DE2629017A1 - METHOD AND DEVICE FOR MANUFACTURING A THERMOPLASTIC MULTIPLE PLATE - Google Patents

Description

FROM KREISLER SCHÖNWALD MEYER EISHOLD FUES FROM KREISLER KELLER SELTING

PATENT LAWYERS Applicant in Dr.-Ing. by Kreisler f 1973

Dr.-Ing. K. Schönwald, Cologne Nippon Paint CO. , Ltd. Dr.-Ing. Th. Meyer, Cologne

1-1, Oyodo-Cho Kita 2-chome, Dr.-Ing. K. W. Eishold, Bad Soden

Oyodo-ku, Osaka-Shi, Dr J.FFues Cologne

_n ■■ _T Dipl.-Chem. Alek von Kreisler, Cologne

USaJta, Japan Dipl.-Chem. Carola Keller, Cologne

Dipl.-Ing. G. Selting, Cologne

Sg-Is 5 COLOGNE T June 25, 1976

DEICHMANNHAUS AT THE MAIN RAILWAY STATION

Method and apparatus for making a thermoplastic duplicating plate

The invention relates to a method and apparatus for making a thermoplastic duplicating plate with relief image on one surface side.

In particular, the invention relates to a device in which a relief image of a matrix containing the Has negative pattern of the relief image on a thermoplastic Duplicating plate is transferred.

Devices for making thermoplastic duplicating plates are known, for example from JA-AS 12 933, published on April 24, 1973. In the known device are sheet of thermoplastic material made of polyethylene or polypropylene resin are prepared, sent one after the other through a heating furnace and through a nip. Of the The nip is formed by two pressure rollers, between which the transfer nip is located.

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The device in question here has an endless metallic conveyor belt, the upper run of which by the Oven and then through the transfer gap runs, as well as an endlessly rotating paper release medium, which is externally from the metallic endless conveyor is driven and its upper run runs through the heating furnace and then through the transfer gap, wherein it is in contact with the upper run of the metallic conveyor belt. While the pressure roller and the counter pressure roller are water-cooled are, the device also contains a water-cooled roller, which is to the side of the pressure roller is arranged on the sides lying at the front in the direction of movement of the upper run of the metallic conveyor belt. Of the The front area of the upper run of the paper medium used for detachment is from the upper run of the metallic conveyor belt bent and then leads around the cooling roller.

With a device constructed in this way, the thermoplastic sheet is heated as it passes through the heating furnace substantially melted and softened so that the thermoplastic resin of which it is made during of the subsequent transfer process penetrate into the indentations or cavities of the relief pattern of the paper matrix can. As it passes through the furnace, the thermoplastic sheet is removed from the upper run of the metallic one Conveyor belt carried with the upper run of the paper medium between the thermoplastic sheet and the Upper run of the conveyor lies. The thermoplastic sheet then passes through between the pressure roller and the back pressure roller formed transfer gap through, wherein the paper matrix firmly on the circumferential surface of the pressure roller is appropriate. The transfer of the relief pattern of the pa-

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piermatrix on the thermoplastic sheet that is used in the Passage through the heating furnace has been made substantially semi-liquid takes place during the passage of the thermoplastic sheet instead of through the transfer gap.

Since in this device the starting area of the releasing paper medium, which is used to stick the thermoplastic Arc on the conveyor belt to avoid bending around the platen in a direction that diverges from the upper run of the conveyor belt, and since the paper is also in a deviating from the pressure roller Direction is placed around the cooling roller, the thermoplastic sheet is after its transfer on a curved path moved by the platen and a portion of the release paper media between the first and second Deflection point is determined.

Such a device is suitable for the production of thermoplastic duplicating plates for Used as printing plates in newspaper printing or in the production of other printed products that are large in size Edition to be produced. However, there are the following disadvantages:

1. As the paper matrix when applied to the outer peripheral surface the pressure roller during the transfer of the relief pattern of the paper matrix to the thermoplastic Arch is curved in a semi-fluid state, there is insufficient detail reproduction and the The resulting duplicating plate is also curved so that the subsequent processing at the

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the edges cut off any approaches or surface parts from the Vervxelfältxgungsplatte become difficult.

2. As the paper matrix, the thermoplastic sheet, the Release paper media and the metallic conveyor belt all at the same time through the transfer nip between the pressure roller and the counter pressure roller are passed through during the transfer process, Not only is it difficult to accurately transfer, but there is also a possibility of changes in the thickness of the thermoplastic corrugated sheet .

3. As the metallic conveyor belt during passage through the heating furnace and in contact with the water-cooled Counter-pressure roller is repeatedly heated and cooled, not only must the conveyor as a whole complicated and bulky, but one can expect only a short life of the conveyor belt.

4. An automatic transport of the manufactured thermoplastics Vervxelfältxgungsplatte to the subsequent processing station, for example a Trimming or trimming station, and an automatic positioning of the thermoplastic Vervxelfältxgungsplatte at the trimming station in relation to a cutting or trimming machine are not possible or difficult to achieve without particular constructional difficulties. This is in part because the thermoplastic duplicating panels made in the above manner are curved as above

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already described _/ and in part on the presence of the release paper media. This means that the manufacture of the thermoplastic duplicating plates and the further processing into printing plates which can be used in a high-speed rotary press is not possible without additional processing steps which in principle cannot be automated.

5. As a result of the simultaneous application of the release paper media and the metallic conveyor belt, both circulating endlessly, synchronized drives for the paper medium and the conveyor belt being separated are hardly closed realize. In addition, there is the need for synchronization with the pressure roller and / or the counter-pressure roller to undertake. In other words: the transport speed of the thermoplastic sheet to and from the transfer gap by means of the conveyor can hardly match the speed of the angular movement of the Paper matrix can be synchronized on the peripheral surface of the rotating platen.

6. If the releasing paper medium is not used in any other way than an obvious stopgap measure, it is easy to kick a frictional displacement between the thermoplastic sheet and the paper matrix during passage through the transmission gap, resulting in an inaccurate transmission the relief pattern of the paper matrix leads to the thermoplastic sheet.

7. Because of the use of the peeling paper medium, which requires frequent renewal, the manufacturers

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Positioning cost of thermoplastic duplicating plate high.

