Method and device for the merging of different paper webs

Abstract

The invention relates to a method and device for the merging and finishing of at least two paper webs (1, 2, 3, 4), controlled in the longitudinal register, which are distinctly different in quality and in finishing steps to be undertaken. The device comprises at least two web-specific processing regions (13A, 13B, 13C), a merging unit (21), a common processing region (22), controlled in the longitudinal register and means for the control of the longitudinal register (14), essentially comprising one longitudinal register sensor per paper web. Markings are placed on the paper web with periodic separations. Longitudinal register sensors (14) recognise said markings and transmit signals to the control unit, which determines possible variations and controls the means for regulation of the longitudinal register in such a way that variations in the longitudinal register are compensated. The device further comprises means for setting the web tension of the individual paper webs, with at least two tension-adjusting devices (19A-D, 20A-D) in the course of the paper webs and, on at least one paper web, at least three adjusters, with which the web tension may be adjusted independently of each other in at least two partial regions, defined by the above. The partial regions preferably essentially correspond to the web-specific and the common processing regions. The web tension in the web-specific processing regions can thus be optimally adjusted to match the paper quality and the finishing process requirements.

Description

[0001] The invention relates to a method and a device suitable for carrying out the method and for finishing and merging a plurality of different paper webs controlled in the longitudinal register, according to the precharacterizing clause of claims 1 and 11, respectively.

[0002] In the context of the invention, the “paper web” is understood as meaning any material which is present in web form. A web may consist, for example, of paper or of a film material, for example a plastic material. The paper web may already have been preprocessed. Examples of preprocessing are the printing and coating of individual paper webs or the association of a plurality of individual paper webs to form a new, multilayer paper web.

[0003] In the context of the invention, the “finishing” of a paper web is understood as meaning any form of processing of a paper web, printing, coating or embossing of patterns, folding, perforating or punching, numbering and/or personalization of longitudinal sections of the paper web, creation of address windows and optionally the covering thereof, for example with transparent films, and application of labels, paper or plastic cards or sample packs being mentioned as examples of finishing processes.

[0004] In the context of the invention, the “merging” of individual paper webs is understood as meaning the arrangement, one under the other, of the individual paper webs which have been finished separately and independently of one another. The term “arrangement one under the other” is usually understood here as meaning that the paper webs are brought into direct contact with one another. In particular applications, however, the paper webs may also remain a certain distance apart, but without moving relative to one another. After the merging, the paper webs may pass through a further, common processing region.

[0005] During the finishing of an individual, endless paper web, the web speed must in general be correctly maintained for a synchronization of sequences and for error-free further processing.

[0006] The correct maintenance of the web speed can be achieved by providing, on both sides at the edges of the paper web, register perforations which are engaged by spike belts arranged along the processing or finishing zone and which thus ensure a controllable, synchronous speed. However, the longitudinal registration using register perforations has the disadvantage that the edge provided with the register perforations generally has to be removed in a further, additional processing step. Moreover, the removal of the perforated edge represents the loss of material which is of high quality per se. Finally, the method involving the register perforations on both sides cannot be used if the paper web is to be folded in one of the finishing steps.

[0007] In an alternative method of longitudinal registration, the paper web is provided with markings which are applied to the paper web at regular intervals in the longitudinal direction, advantageously with the exact register of the longitudinal register. These markings are recognized by a web sensor, and further processing of the paper web with exact register is permitted by means of the signals generated by the web sensor, via a corresponding web feed control. The web feed control acts, for example, on the drive of draw rollers which are arranged behind the processing region, viewed in the running direction of the paper web, or has a braking effect on unwinding rollers which are arranged between the rolled or folded stock of the paper web to be finished and the processing region. The disadvantages of register perforations are avoided by the method of longitudinal registration.

[0008] If not just one but a plurality of paper webs are to be finished and then further processed together, a completely different state of affairs is encountered. Such a requirement arises, for example, in newspaper printing.

[0009] In an approach known per se for achieving these objects (WO 95/28345), a method and a device for finishing paper webs independently of one another, merging them accurately, in the longitudinal register and optionally processing them together are proposed. According to this method, the various paper webs are passed from a storage drum via a pair of take-off rollers which serves as a first tension-adjusting unit in web-specific finishing regions, finished there individually and independently of one another, optionally merged via deflection rollers and fed to a common processing region. A draw unit, by means of which a tension substantially identical for all paper webs is established in all paper webs between the take-off rollers and the draw unit in the longitudinal direction of the paper web is arranged in the common processing region, preferably after the web-specific finishing regions and immediately before the common processing region. Preferably, the propellers are formed so that in each case a substantially constant tension prevails over the whole width of the respective paper webs. The draw unit is preferably also in the form of a pair of rubber draw rollers. The common feed velocity of the paper webs and hence the processing speeds are determined by means of the rotational velocity of the draw rollers. Markings which are recognized by web sensors are applied to the paper webs at equal intervals. The take-off rollers are controlled by means of a control unit controlled by the signals of the web sensor. The take-off rollers are substantially braked and thus the web tension prevailing on the web-specific finishing region between the take-off rollers and the tension unit is regulated.

