Method and device for supplying foil to a printing press

Abstract

 In order to realize efficient use of foil (3) in a printing process, a method and a device for supplying foil (3) to a printing press have been developed, which are suitable to be applied for re-using a length of foil (3) which has already been used in a printing process. In a practical embodiment of the device, a foil re-use unit (15) is present, which is adapted to receive a used length of foil (3) from the printing press, to change a mutual position of the length of foil (3) and the printing press, and to feed the length of foil (3) back to the printing press. By changing the mutual position as mentioned, it is ensured that portions of a substrate to which a layer of the foil (3) needs to be transferred are covered by unused portions of the length of foil (3).

Description

[0001] The present invention relates to a method and a device for supplying foil to a printing press, wherein the foil is intended to be used in a printing process during which portions of a layer of the foil are transferred to a substrate to be printed.

[0002] In general, the present invention is applicable in the field of applying a thin layer of a metal such as aluminium to a substrate such as paper or carton during a printing process, as in this field, there is a need for useful methods for supplying a foil comprising the thin metal layer and a carrier layer to a printing press. In this respect, techniques for transferring the metal layer from the carrier layer of the foil to the substrate have been developed which do not require any heating process for letting the desired transfer take place. The foil which is used in carrying out these techniques usually comprises a carrier layer made of polyethene, wherein a layer of aluminium is deposited on this carrier layer. In the following, for sake of clarity, the term "transfer layer" will be used as a general term for the layer which is suitable for transfer to the substrate.

[0003] By using the foil as described in the foregoing, it is possible to realize printed matter having shiny, silver-like or gold-like portions, wherein the exact colour of the portions is dependent on the colour of the transfer layer of the foil which has been used during the printing process. In particular, the shiny portions are obtained by performing the following steps: applying a specific type of glue or varnish to predetermined areas on the substrate to be printed; and pressing the substrate and a length of the foil against each other, with the transfer layer of the foil facing the substrate. During the latter step, a transfer of the transfer layer from the carrier layer of the foil to the substrate to be printed takes place at the areas where the glue or varnish is present, so that the material of the transfer layer is arranged on the substrate according to the pattern of the glue or varnish.

[0004] Normally, the foil is taken from a coil, which is unwound during a printing process in which the foil is used, so that the supply of foil can be continuous. In the printing press, the foil is moved through a narrow gap between two cylinders of the printing press, wherein the substrate to be printed is arranged on one of the cylinders. When the foil is pressed against the substrate on the basis of pressing forces which are exerted on the foil due to interaction of the two cylinders of the printing press, predetermined portions of the transfer layer are transferred from the foil to the substrate. After a length of foil has passed the narrow gap between the cylinders of the printing press, and some portions of the transfer layer of the length of foil have been used in the process of printing a substrate, the length of foil is disposed of. For example, the length of foil is moved to a device which is adapted to shred the foil.

[0005] A problem associated with the usual way of handling a length of foil to be used in a printing process is the inefficient use of the foil, wherein a considerable portion of the length of.foil is wasted. In the first place, regardless of the size of the substrate to be printed, a length of foil is made to move along with the cylinder of the printing press on which the substrate is arranged, wherein the cylinder performs one revolution. Hence, the dimension of the foil in a direction of movement, which is needed per substrate, is determined by the size of the cylinder as mentioned. In the second place, most patterns to be printed comprise one or more areas which should be free from the material of the transfer layer. At those areas, the transfer layer of the foil remains intact. All in all, when a used length of foil is disposed of, there are unused portions of the foil which are thrown away as well, which is disadvantageous from an economical point of view and an environmental point of view.

[0006] It is an object of the present invention to provide a solution to the waste of foil as described in the foregoing. This object is achieved by a method for supplying foil to a printing press, wherein a new, unused length of foil is directed towards and moved through the printing press, wherein the same length of foil is received back from the printing press after use, and wherein the length of foil is fed back to the printing press for at least a second time, wherein a mutual position of the length of foil and the printing press is changed every time that the.length of foil is fed to the printing press.

[0007] The present invention is based on the insight that a used length of foil can be re-used, so that the foil can be used in a manner which is far more sufficient than known from the art. A used length of foil is received back from the printing press after use, the mutual position of the length of foil and the printing press is changed, and the length of foil is fed to the printing press once again. These steps can be repeated until there are no portions left on the length of foil which can be used for covering printing areas which need to be provided with the material of the transfer layer.