In view of the above-mentioned disadvantages, the conventional method of making duplicating plates the inventors endeavored to provide a device similar to that of the above essentially avoids the disadvantages described and not the transport of the paper matrix along a curved Requires path, but in which the matrix performs linear motion without being curved or deformed and maintains this linear motion even when passing through the transfer gap.

To solve this problem, the invention provides that a rotating hollow cylinder is provided, which with each rotation at a receiving station and at one arranged behind the receiving station in the direction of rotation Transfer station moves past that a feeder successively thermoplastic sheets onto the hollow cylinder applies where they adhere along the transport path between the receiving station and the transfer station that a carriage with a flat surface for attachment a matrix that contains the complementary relief image of the relief image to be produced on the thermoplastic sheet having, along a path which is transverse to a through the longitudinal axis of the hollow cylinder imaginary plane runs, can be moved between a waiting position and an end position, and that the movement of the carriage from the waiting position to the end position with the rotation of the hollow cylinder in such a way synchronized is that the thermo-

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mm _ _

plastic arches at the transfer station come into agreement with the matrix lying on the carriage.

The device according to the invention has a pressure roller over which the thermoplastic sheet of a transfer station is fed at which the transfer nip is formed and at which the thermoplastic sheet is pressed against the matrix having the relief pattern and transferred to it. This is possible, because the pressure roller and especially the peripheral surface the pressure roller is heated by a first heating device to a temperature which is sufficient to produce the thermoplastic To soften the resin or to melt it so that it adheres to the outer peripheral surface of the pressure roller if the thermoplastic sheet adheres to the peripheral surface the rotating platen comes into contact.

The first heating device may have a hot air source which is arranged outside of the pressure roller and whose hot air is passed into the hollow interior of the printing roller to bring the printing roller to a certain temperature to heat up. In addition to the first heating device, an external heating device can be provided, which is fixedly arranged along the outer peripheral surface of the pressure roller and substantially along of the path between the receiving station and the transfer station is effective. The receiving station is located where the thermoplastic sheet first contacts the outer peripheral surface of the pressure roller. Alternatively, only a single external heating device can be provided, the inner heating device the pressure roller is omitted.

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In any case, during the transport of the thermoplastic sheet from the receiving station to the transfer station, when the sheet adheres to the circumferential surface of the unidirectional roller, the thermoplastic Sheet through the thermal energy of the printing roller exclusively or in combination with the thermal energy an external heating device is heated to a temperature sufficient for the material of the thermoplastic The arc essentially melts. This will prepare the thermoplastic sheet to fit into the indentations or to be able to penetrate cavities in the negative matrix during the subsequent transfer process. These indentations or cavities form the relief pattern of the matrix.

The apparatus of the invention for making duplicating plates also includes a linearly reciprocating plate on which the matrix is placed. The plate is carried by the machine bed and is substantially tangential to the circumferential surface of the pressure roller moved, but their surface has a certain distance from the peripheral surface. The plate is from box-shaped construction and has a perforated flat support surface, on which the paper matrix by suction forces is being held. A vacuum is created inside the plate chamber, which is drawn through the perforations in the flat contact surface acts on the matrix. The inner chamber of the plate is connected to a vacuum source.

The movable platen and the platen are synchronized with each other so that the thermoplastic sheet, the

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adheres to the circumferential surface of the pressure roller and with this rotates at the transfer station with the one on the linear movable plate attached matrix can be made to coincide. This is done while the plate is moving moved from a waiting position to the opposite end position. During this movement, the transfer process begins carried out. The plate is preferably water cooled and the thermoplastic sheet that is on This way from the pressure roller has been transferred to the matrix on the plate, is within the shortest possible time Cooled time in contact with the plate. The transfer of the thermoplastic sheet from the pressure roller to the Plate is made by the action of the temperature difference between the printing roller and the matrix. The outer The circumferential surface of the pressure roller is substantially polished or otherwise smoothed or is on it a release agent applied. The plate therefore does not always have to have water cooling, but the Water cooling the transfer of the thermoplastic sheet from the pressure roller to the plate because of the reinforced Cooling of the matrix as it contacts the plate is facilitated and so is processing of the duplicating plate relieved before their separation from the matrix.

In order to achieve essentially complete cooling of the thermoplastic Ensure that the sheet is transferred to the matrix, which is then the end position behind the transmission station is supplied, the device contain a source of cooling air through which the thermoplastic sheet on the matrix is supplied with cooling air will.

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In addition, it can be used to create thermoplastic duplicating plates at high speeds the device have a preheating oven through which the thermoplastic Sheets are transported through by a conveyor, starting from a stack of sheets. the Immediately after leaving the preheating device, sheets are placed in the receiving station above the printing roller fed. During their passage through the preheating oven, they are heated to such a temperature that they soften immediately upon subsequent contact with the circumferential surface of the pressure roller. The use of the preheating oven therefore enables the printing roller to rotate at a higher speed.

The conveyor passing through the preheating furnace can either consist of an endless metallic belt or of a roller conveyor exist, Other types of suitable conveyor devices can also be used, for example Conveyor with an endless metal grid.

Is the produced with the device according to the invention Duplicating plate used, for example, as a printing plate in a high-speed rotary press, so the device according to the invention can be followed by a molding device which is the thermoplastic Arch with the embossed relief two warts or lugs formed by two opposite edges of the The duplicating plate can be bent following the trimming process. With such approaches, the duplicating disk on a printing cylinder of a high speed rotary press can be attached as a pressure plate.

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Since in the device designed according to the invention Matrix fed to the transfer station without being bent or to become curved, and since the plasticized thermoplastic sheet is pressed against the matrix, while it is curved when it hits the peripheral surface When the pressure roller is applied, the thermoplastic resin can penetrate deep into the indentations or cavities of the matrix penetrate at the transfer station as if a glue or Paste material for filling cavities is pressed in with a spatula. As a result, it can be stated that that the device according to the invention makes it possible to produce a thermoplastic duplicating plate, which ensures a reliable reproduction of all print details. Furthermore, the subsequent processing, such as trimming, easily with a duplicating plate made with the present invention Device has been made, can be performed by machine. A duplicating plate is therefore obtained which maintains the required dimensions within an acceptable tolerance range.

