WO2017207471A1

WO2017207471A1 - Foil stamping machine

Info

Publication number: WO2017207471A1
Application number: PCT/EP2017/062859
Authority: WO
Inventors: Armin Steuer
Original assignee: Armin Steuer
Priority date: 2016-05-30
Filing date: 2017-05-29
Publication date: 2017-12-07
Also published as: CN109641445B; EP3463887B1; CN109641445A; EP3463887A1; DE102016209328A1

Abstract

A sheet-processing foil stamping machine (100) comprises a main frame (120), a stamping unit (110) which is supported by the main frame and comprises a stamping base (130) which can be moved to and fro in a linear manner and a stamping cylinder (140) which is arranged with a horizontal rotational axis above the stamping base, and a foil unit (180) with control devices for transporting at least one foil stamping web (170) through a stamping nip (145) which is formed between the stamping base and the stamping cylinder during a stamping interval. The stamping cylinder (140) is configured as a cylinder with a first gripper bar (142-1) and a second gripper bar (142-2) which is offset circumferentially with respect to the first gripper bar. The stamping cylinder is assigned a storage drum (150) for accepting and transferring printing material sheets (B1, B2, B3) between the stamping cylinder (140) and the storage drum (150). A height adjustment device is provided with an actuating drive (138) for adjusting the height of the stamping base (130) in relation to the main frame (120).

Description

Foil stamping machine

Field of application and state of the art

The invention relates to a sheet-processing foil embossing machine according to the preamble of claim 1. In hot embossing, a material layer to be embossed, for example a printing material sheet or a printing material web, is passed through an embossing gap in a foil embossing machine, which is between an embossing tool carrier device and a counterpressure element, for. B. a counter-pressure cylinder or a counter-pressure plate is formed. The embossing tool carrier device carries one or more embossing tools which can be heated during hot stamping by means of a heating device. Depending on the type of embossing device, the embossing tool carrier device, for example, a flat shape - in so-called round-flat machines or flat-flat machines - or a cylindrical shape - in so-called round-round machines or rotary machines - have.

The field of application of the invention are sheet-processing sheet embossing machines in a round-flat technique. Here, the stamping tool carrier device is formed by a stamping foundation, which is linearly reciprocated on a base frame of the machine. The embossing foundation works with round-flat machines with an embossing cylinder arranged with a horizontal axis of rotation above the embossing foundation.

During operation of the foil embossing machine, at least one stamping foil web is guided through the embossing gap in such a way that it has the same state of movement during the embossing interval as the material layer to be embossed. During the embossing interval, embossing material located on the embossing foil web, for example discrete stamping units lying one behind another, such as images, texts and / or holograms, or a part of a color layer or metal layer to be coated, is transferred to the material layer under the action of pressure and temperature.

The stamping foil web is pulled off a film supply by a film transport device and moved forward. The used stamping foil is taken away and disposed of. The film transport device, which is also referred to below as a "film plant", has one or more control devices actively involved in the control of the film web movement, to accurately determine the preferred distance of the embossing film web when the film preference in accordance with a control program.

EP 2 128 060 A2 describes a sheet-processing film embossing machine in a round-flat technique. At the embossing foundation a film storage container for receiving at least one supply roll for stamping foils is attached. A film brake device for generating web tension between the supply roll and a control device of the film work immediately following the supply roll is designed to generate a braking force acting at a distance from the supply roll directly on the stamping film web. The embossing cylinder makes one revolution (a "tour") while the embossing foundation moves once forward and once backwards under the embossing cylinder. In the forward movement of the embossing process. The backward movement of the embossing foundation takes place in the non-printing part of the embossing cylinder, in which a recess for passing through the embossing foundation is provided on the embossing cylinder. The circumference of the embossing cylinder corresponds to the one-way principle of the sum of the path, which traverses the embossing foundation in its forward movement and backward movement. The paper feeder and the paper delivery are on top of each other on the same side of the stamping unit.

Task and solution

The invention has for its object to provide a generic sheet-processing foil stamping machine, which is flexible, if necessary, can process larger quantities of sheets without reloading and can be switched to different embossing processes preferably at low set-up times and non-productive times.

