Method for laminating several film-like layers to form a homogeneous layered composite

Abstract

Method for laminating several film-like layers (28) of a thermoplastic material to form a homogeneous layer composite (30), - in which several layers (28) provided as web-shaped material are aligned to each other to form a film arrangement (29), - in which the film arrangement (29) is fed to a heating station (12), in which a process duration in the heating station (12) for laminating the layers into a layer composite is divided into more than two successive heating segments (13, 14, 15) in the heating station (12) in order to transfer the layers (28) as a laminated layer composite (30) to a cooling station (16) after passing through the heating segments (13, 14), and - in which the layer assembly (30) is cooled in the downstream cooling station (16), wherein the number of cooling segments (17) in the cooling station (16) is at least one number less than the number of heating segments (13, 14, 15) in the upstream heating station (12), and - in which, after the last cooling segment (17) of the cooling station (16), the layer assembly (30) is fed to a further processing station or removal station (21), characterized in that - that the heating segments (13, 14, 15) of the heating station (12) are heated to the same heating temperature.

Description

[0001] The invention relates to a method for laminating several film-like layers to form a homogeneous layer composite.

[0002] From DE 10 2017 112 509 A1, a laminating station for laminating several film-like layers of a thermoplastic material into a homogeneous composite is known. The individual layers are stacked on top of each other and placed in a laminating cassette. A heating element is positioned next to the laminating cassette. The film-like layers of thermoplastic material are laminated together under temperature and pressure to form a homogeneous composite. Subsequently, a cooling element is introduced into the laminating cassette. After the composite has cooled, the laminating cassette is removed from the laminating station. The homogeneous composite is then cooled to room temperature before being transferred to the next processing station.

[0003] US Patent 2006 / 0 000 918 A1 discloses a laminating device comprising a first and a second laminating section. In the first laminating section, layers arranged in a laminating cassette are bonded together. This first laminating section includes two preheating presses and one heating press. Following the heating press are a slow cooling press and another cooling press. The laminating cassettes are individually moved into the respective press to perform the work steps.

[0004] From US 2004 / 0 011 225 A, a laminating device is also known in which laminating cassettes are fed to a first laminating station for the production of a card body and subsequently to a second laminating station for the application of further layers to the laminating body.

[0005] From WO 2018 / 046 628 A1, a device for laminating a booklet of material sheets is known, in which the booklets of material sheets are fed into a laminating cassette at a laminating station. This laminating station is designed as a rotary indexing machine with a turntable, so that the laminating cassette is indexed from station to station.

[0006] From EP 0 134 820 A1, a method for producing plastic cards is known. In this method, several film-like layers are laminated to form a homogeneous composite in a laminating station. The layers, provided as web-like material, are fed between an upper and lower chord of a heating station and subsequently a cooling station, with a cycle-wise feed. The number of cooling segments in the cooling station, which is downstream of the heating station, is reduced compared to the number of heating segments in the heating station.

[0007] German patent application DE 29 22 151 A1 discloses a double-belt press. Press plates are arranged within an upper and a lower circulating belt, which in turn are surrounded by circulating roller chains. A heating and / or cooling device for influencing the temperature of the roller bodies of the roller chain can be associated with these press plates.

[0008] DE 85 60 011 U1 discloses a device for producing metal-clad base material for printed circuit boards. For this purpose, a double belt press is used to laminate individual prepreg layers with a resin system onto a copper foil.

[0009] DE 199 50 474 A1 discloses a device for laminating a layer structure made of at least two plastic strips in sections.

[0010] From DE 15 04 816 B, a device for the surface treatment of plastic sheets or sheets is also known. For this purpose, endlessly driven steel belts are used, which pass through heating and cooling devices arranged one behind the other in the direction of travel within the working area.

[0011] Furthermore, a laminating process is known with a laminating device designed as a rotary indexing table. A loading station is provided on this rotary indexing table, which can also be designed as a turntable. A booklet is fed into the machine, which is sandwiched between two laminating sheets, forming a laminating cassette. This laminating cassette is then fed to a heating station with a heating press. In a subsequent cycle, the laminated booklet in the laminating cassette is fed to a cooling station. The cooled laminated unit is then removed from the laminating cassette at a removal station. The laminating cassette is then indexed back to the loading station.