Furthermore, since the duplicating plate is made of thermoplastic resin, it can be recycled after use i.e. their material can be reused to make a new duplicating plate. This also reduces the cost of manufacturing the duplicating plate.

Since the thermoplastic duplicating plate to the Point of time at which their manufacture is finished, has a planar and flat shape, can not only the subsequent one The pruning or trimming process can be carried out easily.

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but it is also an axact positioning of the plate with respect to the trimming unit and also with respect to the molding unit. The simplification the further processing is due to the advantages of using the device according to the invention.

In the device according to the invention, the number is Parts whose movements have to be mutually synchronized are very small. Only the transport speed of the supported by the plate matrix in their movement from the waiting position in the end position must with the peripheral speed synchronized with the print roller. When the conveyor that holds the thermoplastic sheets each transported individually from the stack of sheets to the receiving station, the sheets either going through a preheating oven or not, the speed at which the thermoplastic sheets can be transferred to the receiving station from this Conveyors are fed to be equal to or less than the peripheral speed with which the pressure roller rotates will.

In view of the fact that the number of movable parts to be synchronized with one another is very small, and that the pressure roller also acts as a heating device for heating the thermoplastic sheets during their transport from the receiving station to the transfer station and at the same time serves as a conveyor for the transport of the thermoplastic sheets, it is easy to see that the device according to the invention is more compact in its dimensions than the known devices.

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In the following, an embodiment of the invention is explained in more detail with reference to the figures.

Fig. 1 shows a side view of a device according to the invention for producing thermoplastic copies,

Fig. 2 shows, on an enlarged scale, a perspective view of a pressure roller and the associated support device in the device according to FIG. 1,

Fig. 3 shows, on an enlarged scale, an end view, with part of the device being cut away, and illustrates the details of the pressure roller and the associated support device.

Fig. 4 shows, partly broken away, a side view of the plate and its associated parts in the device according to Fig. 1,

Fig. 5 shows a rear view of the device shown in Fig. 4 with the plate in section;

Fig. 6 shows a front view of part of the device with the finishing roll and its support device and a fluid circuit are visible on an enlarged scale.

FIG. 7 shows a front view of a trimming unit which is present in the device according to FIG. 1.

Fig. 8 shows a longitudinal section on an enlarged scale

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by a molding unit which is present in the apparatus of Fig. 1 and illustrates the details of a the opposing tenons formed in the duplicating board, and

Fig. 9 shows a side view of a modified embodiment the finishing roller that can be used in the device according to the invention.

Before the detailed description of the exemplary embodiment, it should be noted that through all of the figures the same parts are provided with the same reference numerals. The invention is based on an apparatus for manufacturing illustrated by duplicating disks capable of three duplicating plates per minute of thermoplastic sheets of polypropylene resin with dimensions approximately a newspaper format 420 mm wide and 594 mm long correspond to produce. According to FIG. 1, the device according to the invention contains a feed device A, one after the other removes individual sheets of thermoplastic resin from a stack of sheets 1a and feeds them to the machine. the Feeder A delivers the sheets to a preheater B in which the thermoplastic resin is preheated will. The sheets of preheated thermoplastic resin are fed to a rolling device C, where they are attached to a Pick-up station to be placed on a pressure roller. The pressure roller transports the sheets while they continue to heat up become a transfer station. Furthermore, a heating device is provided, the sheets of thermoplastic Resin as it is transported through the platen from the pick-up station to the transfer station on a certain temperature that heats up the transfer process

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at the transfer station. Furthermore, a movable support unit E is provided, the one between a Waiting position and a working position in the horizontal direction in synchronism with the rotation of the platen back and forth has forth movable plate. The plate has a flat support surface on which a paper matrix 2 is placed. This paper matrix has indentations or cavities, which are to be transferred to the thermoplastic sheet Form relief patterns. The transfer takes place at the transfer station during the passage of the plate from the waiting position to the working position. In a pressing device F the transferred thermoplastic sheet is pressed against the paper matrix lying on the plate. A trimming device G separates the thermoplastic sheet, i.e., the duplicating plate, from the one on top of the plate Paper matrix while the plate is in the working position. When trimming the thermoplastic arch or unnecessary lugs that may be present along the outer edge are removed from the duplicating plate. A conveyor H is used to transport the trimmed duplicating plate to a subsequent one Processing station and a forming unit I form the duplicating plate at least one pair of opposite one another Approaches.

The feed device A for the sheets can be of known construction and, as far as it is shown, consist of a vertically movable tray containing a stack of thermoplastic sheets 1a of the same and a predetermined format. The sheets are fed in by a known suction conveyor, the thermoplastic Sheets one at a time from the stack

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decreases as the tray is gradually moved upwards.

The Vorheiζvorrichtung B consists of a low temperature oven 11 through which a conveyor 13 extends and a high temperature furnace 12 below the rear end of the conveyor 13 is arranged. The rear end is determined by the direction of transport of the thermoplastic sheet 1a. The furnace 12 also includes a conveyor 14, but in the opposite direction to the conveyor 13 promotes. The rear end of the conveyor 13 and the front end of the conveyor 14, which is near the rear end of conveyor 13 and immediately below it are by a fork lift 15 connected to each other, which moves up and down to remove the thermoplastic sheet from the conveyor 13 to be transferred to the conveyor 14, and then to the to return to the top position for the next Ready to transport the next thermoplastic sheet.

Preferably, the thermoplastic sheet is fed through the ovens 11 and 12 at a speed of 2 to 3 meters moved therethrough by the conveyors 13 and 14 per minute and heated during this transport to a temperature at which the thermoplastic material becomes soft. Since it is important during preheating, substantially uniform heating of the thermoplastic sheet hot air circulation is preferably used in these ovens. Though the temperature of the hot air, with which the thermoplastic sheet is preheated, depends on the material type of the thermoplastic sheet,

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it should be noted that a temperature of 120 ° to 130 ° C has been found suitable for preheating thermoplastic sheets made of polypropylene resin. The temperature of the hot air is preferably regulated and thereby in a Ti
keep.

within a tolerance range of - 3 ° C to the target temperature

The time for which the thermoplastic sheet is heated is preferably 3 to 4 minutes in consideration the fact that the preheating of the thermoplastic sheet from room or ambient temperature to the Target temperature takes about 2 minutes.

