WO2010102352A1

WO2010102352A1 - Method for manufacturing a conversion machine which can provide a foil, patch or a label on a substrate

Info

Publication number: WO2010102352A1
Application number: PCT/BE2010/000016
Authority: WO
Inventors: Marc Van Den Bergh
Original assignee: Marc Van Den Bergh
Priority date: 2009-03-11
Filing date: 2010-03-02
Publication date: 2010-09-16
Also published as: BE1018509A3; DE112010001142T5; CH703045B1; DE112010001142B4

Abstract

Method for manufacturing a conversion machine which can provide a foil on a substrate, whereby it consists in converting an existing offset press.

Description

METHOD FOR MANUFACTURING A CONVERSION MACHINE WHICH CAN PROVIDE A FOIL , PATCH OR A LABEL ON A SUBSTRATE

The present invention concerns a method for manufacturing a conversion machine which can provide a foil, a patch or a label on a substrate, starting from an existing printing machine.

Such a conversion machine is used to improve or add value to paper or cardboard, either or not imprinted, or another substrate which is processed sheet after sheet, for example for manufacturing either or not self-adhesive labels, envelopes or boxes with windows, plastic protective layers on printed matter and the like, whereby a foil, either or not transparent and either or not provided with a layer of glue, is provided on the substrate.

In particular, the invention aims to build a conversion machine which can provide a foil, a patch or a label on the recto side and/or on the back of an existing substrate.

Continuous form machines which can carry out such a conversion of an either or not pre-printed substrate are already known. A disadvantage of such machines is that they are complex and hence have a high cost price.

The present invention aims to remedy said disadvantage by providing a method to convert an existing offset press in a conversion machine .

Many offset presses are no longer useful for lithographic jobs due to the technological evolution. By converting these offset presses, these machines get a second life and conversion machines are obtained which are much cheaper than a newly built conversion machine .

To this end, the invention concerns a method which consists in converting an existing offset press of the type which was originally formed of a housing with a feeder and a delivery for supplying and removing substrate sheets; a plate cylinder which makes contact with a blanket cylinder, which in turn makes contact with an impression cylinder which presses the substrate against the blanket cylinder; characterised in that a foil guiding system with an independent drive is added to the offset press for supplying a foil provided with a temporary carrier, for separating the temporary carrier from the foil which is to be attached to the substrate and for removing the separated temporary carrier; and whereby the blanket cylinder is replaced by a perforated cylinder made of a hard material with perforations through which air can be sucked in so as to adhere the foil by suction; and whereby a cutting knife is added to cut the separated foil after it has been provided on the perforated cylinder and before the cut-off foil is transferred onto the substrate by the impression cylinder.

The above-mentioned cutting knife is preferably provided on the plate cylinder of the offset press, as a result of which the already existing possibilities of such a plate cylinder can be used for cutting the foil and transferring it at the required height of the substrate sheet.

The impression cylinder is preferably the same as the impression cylinder of the offset press. The distributing rollers and ink rollers of the existing offset press are used at least partly to drive the foil web, whereby the drive preferably meshes in the above-mentioned distributing rollers and/or ink rollers, for example by providing them with a motor such as a stepping motor.

The independent drive is preferably provided with a control to direct the advancement of the foil web as a function of the set length of the foil to be cut off.

The damping system of the original offset press is now preferably used to apply a silicone film on the cutting edge of the above-mentioned cutting knife, whereby the cutting knife is preferably positioned on the plate cylinder such that the knife makes contact with the silicone liquid in the damping system with its cutting edge at every rotation. This is advantageous in that, when cutting, the cut is not obstructed by any contamination of the knife such as adhesive remains coming from the foil web or the like.

Optionally, a die cutting unit and/or creasing unit is added to the original offset press so as to provide perforations and/or creases in the substrate and/or in the foil which adheres to the substrate. Preferably, this can be done by providing dies or creasing tools on the existing imprint cylinder in case the latter is already provided on the existing offset press.