To achieve this object, the invention provides a foil stamping machine having the features of claim 1. Advantageous developments are specified in the dependent claims. The wording of all claims is incorporated herein by reference.

A special feature is that the embossing cylinder is designed as a cylinder with a first gripper bar and a second gripper bar circumferentially offset relative to the first gripper bar. The embossing cylinder is thus able to simultaneously carry two consecutively supplied from the investment stack sheet of printing material. For this purpose, the circumference of the embossing cylinder is dimensioned so large that behind each of the gripper bars there is a cylindrically curved jacket section which is so circumferentially extended, a complete arc held by the leading rapier bar will fit on this shell section.

The embossing cylinder is associated with a storage drum for the acquisition and transfer of printing material between the embossing cylinder and storage drum. The storage drum rotates in operation in opposite directions to the embossing cylinder and is mounted in the vicinity of the embossing cylinder, that an immediate sheet transfer between embossing cylinder and storage drum or storage drum and embossing cylinder can be done. The integrated storage drum is located in the material flow of the substrate between the system, with which fresh printing material sheets are fed, and the embossing process, so that the storage drum can still cache unprinted printing sheets (empty sheets). The storage drum thus serves the temporary caching of empty sheets between system and embossing process.

Due to the storage drum, it is possible to arrange the feeder and the boom on opposite sides of the embossing machine. Corresponding embodiments are characterized in that a device for sheet system and a device for sheet delivery are arranged on opposite sides of the embossing unit. This can be processed in comparison to the prior art much higher investment pile and discard pile, whereby the productivity can be increased.

Furthermore, a height adjustment device is provided with an actuator for adjusting the height of the embossing foundation with respect to the base frame. The actuator is controlled via the control of the foil stamping machine. By means of the height adjustment device, a pressure adjustment between the embossing cylinder and the embossing tools carried by the embossing foundation is possible. As a result, at any time an optimal pressure between the substrate and the embossing tools can be adjusted by the embossing gap (distance between embossing cylinder and embossing tools) is reduced or increased. In addition, the height adjustment device can be used to approach the "pressure on" and "pressure down" positions.

In a development of the embossing cylinder with a fixed axis of rotation, that is not height adjustable with respect to the base frame stored. In this variant, it is thus provided that the embossing gap can be adjusted or adjusted exclusively by means of the height adjustment device for the stamping foundation. The construction on the part of the bearing of the embossing cylinder can be greatly simplified compared to solutions with height-adjustable embossing cylinders. While in variants with height-adjustable embossing cylinder all with the embossing cylinder corresponding assemblies, such as sheet transfers and drums, must be mitverstellt, which can lead to tolerances in the bowing, these sources of error are avoided in this embodiment. If the embossing gap is changed exclusively by means of the height-adjustable embossing foundation, the remaining subassemblies such as embossing cylinders, sheet transfer from installation to embossing cylinder, storage drum and delivery drum can always remain in their predetermined fixed positions. This simplifies the storage of these components.

The embossing machine design preferably comes without bearer rings and Schmitzleisten. Such elements are known to prevent the so-called "Schmitz", that is a mistake in the printing process, which can manifest itself in the form of smeared impressions.On the basis of Schmitzringen the cooperating elements (embossing cylinder and embossing foundation) can be positively constrained to each other via friction, to a register-accurate To allow settlement.

In embodiments without bearer rings and Schmitzleisten the peripheral speed of the embossing cylinder can be adjusted independently of the speed of movement of the embossing foundation, possibly continuously with the machine running. This allows the printing length to be infinitely varied. In some embodiments, such means is provided for changing the printing length in both directions (increasing the printing length or decreasing the printing length). In some embodiments, this is realized in that a stamping foundation drive is provided for generating the working movement of the stamping foundation, wherein the stamping foundation drive is controllable independently of a rotary drive for the stamping cylinder. In this way, a device for changing the printing length can be realized.