[0010] The difficulties encountered during finishing increase further if paper webs of different quality are to be finished or if individual paper webs are to undergo very different finishing steps. Possible paper webs having substantially differing quality are tissue paper and so-called chemical papers. These are, for example, copying papers which are provided with microscopic capsules which release the ink contained in them when pressure is exerted. Examples of different finishing steps are the punching out of address windows, sticking in of publicity packs or the folding together of essentially broader paper webs in the longitudinal direction to give narrower, unfoldable paper webs. Such different finishing steps may be required, for example, when tying together publicity material for stitching.

[0011] When the proposed solution is used in practice, however, disadvantages are encountered. Particularly when the web tensions of the individual paper webs which prevail in the web-specific finishing region have to be set very differently for an optimal course of the finishing processes, it is observed that individual paper webs “coincide” and/or that they wrinkle in an undesired manner in the common processing region. Consequently, the implementation of the finishing processes is disturbed and/or more waste is produced.

[0012] It is the object of the present invention to eliminate the described disadvantages of this known solution for finishing and merging a plurality of paper webs. In particular, the present invention should make it possible to finish paper webs of very different quality independently of one another, but with exact register, and simultaneously to carry out very different types of finishing processes correctly and reliably, it also being intended to keep the quantity of waste as low as possible. The object is achieved by using a method in which all features of claim 1 are realized or with the use of a device having all features of claims 11 and 12. Advantageous or alternative embodiments are described in the dependent Claims.

[0013] The substantial feature of the achievement according to the invention is that, in the device for merging and finishing with control in the longitudinal register, at least two tension-adjusting units are present in addition to the tension unit mounted after the common finishing region, in at least one web-specific processing region, of which tension-adjusting units a first tension-adjusting unit is arranged before the web-specific processing zone and a second tension-adjusting unit between the first tension-adjusting unit and the merging unit. The web tension prevailing in the paper web between the first and the second tension-adjusting unit—usually along the web-specific processing region—can thus be adjusted substantially independently of the web tension prevailing between the second tension-adjusting unit and the draw unit, in particular in the common finishing region. By decoupling the web tensions in the two partial regions, it is possible on the one hand to adapt the web tension in the web-specific processing region optimally to the requirements of the web-specific finishing process. On the other hand, the web tension in the common processing region can be adjusted to a value substantially agreeing with the web tensions of the other webs, independently of the web-specific finishing step. Thus, for example, undesired wrinkling is avoided.

[0014] Depending on the requirements of the finishing process, further tension-adjusting units may also be included in addition to the first and the second tension-adjusting units and to the draw unit. Thus, more than two partial regions having defined web tensions can be set up. This is advantageous in particular when a paper web has to pass through a plurality of different finishing processes in succession.

[0015] In the partial regions, the web tension is substantially constant, viewed in the running direction of the paper web. The tension-adjusting units are preferably controlled in such a way that the web tension in the running direction of the paper web decreases in a cascade-like manner from partial region to partial region.

[0016] In the common processing region, the web tensions are preferably adjusted to a common, substantially equal value. Behind the draw unit, in particular in the collecting device, the merged paper webs are substantially tension-free.

[0017] In order to achieve the cascade-like, stepwise decrease in the web tension in the running direction, the draw unit must draw the most strongly. The upstream tension-adjusting units are controlled in such a way that they each draw less strongly than the downstream tension-adjusting unit. Alternatively, they may also be controlled in such a way that they have a braking effect, with in each case a greater braking effect compared with the downstream tension-adjusting unit.

[0018] Frequently, the web quality or the web-specific finishing step differs from the substantially equal web qualities or the finishing step of the remaining paper webs only in the case of one paper web. One example each may be mentioned for the two above-mentioned cases: i) the introduction of a particularly thin web of copying paper sensitive to tearing into a stack of paper webs of normal web quality; ii) the merging of paper webs, which in principle are only to be printed on, to give a personalized advertising brochure in which the title page is to have an opening for the address window, the opening being punched out of the paper web. In these cases, it is generally sufficient separately to adjust the web tension only on the paper web differing with respect to web quality or a web-specific finishing step.

[0019] Depending on the type of finishing process, the paper webs are firmly joined together in common processing steps, so that they can no longer be moved relative to one another in the longitudinal direction. For example, they are held together there with staples or in some cases are glued together.

[0020] In yet other finishing processes, it may only be necessary for the paper webs merely to rest against one another, optionally with friction, in the common processing region. It is then tolerable within specific limits to adjust the web tension in each paper web in the common processing region slightly differently but substantially to a value common to all webs. If, however, the paper webs are to be firmly joined together in the common processing region, it is then necessary to adjust the web tensions very accurately to the same value.

[0021] The means for establishing and adjusting the web tension, in particular the first, the second and possible further tension-adjusting units, and the draw unit are advantageously designed in such a way that the web tension remains substantially constant over the total width of the paper web. This is achieved approximately by virtue of the fact that tension-adjusting units and the draw unit are in the form of draw roller pairs, in particular in the form of rubber rollers. In the case of rubber rollers, the pressure is distributed in general more uniformly over the paper web running through the pair of rollers than in the case of known (hard) draw rollers, so that the web tension is adjusted uniformly over the width.

