EP2314533B1 - Method for making a printed product - Google Patents

Abstract

The method involves cutting crosswise to a longitudinal direction of a printed paper web (1) to produce a cut-off section. The cut-off section has a length based on multiple lengths of a finished printed product (7). The cut-off section is folded in a crosswise direction in a location based on the length of the finished product using a folding unit (4). The folded cut-off section is cut in the longitudinal direction to form a partial web (5a) of the paper web having a width corresponding to the width of the finished printed product.

Description

Technical area

The invention relates to a method for producing a printed product according to the preamble of claims 1 or 2.

State of the art

From the EP-A2 2075 208 a method has become known which is operated as single sheet processing. In this method, the printed paper web, according to the predetermined format of the printed product, longitudinally cut into webs and then transversely into individual sheets. Each web contains all pages of a printed product in sequential order. The belonging to a printed product single sheets are stacked on each other and then fed, for example, a binding process. In this method, it has been found that the system tends to large susceptibility, which are essentially related to the mechanical compliance of the paper. It has also been found in this method on the occasion of transporting and stacking the individual sheets that the initial susceptibility to increase in web speed due to the properties of the paper then even increase, resulting in that susceptibility to the exact alignment of the paper Transfer single sheets in the stack. If such a 100 percent alignment is missing, ie if individual sheets in the stack are not perpendicular to one another, they can hardly be aligned later, and this inevitably leads to a high amount of paper waste. It should be emphasized that basically only a single non-perpendicular aligned sheet in the stack is sufficient to leave the whole stack as waste.

In order to remedy this, it has been variously tried to improve transport and stacking with additional auxiliary arrangements, which made the system but unnecessarily involved. In some cases, one even started to reduce the web speed of the printed paper in order to minimize the transverse forces acting on the printed product during transport and stacking, which in turn did not lead to the expected results, except that this was a result of a reduction in production ,

Presentation of the invention

Here now the invention wants to remedy. The invention, as characterized in the claims, the object is to propose provisions in a method of the type mentioned above, which are able to eliminate the disadvantages of the known methods. The object hereof must be seen in the context of the growing demands on the operation of modern digital printing machines which seek to maximize both the paper web width and the web speed of the printed paper to meet the economic requirements.

According to the invention, this object is achieved by dividing the paper web into a variable number of printing-specific partial webs according to a first format extent of the finished product, each of these partial webs being printed sequentially with all sides of a printed product. Subsequent to the printing phase, the paper web is continuously separated in the transverse direction, such that the respective section length is a multiple of a second format extent of the finished printed product. These partial webs, individually or in association with each other, are then transversely folded at least once, and then cut in the longitudinal direction of the paper web, corresponding to the width of the printed product, whereby it is also possible to perform the folding after the formation of the partial webs.

A significant advantage of the invention is the fact that the rigidity of such products is increased or maximized by the measures mentioned. The rigidity itself is a measure of the resistance of a body to deformation by a force. This stiffness is heavily dependent on the material thickness of the body. Especially with printed products, this material thickness is due to the minimal mechanical resistance of the Material (paper) is the decisive property for the formation of an operationally suitable degree of rigidity.

Thus, if a plurality of layers stacked on top of each other result from one or more folds of the printed sheet, the resistance moment of such a folded body inevitably increases.

Since the determination of the resistance coefficient of a body whose height squared in the W formula flows, it follows that even by a simple first fold the moment of resistance, which induces the stiffness against bending, theoretically increases by a factor of four, here a small reduction This factor is to be expected because the individual superimposed leaves do not form a body-splitting connection with each other.

In contrast, in our case, however, comes into play that the layers at each assignment have a peripheral contiguous fold, on the one hand, the primary stiffness is greater, and on the other hand forms a greater resistance to Querallenfalls torsional forces.

Since these forces can occur again and again on the body in the case of transport designed for high performance and the subsequent stacking of printed sheets, it is important to remedy this. These forces acting on transport and stacking are also related to the system having acceleration phases and intertemporal delays, so that even a first fold advantageously acts by resulting in a substantial reduction in the compliance of a body thus formed.

Seen in this way, one obtains a smooth multiplication of the resulting stiffness compared to a simple unfolded sheet for transport and stacking of such a single or multiple folded sheet, which is crucial, because in itself the material-related resistance of the sheet is usually classified as minimal.