The embossing foundation drive preferably has a servomotor or an electric direct drive, for example a linear drive. If a servomotor is provided, it can drive a threaded spindle on which a spindle nut runs, which is connected to the embossing foundation. In comparison to conventional drives by means of crankshafts, etc., significantly higher production capacities can be achieved, among other things, due to lower masses. The movement speed of the embossing foundation can be changed by controlling the embossing foundation drive in relation to the peripheral speed of the embossing cylinder so that an extension or shortening of the printed image is possible. An adjustment while the machine is running is possible. In a further development, the embossing foundation can be moved by means of the embossing foundation drive from a pressure movement range assigned to the embossing cylinder into a maintenance area remote from the embossing cylinder. In these variants, it is possible by the separate embossing foundation drive to move the embossing foundation separately when the machine is stationary and, for example, to approach a change position. This position is in extension of the travel distance of the stamping foundation required for stamping, but outside this travel range.

Preferably, the change position is arranged so that the complete embossing foundation with all embossing tools can be taken laterally from the foil embossing machine or inserted into the foil embossing machine. Here, the complete embossing mold can be exchanged for another and individual embossing tools can be adjusted. This variant reduces set-up times and non-productive times.

The height adjustability of the stamping foundation can be realized in different ways. A particularly robust construction is characterized in that the embossing foundation is linearly reciprocated by means of linear guides on a support frame and that the support frame is pivotally mounted on the base frame of the foil embossing machine, wherein a pivot axis of the support frame is arranged at a lateral distance to the embossing gap. Although it would also be possible to design the construction so that the embossing foundation is displaced perpendicular to the used during productive operation movement plane by parallel displacement; However, a pivoting or tilting is structurally particularly easy to implement.

Preferably, the embossing foundation drive is mounted on the support frame so that it can move with it.

Preferably, the film work is configured to produce a discontinuous film web movement with retraction phases. As a result, the film consumption can be minimized.

The film transport device, which is also referred to below as a "film plant", may, for example, have one or more control devices actively involved in the control of the film web movement in order to precisely determine the preferred path and the movements of the embossed film web in accordance with a control program Control devices in one embodiment include one or more so-called clock rollers (or control rollers), which in slip-free rolling contact with the Stamping foil web and are exactly controllable in terms of their rotation angle and its direction of rotation, and a towing device with slip drive. The timing rollers (control rollers) and the pulling device are located on opposite sides of the embossing gap. In addition to the active control devices, a plurality of passive devices, eg deflecting rollers and / or air deflection rods, are generally provided in the film factory in order to determine the course of the embossing film web (s) through the film work.

The novel embossing mill can be used in combination with differently designed foil works. For example, it is possible to design the film work as described in EP 2 128 060 A2. Variants according to DE 3713666 A1 or EP 0 718 099 A2 or EP 1 155 831 A2 are also possible. The disclosure of these publications is to this extent made by reference to the content of this description.

Brief description of the drawings

Further advantages and aspects of the invention will become apparent from the claims and from the following description of preferred embodiments of the invention, which are explained below with reference to the figures.

Fig. 1 shows a schematic side view of an embodiment of a sheet-processing foil embossing machine;

FIGS. 2 to 5 show components of the foil embossing machine in four temporally successive phases during the embossing operation. Detailed description of the embodiments

1 shows a schematic side view of an embodiment of a sheet-processing foil stamping machine 100 in a round-flat technique. The embossing machine comprises an embossing foundation 130, which can also be referred to as a tool carriage, running essentially horizontally on the base frame 120 of the machine, and an embossing cylinder 140 which is disposed above the base frame and the horizontal axis of rotation 141 Stamping foundations is arranged and serves as a counter-pressure element. The embossing cylinder can also be referred to as a pressure cylinder. Between the embossing foundation 130 and the embossing cylinder 140, an embossing gap 145 is temporarily formed during operation of the embossing machine when the embossing foundation is below the embossing cylinder 140 during its horizontal linear reciprocating movement. The embossing further includes an axis-parallel hit the embossing cylinder mounted storage drum 150, which rotates in opposite directions to the embossing cylinder and is arranged with its largely cylindrical surface so close to the lateral surface of the embossing cylinder that printed material sheets can be transferred directly between embossing cylinder 140 and storage drum 150 and taken over. The embossing cylinder 140 is mounted with a fixed axis of rotation 141, ie not height-adjustable with respect to the base frame, in side walls of the base frame 120, not shown. The construction of the bearings of the embossing cylinder can thereby be greatly simplified compared to solutions with height-adjustable embossing cylinders. The embossing cylinder 140 is driven via an electric rotary drive, not shown, which is connected to the control unit of the film embossing machine and rotates the embossing cylinder in operation at a uniform rotational speed about the rotation axis 141, so that it is a one-trip system.