[0022] It is precisely for finished paper webs that the requirement for as good a uniformity as possible of the web tension over the width of the paper web is of substantial importance, in particular so that tearing of the paper web or the occurrence of undesired creases and hence the loss of the finished material is as far as possible avoided. Advantageously, draw rollers, in particular rubber rollers, can therefore also be provided on their circumference with a specific profile adapted to the shape of the surface of the paper web running through. For example, finishing products applied to the paper webs when the paper webs pass through the corresponding pairs of draw rollers can be taken up via suitable passages in the profile so that, in this case too, the pressure is distributed approximately uniformly over the width of the paper web.

[0023] In general, the draw rollers used are cylindrical rollers having a standard circumference of 24″ (60.96 cm). Both cylindrical rollers of the draw roller pair are usually synchronously driven so that the circumferential velocity is the same. The axes of the two cylindrical rollers are exactly aligned with one another and are perpendicular to the paper transport direction. Consequently, the contact pressure exerted by the draw roller pair on the paper webs in between is the same and the paper webs are transported linearly without the slightest angle of wrap. It is evident that, depending on the material or the resilience of the covering of the draw rollers or on the smoothness of the surface of the paper web, the circumferential velocity of the draw roller pairs has to be adapted to the respective thickness of the paper webs transported in between. In particular applications, it may also be advantageous to drive the two draw rollers separately and independently of one another.

[0024] The adjustment of the longitudinal register of a paper web can be effected in principle in two ways. Firstly by virtue of the fact that the travel of the paper web within the web-specific processing region is directly adjustable by means of a longitudinal register adjusting unit. Secondly, by virtue of the fact that the stretching of the paper webs, which is associated with the elasticity of the paper webs and dependent on the web tension, is utilized for moving the markings on the different paper webs relative to one another so that they coincide accurately in the longitudinal register in the common processing region.

[0025] The direct adjustment of the travel has the advantage that the longitudinal register of a paper web can be adjusted directly and independently of the web tension. It is then necessary to ensure that, simultaneously with the change of travel of the paper web, its feed is adapted synchronously with the change in the travel in the partial region located before the longitudinal register adjusting unit.

[0026] In the second possibility for adjusting the longitudinal register with utilization of the elastic stretching of the webs, problems may be encountered if in fact paper webs are printed in a stretched state differing from that in which they are present in the finished product. Unacceptable distortions of the printed image may then result. A remedy for this problem is provided by the digital printing technique. In digital printing, the subsequent distortion of the printed image can be compensated as early as during printing, by deliberately applying the printed image distorted in the opposite direction so that the subsequent distortion due to the changing stretching of the paper web is compensated. Printing is one of the most frequent types of preliminary processing of paper webs to be finished. The combination of the digital printing technique with the technique of stretch-based longitudinal register adjustment, which combination is described here, offers here particular potential for simplification and cost reduction of finishing processes, because preliminary processing of the paper webs can be dispensed with and more economical base paper can be used if all finishing processes required for the finished product can be carried out through integration in one device.

[0027] Preferably, tension-adjusting units are formed by draw roller pairs. The arrangement of further such tension-adjusting units is advantageous particularly when the processing region is particularly long or when a plurality of finishing steps have to be implemented in succession in the processing region in order to adapt the web tension in each partial region for the appropriate processing steps and to reliably maintain the web tension in each partial region.

[0028] Depending on the quality of the paper web, in particular in the case of paper webs having a particularly smooth surface, it is also possible to combine a plurality of draw roller pairs adjusted to the same transport velocity to give a tension-adjusting unit. The purpose of this is to ensure a sufficient frictional connection between the individual paper webs and to press out any existing air bubbles between the paper webs, a problem frequently encountered particularly in the case of multilayer paper webs.

[0029] With a device according to the invention, it is also possible, depending on requirements, for at least one finishing process to consist in the merging of at least two paper webs, even before the merging of all paper webs.

[0030] The invention is now described purely by way of example below with reference to the drawing.

[0031] FIG. 1 shows a partial schematic side view of a first embodiment of a complete device;

[0032] FIG. 2 shows a longitudinal register adjusting unit for the direct adjustment of the longitudinal register;

[0033] FIG. 3 shows a realistic side view of a second embodiment of a complete device;

[0034] FIG. 4 shows a plan view of the second embodiment of a complete device;

[0035] FIG. 5 shows a schematic side view of the first embodiment, with a direction of view perpendicular to that in FIG. 1, and

[0036] FIG. 6 shows a schematic side view of a third embodiment, particularly clearly showing the elements of the control unit.

[0037] The figures are described in relation to one another below.

[0038] FIG. 1 shows a simplified, partially schematic diagram of an embodiment of a device according to the invention, which diagram is not true to scale in all parts. Four paper webs 1, 2, 3 and 4 are unwound, in the direction of view of the observer, in each case from feed units (not shown) and are deflected by means of deflection units (in the drawing, a deflection unit for the third paper web is denoted by 12c) through a right angle to the right in the drawing.