Thus, if the compliance is minimized, the secure positioning of the body increases after a translational transport movement, then also increases the resistance to slipping of the folded sheet within the stack, thus proving his once assumed position stable. Compared to a loose sheet thus has a single or multiply folded printed sheet same end surface a corresponding several times greater stiffness, which proves advantageous in terms of positional stability on transport and stacking.

Another advantage of the invention is the fact that the sheet with each Querfalzung experiences an increase in stiffness, since in such an operation, the width of the web portion remains untouched, and only with each fold, a reduction of the resulting surface while doubling the mass he follows.

As the stiffness moment increases, the counterforce of the sheet formed body also increases in proportion to its mass due to gravitational force, which also leads to an increase in its holding power, especially when these folded sheets are stacked together in a composite.

This makes it possible to achieve that the stacking formed by the folded printed sheets is characterized by a strong inner surface tension force, which ensures that the printed sheets within the stack remain perpendicular during the entire process. Diving during transport and stacking of such sheets interfering transverse forces, these assets no inner slippage of single sheets more trigger, whereby the compactness of such stacks is guaranteed, so maculatures no longer form an issue.

Another significant advantage of the invention is the fact that the processing speed of the digitized printing process can be significantly increased by the folds of the sheet. At constant web speed reduces the clock frequency of the sheet to be stacked by a factor of 2 per fold.

Another significant advantage of the invention is the fact that the fold (s) of the sheet, as already briefly mentioned above, can generally take place before or after at least one separation operation, which ensures a high flexibility in production, with in this separation operation to It is different, whether it is longitudinal or cross sections. Furthermore, it is to be distinguished for the essence of the invention, whether it is a single or double or multiple fold.

A first embodiment according to the invention consists in first making one or more folds over the entire width of the printed paper web; subsequently After folding (s) the individual sheets are separated to a certain width in the longitudinal direction of the paper web and then fed to a respective stack. Thus, if the width of the paper web, for example, divided into four longitudinal paper webs, then four parallel stacks are also provided.

A further embodiment according to the invention consists in first of all separating the partial webs in the longitudinal direction of the paper web, before the folds occur, i. the folding takes place here transversely to the separating cuts already made in the longitudinal direction of the paper web and relates to a number of printed sheets which corresponds to the number of partial webs created in advance.

If a double or multiple folding is used as the basis, then a combination of four two-sided, resp. eight two-sided printed pages. Regardless, the separating cuts in the longitudinal direction of the paper web can also be made here before or after the folds, analogous to the above explanations in a simple fold.

The advantage of the invention is further to be seen in the fact that both in the previously carried out separating cuts in the longitudinal direction of the paper web, as well as in the made after the folding or folds separating operations, a prior Querperforierung the paper web can be made, and that this perforation with the respective subsequent folding plane coincides. Thus, a fold can be produced, which is extremely flat, which is not to fear a bead-like Auftürmung the fold edges, because just such a one-sided accumulated bead-like Auftürmung a border zone would prove to be extremely negative for the further processing of the book block.

Advantageous and expedient developments of the inventive task solution are characterized in the further dependent claims.

In the following, embodiments of the invention will be explained in more detail with reference to the drawing. All features that are immaterial to the instant understanding of the invention have been omitted. Identical features are provided in the various figures with the same reference numerals.

Brief description of the figures

Fig. 1

eine sequentiell bedruckte Papierbahn, mit einer einfach gehaltenen Falzung und mit einem anschliessenden Trennschnitt in Längsrichtung und Stapelung der gefalz- ten Druckbogen;

Fig. 2

eine sequentiell bedruckte Papierbahn, mit einer zweifachen Falzung und anschliessender und Stapelung der gefalzten Druckbogen;

Fig. 3

eine sequentiell bedruckte Papierbahn mit einer einfach gehaltenen Falzung, wobei der längs der Papierbahn durchgeführte Trennschnitt vorgängig der Falzung stattfin- det und

Fig. 4

eine sequentiell bedruckte Papierbahn mit einer zweifachen Falzung, wobei der längs der Papierbahn durchgeführte Trennschnitt vorgängig der Falzung stattfindet.

