lower than the rotation axis 57 of the squeeze cylinder. change.

5

In order to minimize the height at which the ram 55 is to be disassembled and lowered during assembly, as shown in Figure 3, the end 87 of the shaft is preferably mounted on an auxiliary bearing 90 comprising, for example, three bearings 88 10.

On the other hand, for the entire device, it is essential that the printing devices necessary for printing one side of the paper web are arranged so that each other can move from one pair of rack-and-roll presses to the next without requiring a major change of direction. In this manner, sufficient for the plate cylinder and clamps the associated control effect provided by the fully control the paper web at least through all the printing devices that are 20 required for one-side printing. This operation, which results in a substantial reduction in the number of guide screws required, is achieved not only by the tower arrangement shown in the application example, but also when the printing devices are horizontally disposed relative to one another. It is also within the scope of the invention to consider rotogravure printing equipment in which the eight printing equipment required for two-color printing on both sides is divided into four towers, each comprising two stacked printing equipment. The invention is also not limited to double-sided printing, but can be used whenever the paper web is printed by two or more printing devices.

On the other hand, it is of great importance that the removal of the guide screws in the immediate vicinity of the weight gaps, the deeper mounting of the squeegee assembly and the use of auxiliary bearings transverse to the longitudinal direction »· 14 106941 to do very advanced automatically.

The lifting devices 80, 81 may also be arranged from the outside of the frame housing 12, whereby each printing device has a mounting device on the outside of the housing which, during printing, is insulated, for example, by a shutter in the form of a blind. This gives the advantage of having all the rack cylinders needed for the next print run in one weight machine tower in one simple lift to the position while the previous press is still in progress. When this is complete, the shut-off devices are opened, the previously used development cylinders are removed from the printing devices and the housing, and mounted between the standby device. The racking cylinders needed for the next printing operation can then be introduced into the housing and mounted on the printing equipment. The shutter devices are then closed and the next printing event can begin. 20 The time needed to lower the previously used rack cylinders in the preparation unit by means of a lifting device alone to and from the bottom has been won again.

Also, the final drying device 75 may be located outside the frame housing 12.

Alternatively, the drying apparatus 58 located below the primary weight tower as an alternative to the horizontal positioning shown in Fig. 1 may also be formed vertically, as shown in the imaging apparatus 70 following the secondary tower. In this case, the guide screw 61 is positioned after the drying apparatus 58 .35 downward.

Claims (14)

106941 15 An rotogravure printing apparatus in which a web of printable material is imaged to pass through at least two printing presses and one drying apparatus 4 arranged between these printing presses to successively print at least two colors on one side of the paper web, characterized in that at least two printing presses are 2) guided linearly from the previous printing device through the dryer press (34-36; 38-40) to the next printing device from the pile cylinders (55, 55) and presses (56, 56) of both printing presses (24-27; 30-33), and the side being in contact only with the rack cylinders (55, 55). Rotogravure printing device according to claim 1, characterized in that in both printing devices the non-pressed side of the paper web is in contact only with the presses (56, 56). The rotogravure printing device according to claim 1 or 2. characterized in that the weight of equipment for the second side printing for mutual multi-color printing paper web (2), (24-27; 30-33) is structured tominmuotoisesti on top of each other, and 20 of the paper web (2) inside the tower is in contact with only the plate cylinder (55) and presses (56). Rotogravure printing device according to Claim 3, characterized in that, when leaving the paper web (2), each printing device tome is rotated by two guide screws (61, 62; 72, 74) 25 to the horizontal direction and then again to the vertical direction. Rotogravure printing apparatus according to Claim 4, characterized in that the paper web (2) after the second guide screw (62; 74) passes vertically through the drying apparatus (65; 75) without contact, the drying apparatus having a length approximately equal to the height of the printing apparatus. • 6. any one of claims 3-5 rotogravure printing device, characterized in that the paper web (2) direction of motion prior to the secondary side by its own has the reeling device (67, 68, 69) for coarsely adjusting kohdistusaseman, and that the fine adjustment for each plate cylinder 35 (55) to within the printing device occurs by means of a speed changing device of the contacting rack cylinder (55). 16 106941 Rotogravure printing device according to one of the preceding claims, characterized in that each of the two shaft ends (87) of the rack cylinder (55) is mounted on an auxiliary bearing (90). Rotogravure printing device according to one of the preceding claims, characterized in that the squeegee device (86) for the at least one rack cylinder (55) is located so that the jacket line parallel to the rake blade rests on the rack cylinder (55). axis of rotation (57). 10 Rotogravure printing device according to one of Claims 3 to 8, characterized in that a lifting device (80, 81) is provided adjacent to each printing device bar for automatic removal and insertion of the cradle cylinder (55). Rotogravure printing device according to one of Claims 3 to 9, characterized in that both printing presses are housed in a housing-enclosed body (12) whose interior space is in direct contact with the inlet slot (10) and outlet slot (13) required for the printed paper web (2). the surrounding space. 20 11. A rotogravure printing process in which a paper web to be printed is passed through at least two printing presses, whereby two colors are successively printed on the same side of the paper web, and wherein the printing ink is dried in both of the above printing presses . Long time that dry continuous printing on the next printing device is possible, and that the paper web is transferred from the previous printing press to the printing slot on the next printing press so that at least both printing presses have no contact with the printed side of the paper. The rotogravure printing process according to claim 11, characterized in that the paper web is passed through both weight slots completely without contact. The rotogravure printing process according to claim 11 or 12, characterized in that the deep drying occurs only when all the colors have been printed on one side of the paper web. 17 106941 Rotogravure printing process according to one of Claims 11 to 13, characterized in that both sides of the paper web are printed in several colors and the complete through-drying only occurs after passing through the last printing device. 5 10 18 106941