[0039] In the example shown, the deflection units are designed as so-called angle bars 59a, 59b, 59c and 59d. An angle bar is a deflection unit consisting of at least one cylindrical deflection roller, the deflection roller being arranged with its axis of rotation parallel to the plane defined by the paper surface and at an angle of 45° to the running direction of the paper fed in. After passing through the angle bar, the normal to the plane defined by the paper surface has remained unchanged or has inverted (i.e. the paper web was turned “from top to bottom”) but the running direction of the paper web has been deflected through a right angle (90°). A side view of such angle bars 59a, 59b, 59c, 59d, 59e and 59f is shown in FIG. 3 and a plan view in FIG. 4.

[0040] The exact mode of operation of an angle bar is unimportant for the invention. Advantageously, however, such angle bars permit a spatially compact and space-saving design of the entire device, as shown clearly in FIGS. 2 and 3. All paper webs 1 to 6 to be finished are fed from unwinding units 40a to 40f arranged parallel side by side and substantially of the same design (FIG. 4) into digital printing systems 71a to 71f likewise arranged parallel side by side and through [sic] substantially of the same design (FIG. 4) and are printed there and then deflected via angle bars 59a to 59f into the same running direction.

[0041] The angle bar is followed, for each paper web, by a first tension-adjusting unit 19 as a first means for regulating the web tension. By way of example, the first tension-adjusting unit for paper web 4 is denoted by 19d and surrounded by a dashed line by way of example in FIG. 1.

[0042] This preferred embodiment of a tension-adjusting device 19d will now be described with reference to the diagram in FIG. 1. The tension-adjusting device 19d consists of a first deflection roller 81, a variator 82, a pressure roller 83, a tension-measuring roller 84 and an optional second deflection roller 85. The axes of all rollers are aligned parallel to one another. The variator 82 is arranged in the plane of symmetry which belongs to the first deflection roller 81 and to the tension-measuring roller 84. The position of the variator 82 can be changed in the plane of symmetry relative to the first deflection roller 81 and the tension-measuring roller 84 (i.e. upwards or downwards in the diagram of FIG. 1) in the case of a substantially constant angle of wrap of the paper web around the variator 82. Together with the variator 82, the pressure roller 83 forms a pair of rollers; said pressure roller is arranged so as to lock under pressure against the variator 82. The, paper web is wrapped around the tension-measuring roller 84 so that the web tension can be measured on the basis of the force exerted by the tensioned paper web on the tension-measuring roller 84 (in FIG. 1, a force pulling the tension-measuring roller 84 upwards). Expediently, the bearings (not shown) of the axle of the tension-measuring roller 84 are mounted in a force transducer (not shown). The second deflection roller 85 deflects the paper web at the exit of the tension-adjusting device 19d into a desired delivery direction. This function of the second deflection roller 85 is not important for the operation of the arrangement shown as a tension-adjusting unit.

[0043] As shown in FIGS. 1 (and 3), all 4 (and 6, respectively) paper webs run above or below one another when viewed in three dimensions, after passing through the angle bars 59a to 59d (or 59f). However, they have not yet been merged but first pass through web-specific processing regions 10a to 10d still independently of one another.

[0044] The web-specific processing regions 10a to 10d initially include the first tension-adjusting units 19a to 19d already described above and of substantially the same design. These are followed by different web-specific finishing regions 13a to 13d, a second tension-adjusting unit 20a to 20d and means for congruent regulation of the longitudinal registers 14a to 14d. Thereafter, paper webs 1 to 4 are merged in the merging unit 21 and fed to a common processing region 22.

[0045] In the example shown in FIG. 1, the paper web 1 no longer passes through any web-specific finishing process. The paper web 2 is folded along its longitudinal direction in a folding plough 77. The paper web 3 passes through a gluing unit 72. The paper web 4 initially passes through a punching device 73 having a punch waste remover 74, to which a collecting container for punch waste 75 is fastened and then through a dispensing assembly 76 for applying objects, such as, for example, reply cards, sample packs or the like, which are attached by means of the glue nozzle 78.

[0046] In FIG. 1, the common processing region 22 consists of a folding plough 79 which folds the four merged paper webs together in the longitudinal direction, the web sensor 24 and the draw unit 25, which is in the form of a pair of two identical draw rollers pressed against one another and driven so as to rotate against one another.

[0047] The common processing region 22 is followed by a collecting direction [sic] 26 for the finished and merged paper webs. A size cutter 27 is also shown in FIG. 1, as the first element of the collecting device 26. In the plan view of FIG. 4, possible further downstream elements of a collecting device 26, in particular a first rotary size cutter 28, a 90° deflection station 29, a second rotary size cutter 30 and compensating stacking device 31 for the finished products cut to size, are evident in an exemplary embodiment.

[0048] In FIG. 1, for each paper web 1 to 4, the second tension-adjusting unit 20a to 20d substantially comprises a pair of different, cylindrical rollers pressed against one another so as to lock under pressure, namely comprises the thicker, stationary second roller 92 and the thinner pressure roller 93 pressed against the stationary second roller 92.