[0012] Alternatively, a laminating device is already known which comprises a heating station with two successive heating segments and a cooling station with two successive cooling segments, the cooling station being arranged downstream of the heating station. An upper and a lower laminating belt each run through the heating station and the cooling station. Several film-like layers are fed to these upper and lower laminating belts, which function as laminating sheets, as web-shaped material. As the film-like layers pass through the heating station and the cooling station, they are divided into two cycles. Uniform heating and lamination are achieved in the heating station. In the cooling station, the layers are cooled to room temperature before being conveyed out of the laminating station by the upper and lower laminating belts.

[0013] Since heating the foil-like layers to laminate them into a homogeneous layer composite requires a similar process time as cooling the layer composite to room temperature, the number of heating segments or cycles in the heating station and the number of cooling segments or cycles in the cooling station are the same.

[0014] The invention is based on the objective of proposing a method and a lamination station for laminating several film-like layers of a thermoplastic material into a homogeneous layer composite, in which the throughput is increased while maintaining product quality, in particular while maintaining the process time.

[0015] This task is solved by a process for laminating several film-like layers of a thermoplastic material into a homogeneous layered composite, in which several layers provided as web-like material are aligned to each other to form a film arrangement and in which the film arrangement is fed to a heating station, in which the process time for laminating the layers into a layered composite is divided across more than two successive heating segments of the heating station in order to transfer the layers as a laminated layered composite to a cooling station after passing through the heating segments of the heating station and in which the homogeneous layered composite is cooled in the downstream cooling station.wherein the number of cooling segments in the cooling device is at least one fewer than the number of heating segments in the upstream heating station, and wherein, after the last cooling segment of the cooling station, the layered composite is fed to a further processing station or removal station. This method has the advantage that the individual cycle times of the respective heating or cooling segments are shortened; at least within the heating station, the total process duration for heating and laminating the layers into a composite remains the same, but the number of heating segments is increased to more than two. This allows a shorter cycle time to be controlled for each heating segment with the increased number of heating segments than with a smaller number of heating segments in the heating station. This makes it possible to configure the cooling station with only one cooling segment or at least a certain number of cooling segments,Since the number of heating segments is at least one less than the number of heating segments, the overall cycle time can be shortened by the cycle time of one cooling segment. This leads to an increase in the throughput of the manufactured laminates. Surprisingly, it has been found that premature removal of the laminate in a state that is not yet fully cooled, such as to room temperature, does not significantly affect the quality of the laminate. Rather, it can increase productivity due to the shorter overall cycle time. Furthermore, eliminating at least one cooling segment in the cooling station can reduce costs for the entire laminating station.

[0016] In contrast to the prior art laminating station, in which two heating segments are provided in a heating station and subsequently two cooling segments in a cooling station, the method according to the invention, for example, uses only one cooling segment in the cooling station, and the heating station now has three heating segments instead of two. In this embodiment, the time required for heating is divided into three cycles instead of two. This reduces the cycle time for each heating segment by one-third, thereby shortening the cycle time in the cooling station and allowing for a corresponding increase in throughput. Preferably, the cycle times of the heating and cooling segments in the heating station and the cooling station are the same.The total process time for heating the layers to be laminated in the heating station is divided across more than two heating segments, thereby reducing the cycle time of each heating segment. This allows the cycle time of the cooling segment(s) in the cooling unit to be reduced, resulting in a shorter overall process time for producing the layer composite. Furthermore, the throughput per unit of time can be increased by using fewer cooling segments compared to the number of heating segments, or even by using only a single cooling segment in the cooling station.

[0017] The heating segments in the heating station are controlled with the same heating temperature. This prevents overheating or melting of an outer layer of the composite material being formed.

[0018] Furthermore, it is preferably provided that the laminated layer composite is cooled in the cooling station and removed from the cooling station when the layer composite temperature exceeds 313 K. Surprisingly, it has been shown that further processing of the layer composite is possible without any impairment of quality, even with regard to indentations on the respective top surface of the layer composite. Advantageously, the layer composite is removed from the cooling station after cooling to a temperature range between 320 K and 413 K.