It shows:

Fig. 1

a sequentially printed paper web, with a simply held fold and with a subsequent separating cut in the longitudinal direction and stacking of the folded printed sheets;

Fig. 2

a sequentially printed paper web, with a double fold and subsequent and stacking of the folded sheet;

Fig. 3

a sequentially printed paper web with a simply held fold, whereby the separating cut carried out along the paper web takes place in advance of the fold, and

Fig. 4

a sequentially printed paper web with a double fold, whereby the separating cut carried out along the paper web takes place before the fold.

Ways to carry out the invention, industrial usability

Fig. 1 shows a sequentially printed paper web 1, which is preferably printed on both sides. This paper web 1 is transferred in operative connection with a deflection roller 2 from a horizontal to a vertical path. As such, this 90 ° deflection shown here is not systemically relevant; Any other guidance of the paper web underlying the space is also possible, and in principle, a deflection is not necessarily provided, as for example Fig. 2 evident. In the FIG. 1 shows that after the deflection of a preferably motor-driven cutting roller 3 is in use, which cuts off a certain length of the paper web 1 transverse to its longitudinal direction. This length is determined so that in the subsequent folding by a folding blade 4 folding the sheet undergoes a single-acting folding. Subsequently, the folded printed sheet 5 is divided by cutting devices 6 or cutting modules into several partial webs AD. In these separating cuts, it is advantageous for the cutting stability of the individual partial webs if the individual cutting elements 13a are not simultaneously in use along a progressive cutting plane. Such a cut-away in the cutting direction cutting technology goes out Fig. 1 (See also Fig. 2-4 ). Then be the individual sheets AD individually stacked and palletized, which then individual book blocks 7 are present, which can be fed to further processing. Thus, four pages of a book block are created with a simple fold. Such folding substantially increases the degree of stiffness of the folded signature, based on the realization that rigidity itself is a measure of the resistance of a body to deformation by a force. This rigidity is weight dependent on the cross section of the body. Especially in the case of printed products, the moment of resistance due to the thin layer of the sheet and its material (paper) is the decisive factor for the formation of a degree of rigidity suitable for transport and stacking. With each reduction of the material-moderate predetermined compliance with the sheet immediately increases the safe transportability of such a body, which then also its stacking can be positionally stable. If all printed sheets belonging to a book block can be neatly and mutually stacked, the further processing of such book blocks is qualitatively secured, otherwise expensive remedy measures would have to be made, but their success is not considered certain, because the reprints resp. Engaging individual non-perpendicularly arranged sheets into the stack is virtually impossible, which then, on a qualitative basis, must regularly lead to the rejection of such a book block.

Then it is not the case that a reduction of the production cadence would have to be accepted by the fold: Since it is possible to work here with a wide paper web, it is readily possible to provide four or more partial webs, each of which is assigned to a book block , Thus, with such a system, a large increase in productivity compared to the production and stacking of individual non-folded printed sheets can be achieved, even at a constant printing speed of the system.

Fig. 2 is different too Fig. 1 in that here is based on a double fold, and moreover, before the first fold is a perforating roller 8 in use, which performs a dual function. On the one hand, a perforation is thus made transversely to the paper web; then at the next cycle, the same roller then acts as a cutting mechanism, for example as a cutting blade. The cut length of a printing sheet 9 thus has centrally in the drawing not shown in more detail perforation, which preferably then forms the plane of the first performed by a folding blade 4 fold. After this first folding of the sheet is fed to another station 10, where a second folding blade 11 is used for the second fold.

This gives a printed sheet which is now printed eight times, and finally, after the separation cut in the longitudinal direction of the paper web, which analogous to Fig. 1 It now appears that the stiffness is a multiple of what can be achieved in a simple folding. Thus, the compliance of such a body is minimized so much that both transport and stacking can be maximized in position and position. Of course, the system can be extended to three folds, which would then have the single sheet sixteen printed pages. The provision that the first fold lies in the plane of the perforation has a double positive effect. On the one hand, the fold can be attached there more easily because the resistance in this plane has become smaller due to the perforation, in which case the fold plane is already predetermined, which means a strong position specification for this operation. On the other hand forms in the region of the back of the fold a shallower transition of the two folded sides to each other. This proves to be advantageous in the stacking, as the book block does not tend to a bulge in the edges, which could be very hindering for further processing.

Related to a simple fold corresponds Fig. 3 the already described procedures in Fig. 1 , with the essential difference that here the separation cut 13 made along the paper web is carried out to form individual signature lengths before the actual folding operation 14. This means that during the folding operation 14 there are already individual cut printed sheets 15, which then have transport in a proven manner be stacked to book block 12. At the rigidity of the individual sheet 15 nothing changes here. The achievable by the folding stiffness remains therefore also here. Significant differences in positional stability during transport and stacking are opposite Fig. 1 not make out.