[0049] In the case of firm pressure locking, i.e. when the paper web cannot slide through the rollers pressed against one another, the velocity of forward travel of the paper web and hence a preferably braking effect defined relative to the draw unit 25 can be achieved via the rotational velocity of the pressure roller 93, and a defined web tension identical for all paper webs can thus be adjusted to the paper web section between and hence in the common processing region 22. Accordingly, a pulling effect and hence likewise a defined web tension can be established relative to the first tension-adjusting unit 19, in particular the pressure roller pair formed from the contact pressure roller 83 and the variator 82.

[0050] The means shown in the example in FIG. 1 for the congruent regulation of the longitudinal register 14 comprise the longitudinal register adjusting unit 15, longitudinal register sensor 16 and the longitudinal register regulating device (not shown). The longitudinal register adjusting unit 15 is advantageously arranged between the end of the web-specific finishing region 13 and immediately before the merging unit 21 and permits a direct adjustment of the travel of the paper web in the web-specific finishing region 13.

[0051] In general, a direct adjustment of the travel of the paper web can be effected, for example, by pressing a deflection roller, which is arranged with its axis perpendicular to the running direction of the paper web, substantially perpendicular to the surface of the paper web, against the paper web so that the angle of wrap of the paper web around the deflection roller changes. If the angle of wrap becomes larger, the travel of the paper web also increases and, viewed in the running direction, its register is set back relative to the register of other paper webs.

[0052] The longitudinal register adjusting unit 15 shown in FIG. 1 includes the movable first roller 91 and the stationary second roller 92. By changing the position of the first roller 91 substantially in the azimuthal direction around the second roller 92, the angle of wrap of the paper web on the second roller 92 and hence the travel of the paper web are changed.

[0053] As shown in FIG. 1, a longitudinal register adjusting unit can particularly advantageously be combined with a tension-adjusting unit to give an arrangement consisting of only three rollers. FIG. 1 shows the combination of the longitudinal register adjusting unit 15 with the second tension-adjusting unit 20 to give an arrangement consisting of only three rollers, namely the movable first roller 91, the stationary second roller 92 and the pressure roller 93.

[0054] As an alternative to the first embodiment of a longitudinal register adjusting unit 15, consisting of the rollers 91 and 92, the longitudinal register can, for example, also be adjusted directly, with a second embodiment shown in FIG. 2 and consisting of three rollers. A stationary entry roller 97 deflects the direction of the paper web 1 running into the arrangement into a specific first running direction denoted by adjusting direction 102. A deflection roller 98 arranged displaceably in the adjusting direction 102 deflects the running direction of the paper web out of the adjusting direction 102 into the exactly opposite direction 103. Finally, the likewise stationary exit roller 99 deflects the paper web 1 in a freely selectable, wide range 101 of delivery angles. The infeed angle of the paper web 1 is also freely selectable in a wide range. What is important is that the angle of wrap of the paper web around the deflection roller 98 is exactly 180°. This condition can be easily fulfilled by a suitable choice of the relative arrangement of the entry roller 97 and of the exit roller 99 relative to the deflection roller 98. The position of the deflection roller 98 can be moved along the adjusting direction 102. If the deflection roller 98 is moved by a certain distance &Dgr;x towards the entry roller 97 or exit roller 99 (or away from it), the travel of the paper web is shortened (lengthened) by exactly twice the distance 2&Dgr;x. This makes it particularly easy to calibrate the adjustment of the longitudinal register accurately for each region.

[0055] FIG. 3 shows a side view of a complete device according to the invention for finishing and merging six paper webs 1 to 6, which side view is true to scale and is technically detailed in particular in the region of the deflection units realized by angle bars 59a to 59f and in the region of the merging unit. The paper webs are dispensed, as in FIG. 1, in the direction of view of the observer, from feed units (not shown), printed in digital printing systems (not shown) and introduced into the device shown via the angle bars 59a to 59f after deflection to the right. After passing through the angle bars, the paper webs, viewed in three dimensions, run above or below one another but have not yet been merged in the context of the invention. On the right in FIG. 3, adjacent to each of the angle bars 59a to 59f of identical design, a web-specific processing region comprising the following finishing stations begins for each paper web 1 to 6 with the first tension-adjusting units 19a to 19f likewise of identical design: the paper webs 1 and 2 run without a further finishing step directly into the combination, already described further above with reference to FIG. 1, of longitudinal register adjusting units 15a and 15b, and second tension-adjusting units 20a and 20b, before they travel past the longitudinal register sensors 16a and 16b into the merging unit 21. The paper web 3 first passes through a folding plough 77, the paper web 4 passes through a gluing unit 72 and the paper web 5 passes through a punching device 73. The paper web 6 passes through a dispensing assembly 76, is then coated with glue by the glue nozzle 78 and is glued to the paper web 5 to become paper web 5′. The paper webs 3, 4 and 5′ then run, in each case still separately, into a combination of longitudinal register adjusting unit 15c to 15e and second tension-adjusting unit 20c to 20e. The paper webs 3 and 4 then also run past the longitudinal register sensors 16c and 16d before they too, together with paper web 5, reach the merging unit 21 and are merged.