[0019] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The features that can be derived from the description and the drawings can be applied individually or in any combination according to the invention. The drawings show: Fig. 1 a schematic view of a first non-inventive embodiment of a laminating station, Fig. 2 a schematic side view of a foil cassette, Fig. 3 a schematic side view of an embodiment of the laminating station according to the invention, and Fig. 4 a schematic view of another alternative embodiment of the lamination station that is not according to the invention.

[0020] Fig. Figure 1 shows a schematic view of a laminating station 11. This laminating station 11 comprises a heating station 12 and a cooling station 16 downstream of this heating station 12. The heating station 12 and cooling station 16 are arranged on a rotary indexing table 19. This rotary indexing table 19 can, for example, be designed as a turntable.

[0021] A loading station 20 is located upstream of the heating station 12. A dispensing station 21 is located downstream of the cooling station 16.

[0022] In the exemplary embodiment, the heating station 12 consists of two consecutive heating segments 13, 14, the cooling station 16 consists of only one cooling segment 17.

[0023] In the loading station 20, a film arrangement 29, for example in the form of a film booklet, is fed in and positioned between laminating sheets 24, 25 of a laminating cassette 26. This arrangement is shown as an example in a side view in Fig. Figure 2 shows the foil booklet. It consists of several foil-like layers 28 made of a thermoplastic material. These layers 28 are preferably die-cut to an oversize compared to a finished card body and stapled together. This forms the foil booklet. It is inserted between the laminating plates 24, 25. The laminating cassette 26 is then closed, meaning the foil booklet is held under pressure between the laminating plates 24, 25.

[0024] This foil cassette 26 is fed from the placement station 20 to the first heating segment 13 of the heating station 12. In this heating segment 13, the foil booklet is heated to a laminating temperature in order to laminate the individual layers 28. This laminating process can, for example, be divided between two or more further heating stations 14.

[0025] After the formation of a homogeneous layered composite 30 from the foil booklet, this composite layer 30 is transferred in the laminating cassette 26 to the cooling station 16, which, for example, has a cooling segment 17. In the cooling segment 17, the homogeneous composite layer is cooled. Subsequently, the homogeneous composite layer 30 is transferred with the laminating cassette 26 to the dispensing station 21. The composite layer 30 is removed from the dispensing station 21 at a temperature higher than room temperature. The composite layer 30 is preferably not cooled to room temperature before being removed from the laminating cassette 26.

[0026] This layered structure (30 layers) can be designed as a document body, particularly as a security or valuables document. Other identification documents, such as check cards, VISA cards, or similar items, can also be formed by this layered structure. In the case of a security document body, for example, an ID3 or ID1 document can be used. The ID1 or ID3 document can consist of, for example, three to fifteen layers. Security documents can also be designed with an RFID chip or other electronic components, so-called inlays, placed between or within the individual layers, which, after lamination, form a layered structure or composite body.

[0027] For example, thermoplastic layers, especially polycarbonate, are used as layers 28 for such a layer composite 30. Other materials that can be laminated with another material by pressure and temperature are also used.

[0028] In this laminating station 11, the number of heating segments 13, 14, 15 is provided to be at least one greater than the number of cooling segments 17. With three heating segments 13, 14, 15, only two cooling segments, preferably only one cooling segment 17, are provided. If four heating segments are provided in the heating station 12, two or even only one cooling segment 17 may be provided.

[0029] The homogeneous layer assembly 30 is removed from the cooling station 16 at temperatures greater than 313 K compared to the lamination temperature. Preferably, a temperature range of 320 K to 413 K is provided, at which point the homogeneous layer assembly 30 is removed from the cooling station 16. This design of the lamination station 11 allows for... Fig. Both the premature removal of the layer assembly 30 at a temperature above room temperature can lead to a significant increase in productivity through a reduction in cycle time.