[0008] Normally, changing the mutual position of the length of foil and the printing press will be realized by displacing the length of foil with respect to the printing press, as the printing press is a heavy device having a fixed position. Changing the mutual position of the length of foil and the printing press has two aspects. In the first place, the position can be changed in a direction perpendicular to a direction of movement of the length of foil. In the second place, the position can be changed in a direction corresponding to the direction of movement of the length of foil. Naturally, one act of changing the mutual position of the length of foil and the printing press can involve changes of positions in both directions as mentioned, so that a combined displacement is obtained, as it were.

[0009] In a practical application of the present invention, means are applied for guiding the length of foil, which means comprise a set of at least two elements for contacting and supporting the length of foil, which elements are movable with respect to each other, wherein a change of the mutual position of the length of foil and the printing press is realized by setting a distance between the elements on the basis of information regarding a positioning of sections to be provided with portions of the transfer layer of the foil on the substrate to be printed.

[0010] In the set of elements, one element serves for receiving the used length of foil from the printing press, and directing the used length of foil to another element of the set, wherein the other element of the set serves for receiving the used length of foil from the one element and directing the length of foil towards the printing press. For example, the elements can be bars from an adjustable angle bar arrangement. The length of foil can have a smaller dimension than the substrate to be printed, in a direction perpendicular to the direction of movement of the length of foil. By using the angle bars for guiding the length of foil and setting an appropriate distance between the angle bars, it is achieved that a new portion of the substrate, which has a displaced position with respect to a previous portion, in the direction perpendicular to the direction of movement of the length of foil, can be covered by the length of foil which has already been used to cover the previous portion.

[0011] Adjusting the mutual position of the length of foil and the printing press can also involve setting a distance between the set of elements for contacting and supporting the length of foil and the printing press on the basis of information regarding a positioning of unused portions of the foil and a positioning of sections to be provided with portions of the transfer layer of the foil on the substrate to be printed. By choosing an appropriate distance between the set of elements and the printing press, it is possible to determine a position of the length of foil with respect to the substrate in the direction corresponding to the direction of movement of the length of foil. In particular, in order to be able to use the length of foil once again, the position is chosen such that areas of the substrate which need to be provided with the material of the transfer layer are covered by portions of the used foil where the transfer layer is still present.

[0012] It is noted that the information regarding the positioning of sections to be provided with portions of the transfer layer of the foil on the substrate to be printed is predetermined information, dependent on the actual design of a printed matter. Information regarding a positioning of unused portions of the foil can be obtained by using suitable detecting means such as optical sensors, which does not alter the fact that other ways of obtaining the necessary information can be realized within the scope of the present invention.

[0013] It is possible to use the foil as many times as possible, and used foil may be fed back to the printing press more than one time. For example, a situation in which the foil is used for a total of three times, including a first time that the foil is new and unused, can be realized by applying two sets of elements for contacting and supporting the length of foil, wherein each set of elements can be positioned at a suitable level with respect to the printing press.

[0014] Advantageously, the length of foil to be fed to the printing press is obtained by dividing a basic length of foil having a larger dimension in a direction perpendicular to a direction of movement of the length of foil in at least two smaller portions in the direction of movement of the length of foil. For example, one basic length of foil may be divided in at least two lengths of foil by performing a cutting process on the basic length of foil. This is a practical way of having lengths of foil which are smaller than the substrate to be printed in the direction perpendicular to the direction of movement of the length of foil, in which situation the present invention is very well applicable for realizing a most efficient use of the foil.

[0015] A device according to the present invention may comprise an adjustable angle bar arrangement as described earlier, wherein means may be provided for controlling a mutual distance of the bars of the angle bar arrangement on the basis of information regarding a positioning of sections to be provided with portions of the transfer layer of the foil on the substrate to be printed. Another suitable set of elements for contacting and supporting the length of foil, which elements are movable with respect to each other, is feasible as well within the scope of the present invention.