The embossing cylinder 140 is designed as a cylinder with a first gripper bar 142-1 and a second gripper bar 142-2 circumferentially offset relative to the first gripper bar and works together for the sheet guide with the storage drum 150, in the direction of the guided sheets between the application cylinder 166 and the Embossing gap 145 is arranged. Details will be explained in more detail in connection with FIGS. 2 to 5.

The embossing foundation 130 is intended to carry replaceable embossing tools (types) on its upper side facing the embossing cylinder 140. In the embossing foundation a heating device is integrated, which makes it possible to heat the embossing tools during operation to temperatures well above 100 ° C, preferably above 200 ° C.

The embossing foundation 130 is reciprocable linearly by means of a group of a plurality of mutually parallel linear guides on a support frame 134 in a sliding plane. Instead of also possible roller guides guide elements are slidably guided on rectilinear guide elements on the support frame at the bottom of the embossing foundation. The support frame 134 is mounted continuously pivotable on the base frame 120. The horizontal pivot axis 136 of the pivot bearing is located in Fig. 1 below the slip plane at the right end of the support frame on the side of the investment stack at a relatively large distance from the embossing gap, this distance is greater than the travel, which traverses the embossing foundation during a stamping interval. By pivoting the support frame 134 about the pivot axis 136, the sliding plane of the embossing foundation can be brought from the illustrated horizontal orientation in a tilted relative to the horizontal tilted position. A maximum tilt angle is a few degrees, eg a maximum of 2 degrees to a maximum of 5 degrees. It can be seen that the pivoting of the support frame 134 with respect to the base frame, the size (or height) of the embossing gap 145 can be adjusted continuously.

The pivotal movement is performed by means of an actuator 138 which engages in the opposite end of the pivot axis of the support frame at a greater distance from the embossing gap at the bottom of the support frame. The example pneumatically operating actuator is connected to the control unit of the foil stamping machine and can be controlled by this during operation of the machine or in embossing breaks. By means of the actuator, the embossing gap, so the distance between the embossing cylinder and embossing tools, be reduced or increased by pivoting the support frame to adjust the optimum for the embossing process pressure between the substrate and the embossing tools. This pressure setting is possible when needed while the machine is running. In addition, the actuator can be used to approach the predefinable positions "pressure on" and "pressure down". In the "pressure on" position, the sliding plane of the embossing foundation runs substantially horizontally and hot embossing is possible In the "pressure down" position, the glide plane is slightly inclined (a few degrees) from the horizontal and the embossing foundation is disengaged from the embossing cylinder ,

The pivotable support frame 134 and provided for adjusting the pivot position actuator 134 are functional components of a height adjustment for adjusting the height of the embossing foundation with respect to the base frame 120. The embossing gap is here exclusively on the height adjustment (here: pivoting) changed the embossing foundation. Serving for sheet guiding assemblies, in particular the embossing cylinder 140, the storage drum 150 and the cylinder on the plant side and the boom side are stored in non-height-adjustable bearings and thus always remain in their fixed positions. As a result, a long-term stable register accurate bowing is possible. The linear reciprocating embossing foundation 130 is moved by means of a stamping foundation drive 132 in the form of an electric servomotor, which can be controlled independently of the rotary drive of the embossing cylinder 140 by the control unit of the film embossing machine. The servo motor drives a threaded spindle 133 mounted in the support frame 134, on which a spindle nut runs, which is fastened to the underside of the embossing foundation 130. In other embodiments, instead, an electric linear drive may be provided which comprises, for example, a stator permanently installed in the carrier frame and a rotor fastened to the stamping foundation. This drive concept has compared to conventional drives with crankshafts, etc. a much lower weight and thus enables higher production rates.

Since the embossing foundation drive 132 can be controlled independently of the rotary drive for the embossing cylinder 140 and the embossing cylinder and the embossing foundations are not about Schmitz rings or the like engaged with each other, the speed of movement of the embossing foundation in relation to the peripheral speed of the embossing cylinder can be changed if necessary so that an extension or shortening of the printed image is possible. Such an adjustment is possible while the machine is running by the drives for embossing foundation and embossing cylinder are controlled accordingly. The entire travel path of the stamping foundation can be variably corrected so that the travel path of the respective printing length can be adjusted. The control can be realized so that no unnecessary way is driven, whereby improved production speeds can be achieved.