Although in the embodiment described here, the preheating unit B has a low-temperature furnace 11 and a Having high temperature furnace 12, the invention is based on this not limited because a single stage preheat oven can also be used. The use of the low temperature oven 11 and the high-temperature furnace 12 for the preheating, however, not only has the advantage of being arranged of the two ovens on top of each other to result in a space-saving construction, but also enables effective preheating of the thermoplastic arch.

The roller unit C, which can best be seen in FIGS. 2 and 3, has a pressure roller 16 which is arranged below the preheating unit B and rotates in a direction, as indicated by the arrow in FIGS. 1 and 2 is indicated. Above the pressure roller 16 there are two feed rollers 17 arranged next to one another. Each of the feed rollers 17 is on its roller surface with provided with a coating of elastic material, both

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for example made of natural or synthetic rubber. This coating must be and is temperature resistant coated in turn with a film of a fluorine-containing resin on its outer peripheral surface. How one best seen from Fig. 2, the feed rollers 17 are freely rotatably mounted above the pressure roller 16, so that they exert a downward compressive force equal to the sum of their two weights on the thermoplastic Exercise sheet that has emerged from the preheating unit B and that between these rollers 17 and the pressure roller 16 formed nip was fed. Since the pressure roller 16 in a manner to be explained in more detail below is heated, the thermoplastic sheet is during its passage through the feed gap from the weight of the Rollers 17 pressed against the outer peripheral surface of the pressure roller 16 and then adheres to this peripheral surface, as that of the two surfaces of the preheated thermoplastic sheet which are on the circumferential surface of the pressure roller 16 is applied, first plasticized to such an extent is that a possible slip between the thermoplastic sheet and the roll surface no longer occurs. The feed rollers 17 run during the passage of the preheated thermoplastic sheet through the feed gap in contact with the thermoplastic sheet empty with and the sheet enlarges the feed gap against the action the downwardly pressing feed rollers 17 which are freely raised will.

The peripheral surface of the platen 16 is chrome plated and then polished smooth. The pressure roller 16 is mounted on a shaft 18 and rotates together with this. The shaft 18 is via a transmission with a

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Drive motor 19 coupled, which is for example can be an electric motor, as FIG. 3 shows. The pressure roller 16 is driven by the motor via the Transmission rotated in the direction of the arrows shown in Figs. The ends of the shaft 18 are each in bearing blocks 21 supported on the machine bed 20 in a manner as follows will be explained in detail with reference to Figs.

According to FIGS. 2 and 3, the machine bed has two upright ones Side walls 20a, each of which has a substantially U-shaped recess 20b. The corresponding Bearing block 18 is adapted to the recess 20b and by means of a wedge piece 22 on the base part of the upright side wall 20a mounted. The wedge 22 engages the underside of the bearing block while a counter wedge 23 is arranged between the wedge piece 22 and the base part of the vertical side wall 20a. This Counter wedge is adjustable.

A set screw 24 is provided on each of the vertical side walls 20a, which is secured by an overhanging The area of the side wall 20a passes through vertically and engages the upper end of the bearing block 21. Through this the bearing block 21 is held in position within the horizontal recess 20b.

With this support device, the pressure roller 16 is supported so that the size of the transfer gap between the peripheral surface of the pressure roller 16 and the flat Support surface of the plate 25 is formed, thereby

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can be changed so that the mating wedges 23 towards one another or moved away from each other, which can be done by turning the respective adjusting screws 23a. During the Rotation of the set screws 23a, the screws 24 are loosened so that the height of the bearing blocks can be adjusted freely can. Through this adjustment, the inventive Device adapt to different thicknesses of the processing thermoplastic sheets.

A head piece is located between each end face of the pressure roller 16 and the associated vertical side wall 20a 26 that does not rotate with shaft 18. Each head piece has a central bore that supports the shaft 18 surrounds and this central bore is sealed by an annular sealing part 27. Each of the head pieces 26 has an outer edge to which an axially protruding flange, which faces the end wall of the pressure roller 16, is integrally formed is. Between the free end of the axial flange and the end face of the pressure roller 16 is a Sealing part 27. These head pieces 26 are in communication with the interior of the pressure roller 16 through holes 28, which are provided in the end faces of the pressure roller 16.

The head pieces 26, which are designed as collectors, are in turn connected to a hot air source 31, to which the head piece 26 is connected with a pipe 29 via a fan 30, while the other head piece 26 is connected to the hot air source via a pipe 29a. In this way, the hot air also circulates increased temperature between the hot air source 31 and the pressure roller, whereby they first through the tube 29a and through a head piece 26 into the interior of the

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Pressure roller arrives and then through the other head piece 26,. the pipe 29 and the blower 30 to the hot air source 31 is returned. While the hot air is circulating through the inside of the hollow platen 16, the platen becomes and in particular, their outer peripheral surface is heated to a certain temperature. The hot air source 31 has a thermostat 33 that controls the temperature of the hot air as a function of the temperature of the peripheral surface the pressure roller 16 regulates. The temperature of the roll surface is recorded by a temperature sensor 32, which is arranged in the vicinity of the outer surface of the pressure roller 16.

The outer diameter of the pressure roller 16 can be in one Range from 400 to 800 mm. The pressure roller is preferably rotated in such a way that the peripheral speed is between 6 to 8 m per minute. The size of the transfer gap between the circumferential surface of the pressure roller 16 and the flat support surface of the plate 25, on which a paper matrix 2 lies, is dependent on the sum of the thickness of the paper matrix 2 and the thickness of the thermoplastic sheet 1b selected and is preferably no more than 2 mm.

So that the thermoplastic arch evenly on the roller surface and then during the passage through between the feed rollers 17 and the pressure roller 16 formed insertion gap adheres to her, the temperature of the peripheral surface of the pressure roller 16 is on a Set value which is slightly above the melting point of the thermoplastic material from which the sheet 1a is made, lies. For example, this temperature is in

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Case of a thermoplastic sheet 1a made of polypropylene resin exists in the range between 130 ° and 170 ° C. The temperature setting on this range can be done by adjusting the temperature of the hot air emanating from the hot air source 31 with the aid of the thermostat 33 is set to the appropriate value.