Said perforations make it possible to remove part of the substrate from the end product, whereby for example the underlying foil remains as a transparent layer underneath the formed window. Further, it is possible to determine the shape of the self-adhesive labels by means of the perforations, whereby the self-adhesive labels can be peeled from the underlying foil.

A preferred embodiment starts with an offset press having at least two printing towers, each with their own set of the above-mentioned rollers and cylinders, separated by a turning mechanism for the substrate, whereby every printing tower is transformed into a conversion tower in the previously described manner, such that the foil can be provided on the recto side and the back of the substrate in a single passage of the machine.

Preferably, the foil guiding system contains a separation system for separating the foil and the temporary carrier, arranged upstream of the above-mentioned cutting knife in relation to the direction in which the foil advances, such that the temporary carrier is never cut through itself, and can be wound. The separation system may be formed by a peeling knife, over which the foil web is diverted at an acute angle.

The foil to be provided can be held on a temporary carrier by means of layer of glue either or not for one time use. Optionally, the foil to be provided may not be provided with a layer of glue, but with a temporary carrier, and it may serve as a loose interlayer for the substrate being carried through.

Preferably, the plate cylinder is provided with an adjusting mechanism whereby the position of the plate cylinder can be adjusted round its driving axis by 360°, and whereby said adjusting mechanism is used to set the height at which the cut-off foil is transferred onto the substrate sheet. The foil guiding system makes sure that the foil with the temporary carrier is supplied from an unwinding device, and that the used temporary carrier is removed by carrying it back to a winding device .

Optionally, the unwinding device can be arranged next to the offset press to be converted, whereby a foil web turning system is provided which bends the foil web as of the unwinding device at an angle of 90° so as to introduce it in the converted printing press. This arrangement is advantageous in that it is more easily accessible when the rollers of foil with the temporary carrier need to be replaced in the unwinding unit.

In order to better explain the characteristics of the invention, the following preferred embodiment of a conversion machine, obtained by converting an offset press according to the invention, is described with reference to the accompanying drawings, in which:

figure 1 represents a longitudinal section of an offset press before it was converted; figure 2 represents a longitudinal section of an offset press as seen in figure 1, converted into a conversion machine; figures 3 and 4 show views according to arrows F3 and F4 in figure 2; figure 5 is a detailed illustration of the part indicated by

F5 in figure 2.

The existing printing press of figure 1, for example of the

Heidelberg GTO type, consists of a housing 1 in which are provided two printing towers 2,3. Every printing tower 2,3 is provided with a number of parallel rollers 7 and cylinders 10, 12, 13 whose rotation is synchronised via a non-represented drive.

Every printing tower 2,3 contains an inking system 4 formed of an ink duct 5 with ductor roller 6, distributing rollers 7, ink rollers 8 and forme rollers 9, which make contact with a plate cylinder 10 with a damping system 11, which makes contact with a blanket cylinder 12 which makes contact with an impression cylinder 13, which makes contact with an imprint cylinder 14 and makes contact with a transfer cylinder 15 which makes contact with a turning mechanism 16. The printing press also comprises a sheet feeder 17 and delivery 18, arranged on opposite sides of an offset press having one or several printing towers .

The working of the offset press represented in figure 1 can be explained as follows.

The printing ink from the ink duct 5 is transferred via the ductor roller 6 and distributing rollers 7 to the ink rollers

8, which transfer the printing ink on the printing plate onto the plate cylinder 10 via forme rollers 9. The plate cylinder

10 is dampened by means of a damping system 11 which provides a water layer on the printing plate round the plate cylinder 10.

The plate cylinder 10 transfers its ink as an image onto the blanket cylinder 12 which in turn transfers the image onto the substrate to be printed which is fed between the blanket cylinder 12 and the impression cylinder 13 as of the feeder 18 to the delivery 17. The supplied substrate is supplied as of a preceding printing tower 2 via the transfer cylinder 15 and the turning mechanism 16, such that also the back of the substrate, which had already been printed on the recto side in the preceding printing tower 2, can be printed in a single passage of the machine.