Due to the separate drive for the embossing foundation, it is also possible to move the embossing foundation separately with respect to an example embossing cylinder when the machine is stationary. For example, hereby a change position can be approached, which lies in extension of the travel distance of the embossing foundation required for embossing outside of the pressure travel path required for this purpose. In the example of Fig. 1, the change position is left of the embossing cylinder under the Auslegesystem 190. The change position is arranged in the example so that the complete embossing foundation with all embossing tools can be taken laterally from the machine or used. In this case, the entire embossing foundation can be exchanged for another or it can be exchanged individual stamping tools and / or adjusted. Such a design reduces setup and non-productive times.

The sheets of material to be printed are held up on a stock pile or stack 162 shown on the right with the side to be embossed. The bows are in the Operation of the film embossing machine via an inclined feed table 164 and an application cylinder 166 individually fed to the embossing cylinder 140 of the embossing.

A gripper bar of the embossing cylinder detects each of the leading edge of a sheet and pulls the sheet on the lying behind the gripper bar shell portion of the lateral surface. During the gripping process, an alignment of the printing material sheet takes place. Then there is a later explained in more detail caching an empty sheet instead. Each sheet is later guided in the illustrated direction of rotation (arrow) of the printing cylinder during a stamping interval from left to right through the embossing gap 145 and thereby stamped. When passing through the embossing gap (in the figure from left to right), the surface of the material sheet to be printed has a speed which (depending on the thickness of the sheet) substantially corresponds to the peripheral speed of the sheet-carrying surface of the continuously rotating embossing cylinder. After the embossing interval, the embossed material sheet is transferred to the delivery system 190, which successively promotes the printed sheets of material via a delivery cylinder 196 and a partially inclined boom section 194 on a discard pile 192 which is located on the side of the embossing mill 1 10 opposite the investment stack 162.

In the following, features of the sheet guide will be explained with reference to FIGS. 1 to 5. As already mentioned, the embossing cylinder 140 is designed as a simple large cylinder with two circumferentially offset gripper bars and works together with a storage drum 150. Figs. 2 to 5 show these two elements together with the application cylinder 166 on the side of the system and the delivery cylinder 196 on the boom side in four temporally successive phases during the embossing operation.

The embossing cylinder 140 has two gripper bars, each running parallel to the axis of rotation 141 on the outer circumference of the embossing cylinder, namely a first gripper bar 142-1 and a second gripper bar 142-2 diametrically opposite the axis of rotation 141. The first gripper bar 142-1 is adjoined by a cylindrically curved first shroud portion 144-1 which is circumferentially expanded so that a complete arc held by the leading first gripper bar will fit on this first shroud portion. In the situation in Fig. 1, a first sheet B1 is held at its leading edge in the first gripper bar 142-1 and rests on the first casing portion 144-1. The first jacket portion 144-1 is the jacket portion with which the embossing cylinder can engage the embossing foundation 130 during the embossing interval, so it will be referred to herein as the "pressure portion". Behind the first gripper bar 142-1 diametrically opposed second gripper bar 142-2 is a cylindrically curved second shell portion 144-2 whose radial distance from the axis of rotation is smaller than the radial distance of the first lateral surface 144-1 to the axis of rotation, for example by 4 mm up to 5 mm smaller. An arc held by the second gripper bar 142-2 can rest over the entire surface of the second casing section. The second jacket portion is used inter alia for the transport of the sheets between the contact cylinder 166 and the storage drum 150 and is therefore also referred to as "transport section" here.

FIG. 2 shows the embossing machine 110 in an operating phase in which an already printed first sheet B1 is transferred from the first jacket section 144-1 via the delivery cylinder 196 to the delivery arm. A time after the first sheet from the investor drawn second sheet B2 is in this phase on the circumference of the storage drum 150, which has its own gripper bar 152 for taking over sheets from the embossing cylinder 140. The diameter of the storage drum is dimensioned so that exactly one arc on the cylindrical surface of the storage drum outside the recess for the gripper bar fits. A third sheet B3 (blank sheet) is being guided by means of the abutment cylinder 166 to the embossing cylinder 140. Its leading edge is being gripped and aligned by the second gripper bar 142-2. The embossing foundation 130 is at this time in the start position shown on the left and waiting for the start of printing for embossing the second sheet B2.