According to FIGS. 1 and 2, the heating unit D extends essentially from the receiving station at which the feed gap is arranged up to a point in front of the transfer station, at which the transfer gap is formed. The heating unit D therefore surrounds the platen 16, in Viewed circumferentially, approximately from the inlet gap to the transfer gap and .follows the curvature the pressure roller. 'The heating unit D has several widths Infrared radiator 34, which is parallel to the peripheral surface the pressure roller 16 run and equidistant from this to have. The heater D heats the thermoplastic sheet 1 a, which is on the peripheral surface of the pressure roller 16 adheres to a temperature substantially equal to the melting temperature of the thermoplastic sheet and is, for example, in the range from 160 ° to 190 °, when the thermoplastic sheet is a polypropylene resin.

As shown in FIGS. 4 and 5, the plate 25 which forms the movable support device E has at least two Pairs of wheels 36 with which it can be moved on two guide rails 35 which are rigidly attached to the machine bed 20 are. The plate 25 can move horizontally linearly between a waiting position and the working position will. The flat supporting surface of the plate 25 is

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provided with numerous bores 37 which are connected to a suction source 39 via a flexible hose 38 are. In the case shown, the vacuum source 39 consists of a blower that blows the air through the pores 37 suctioned in the flat support surface of the plate 25 and then blown out. The suction source 39 has the task of to generate a vacuum in order to hold the paper matrix 2 firmly on the flat support surface of the plate 25, because of the suction power it has developed. To facilitate the positioning of the paper matrix 2 Positioning rods are used on the perforated flat support surface of the plate 25 before the suction force is applied or jigs 40 which are arranged on the flat bearing surface of the plate 25 in the vicinity of the marginal edges.

The plate 25 has a water cooler 41 through which cooling water flows around the plate 25 and thus also to cool the paper matrix 2, which rests on the flat support surface of the plate 25. As a result of the water cooling in the plate 25 is an excessive sticking of the thermoplastic resin to the paper matrix 2, the otherwise it could occur at the transmitting station, when the thermoplastic sheet is in a semi-flowable state and is pressed against the paper matrix, avoided. In addition, the rapid cooling of the thermoplastic sheet, which is applied to the paper matrix 2 the plate 25 was transferred, facilitated.

The linear back and forth movement of the plate 25 is done by a hydraulic cylinder 42. The hydraulic cylinder 42 has a left chamber and a right chamber. Both chambers are in a cylinder and are through

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a piston (not shown) connected to each other, one end of which is attached to a piston rod 42a is. The other end of the piston rod 42a is connected to the plate 25.

In the construction described so far, the plate 25 is moved from the waiting position to the working position, when a pressure medium is supplied to the left chamber of the cylinder 42 with the piston rod 42a extended will. The plate 25 is moved back from the working position to the waiting position when the print medium is in the right chamber of the cylinder 42 is let in, the piston rod 42 being retracted into the cylinder.

Since the paper matrix 2, which is on the flat support surface of the plate 25 must be precisely aligned with the thermoplastic sheet 1 a, which is produced by the pressure roller 16 transported from the receiving station to the transfer station is while he is on the ümfangsflache of the pressure roller 16 adheres, the speed of movement of the plate 25 must be during the movement from the waiting position to Working position can be synchronized with the peripheral speed of the pressure roller 16. The speed of movement of the plate 25 from the working position back to the waiting position can preferably be higher than the forward speed from the waiting position to the working position.

For the purpose of synchronization is a fluid circuit with a solenoid-controlled switching valve SV with a first and a second limit switch 43 and 44 connected in such a way that only when the plate 25 is in the waiting

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position is withdrawn, the first limit switch 43 supplies an electrical signal to the switching valve SV so that this connects the left chamber of the cylinder 42 to an electric pump P, the suction line with connected to the swamp. As a result, the plate 25 moves into the working position shown in phantom in FIG. 4. The second limit switch 44 generates an electrical one Signal to switch the switching valve SV as soon as the plate has reached the working position. Then it will be the right chamber of the cylinder 42 is connected to the pump P and the left chamber to the return line tied together.

It is assumed that the plate 25 is in the waiting position shown and that the switching valve SV connects the pressure line of the pump P to the left chamber of the cylinder 42. The pump starts running like this that pressure medium is pumped from the sump into the left chamber of the cylinder 42 as soon as an electrical signal, generated by a photoelectric element 45 arrives. The photoelectric element 45 responds to the passage of the front end of the thermoplastic sheet la, which rests on the rotating pressure roller 16. In this way, the plate 25 is moved from the waiting position to the working position as soon as the leading edge of the thermoplastic sheet on the platen was detected by the detector 45. In the working position protrudes the piston rod 42a out of the cylinder 42.

When the plate 25 has reached the working position, the second limit switch 44 is actuated and generates an electrical one Signal that switches the switching valve in such a way that

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that the fluid line leading to the right chamber of the cylinder

42 leads, connected to the pump P, which is still switched on will. Therefore, the plate 25, which is in the working position, can now be withdrawn, by retracting the piston rod 42a into the cylinder 42. After the plate 25 in the illustrated Has returned to the waiting position, the limit switch generates

43 the electrical signal with which the pump P is switched off is and the switching valve SV is switched to a position in which the fluid line between the sump or the pump P and the left chamber of the cylinder 42 is closed in order for the next movement cycle the plate 25 to be ready.

Between the limit switch 44 and the switching valve SV there is a delay circuit (not shown), which causes the plate 25 for a certain period of time, the purpose of which will be explained in the Working position remains.

The process of transferring the thermoplastic sheet, which is essentially semi-fluidized, into the Indentations or cavities in the paper matrix 2 are pressed in when the pressure roller is rotating sheets rotated in the direction of the transfer station and the paper matrix 2 lying on the plate 25 moved from the waiting position to the working position pass through the transfer gap at the same time, between the peripheral surface of the pressure roller 16 and the surface of the plate 25 is formed.

After the transfer process, the thermal

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plastic sheet which was pressed against the paper matrix 2 during the passage through the transfer gap, to stretch as a result of the cooling of the paper matrix 2 on the water-cooled plate 25 after being in contact is cooled with the paper matrix 2. Therefore, the thermoplastic sheet is on the paper matrix 2 on the Plate 25 transferred and moved with the bow in the working position after it has moved from the peripheral surface the pressure roller 16 has detached. From the moment in which the rear edge of the plate 25 (based on the direction of movement of the plate in the working position) the Transfer gap has passed while the plate 25 moves into the working position and until it reaches this has, the thermoplastic material sheet is transported on the paper matrix 2, which in turn on the flat support surface the plate 25 is and is held by the suction force.