[0030] In Fig. Figure 3 shows a schematic side view of an alternative embodiment of the laminating station 11. This laminating station 11 comprises an upper and lower circulating conveyor belt and laminating belt 31, 32, respectively. Within the upper and lower circulating conveyor belts 31, 32, a portion of the heating station 12 and the cooling station 16 are each provided, such that the conveyor belts 31 pass between them. At the inlet to the laminating station 11, several layers 28 are fed in as web-like material and guided between the laminating belts 31, 32 by a pair of inlet rollers 33. The heating segments 13, 14, 15 of the heating station 12 consist of an upper and / or lower movable press section. The cooling segment 17 of the cooling station 16 also consists of an upper and / or lower movable press section. The upper and / or lower pressing parts of the heating and / or cooling segments are moved towards each other by drives, in particular cylinder 34.Laminating belts 31 and 32 are guided through the intermediate layers. The layers 28 are guided through intermittently. The intermittent feed corresponds, for example, to a length 36 for the respective heating segments 13, 14, and 15, and for at least one cooling segment 17. The heating segments 13 and 14 and the cooling segment 17 are of the same length.

[0031] In this laminating station 11, the number of cooling segments 17 is also provided to be at least one fewer than the number of heating segments 13, 14. This allows for the same advantage as in the embodiment of laminating station 11 according to Fig. 1 will be achieved.

[0032] In Fig. Figure 4 shows another alternative embodiment of the laminating station 11. This laminating station 11 also comprises a loading station 20, a heating station 12, a cooling station 16, and a dispensing station 21. The individual stations are connected to one another by a rail arrangement, which is not shown in detail. This rail arrangement allows the laminating cassette 26 to be moved between the individual stations 12, 15, and 21. Preferably, in this embodiment, two heating stations 12 are connected in parallel, each heating station 12 having at least three heating segments 13, 14, 15. The number of cooling segments 17, or the cooling segment 17 in the cooling station 16, is at least one fewer than the number of heating segments 13, 14, 15.

[0033] This alternative embodiment of the laminating station 11 also exhibits the advantages of the previously described embodiments of the laminating stations 11 according to Fig. 1 and Fig. 3 up. Reference symbol list 11 Laminating stations 12 Heating station 13 Heating segment 14 Heating segment 15 heating segment 16 Cooling station 17 Cooling segment 19 Rotary indexing table 20 assembly stations 21 sampling station 23 slide booklet 24 laminating sheets 25 laminating sheets 26 laminating cassettes 28 multiple layers 29 Slide layout 30-layer composite 31 Conveyor belt 32 conveyor belt 33 Inlet roller 36 Feed

Claims

[1] Method for laminating several film-like layers (28) of a thermoplastic material to form a homogeneous layer composite (30), - in which several layers (28) provided as web-shaped material are aligned to each other to form a film arrangement (29), - in which the film arrangement (29) is fed to a heating station (12), in which a process duration in the heating station (12) for laminating the layers into a layer composite is divided into more than two successive heating segments (13, 14, 15) in the heating station (12) in order to transfer the layers (28) as a laminated layer composite (30) to a cooling station (16) after passing through the heating segments (13, 14), and - in which the layer assembly (30) is cooled in the downstream cooling station (16), wherein the number of cooling segments (17) in the cooling station (16) is at least one number less than the number of heating segments (13, 14, 15) in the upstream heating station (12), and - in which, after the last cooling segment (17) of the cooling station (16), the layer assembly (30) is fed to a further processing station or removal station (21), characterized by , - that the heating segments (13, 14, 15) of the heating station (12) are heated to the same heating temperature. [2] Method according to claim 1, characterized by , that the heating segments (13, 14, 15) and the at least one cooling segment (17) are controlled with the same cycle times for the heating or cooling process. [3] Method according to any one of the preceding claims, characterized by, that the homogeneous layer composite is cooled in the cooling station (16) and is removed from the cooling station (16) at a cooling temperature of the layer composite of greater than 313K, preferably in a temperature range between 320K and 413K. [4] Method according to any one of the preceding claims, characterized by , that the layers (28) are passed through the heating station (12) and the cooling station (16) in cycles.

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