[0056] The longitudinal register sensors 16a to 16d detect the markings applied at regular intervals to each of the paper webs 1 to 4 running past and in each case transmit a signal to the control unit (not shown) of the device. On the basis of the time sequence of the arrival of the signals, the control unit checks whether the longitudinal registers of the individual paper webs 1 to 4 are congruent with one another and detects a possible deviation for each paper web 1 to 4. If a deviation is detected for one of the paper webs 1 to 4, a control signal is transmitted to the corresponding longitudinal register adjusting unit 15a to 15d for each paper web running with deviating register, via a coordinated longitudinal register regulating device (not shown), in order to correct the deviation.

[0057] The web sensor 24 mounted immediately before the draw unit 25 detects the markings which are applied to the paper web 5′ lying above the other paper webs in the region of the merging unit 21 and the downstream common processing region, and transmits appropriate signals to the control unit. With the aid of the signals generated by the web sensor 24, the control unit recognizes the common running velocity of the merged paper web and can adjust the absolute running velocity by means of a regulating device controlling the draw unit. Moreover, a possible deviation of the longitudinal register of the paper web 5′ from the longitudinal registers of the paper webs 1 to 4 can be determined from a comparison of the time sequence of the arrival of the signals from the web sensor 24 with the sequence of the signals generated by the longitudinal register sensors 16a to 16d and can be corrected by controlling the longitudinal register adjusting unit 15e coordinated with the paper web 5′.

[0058] As shown in FIG. 3, the merging unit 21 advantageously has, at least for each of the infed paper webs 1 to 5′, a deflection roller 94a to 94e and a guide roller 95a to 95e. The axis of rotation of all deflection rollers 94a to 94e are arranged in a plane, with the result that, after running around the deflection rollers 94a to 94e, the paper webs 1 to 5′ are adjacent to one another. Each of the deflection rollers is supported by a force transducer with which the web tension of the relevant paper web is measured.

[0059] In FIG. 3, in the common processing region, the merged paper webs pass through a final folding plough 79, the draw unit 25, a size cutter and further assemblies (not shown in FIG. 3 but shown in plan view in FIG. 4), in particular a first rotary cutter 28, a 90° deflection station 29 and a second size cutter 30. The individual finished products of the finishing process which have been cut to size from the merged, endless paper web are finally stacked one on top of the other in a compensating stacking device 31.

[0060] An overall view of the arrangement and mounting of the functional elements of the device shows a modular design of the device. It is therefore possible with relatively little effort to expand the device for the simultaneous finishing of further paper webs by adding the appropriate additionally required elements, or to adapt or convert the device for other applications by replacement of individual elements, in particular of finishing assemblies.

[0061] FIG. 4 shows a plan view of the same device which is shown in side view in FIG. 3. This view once again clearly illustrates the modular design of the entire device.

[0062] The parallel arrangement of the six feed units for the six paper webs 1 to 6 is clearly evident. Specifically, each of the feed units 10a to 10f comprises an unwinding unit 40a to 40f, to which in particular the unwinding devices 41a to 41f in FIG. 4 with storage drums 42a to 42f, and the web guiding device 49a to 49f, belong. Each paper web 1 to 6 passes through a digital printing system 71a to 71f as a first finishing step. The paper webs 1 to 6 then pass through the angle bars 59a to 59f clearly recognizable from above and, viewed in three dimensions, run above or below one another in the following regions so that, in this view, those elements of the web-specific finishing regions which are shown in FIG. 3 are not recognizable. However, the processing assemblies of the common processing region are once again clearly evident from above. In the sequence of passage of the merged paper web, these include specifically: the final folding plough 79, the draw unit 25, the size cutter 27, the first rotary cutter 28, the 90° deflection station 29, the second size cutter 30 and the compensating stacking device 31 which stacks the cut finished products one on top of the other.

[0063] FIG. 5 shows a detailed side view of an individual feed unit as provided for each paper web in the device shown in FIGS. 3 and 4. In particular, the unwinding device 41 having, inter alia, the storage drum 42 and the web guiding device 49 is clearly detectable in the unwinding unit 40, and, in the further course of the paper web, the digital printing system 71 is clearly evident.

[0064] The diagram showing the arrangement of the elements of the feed unit serves merely to complete the description of a preferred embodiment of the device according to the invention. However, the details are not important for the present invention; no further description will therefore be given here.

[0065] Usually, a stock of a paper web to be finished is present wound up into a roll. However, in another embodiment of a feed unit which is not shown, it is also conceivable for a paper web to be present folded into longitudinal sections. In this case, the folds on the paper web are advantageously made synchronous with a possible side register and arranged in such a way that they adversely affect the appearance of the paper web as little as possible.

[0066] The invention was described above by way of example with reference to specific, preferred embodiments. Various changes and modifications are obvious to a person skilled in the art on reading the description. It is intended that all these changes and modifications be regarded as being covered by the invention and thus belonging to the scope of the following Patent Claims.