The squeezing device F, which is located above the machine bed 20 is arranged and lies essentially between the transfer gap and the working position of the plate 25, contains a hollow cylindrical squeegee roller 46 whose circumferential surface is similar to that of the pressure roller 16 is polished smooth. The nip roller is at such a vertical distance from the flat support surface the plate 25 arranged so that between it and the plate 25 there is a nip. This squeegee roller 46 has WoIlenstubfen from the respective end faces stand out and run along the longitudinal axis of the roll. These stub shafts are rotatably mounted in bearing blocks 47. These bearing blocks 47 are adjustably attached to the machine bed 20 in a similar manner to the bearing blocks

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21 so that the size and width of the squeeze area between the peripheral surface of the squeegee roller 46 and the flat support surface of the plate 25 can be set can be done by making similar adjustments to adjust the size and width of the transfer gap can be.

The nip roller 46 can be coupled to a drive device that sets it in rotation. In the illustrated In the case, however, the squeegee roller 46 is freely rotatable about the stub shafts attached to each end. Although the roller 46 is not driven separately, it does its job by moving itself while it is moving of the thermoelastic sheet transferred to the paper matrix together with the plate 25 through the nip rotates into the working position in contact with the thermoplastic sheet and exerts a compressive force on the exerts thermoplastic arch. The nip roller preferably has an outside diameter of about 300 mm. As 6 shows, the squeegee roller 46 is water-cooled and for this purpose one of the stub shafts is the roller 46 pierced in the longitudinal direction so that a cooling line 49a can protrude into the interior of the roll. One end of the cooling line 49a is connected to a manifold 49b, which in turn is connected to a coolant source 49, which supplies the cooling medium, e.g. cooling water, via a feed pump Pa. The hollow interior of the squeegee roller 46 is in connection with the coolant source 49 via the distributor 49b, because the coolant pipe 49a ends open inside the nip roll 46, and between its tube wall and the roll shell, the cooling medium can to the Flow back to distributor 49b. With the one described so far

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Construction, the cooling medium flows in the direction of the arrow from the pipe 49a into the interior of the squeegee roller 46 and from there back to the coolant source 49. To maintain the temperature of the squeegee roller 46 at a certain level A thermostat 48 is provided which has a temperature sensor for determining the temperature of the cooling medium in the coolant source 49. A heater H serves within the coolant source 49 to heat the cooling medium in the event that the determined temperature the cooling medium falls below a predetermined value,

Since the thermoplastic sheet transferred to the matrix can be cooled quickly when the temperature of the Squeegee roller 46 is low, squeegee roller 46 is preferably set to a temperature in the range of 5 ° to 80 ° C cooled, which is lower than the temperature of the thermoplastic sheet.

The use of the squeezing unit F in the embodiment described is advantageous because the thermoplastic sheet which has been pressed against the paper matrix 2 and onto which the plate 25 during the movement of which was transferred to the paper matrix carried in the working position, during the passage through the nip is rolled flat again against the Papxermatrix 2. So the 'details of the relief pattern are transferred on the paper matrix to the thermoplastic sheet or the thermoplastic sheet.

The trimming unit G separates the thermoplastic sheet from the paper matrix lying on the plate 25 and

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then cuts the edges of the loosened thermoplastic sheet. It is at the work position or End position of the plate 25. As FIG. 7 best shows, the trimming unit G contains a cutting device 52, which is arranged immediately above the plate 25 at the end position and perpendicular to the plane of the support surface the plate 25 is movable between a lifting and a lowering position. For this purpose is the cutting device 52 articulated to the ends of piston rods 51 which are adjusted by hydraulic cylinders 50. the Hydraulic cylinders 50 are connected to a pressure source 56 and attached to a beam 20c that supports the machine bed 20 is spanned and arranged above the cutting device 52. The cutting device 52 has several Vacuum suction cups 53 on the type of pneumatic cylinders that can be advanced and withdrawn. the Suckers 53 are pneumatically connected to a vacuum source 57. On the cutting device 52 is also a Pressure plate 54 attached, which is also perpendicular to the plane of the support surface of the plate 25 upwards and downwards is movable below.

A counter knife 55, which is fastened to the machine bed 20, interacts with the cutting device 52. the Cutting device 52 effects, together with counter knife 55, the cutting off (trimming) of the edge of the thermoplastic Arc when it is lowered, starting from its lifting position, as will be explained below.

To facilitate the separation of the thermoplastic sheet from the paper matrix, which is on the flat support surface the plate 25 is firmly sucked in the end position,

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can according to FIG. 1, a cooling air dispenser 58 between the Squeezing unit F and the trimming unit G can be arranged so that the cooling air is directed onto the thermoplastic sheet which rests on the paper matrix covering the plate 25 in the working position. This will make the thermoplastic sheet cooled.

If, during operation of the device, the plate 25 carrying the thermoplastic sheet on the paper matrix 2 in the End position arrives and if the corresponding signal is generated by the limit switch 44, which indicates that the plate 25 has reached the end position, this signal is sent to the switching valve SV via the (not shown) Delay circuit supplied and on the other hand also the Vacuum source 57 to put this into operation.

During the time set on the delay circuit, there will be vacuum source 57 upon arrival the plate 25 is switched on in the end position, the vacuum suction cups 53 shut down and suck the thermoplastic Sheet 1b which rests on the paper matrix 2 covering the plate 25. After that, the suckers 53, while they are still sucking on the thermoplastic sheet 1b, raised again and released in the process, the thermoplastic sheet from the paper matrix 2, which is still on the flat support surface of the plate 25, which is in the end position, is held. While the sucker 53 is back in the retracted position enter, the time set on the delay circuit expires and the plate 25 therefore begins its retreat movement from the end position at a predetermined speed to the waiting position. She takes the

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Paper matrix 2 with.