[0016] Furthermore, the set of elements for contacting and supporting the length of foil may be incorporated in a frame portion which is movable in the device. Means for controlling a level of the frame portion in the device on the basis of information regarding a positioning of unused portions of the foil and a positioning of sections to be provided with portions of the transfer layer of the foil on the substrate to be printed may be used in order to ensure that the used foil is re-used in such a manner that portions of the substrate to be provided with a layer of the material of the transfer layer are covered by portions of the foil where the transfer layer is still intact.

[0017] The device according to the present invention may comprise suitable means for making at least two smaller lengths of foil out of a basic length of foil having a larger dimension in a direction perpendicular to a direction of movement of the length of foil. As has been explained in the foregoing, such means may be means for performing a cutting action on the foil, for example. The device may further comprise means such as an adjustable angle bar arrangement for accurately positioning the smaller lengths of the foil.

[0018] The present invention furthermore relates to a combination of a printing press and a device as described in the preceding paragraphs, wherein the device is arranged at a position for supplying a length of foil to the printing press and for receiving a used length of foil from the printing press. Preferably, this position is a position above printing cylinders of the printing press.

[0019] The present invention will further be explained on the basis of the following description, wherein reference will be made to the drawing, in which equal reference signs indicate equal or similar components, and in which:

figure 1 diagrammatically shows a combination of a printing press and a foil supplying device according to the present invention;

figure 2 diagrammatically shows a perspective view of components of the foil supplying device according to the present invention, a number of printing cylinders of the printing press, and foil which is used and re-used in a printing process;

figure 3 illustrates how a position of a length of foil with respect to the printing press can be set by using movable components of the foil supplying device according to the present invention; and figures 4-6 diagrammatically show perspective views of a slitter unit and a number of bars, which may be part of the foil supplying device according to the present invention, wherein, for sake of clarity, a part of a length of foil is cut away.

[0020] Figure 1 diagrammatically shows a combination of a printing press 1 and a device 2 according to the present invention, which serves for supplying foil 3 to be used in a printing process to the printing press 1. In particular, the foil 3 comprises two layers, namely a transfer layer such as a metal layer, and a carrier layer. It is intended to have a transfer of portions of the transfer layer from the carrier layer to a substrate (not shown) such as a sheet of paper or a web of paper in the printing press 1, so that shiny portions are obtained on this substrate. The transfer may be realized in a way known per se, for example, by applying glue or varnish to the substrate to be printed and pressing the foil 3 against the substrate, in such a way that the transfer layer of the foil 3 contacts the substrate and is removed from the carrier layer at the areas where the glue or varnish is present.

[0021] With respect to the printing press 1, it is noted that this may be any type of printing press 1 which is capable of processing the foil 3 and making shiny portions on printed matter by using the foil 3. In the example as shown in figure 1, the printing press 1 is a so-called offset press, and comprises a number of printing units 4 for adding various colours to the substrate to be printed. Figure 1 shows a sectional view of the printing press 1, and a number of cylinders of this printing press 1 may be seen in this figure.

[0022] In each unit 4 of the printing press 1, a plate cylinder 5 is arranged, which is a carrier of a printing plate. During a printing process, oil-based printing ink is supplied to the printing plate, and to this end, ink rollers 6 are arranged in the unit 4 as well. Furthermore, dampening rollers 7 are arranged in the unit 4. Areas of the printing plate which are not having an image to be transferred to the substrate are kept in a humid state, as a result of which the ink can not settle in these areas. According to the principles of offset printing technology, the image is not transferred directly from the printing plate to the substrate. Instead, an intermediate step is performed, in which a blanket is used for receiving the image from the printing plate and transferring the image to the substrate. In the printing unit 4, the blanket is mounted on a blanket cylinder 8 which is arranged at a position between the plate cylinder 5 and a cylinder 9 for supporting the substrate. This substrate supporting cylinder 9 could be an impression cylinder in case of a sheet fed press or a blanket cylinder in case of a web press.

[0023] As the offset printing process is known per se, this process will not be further explained here. In the context of the present invention, it is important to note that the foil 3 is intended to be supplied to a printing area of the printing press 1, i.e. an area between the blanket cylinder 8 and the substrate supporting cylinder 9.