The same can be said with regard to Fig. 4 say. For one, this corresponds Fig. 4 As regards the perforation, the separation across the web and the double fold, according to the procedures Fig. 2 , As regards the longitudinally matched to the paper web formation of the individual sheet lengths 16, the separation section along the paper web with cutting means 13 before the first perforation resp. Dividing cut made in the transverse direction to the paper web.

Concerning the physical considerations regarding the increase of the stiffness of the printing sheet in one or more folds, reference is made to the explanations under the chapter "Presentation of the invention".

Furthermore, it should be noted in all embodiments that at least one fold can be done off-center, whereby a so-called pre-or Nachfalz arises, which is advantageous if such a sheet is supplemented in the course of further processing with deposits of other printed products, as the pros or Nachfalz forms a unique reference surface for the respective spreading device.

As already mentioned, not only one or two folds can be made, but also three or more can be provided. If initially a higher number of folds is provided, this can be continuously increased or decreased in the course of the formation of a book block. In particular, at a higher contiguous fold, which is reflected on the number of pages of the book block (with 3 folds would then receive a printed product of 16 pages), can be moved to a deeper fold number in the final phase, so that unnecessarily empty pages become part of the Buck block ,

Claims (10)

1. Method for producing a printed product by means of a digital method, in which the entire content of the printed product is printed in sequential succession along a paper web, the printed paper web then being further processed to produce a printed product, the paper web being printed on one side or both sides and the width of the paper web being used as the basis of at least a first format extent (X) with respect to the finished printed product, characterised in that, by means of a first cutting operation transverse to the longitudinal direction of the paper web (1), a section length (9) amounting to a multiple of a second format extent (Y) of the finished printed product (7) is formed, in that the section length (9) is folded transversely at least once by means of folding means (4) and in that, by means of at least one cutting operation performed on the thus folded printed product in the longitudinal direction of the paper web (1), at least one partial web (5a) having a width corresponding to the first format extent (X) of the finished printed product (7) is formed.
2. Method for producing a printed product by means of a digital method, in which the entire content of the printed product is printed in sequential succession along a paper web, the printed paper web then being further processed to produce a printed product, the paper web being printed on one side or both sides and the width of the paper web being used as the basis of at least a first format extent (X) with respect to the finished printed product, characterised in that, by means of at least one first cutting operation in the longitudinal direction of the paper web (1), at least one partial web (16) is formed in correspondence to the width of the first format extent (X) of the finished printed product (7), in that, by means of a second cutting operation transverse to the longitudinal direction of the paper web, a section length of the partial web having a length amounting to a multiple of a second format extent (Y) of the finished printed product (7) is formed, and in that the partial web (16) is folded transversely at least once in correspondence to the second format extent (Y).
3. Method according to Claim 1 or 2, characterised in that the second format extent (Y) is folded twice or multiple times transversely to the longitudinal direction of the paper web (1), and in that two and more partial webs (5a, 16) disposed parallel to one another are formed in the longitudinal direction of the paper web (1).
4. Method according to Claim 1 or 2, characterised in that, in the course of the formation of a book block (7), the number of folds transverse to the longitudinal direction of the paper web (1) is varied intermittently or at specific points in relation to the second format extent (Y).
5. Method according to Claim 4, characterised in that a change in the number of folds is governed by the number of pages of the book block (7).
6. Method according to Claim 1 or 2, characterised in that, prior to a folding, the paper web (1) or the partial web (16) receives a transverse perforation (8) which forms at least the plane of the first fold.
7. Method according to Claim 1 or 2, characterised in that the cut is executed in the longitudinal direction of the paper web by means of motor-driven cutting modules (13).
8. Method according to Claim 7, characterised in that, in the case of a plurality of partial webs, the cutting elements (13a) associated with the cutting modules (13) operate offset from one another in the longitudinal direction of the paper web.
9. Method according to Claim 1 or 2, characterised in that the cutter for the cut executed transversely to the longitudinal direction of the paper web and/or the folding modules is/are motor-driven.
10. Method according to one or more of Claims 1 to 9, characterised in that at least one transverse fold is executed off-centre.

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