Fig. 3 shows the embossing machine 1 10 after the embossing cylinder 140 has rotated relative to the starting situation shown in Fig. 2 by half a turn counterclockwise. The third sheet (blank sheet) B3 is now completely on the second shell portion 142-2 and is just before the transfer to the storage drum 150. The second gripper bar 142-2 passes the third sheet straight to the gripper bar 152 of the storage drum. The second sheet B2, which is still in the phase shown in Fig. 2 on the storage drum 150, has now been gripped by the first gripper bar 142-1, placed on the first shell portion 144-1 and conveyed through the embossing gap 145, while the Embossing foundation 130 is moved from its starting position in a forward movement in the direction of the end position. During this embossing interval, the peripheral speed of the first shell portion 144-1 corresponds to the moving speed of the embossing foundation.

In Fig. 4, the embossing machine 1 10 is shown after another half turn of the embossing cylinder 140. The now completely embossed second sheet B2 is released by the first gripper bar 142-1 and an anticipatory section has been taken over by means of the delivery cylinder 196 in the direction of the delivery. Simultaneously with this transfer of the printed Arc from the embossing cylinder to the boom takes place on the contact cylinder 166, the transfer of a fresh blank sheet (fourth sheet B4) of the plant on the second shell portion 144-2 of the embossing cylinder, ie on those shell portion with the smaller radius. This jacket section is used for transporting from the feeder to the storage drum 150. The front edge of the fourth sheet is gripped by the second gripper bar 142-2 for this purpose. The third sheet B3, which has just been drawn onto the embossing cylinder during the phase of FIG. 2, has in the meantime been transported further to the storage drum 150 and completely transferred to it. The leading edge of the third sheet B3 is being transferred from the gripper bar 152 of the storage drum to the first gripper bar 142-1, which in the subsequent phase will pull the third sheet onto the printing section (first casing section 144-1). During this phase, in which there is no arc in the region of the embossing gap, the embossing foundation 130 travels from its right-hand end position back to the starting position on the left after the end of the embossing interval. This retraction movement is possible without contact with the embossing cylinder, since in this phase of the transport section (second shell portion 144-2) is located with a smaller radius relative to the travel path of the embossing foundation.

Fig. 5 shows the embossing machine 1 10 after a further rotation of the embossing cylinder 140 by approximately 45 ° relative to the situation shown in Fig. 4. The third sheet B3, which was still completely held in FIG. 4 on the lateral surface of the storage drum, has in the meantime been gripped by the first gripper bar 142-1 and is already partially engaged with the trailing first casing section 144-1, i. the printing section, pulled. After another quarter turn, the area of the leading edge of the third sheet B3 will fall into the embossing gap and be embossed.

The embossing cylinder thus has two gripper bars, which are circumferentially offset by 180 ° to each other. A second gripper bar 142-2 takes an arc from the system and transports it to the storage drum 150 for transfer. The storage drum makes one revolution and then transfers the sheet to the first gripper bar 142-1. In this case, the embossing cylinder 140 has now rotated by 180 °. The first gripper bar 142-1 transports the sheet during the embossing interval through the embossing nip, where the sheet is embossed, and from there to the delivery gripper bridge. Thereafter, the next sheet is removed from the storage drum by the first gripper bar and so on.

During operation of the foil embossing machine, at least one embossing foil web 170 is moved through the embossing gap 145. Those devices which guide the embossing foil web and control the preferential movement of the embossing foil web belong to the so-called film factory 180 of the foil stamping machine. The embossing foil web is generally very thin (between 10 μm and 20 μm) and normally consists of a relatively tough plastic carrier film, on the front side of which a layer system with a thermally activatable separating layer, the actual embossing layer (for example color layer or metal layer or hologram or individual images ), and a thermally activatable hot-melt adhesive layer is applied, which forms the front side of the stamping foil web facing the substrate.