After the substrate has been put through and printed between the blanket cylinder 12 and the impression cylinder 13, the printed substrate can further be provided with an additional overprinting such as a serial number or identification by means of an imprint cylinder 14.

Next, the finished printed matter is collected in a delivery mechanism 18 to stack the finished sheets in a non-represented stacker.

New substrate to be printed is supplied from a substrate stack from where a sheet supply mechanism 17 transfers sheet per sheet to the first or sole printing tower 2 of the offset press.

Figure 2 schematically shows the same section of an offset press as in figure 1, whereby the printing press has been converted into a conversion machine according to the present invention. The conversion machine has the same housing 1 as the offset press. The ink duct 5 and ductor roller 16 have been removed and some distributing rollers 7 are now being used as pulling rollers 19a and 19b for foil webs 20a and 20b, supplied by a foil web guiding system 21 situated on top of each printing tower 22,23.

The plate cylinder 24 no longer carries a printing plate but a cutting knife which is provided on the outer perimeter of the plate cylinder and which extends in the axial direction of the plate cylinder. The blanket cylinder 12 has been replaced by a perforated cylinder 26 with a central air exhaust. The impression cylinder 13 remains unaltered. The imprint cylinder 14 has been replaced by a die cutting device 27.

The working of the conversion machine as represented in figure 2 can be illustrated as follows.

The foil webs 20a, 20b are fed from the foil web guiding system 21 to the separating mechanism 28, where the foil is separated from its temporary carrier 29a, 29b. The temporary carrier 29 is guided back to the foil web guiding system 21 so as to wind up the separated temporary carrier 29. In the given embodiment, two foil webs 20a, 20b of equal width are supplied next to one another, such that together they can cover the entire width of the substrate in the conversion machine. The two foil webs can also have different widths, or optionally only one foil web can be used if not the entire width of the substrate must be covered. The two webs with a separated temporary carrier 29a, 29b are wound on the collection rollers 30a, 30b situated next to one another on top of each printing tower by the driving rollers 19a, 19b respectively. The driving rollers 19a and 19b are driven by an additional stepping motor or servomotor, independently of the drive of the offset printing press.

The foil webs 20a, 20b are carried as of the separating mechanism 28 where they have been stripped from their temporary carrier to the perforated cylinder 26, where they are being held by the suction force of the central air intake, after which they are cut in sheets of the required length by the cutting knife 25 mounted on the plate cylinder 24. The independent drive of the foil web 20 by means of the driving rollers 19a and 19b determines the length of the cut-off piece of foil.

The width of the foil web 20 is determined by the width of the supplied foil web rollers. In the given example, the foil web rollers are half as wide as the substrate to be treated, and thus two foil webs (20a and 20b) will have to placed next to one another if the substrate must be entirely covered by foil.

By adjusting the position of the plate cylinder 24 along its longitudinal axis at an angle varying between 0° and 360°, the height at which the piece of foil is transferred onto the substrate sheet is set, and thus whether the piece of foil will adhere for example at the top, in the middle or at the bottom of the substrate sheet, whereby the height is expressed as a function of the feed-through direction of the substrate sheet.

The perforated cylinder 26 transfers the piece of foil onto a substrate sheet which is being fed between the perforated cylinder 26 and an impression cylinder 13, whereby the foil 30 adheres to the substrate with its layer of glue.

The substrate with the foil is subsequently carried to a die cutting device 27 situated on the place of the former imprint cylinder 14 in the offset press. The die cutting device 27 makes perforations in the substrate in the required places. If need be, the die cutting device 27 may also be a creasing device.