[0024] The foil 3 is normally provided on a coil 10, and the foil supplying device 2 according to the present invention is adapted to realize a continuous supply of foil 3 to the printing press 1. Furthermore, the foil supplying device 2 according to the present invention comprises buffer means 11 for storing a length of the foil 3. In the shown example, the buffer means 11 comprise a unit 12 as diagrammatically shown in figure 1. This unit 12 comprises a space 13 for accommodating a loop 14 of the foil 3, and the unit 12 is associated with means (not shown) for creating an underpressure in the space 13. Suitable detecting and controlling means (not shown) are provided for ensuring a proper operation of the buffer means 11, which process is known per se and will not be further explained here. Due to the presence of the buffer means 11 in the foil supplying device 2 according to the present invention, it is possible to have a speed difference between a length of foil 3 in a path extending between the coil 10 and the buffer means 11, and a length of foil 3 in a path extending between the buffer means 11 and the printing press 1.

[0025] At a position between the buffer means 11 and the printing press 1, the foil supplying device 2 is equipped with a unit 15 which is adapted to receive a used length of foil 3 from the printing press 1, and to feed the length of foil 3 back to the printing press 1, while changing a mutual position of the length of foil 3 and the printing press 1. Therefore, in the following, the unit 15 will be referred to as foil re-use unit 15. It is noted that further details of the foil re-use unit 15 and an explanation of the way in which this unit 15 is operated will be given later, with reference to figures 2 and 3.

[0026] In order to achieve excellent printing results, it is important that the speed of the foil 3 corresponds to the speed of the substrate in the printing press 1. In view of this, the foil supplying device 2 may be equipped with means (not shown) for detecting the speed of the substrate, which may involve detecting a rotational speed of the substrate supporting cylinder 9 of the printing press 1 in practice. Furthermore, a servo system (not shown) may be provided for controlling the rotational speed of various rollers of the foil supplying device 2 which serve for pulling the foil 3.

[0027] Any suitable unit may be used for receiving and processing a portion of the foil 3 which is no longer destined to be used again. For example, a unit 16 which is suitable for performing a shredding action is provided. Furthermore, the unit 16 may be adapted to press the shreds in blocks which are suitable to be used for recycling purposes. In this way, automatic processing of the waste of the foil 3 is realized.

[0028] A perspective view of components of the foil re-use unit 15 is shown in figure 2. Furthermore, figure 2 shows three cylinders of the printing press 1, namely the plate cylinder 5, the blanket cylinder 8, and the substrate supporting cylinder 9, and foil 3 which is directed from the printing press 1 to the foil re-use unit 15, and back. In the shown example, the foil re-use unit 15 is positioned above the printing press 1, and comprises two adjustable angle bar arrangements 17, 18, and two frame portions 19, 20, wherein each of the angle bar arrangements 17, 18 is arranged in another of the frame portions 19, 20, and wherein a level of each of the frame portions 19, 20 with respect to the printing press 1 is adjustable. In respect of the latter aspect, it is noted that a frame portion 19 which is located at a higher level may be displaceable along guiding rods 21 extending from a frame portion 20 which is located at a lower level, as is the case with the embodiment of the foil re-use unit 15 as illustrated in figure 2. For sake of completeness, it is noted that this is just one example of many possibilities of realizing a suitable positioning of components of the foil re-use unit 15.

[0029] In the following, an explanation will be given of the functioning of the foil re-use unit 15. In particular, a path followed by a length of foil 3 when moving from the buffer means 11 to the shredding unit 16 will be described.

[0030] First, the length of foil 3 moves from the buffer means 11 to the printing press 1, where the length of foil 3 passes between the blanket cylinder 8 and the substrate supporting cylinder 9 for a first time. In the printing process which takes place, a first portion of the transfer layer of the foil 3 is transferred to a substrate to be printed, which portion is depicted as a diamond in figure 2. The length of foil 3 then moves towards the foil re-use unit 15, and enters this unit 15 when passing a first angle bar 22 of the angle bar arrangement 18 which is located in the lower frame portion 20.

[0031] The length of foil 3 moves from the first angle bar 22 to a second angle bar 23 of the angle bar arrangement 18 as mentioned. In the process, due to the positioning of the second angle bar 23, the length of foil 3 is displaced with respect to the printing press 1 in a direction perpendicular to a direction of movement of the length of foil 3. Furthermore, a displacement of the length of foil 3 with respect to the printing press in a direction corresponding to the direction of movement of the length of foil 3 is determined by the mutual distance of the angle bars 22, 23, and the level of the lower frame portion 20 with respect to the printing press 1. On the basis of the first displacement, it is realized that another portion of the substrate can be covered by the length of foil 3, which has a smaller dimension in the direction perpendicular to the direction of movement of the length of foil 3 than the substrate. On the basis of the second displacement, it is realized that another portion of the foil 3 than the portion where the transfer layer is no longer present is put in contact with the substrate at positions where new transfers of material from the foil 3 to the substrate need to take place.