During the embossing interval, the embossing foil web runs through the embossing gap 145 at the same speed as the material sheet to be printed. For this purpose, the linearly displaceable embossing foundation 130 is accelerated from its starting position shown in the figure (see Fig. 1) to the left of the embossing cylinder so that the embossing tools during the embossing interval also have the same speed as the material sheet to be embossed and the embossing foil web guided between the material sheet and the embossing tool. During the embossing interval (eg, FIG. 3), under the influence of pressure and temperature, the embossing unit (for example, part of a color coat) is transferred to the material sheet. After the embossing foundation has been moved synchronously with the sheet of material and the embossing foil web in the forward movement during the embossing interval, it is decelerated after the end of the embossing interval until it reaches the right-lying end position. The return of the embossing foundation to the starting position (see Fig. 4) is possible without contact with the embossing foil web or the embossing cylinder. During the trace (from left to right) and during the subsequent rewind, the slide preference takes place by a predefinable, subject-dependent preferred route. The film preference is controlled by clock rollers of the film factory, which rotate for this purpose by a predetermined angle of rotation. With the help of a film memory, a length compensation takes place in order to ensure sufficient web tension at all times. The film unit 180 of the embodiment of FIG. 1 may perform a plurality of adjacent embossing foil webs in parallel. The film unit 180 makes it possible to guide an embossing film web outside the embossing interval slower than the material layer to be embossed, accelerate to the material web speed before the embossing interval and then decelerate again and counter to the main transport direction (from left to right in FIG. 1, see arrow). to withdraw in a withdrawal phase. By means of this discontinuous film web movement with retraction phases it can be achieved that the transferred embossing units or ink layer areas can be arranged directly successively on the embossing film web, even if the embossing locations are significantly further apart on the printing material, whereby the film consumption can be minimized. Each embossing film web is guided by a supply roll 182-1, 182-2 shown on the left (the supply rolls are arranged in two different planes) through a vacuum film loop storage 183 via a so-called clock roll or control roll 184 (in the example, cycle rolls are arranged in four levels one above the other) The stamping foil web is deflected by the associated cam roller via passive deflection devices (eg air rods or blower tubes and / or deflection rollers) in the direction of the embossing gap 145 and from there over a plurality of passive passages Deflection devices (eg air rods or blower tubes and / or deflection rollers) are guided to a pulling device 185 with a suction roll which rotates clockwise, so that the peripheral surface of the suction roll looped around by the stamping foil web (wrap angle, for example, between 130 ° and 180 ° ) in the main transport direction Downstream of the suction roll, the stamping foil webs are guided through a further vacuum film loop store 186 in the direction of the downstream disposal device. In the example, the stamping foil webs are rolled up on take-up reels 187 and then disposed of. Other disposal concepts, for example according to DE 10 2008 01 1 493 A1 are possible.

The clock rollers or control rollers 184 arranged upstream of the embossing gap are controllable with respect to the direction of rotation and rotational speed by means of suitable electromotive drives, thus suitable for forward-reverse operation, and belong to the control-active control devices of the film plant 180. In the example, they are designed as low-mass suction rolls and have each a looped by the film web area with perforations, by means of a suction fan, a negative pressure can be generated, which reliably pulls the wrapping film web portion on the circumference of the suction roll, so that a rolling contact with static friction is ensured without any slippage. Alternatively, or in addition to the suction, the slip-free rolling contact can also be ensured by means of pressure rollers or inflation or the like. The control rollers 184 cooperate with the suction roller of the pulling device 185, which rotates continuously in the main transporting direction, downstream of the embossing gap, in order to ensure sufficient web tension in the useful region therebetween and to precisely control the film web speed and direction. For this purpose, the suction roller downstream of the embossing gap is operated as a traction device 185 with slip drive, which continuously exerts a tensile force in the direction of the downstream film loop accumulator 186 on the at least one embossing foil web guided over it. The tensile force is large enough to ensure the web tension in the embossing gap and to allow a return transport of the embossing foil web, when the control rollers or clock rollers rotate counterclockwise 184, ie in the return direction. The traction generated by the slip drive However, it is not sufficient to overcome the static friction built up between the embossing film web and the cycle roll circumference, so that the web position of the embossing film web and its web speed are exactly determined solely by the rotational position and rotational speed of the tactile roller 184. Thus, during operation of the apparatus, the above-described discontinuous movement of the embossing foil web with retraction phases is effected by the coining gap by the co-operation of the tactile rollers 184 arranged upstream of the embossing gap with the traction drive (suction roller) arranged downstream of the embossing gap. Since at the same time the unused embossing foil web is fed by the continuously rotating supply rolls 182-1, 182-2, the degree of filling of the vacuum foil loop store 183, which partially deflates during acceleration phases with rapid feed of the embossing foil web, continues in braking phases and in retraction phases of the embossing foil web crowded. The film loop storage thus decouples the side of the continuous film entrance from the area of discontinuous film web movement between the slip-free control rollers 184 and the downstream slip drive 185.