Claims

1. Method for the merging and finishing of at least two paper webs controlled in the longitudinal register, in which each paper web is provided with markings applied at periodic intervals, and in which the individual paper webs pass through web-specific processing regions which comprise a feed unit, an optional deflection unit and a web-specific finishing region, are then merged in a merging unit and then also pass through a common processing region which is controlled in the longitudinal register and in which the paper webs are optionally processed in a common finishing region which is controlled in the longitudinal register and in which an optional web sensor measures the web velocity and in which the paper webs are drawn by a draw unit and are collected in a collecting device, the web tension of the paper webs being adjusted by means for regulating the web tension, which include a first tension-adjusting unit arranged before the web-specific finishing region and the draw unit, and the longitudinal register being adjusted by means for the congruent regulation of the longitudinal register, which include a longitudinal register sensor, characterized in that, for at least one paper web, the means for regulating the web tension additionally comprise at least one second tension-adjusting unit which is arranged after the web-specific finishing region and before the merging unit and by means of which the web tension prevailing between the first and second web-adjusting unit and the web tension prevailing between the second tension-adjusting unit and the draw unit are adjusted substantially independently of one another.

2. Method according to claim 1, characterized in that the web tension of the paper web in each partial region formed by a pair of tension-adjusting units and in the partial region between the last tension-adjusting unit in the running direction and the draw unit formed partial region [sic] is adjusted to a defined, substantially constant value.

3. Method according to claim 1 or 2, characterized in that the web tension in the running direction of the paper web decreases in a cascade-like manner from partial region to partial region.

4. Method according to any of claims 1 to 3, characterized in that, for each paper web, the web tension prevailing between the last tension-adjusting unit in the running direction of the paper web and the draw unit is adjusted to a common value substantially equal for all paper webs.

5. Method according to any of claims 1 to 4, characterized in that the means for adjusting the web tension and the draw unit are formed in such a way that the resulting web tension has a substantially constant value over the width of the paper web.

6. Method according to any of claims 1 to 5, characterized in that, for at least one paper web, the longitudinal register is adjusted substantially independently of the web tension.

7. Method according to any of claims 1 to 6, characterized in that at least one paper web is kept under tension up to the last tension-adjusting unit in the running direction.

8. Method according to any of claims 1 to 7, characterized in that, for at least one paper web, the means for adjusting the longitudinal register comprise an optional longitudinal register adjusting unit and a longitudinal register regulating device.

9. Method according to any of claims 1 to 8, characterized in that, in at least one web-specific processing region, the longitudinal register is adjusted via the adjustment of the web tension by means of the first tension-adjusting unit, utilizing the web stretch associated with the elasticity of the web.

10. Method according to any of claims 1 to 9, characterized in that, in at least one web-specific processing region, the longitudinal register is adjusted by means of the longitudinal register adjusting unit by changing the travel of the paper web within the web-specific processing region.

11. Device for the merging and finishing of at least two paper webs controlled in the longitudinal register, consisting of at least two web-specific processing regions which in turn comprise a feed unit, an optional deflection unit and a web-specific finishing region; a merging unit; a common processing region which is controlled in the longitudinal register and in turn comprises an optional common finishing region controlled in the longitudinal register, an optional web sensor and a draw unit; a collecting device and a control unit; each paper web being provided with markings applied at periodic intervals; which apparatus furthermore comprises means for regulating the web tension, which include a first tension-adjusting unit arranged before the web-specific finishing region and the draw unit; and means for regulating the longitudinal register, which comprise a longitudinal register sensor; characterized in that, for at least one paper web, the means for regulating the web tension additionally comprise a second tension-adjusting unit which is arranged after the web-specific finishing region and before the merging unit.

12. Device according to claim 11, characterized in that, for each paper web, the means for regulating the web tension additionally comprise at least one second tension-adjusting unit which is arranged after the web-specific finishing region and before the merging unit.

13. Device according to claim 11 or 12, characterized in that, for each paper web, the first tension-adjusting unit is arranged immediately before the web-specific finishing region.

14. Device according to any of claims 11 to 13, characterized in that, for at least one web-specific processing region, the means for regulating the longitudinal register additionally comprise a further longitudinal register adjusting unit and a longitudinal register regulating device.

15. Device according to claim 14, characterized in that, for at least one web-specific processing region, the means for regulating the longitudinal register permit the longitudinal register of the paper web to be adjusted independently of the web tension.

16. Device according to any of claims 11 to 15, characterized in that at least two different processing stations belong to at least one web-specific finishing region.

17. Device according to claim 16, characterized in that at least one additional tension-adjusting unit is arranged between at least two processing stations.

18. Device according to any of claims 11 to 17, characterized in that, within at least one web-specific processing region, at least one processing station serves for merging a paper web with another paper web.

19. Device according to any of claims 11 to 18, characterized in that the elements of the device each have a modular design so that the entire device can be reconfigured or expanded with little effort by removing or adding individual elements.

20. Device according to any of claims 11 to 19, characterized in that the draw unit is arranged immediately after the finishing region controlled in the longitudinal register and before the collecting device.

21. Device according to any of claims 11 to 20, characterized in that the means for regulating the web tension is formed in such a way that the web tension is substantially constant over the web width.

22. Device according to claim 21, characterized in that at least one tension-adjusting unit and/or the draw unit consists of a pair of draw rollers.

23. Device according to claim 22, characterized in that at least one pair of draw rollers is a pair of rubber rollers.

24. Device according to either of claims 22 and 23, characterized in that the pairs of draw rollers are provided on their circumference with a profile for holding the corresponding finishing products.