[0032] From the second angle bar 23, the length of foil 3 is fed to the printing press 1 again, and moves through the narrow gap between the blanket cylinder 8 and the substrate supporting cylinder 9. In the printing process which takes place, a new portion of the transfer layer of the length of foil 3 is used, which is depicted as a square in figure 2.

[0033] The length of foil 3, which has been used in a printing process two times now, is guided back towards the foil re-use unit 15 once again. In particular, the length of foil 3 moves towards the upper frame portion 19, passes a first angle bar 24 of the angle bar arrangement 17 which located in the upper frame portion 19, and moves towards a second angle bar 25 of the angle bar arrangement 17 as mentioned. After having passed the second angle bar 25, the length of foil 3 moves back to the printing press 1. A change of the position of the length of foil 3 with respect to the printing press 1 is realized in the same manner as has been described with respect to the lower frame portion 20 and the angle bar arrangement 18 located in that frame portion 20.

[0034] The length of foil 3 passes between the cylinders 8, 9 of the printing press 1 again, wherein a third portion of the transfer layer of the length of foil 3 is used in a printing process, on a third portion of the substrate. The third portion of the transfer layer of the length of foil 3 is depicted as a circle in figure 2. When the length of foil 3 has moved through the printing press 1 three times in total, the length of foil 3 moves from the printing press 1 to the shredding unit 16.

[0035] It is clear that applying the foil re-use unit 15 offers the important advantage of efficient use of the foil 3. In a situation without a foil re-use unit 15, only one portion of the transfer layer of the length of foil 3 is used in a printing process, whereas in a situation with the foil re-use unit 15, multiple portions of the transfer layer of the same length of foil 3 are used in a printing process.

[0036] The number of times that a length of foil 3 may be fed back to the printing press 1 is determined by various factors, including a desired design of a printed pattern on the substrate. In any case, the number of times is at least one, the number of times may be two as in the shown example, and the number may be even more.

[0037] For sake of clarity, the way in which a position of a length of foil 3 with respect to a substrate in the direction perpendicular to the direction of movement of the length of foil 3 is set by means of an angle bar arrangement 17 is illustrated in figure 3. On the left side of the figure, the angle bars 24, 25 are shown at a relatively small distance with respect to each other. In this position of the angle bars 24, 25, the length of foil 3 is fed back to the printing press 1 at a position which is relatively close to the previous position. A distance between the positions of the length of foil 3 is indicated as dl in the left portion of figure 3. On the right side of the figure, the angle bars 24, 25 are shown at another distance with respect to each other, namely a relatively large distance. In this position of the angle bars 24, 25, the length of foil 3 is fed back to the printing press 1 at a position which is relatively far from the previous position. A distance between the positions of the length of foil 3 is indicated as d2 in the right portion of figure 3. When the left and right portions of figure 3 are compared, it is clear that the position of the length of foil 3 with respect to the substrate in the direction perpendicular to the direction of movement of the foil 3 can be set by positioning the angle bars 24, 25 at an appropriate distance with respect to each other.

[0038] Throughout the printing process, the shredding unit 16 is kept in an activated state in order to process a portion of the foil 3 which remains after having passed the foil re-use unit 15 and the printing press 1 for the last time. Unnecessary waste of foil 3 is prevented by applying the foil re-use unit 15, as has been explained in the foregoing. The fact that the foil 3 is supplied in a length having a relatively small dimension in the direction perpendicular to the direction of movement of the length of foil 3 is another factor in realizing a most efficient use of the foil 3. Normally, the foil 3 is supplied in lengths having a larger width. However, it is possible to apply an angle bar arrangement 26 and a slitter unit 27 having a number of rotatably arranged slitters, as shown in figures 4-6. In this way, it is possible to make a number of smaller lengths 28 of foil 3 out of one length 29 of foil 3 having the full width, and to supply the smaller lengths 28 of the foil 3 to the printing press 1, wherein the angle bar arrangement 26 is used for accurately positioning the lengths 28 of the foil 3, so that it is possible to feed these lengths 28 to their respective destinations in the printing press 1, wherein the lengths 28 are positioned such as to cover different portions of a substrate to be printed, which are successive portions in the direction perpendicular to the direction of movement of the lengths 28.