Optionally, the feed-through of the substrate between the perforated cylinder 26 and the impression cylinder 13 where the foil is transferred onto the substrate may be supplied via the transfer cylinder 15 and the turning mechanism 16 as of a preceding printing tower 23, such that also the back can be provided with foil and perforations, just like the recto side has already been provided with a perforated substrate with glued foil, in a single machine passage.

Figure 3 shows the collection rollers 30a and 30b on top of the printing tower 22 for winding the separated temporary carrier webs 29a and 29b. Figure 3 also shows a vertical storage tower 33 with an unwinding unit 31 and an unwinding unit 32 suspended one on top of the other to unwind both foil webs, provided with a temporary carrier, 20a and 20b respectively.

The working of the foil web guiding system 21 as shown in figure 3 can be elucidated as follows.

The foil web guiding system 21 which is partly situated on top of a printing tower 22 supplies the foil webs, provided with a temporary carrier 20a, 20b, from the unwinding units 31 and 32 respectively. The foil webs 20a, 20b are diverted at an angle of 90° on top of the printing tower, after which the webs are guided next to one another in the housing 1 of the converted offset press from where, after having passed the separation mechanism 28 and having been stripped from their foil, they are fed back as webs of remaining temporary carrier 29a, 29b to the winding rollers 30a, 30b situated on top of the housing 1 of the converted offset press. The unwinding units 31, 32 are suspended in a vertical storage tower 33 situated next to the converted offset press. Figure 4 is a view from above of a foil web turning system 34a, 34b, consisting of diagonally arranged cylindrical 15 web guides turning the foil web which has been unwound as of the storage tower 33 at an angle of 90°, after which the foil is vertically guided through the housing 1 of the converted offset press.

The working of the conversion machine represented in figure 4 can be elucidated as follows .

The foil web turning system 34a, 34b turns the direction of the foil web 20a, 20b at an angle of 90° by guiding the foil web over a diagonally arranged shaft, i.e. over the diagonal carrier 34a for the foil web 20a, and over the diagonal carrier 34b for the foil web 20b. Per printing tower there is a foil web turning system for two foil webs 20a, 20b which are guided next to one another in the conversion machine. This makes it possible to position the storage tower 33 next to the offset printing machine instead of on top of the latter, such that the unwinding rollers in the storage tower 33 are easily accessible for replacement.

Figure 5 shows the separating system 28 at the perforated cylinder 26 in greater detail, with the supply of foil provided with temporary carrier 20a, 20b, and the removal of the separated temporary carrier 29a, 29b, after the throughput along the peeling knife 36 by means of the guides 37. The remaining foil 38 is transferred onto the perforated cylinder 26.

The working of the separating mechanism 28 is simple and as follows.

Two foil webs provided with temporary carrier 20a, 20b running next to one another are supplied as of the foil guiding system 21 and are carried up to the peeling knife 36 by means of guides 37, where the separation takes place and the foil 38 is transferred onto the perforated cylinder 26 without a temporary carrier, after which the remaining temporary carriers 29a, 29b are carried back to the foil guiding system 21 at an acute angle. The remaining foil 38 is sucked up by the perforated cylinder 26 and carried along.

Naturally, the position of the components may differ, but the conversion of an existing offset press is always the starting point.

The present invention is by no means restricted to the embodiment described by way of example and represented in the accompanying drawings; on the contrary, such a variant according to the invention can be carried out in all sorts of shapes and dimensions while still remaining within the scope of the invention.

Claims

Claims .

1. - Method for manufacturing a conversion machine which can provide foil on a substrate, whereby it consists in converting an existing offset press of the type which is originally formed of a housing (1) with a feeder (18) and a delivery (17) for supplying and removing substrate sheets; a plate cylinder (10) which makes contact with a blanket cylinder (12) , which in turn makes contact with an impression cylinder (13) which presses the substrate against the blanket cylinder (12) ; characterised in that a foil guiding system (21) with an independent drive is added to the offset press for supplying a foil provided with a temporary carrier (20a, 20b), for separating the temporary carrier from the foil which is to be attached to the substrate and for removing the separated temporary carrier (29a, 29b); and whereby the blanket cylinder (12) is replaced by a perforated cylinder (26) made of a hard material with perforations through which air can be sucked in so as to adhere the foil by suction; and whereby a cutting knife (25) is added to cut the separated foil after it has been provided on the perforated cylinder (26) and before the cut-off foil is transferred onto the substrate by the impression cylinder (13) .