Then, by actuating the cylinder, the cutting device, starting from its lifting position, lowered into the lowering position while the thermoplastic sheet 1b is held by the vacuum cups 53 will. During the movement of the cutting device to its lowering position, the cutting device 52 operates with the counter knife 55 and therefore cuts the edges of the thermoplastic sheet 1b, which is from the suckers 53 is detained. Thereafter, the cutting device 52 returns to the lifting position, while the thermoplastic The sheet is released from the suction cups 53. The wrinkle plate 1c produced in this way is now ready for use as a printing plate.

The thermoplastic sheet 1c, i.e., the corrugated sheet, which has been released by the suckers 53 falls by gravity onto a belt conveyor 59, the end of which it feeds is below the counter knife 55. The conveyor 59 leads to a lifting device 60 through which the Vervxelfältxgungsplatte is raised and then fed to a molding unit I, which is referred to below on Fig. 8 will be explained.

The task of the molding unit I is to produce two projections or tenons on two opposite edges of the vervxelfältxgungsplatte 1c to be attached. The approaches should be attached in the opposite direction to the relief formations and serve to attach the sealing plate to the impression cylinder of a high speed rotary press. The mold unit I can be constructed so that during

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the transport of the duplication plate 1c by an endless conveyor 61 the approaches continuously with (not shown) rollers are attached. Alternatively, the molding unit I has such devices as FIG. 8 shows.

In the case of FIG. 8, the duplicating plate or printing plate 1c is placed on a table 62 with one of its edges abutting against a stop rail 63 which is attached to a support structure 20e. The edge region 1c ¹ , which adjoins the edge abutting against the stop rail 43, protrudes above the table 62 and is acted upon by a pressing device 67 with a tapered mandrel, which is held in contact with that surface of the reproduction plate 1c which facing away from the relief surface of this plate. A heating element 66 is also attached to the pressing device. A part 68 is attached to one side surface of the pressing device 67 and the other side surface is provided with a lining 64 made of heat-insulating material. The pressing device also has a rubber layer attached at 65 to protect the duplicating plate 1c, which is thus held in position by the pressing device, from scratches or other damage.

A punch 69 cooperates with the pressing device and can be displaced on the table 62 in the direction of the arrow in FIG. When this punch 69 is brought into its lifting position, it protrudes between the stop rail 63 and the table 62 and thereby bends the area 1c ^{1 of} the reproduction plate 1c

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Way bent area 1c serves as an approach for attaching the duplicating plate to the printing cylinder a High speed rotary press. This allows the lugs to be on opposite edges of the duplicating plate be generated.

As a material for the thermoplastic sheet and therefore also for the thermoplastic duplicating plate that comes with the device according to the invention is produced, any thermoplastic resin can be used, the one has a relatively high softening point and is sufficiently resistant to an oil contained in normal printing inks. The material is extremely inexpensive and can be recycled. The preferred material for the duplicating plate to be made is a polyethylene resin or a polypropylene resin is used. The cheapest material is because of its physical Strength Polypropylene that can withstand very harsh operating conditions. The final thermoplastic reproduction sheet can be used as a printing plate in a rotary press to produce large numbers of newspaper copies from a single printing plate.

In particular, in view of the fact that both polyethylene resin and polypropylene resin can be numerous Have species that show different flow limits when melting, since ihie degrees of polymerization and / or their Molecular weights are different, preferably one or more polyethylene or polypropylene resins as the material for the thermoplastic duplicating plate, the melt flow rate of which is in the range of 3 to 10 at the temperature used during the transfer

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Process arises, lies. The plate according to the invention can be produced easily and with exact reproduction of the print details and it can be recycled, i.e. after the sheet has been used, the material can be reused to make new thermoplastic sheets will.

The size and thickness of the thermoplastic sheets to be processed can be according to the intended use of the Duplicating plate and / or according to the type of paper matrix used to make it will. If the used paper matrix after repeated application of the load by the pressure roller 16 through the thermoplastic sheet during the passage through the transfer gap, its processing properties changed, the thermoplastic sheet to be deformed can have a thickness that extends over changed its entire length according to a gradient. The use of thermoplastic arches with varying Starch also has the added benefit of making the resulting duplicating plate a more uniform one Has strength along its entire length. A similar advantage arises even when there are several holes or recesses are present in the thermoplastic sheet to be processed.

Numerous deviations from the exemplary embodiment described above are possible within the scope of the invention. For example can be a release agent, an oil or silicone, on the roller surface of the pressure roller 16 and / or on the Surface of the paper matrix are applied on which the thermoplastic sheet is placed. Furthermore can

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the matrix 2, which has been described here as consisting of paper, consist of plastic or metal.

The device shown in FIG. 9 could also be used as the squeezing unit F, in which an endless Belt 70 revolves around several rollers 71, 72 and 73. The intermediate roller 73 is not necessary in every case. the Squeeze unit F may further include a tension pulley 74 that keeps the belt under tension. One of the reels 71, 72 can be driven via a corresponding drive device. The lower run of the belt pushes off at the top flat against the thermoplastic sheet which rests on the plate 25 together with the matrix.

To carry out the movement of the plate 25 and the cutting device 52 electric drive systems can also be used instead of hydraulic drive devices will.

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Claims (1)