[0039] In the example illustrated in figures 4-6, three smaller lengths 28 are cut. It is not required for the smaller lengths 28 to have the same dimension in the direction perpendicular to the direction of movement of the lengths 28. Furthermore, in the example shown, a bar assembly 30 is used for directing the length 29 of foil 3 having the full width towards the slitter unit 27 at a first level, as well as for directing a central smaller length 28 of foil 3 from the slitter unit 27 towards the angle bar arrangement 26 at a second level, and for directing two outer smaller lengths 28 of foil 3 from the slitter unit 27 towards the angle bar arrangement 26 at a third level. In figures 4-6, a bar of the bar assembly 30 which is positioned at the first level is indicated by reference numeral 31, a bar of the bar assembly 30 which is positioned at the second level is indicated by reference numeral 32, and a bar of the bar assembly 30 which is positioned at the third level is indicated by reference numeral 33. The angle bar arrangement 26 has bars at the second level and the third level for receiving the central length 28 of foil 3 and the outer lengths 28 of foil 3, respectively. In figures 4-6, a bar of the angle bar arrangement 26 which is positioned at the second level is indicated by reference numeral 34, and bars of the angle bar arrangement 26 which are positioned at the third level are indicated by reference numerals 35 and 36, respectively. By applying the various bars 31, 32, 33, 34, 35, 36 as described, it is achieved that the various smaller lengths 28 of foil 3 cannot get entangled, and that these lengths 28 are supplied to the printing press 1 at predetermined positions. The angle bar arrangement 26 may be adjustable such as to be capable of realizing various desired positions of the lengths 28 of foil 3.

[0040] It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims.

[0041] It is preferred if the user of the combination of the printing press 1 and the foil supplying device 2 is allowed to choose which unit 4 of the printing press 1 is used for receiving and processing the foil 3. Therefore, it is preferred if the foil supplying device 2 is arranged in a displaceable device.

[0042] It is noted that in the foil supplying device 2, the foil 3 is contacted by components of the foil supplying device 2 only at one side, namely the side of the carrier layer, wherein damage to the transfer layer is prevented. Among other things, this is achieved by using angle bar arrangements.

[0043] In the foregoing, a method and a device 2 for supplying foil 3 to a printing press 1 have been described. Both the steps of the method and the design of the device 2 are aimed at using the foil 3 in a manner which is far more sufficient than conventional manners. The basic principle of the method and the device 2 resides in re-using a length of foil 3 which has already been used in a printing process. In virtually every practical case, it is possible to do so, as portions of the transfer layer of the length of foil 3 remain intact during a printing process, due to the fact that not all of the length of foil 3 is used, as determined by the design of a printing pattern on a substrate and the physical features of components of the printing press 1 involved in the printing process, among other things.

[0044] In a practical embodiment of the device 2 according to the present invention, a foil re-use unit 15 is present, which is adapted to receive a used length of foil 3 from the printing press 1, to change a mutual position of the length of foil 3 and the printing press 1, and to feed the length of foil 3 back to the printing press 1. By changing the mutual position as mentioned, it is ensured that portions of the substrate to which a layer of the foil 3 needs to be transferred are covered by unused portions of the length of foil 3. For example, the foil re-use unit 15 may be provided with at least one adjustable angle bar arrangement 17, 18 and at least one movable frame portion 19, 20, wherein the angle bar arrangement 17, 18 is incorporated in the frame portion 19, 20.

Claims

1. Method for supplying foil (3) to a printing press (1), wherein the foil (3) is intended to be used in a printing process during which portions of a layer of the foil (3) are transferred to a substrate to be printed, wherein a new, unused length of foil (3) is directed towards and moved through the printing press (1), wherein the same length of foil (3) is received back from the printing press (1) after use, and wherein the length of foil (3) is fed back to the printing press (1) for at least a second time, wherein a mutual position of the length of foil (3) and the printing press (1) is changed every time that the length of foil (3) is fed to the printing press (1).