2.- Method according to claim 1, characterised in that the above-mentioned cutting knife (25) is provided on the plate cylinder (24) of the offset printing press.

3.- Method according to any one of the preceding claims, characterised in that the above-mentioned impression cylinder (13) is the same as the impression cylinder (13) of the offset printing press.

4.- Method according to any one of the preceding claims, characterised in that the existing offset press is provided with distributing rollers and ink rollers (4), and in that the above-mentioned foil guiding system (21) uses these rollers at least partly to drive the foil web.

5.- Method according to claim 4, characterised in that the above-mentioned drive of the foil guiding system (21) meshes in the above-mentioned distributing rollers and/or ink rollers (4) of the offset press which are used in the foil guiding system.

6.- Method according to claim 4 or 5, characterised in that the independent drive is provided with a control to direct the advancement of the foil as a function of the set length of the foil to be cut off.

7.- Method according to any one of the preceding claims, characterised in that the original offset press is of the type which is provided with a damping system which makes contact with the plate cylinder, and in that this damping system (11) is used to apply a silicone film on the cutting edge of the above-mentioned cutting knife (25) .

8.- Method according to any one of claims 2 to 7, characterised in that the cutting knife (25) is positioned on the plate cylinder in such a way that, with every rotation, its cutting edge makes contact with the silicone liquid in the damping system (11) .

9.- Method according to any one of the preceding claims, characterised in that a die cutting unit and/or creasing unit is added to provide perforations and/or creases in the substrate and/or in the foil which adheres to the substrate.

10.- Method according to claim 9, characterised in that the original offset press is provided with an imprint cylinder (27) , and in that the die cutting unit or the creasing unit is formed by providing dies or creasing tools on the existing imprint cylinder (27) .

11.- Method according to any one of the preceding claims, characterised in that for manufacturing the conversion machine, an offset press with at least two printing towers

(22,23) is taken as a basis, each having its own set of the above-mentioned rollers and cylinders (4) , connected by means of a turning mechanism (16) for the substrate, whereby every printing tower (22,23) is converted into a conversion tower according to the method of claim 1, such that the foil can be provided on the recto side and the back of the substrate in a single machine passage.

12.- Method according to any one of the preceding claims, characterised in that the foil guiding system (21) comprises a separating system (28) for separating the foil and temporary carrier (29a, 29b), and in that this separating system (28) is arranged upstream of the above-mentioned cutting knife (25) in relation to the direction in which the foil advances.

13.- Method according to claim 12, characterised in that the separating system (28) is formed of a peeling knife (36) over which the foil web is diverted at an acute angle.

14.- Method according to any one of the preceding claims, characterised in that the plate cylinder (10) is provided with an adjusting mechanism which can adjust the position of the plate cylinder (10) around its axis by 360°, and in that this adjusting mechanism is used to adjust the height of the substrate sheet at which the cut-off foil is transferred onto the substrate sheet.

15.- Method according to any one of the preceding claims, characterised in that the added foil guiding system (21) comprises the supply of foil (20a, 20b) with a temporary carrier as of an unwinding device (33) , and the removal of used temporary carrier (29a, 29b) to a winding device (30a, 30b).

16.- Method according to claim 15, characterised in that the above-mentioned unwinding device (33) is arranged next to the offset press to be converted, and in that a foil web turning system (34a, 34b) is provided which bends the foil web as of the unwinding device (33) at an angle of 90° so as to introduce it in the converted offset press.