Expectations 1. Apparatus for the production of a thermoplastic., - ■ 'Vervielfxgungsplatte with relief image on one surface side , characterized in that a rotating hollow cylinder (16) is provided, which is behind with each rotation at a receiving station (17) and at one in the direction of rotation The transfer station arranged in the receiving station moves past that a feed device successively applies thermoplastic sheets to the hollow cylinder, where they adhere along the transport path between the receiving station (17) and the transfer station, that a carriage (25) with a flat support surface for attaching a matrix (2 ), which has the complementary relief image of the relief image to be generated on the thermoplastic sheet, along a path which runs transversely to an imaginary plane passing through the longitudinal axis of the hollow cylinder (16), between a waiting position and an end position, and that the movement of the sledge (25) is synchronized from the waiting position to the end position with the rotation of the hollow cylinder in such a way that the thermoplastic sheet (1a) transported by the hollow cylinder at the transfer station matches the matrix (2) lying on the carriage (25). 2. Device according to claim 1, characterized in that a heating device arranged outside the hollow cylinder (16) is provided for heating the thermoplastic sheet transported by the hollow cylinder, the such a hot temperature and such an expansion - 38 - 7 09 810/0288 has that the thermoplastic sheet on the hollow cylinder softens and becomes substantially semi-liquid. 3. Apparatus according to claim 1 or 2, characterized in that the thermoplastic material of the sheet (1 a) during its passage through a transfer gap between the peripheral surface of the hollow cylinder (16) and the Support surface (40) of the slide (25) is formed when the slide is located below the hollow cylinder, is pressed into the negative relief of the matrix, and that a separating device (G) is provided, which on the Matrix (2) removed thermoplastic sheet (1a) from the matrix when the carriage (25) reaches its end position has reached. 4. Device according to one of claims 1 to 3, characterized in that the hollow cylinder (16) has a feed device (26) for introducing a heating medium, and that a regulated heating device (31) is provided which keeps the temperature of the outer cylinder surface at a predetermined value. 5. Device according to one of claims 1 to 4, characterized characterized in that a preheating device (B) is arranged in front of the receiving station (17) which has a device (13, 14) for the individual supply of thermoplastic sheets (1a) to the receiving station. 6. Apparatus according to claim 5, characterized in that the preheating device has a low temperature range (11) and a high temperature region (12), and that a transport device is provided that the - 39 - 709810/0288 thermoplastic sheets successively first through the low temperature range and then through the high temperature range leads through. 7. Device according to one of claims 1 to 6, characterized in that at least at the receiving station a feed roller (17) is arranged, which is rotatable on the hollow cylinder (16) rests and the thermoplastic Arch presses against the circumferential surface of the hollow cylinder. 8. Device according to one of the preceding claims, characterized in that the carriage has a plate (25), has a flat support surface forming plate (25) with an inner chamber that the chamber over numerous openings (37) is in communication with the receiving surface, and that the chamber is connected to a suction source (39) is connected, whereby the matrix (2) is held by suction on the support surface. 9. Device according to one of claims 1 to 8, characterized in that for synchronizing the movement of the carriage (25) with the rotation of the hollow cylinder (16) one on one edge of the thermoplastic sheet (1a) responsive photodetector (45) is arranged along the path of rotation of the hollow cylinder, and that the photodetector (45) the beginning of the linear movement of the slide (25) controls. 10. Device according to one of claims 1 to 9, characterized in that along the path of the slide (25) a pressing unit (F) is arranged between the transfer station (C) and the end position of the carriage, - 40 - 709810/0288 which presses the thermoplastic sheet transferred onto the matrix resting on the carriage into the matrix. 11. The device according to claim 10, characterized in that that the press unit (F) has at least one cylindrical roller (46). 12. The device according to claim 10, characterized in that the pressing unit (F) has an endlessly rotating belt (70). 13. Device according to one of the preceding claims, characterized characterized in that a trim device (G) for Trimming of the edges of the thermoplastic sheet (1a) lying on the carriage (25) is provided in the end position is. 14. Device according to one of claims 1 to 13, characterized characterized in that a shaping device (I) is arranged in the processing path behind the trimming device (G), which forms lumps or lugs on the thermoplastic sheet (1a) provided with the relief. 15. Device according to one of the preceding claims, characterized in that the carriage (25) with the Piston rod (42a) of a hydraulic piston-cylinder unit (42) is connected. 16. A method of making a thermoplastic duplicating plate with a relief pattern on one surface side, characterized in that a sheet of material made of thermoplastic material - 41 - 70981 0/0288 a rotating hollow cylinder is placed, which is heated and whose temperature is adjustable Value is kept constant that the thermoplastic sheet is pressed firmly on the circumferential surface of the hollow cylinder so that it adheres to this, and on the hollow cylinder from a receiving station to a transfer station is transported that the thermoplastic sheet during its transport on the hollow cylinder in addition by is heated outside in such a way that it softens, that a matrix, which is a relief pattern to be applied complementary Has pattern that is fed to the transfer station on a linearly moving carriage, the direction of movement of which. device runs at right angles to an imaginary axis passing through the longitudinal axis of the hollow cylinder, and which is movable between a first and a second position that at the transfer station the thermoplastic Arc is detached from this during the further rotation of the hollow cylinder and on the slide The retained matrix remains adhered to the fact that the softened and essentially semi-liquid thermoplastic sheet material allows the sheet to penetrate into the indentations of the matrix forming the relief pattern and then transfers the semi-liquid thermoplastic sheet to the matrix and these on the carriage together with the sheet in mutual synchronization from the transfer station moved that then a cooling of the thermoplastic sheet transferred to the matrix on the Slide takes place, and that finally the cooled thermoplastic sheet is removed from the matrix and the thermoplastic duplicating plate. 17. The method according to claim 16, characterized in that - 42 - 7 0 9810/0288 the thermoplastic sheet is preheated to a temperature which is lower before being fed to the hollow cylinder is than the temperature of the hollow cylinder. "| 8. The method according to claim 16 or 17, characterized in that that at the receiving station a feed roller with an axis running parallel to the axis of the hollow cylinder in one a predetermined distance from the cylinder surface of the hollow cylinder is arranged, and that the thermoplastic Sheet while passing the feed roller when passing through between the feed roller and the hollow cylinder formed gap sticks to the circumferential surface of the hollow cylinder. 19. The method nach.Anspruch 16, characterized in that after the transfer, the thermoplastic sheet is pressed onto the matrix lying on the carriage while the sheet is transported from the first to the second position. 20. The method according to any one of claims 16 to 19, characterized characterized in that the plastic sheet in addition to the heating by the hollow cylinder during his Way from the receiving station to the transferring station is heated. 21. The method according to any one of claims 16 to 20, characterized in that the matrix is on the flat support surface is held in place by suction. 22. The method according to any one of claims 16 to 21, characterized in that the slide is cooled with water - 43 - 709810/0288 is, and that the matrix lying on the flat support surface of the carriage by contact with the support surface during the movement of the carriage from the first position to the second position to a predetermined one Temperature is cooled. 23. The method according to any one of claims 16 to 22, characterized characterized in that the transfer of the thermoplastic sheet from the hollow cylinder to the matrix by a Temperature difference between the circumferential surface of the hollow cylinder and the matrix takes place. 24. The method according to any one of claims 16 to 23, characterized in that the peripheral surface of the hollow cylinder to facilitate the detachment of the thermoplastic sheet and the transition to the paper matrix with a Release agent is provided. 709810/0288