2. Method according to claim 1, wherein the mutual position of the length of foil (3) and the printing press (1) is changed in a direction perpendicular to a direction of movement of the length of foil (3).

3. Method according to claim 1 or 2, wherein the mutual position of the length of foil (3) and the printing press (1) is changed in a direction corresponding to a direction of movement of the length of foil (3).

4. Method according to any of claims 1-3, wherein means (15) are applied for guiding the length of foil (3), which means comprise a set (17, 18) of at least two elements (22, 23, 24, 25) for contacting and supporting the length of foil (3), which elements (22, 23, 24, 25) are movable with respect to each other, wherein a change of the mutual position of the length of foil (3) and the printing press (1) is realized by setting a distance between the elements (22, 23, 24, 25) on the basis of information regarding a positioning of sections to be provided with portions of the transfer layer of the foil (3) on the substrate to be printed.

5. Method according to claim 4, wherein a change of the mutual position of the length of foil (3) and the printing press (1) is furthermore realized by setting a distance between the set (17, 18) of elements (22, 23, 24, 25) and the printing press (1) on the basis of information regarding a positioning of unused portions of the foil (3) and a positioning of sections to be provided with portions of the transfer layer of the foil (3) on the substrate to be printed.

6. Method according to any of claim 1-5, wherein the length of foil (3) to be fed to the printing press (1) is obtained by dividing a basic length (29) of foil (3) having a larger dimension in a direction perpendicular to a direction of movement of the length of foil (3) in at least two smaller portions (28) in the direction of movement of the length of foil (3).

7. Device (2) for supplying foil (3) to a printing press (1), wherein the foil (3) is intended to be used in a printing process during which portions of a layer of the foil (3) are transferred to a substrate to be printed, the device (2) comprising means (15) for receiving a used length of foil (3) from the printing press (1) and feeding the same length of foil (3) back to the printing press (1), while changing a position of the length of foil (3) with respect to the printing press (1), wherein the means (15) comprise a set (17, 18) of at least two elements (22, 23, 24, 25) for contacting and supporting the length of foil (3), which elements (22, 23, 24, 25) are movable with respect to each other.

8. Device (2) according to claim 7, wherein the set (17, 18) of elements (22, 23, 24, 25) comprises an adjustable angle bar arrangement (17, 18).

9. Device (2) according to claim 8, wherein one bar (22, 24) of the angle bar arrangement (17, 18) serves for receiving the used length of foil (3) from the printing press (1), and directing the used length of foil (3) to another bar (23, 25) of the angle bar arrangement (17, 18), and wherein the other bar (23, 25) of the angle bar arrangement (17, 18) serves for receiving the used length of foil (3) from the one bar (22, 24) and directing the length of foil (3) towards the printing press (1).

10. Device (2) according to claim 9, wherein means are provided for controlling a mutual distance of the bars (22, 23, 24, 25) of the angle bar arrangement (17, 18) on the basis of information regarding a positioning of sections to be provided with portions of the transfer layer of the foil (3) on the substrate to be printed.

11. Device (2) according to any of claims 7-10, wherein the set (17, 18) of elements (22, 23, 24, 25) is incorporated in a frame portion (19, 20) which is movable in the device (2).

12. Device (2) according to claim 11, wherein means are provided for controlling a level of the frame portion (19, 20) in the device (2) on the basis of information regarding a positioning of unused portions of the foil (3) and a positioning of sections to be provided with portions of the transfer layer of the foil (3) on the substrate to be printed.

13. Device (2) according to any of claims 7-12, further comprising means (27) which are adapted to make at least two smaller lengths (28) of foil (3) out of a basic length (29) of foil (3) having a larger dimension in a direction perpendicular to a direction of movement of the length of foil (3).

14. Device (2) according to claim 13, further comprising means such as an adjustable angle bar arrangement (26) for accurately positioning the smaller lengths (28) of the foil (3).

15. Combination of a printing press (1) and a device (2) according to any of claims 7-14, wherein the device (2) is arranged at a position for supplying a length of foil (3) to the printing press (1) and for receiving a used length of foil (3) from the printing press (1), preferably at a position above printing cylinders (5, 8, 9) of the printing press (1).

Drawing