A reverse arrangement of clock rollers and traction device, ie a traction device with slip drive before the embossing gap and controllable slip-free timing rollers downstream of the embossing gap, is possible.

Claims

Patent claims

1 . Sheet-processing foil stamping machine (100) with:

a base frame (120),

an embossing mechanism (1 10) carried by the base frame, which comprises an embossing foundation (130) which can be moved linearly back and forth and an embossing cylinder (140) arranged with a horizontal axis of rotation above the embossing foundation, and

a foil plant (180) with control devices for transporting at least one embossing foil web (170) through an embossing gap (145) formed between the embossing foundation and the embossing cylinder during an embossing interval,

characterized in that

the embossing cylinder (140) is designed as a cylinder with a first gripper bar (142-1) and a second gripper bar (142-2) which is circumferentially offset from the first gripper bar;

the embossing cylinder is assigned a storage drum (150) for taking over and transferring sheets of printing material (B1, B2, B3) between the embossing cylinder (140) and the storage drum (150); and

a height adjustment device with an actuator (138) is provided for adjusting the height of the embossing foundation (130) in relation to the base frame (120).

2. Foil stamping machine according to claim 1, characterized in that a device for sheet contact and a device for sheet delivery on opposite sides of the

Embossing mechanism (1 10) are arranged.

3. Foil embossing machine according to claim 1 or 2, characterized in that the embossing cylinder (140) is mounted with a fixed axis of rotation (141) in relation to the base frame (120).

4. Foil stamping machine according to one of the preceding claims, characterized by a device for increasing or reducing the printing length, the device preferably being usable continuously while the foil stamping machine is running.

5. Foil stamping machine according to one of the preceding claims, characterized by an embossing foundation drive (132) for generating working movements of the embossing foundation (130), the embossing foundation drive being controllable independently of a rotary drive for the embossing cylinder (140), preferably the embossing foundation -Drive (132) has a servo motor or an electric direct drive.

6. Foil embossing machine according to claim 5, characterized in that the embossing foundation (130) can be moved by means of the embossing foundation drive (132) from a pressure movement area assigned to the embossing cylinder (140) into a maintenance area located away from the embossing cylinder, the maintenance area preferably being arranged in this way is that the embossing foundation complete with all embossing tools can be removed from the side of the foil stamping machine or inserted into the foil stamping machine.

7. Foil embossing machine according to one of the preceding claims, characterized in that the embossing foundation (130) is mounted on one by means of linear guides

The support frame (134) is guided to be movable linearly back and forth and that the support frame is pivotably mounted on the base frame of the foil stamping machine, a pivot axis (136) of the support frame being arranged at a lateral distance from the embossing gap (145).

8. Foil stamping machine according to claim 7, characterized in that the stamping foundation drive (132) is mounted on the support frame (134).

9. Foil stamping machine according to one of the preceding claims, characterized in that the foil plant (180) is configured to have a discontinuous

To generate film web movement with withdrawal phases.

10. Foil embossing machine according to one of the preceding claims, characterized in that the foil plant (180) has one or more active control devices actively involved in the control of the film web movement in order to adjust the preferred route and the movements of the embossing foil web (170) when the film is advanced in accordance with a control program determine, the active control devices having one or more timing rollers (184) which are in slip-free rolling contact with the embossing film web (170) and can be controlled with regard to the angle of rotation and direction of rotation, the timing rollers working together with a traction device (185) with slip drive, the timing rollers and the pulling device is arranged on opposite sides of the embossing gap (145).