25. Device according to any of claims 22 to 24, characterized in that the axes of the pairs of draw rollers are aligned with one another and are arranged in a plane perpendicular to the running direction of the paper web.

26. Device according to any of claims 11 to 25, characterized in that the tension-adjusting units can be controlled independently of one another by the control unit.

27. Device according to any of claims 11 to 26, characterized in that the feed unit 10 is an unwinding unit 40 which consists at least of a storage drum 42 and a pair of take-off rollers and in which the paper web is wound onto a storage drum 42.

28. Device according to claim 27, characterized in that the pair of take-off rollers consists of the storage drum 42 itself and a take-off roller which is arranged in such a way that it is pressed against the uppermost layer of the paper web wound on the storage drum 42.

29. Device according to claim 27, characterized in that the unwinding unit 40 consists at least of a storage drum 42, a take-off roller pressed against it and a pair of draw rollers.

30. Device according to any of claims 11 to 26, characterized in that the feed unit is an unfolding unit which consists at least of a storage container and a speed-controlled pair of drive rollers and in which the paper web is present in the folded state in the storage container.

31. Device according to any of claims 11 to 30, characterized in that the collecting device consists of at least one collecting roller.

32. Device according to any of claims 11 to 30, characterized in that the collecting device consists of a size cutter, a stacking device, an optional counting device and an optional packing or banding device.

33. Device according to any of claims 11 to 32, characterized in that the optional deflection unit 12 is arranged between the feed unit 11 and the beginning of the web-specific finishing region 13.

34. Device according to any of claims 11 to 32, characterized in that the optional deflection unit 12 is arranged between the end of the web-specific finishing region 13 and the merging unit 21.

35. Device according to any of claims 1 to 24, characterized in that the optional deflection unit 12 is an angle bar 59.

36. Device according to any of claims 11 to 35, characterized in that, in at least one web-specific processing region 13, the longitudinal register is adjusted via the adjustment of the web tension by means of the first tension-adjusting unit 19, utilizing the web stretch associated with the elasticity of the web.

37. Device according to any of claims 11 to 35, characterized in that, in at least one web-specific processing region 13, the longitudinal register can be adjusted by means of the longitudinal register adjusting unit 15 by changing the travel of the paper web within the web-specific processing region 13.

38. Device according to claim 37, characterized in that the longitudinal register adjusting unit 15 is arranged between the end of the web-specific finishing region 13 and the merging unit 21.

39. Device according to claim 37 or 38, characterized in that the longitudinal register adjusting unit 15 is in the form of a pair of rollers, comprising a movable first roller 91 and a stationary second roller 92, in which the angle of wrap of the paper web on the second roller 92 can be adjusted by changing the position of the first roller 91 substantially in the azimuthal direction around the second roller 92.

40. Device according to any of claims 11 to 39, characterized in that at least one tension-adjusting unit 20 comprises a pressure roller 93 and a second roller 92 as a mating roller, the pressure roller 93 being driven at a regulatable rotational velocity and being arranged so as to lock under pressure against the second roller 92.

41. Device according to any of claims 11 to 40, characterized in that at least one longitudinal register adjusting unit 15 is combined with a tension-adjusting unit 20 to give one unit.

42. Device according to claims 40 and 41, characterized in that the pressure roller 93 of the tension-adjusting unit is arranged so as to lock under pressure against one of the two rollers 91, 92 of the longitudinal register adjusting unit 15, preferably against the stationary second roller 92.

43. Device according to any of claims 11 to 42, characterized in that, in at least one web-specific processing region, a first tension-adjusting unit 19 substantially comprises a first deflection roller 81, a variator 82, a contact pressure roller 83, a tension-measuring roller 84 and an optional second deflection roller 85, the axes of all rollers being aligned parallel to one another, the variator 82 lying in the plane of symmetry belonging to the first deflection roller 81 and to the tension-measuring roller 84, it being possible for the position of the variator 82 in the plane of symmetry to be changed relative to the first deflection roller 81 and the tension-measuring roller 84 with constant angle of wrap, the contact pressure roller 83 being arranged so as to lock under pressure against the variator 82, the paper web being wrapped around the tension-measuring roller 84 and the web tension being measured via the force exerted by the tensioned paper web on the tension-measuring roller 84, and the optional second deflection roller 85 deflecting the paper web into a desired delivery direction.

44. Device according to any of claims 11 to 43, characterized in that, depending on the number of paper webs to be merged, the merging unit 21 comprises at least two deflection rollers 94 which are arranged in a plane so that the axes of the deflection rollers 94 are parallel and that the running direction of the paper web after release by the deflection rollers 94 is parallel to said plane.

45. Device according to any of claims 11 to 44, characterized in that the web tension prevailing between the second tension-adjusting unit and the merging unit is measured by means of the tractive force of the paper web which acts on the deflection rollers 94 of the merging unit 21.

46. Device according to any of claims 11 to 45, characterized in that the longitudinal register sensors 16 are arranged immediately before the merging unit 21.

47. Device according to any of claims 11 to 46, characterized in that, in at least one web-specific processing region, a digital printing technique is used as a finishing process.