Plant for producing a coextruded multi-layer film, apparatus for coextruding a multilayered coextrusion composite and method for coextruding and also method for operating a plant and/or apparatus for this purpose

Abstract

The invention relates to a plant for producing a coextruded multilayer film with at least one extruder device for providing material melts of thermoplastic materials, with a device comprising a coextrusion adapter and a nozzle part for coextruding a multilayer coextrusion composite of interconnected individual layers, wherein the coextrusion adapter has a central channel for producing a central layer of the coextrusion composite, at least one coextrusion channel for producing at least one further layer of the coextrusion composite interacting with the central layer, a plurality of displaceable adjusting elements for adjusting layer thicknesses and/or layer thickness profiles of individual layers of the coextrusion composite, and adjusting devices for actuating the adjusting elements, having a drive unit for driving the adjusting devices, having a measuring device for measuring layer thicknesses and/or layer thickness profiles of individual layers of the multilayer coextrusion composite, the measuring device being set up to measure the individual layer thicknesses and/or the individual layer profiles downstream of the nozzle part, and having a system controller for controlling the system, wherein the system controller comprises a controller unit which is set up so that relative positions of adjusting elements can be manipulated automatically, preferably iteratively, by means of the drive unit as a function of layer thicknesses and/or layer thickness profiles measured on the multilayer film already leaving the nozzle part.

Claims

1. Apparatus (10) for coextruding a multilayer coextrusion composite (3) comprising: interconnected individual layers (5, 6) of thermoplastic materials, having a coextrusion adapter (12) which has a central channel (40) for producing a central layer (5) of the coextrusion composite (3), at least one coextrusion channel (42) for producing at least one further layer (6) of the coextrusion composite (3) interacting with the central layer (5), a plurality of displaceable adjusting elements (47), each comprising a rotatable member mounted in a threaded bore, for adjusting layer thicknesses (50) or layer thickness profiles of the individual layers (5, 6) of the coextrusion composite (3) and adjusting devices (53), each comprising a drive-side engagement structure (55) configured to receive a tool for actuating the adjusting elements (47), and with a nozzle part (33) through which the multilayer coextrusion composite (3) is discharged, wherein a measuring device (24), positioned downstream of the nozzle part (33), configured to automatically measure the layer thicknesses (50) or the layer thickness profiles of the multilayer coextrusion composite (3) is arranged downstream of the nozzle part (33), wherein the apparatus (10) being set up to manipulate the plurality of displaceable adjusting elements (47) automatically by means of measurement data obtained from the measuring device (24), wherein the apparatus further includes an actuator (58) being located at a distance (62) of more than 50 mm from the coextrusion adapter (12), and wherein a flexible, thermally conductive coupling element (66) is arranged between an input-side drive element (55) of an adjusting device (53) and an output-side output element (65) of the actuator (58).

2. Device (10) according to claim 1, wherein the input-side drive element (55) of the adjusting device (53) and the output-side output element (65) of the actuator (58) have different axes of rotation, the axes of rotation being arranged offset from one another.

3. Device (10) according to claim 1, wherein a plurality of actuators (58) are combined to form a drive unit (15).

4. Device (10) according to claim 1 further comprising at least one manipulator, wherein the actuator (58) is arranged on the at least one manipulator and can be brought temporarily in operative contact with the adjusting devices (53) of the coextrusion adapter (12) or can be temporarily spaced apart from the adjusting devices (53) of the coextrusion adapter (12).

5. The apparatus of claim 1, wherein the thermally conductive coupling element (66) is comprised of a flexible heat bridging element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Components, which in the individual figures at least substantially correspond in terms of function, can be marked here with the same reference numbers, whereby the components do not have to be numbered and explained in all figures.

(2) The drawings show as follows:

(3) FIG. 1 schematically shows a reduced partial view of a system for producing a coextruded multilayer film with a coextrusion device essentially comprising a coextrusion adapter and a nozzle part, with a measuring device arranged downstream of the nozzle part, with a drive unit for the coextrusion adapter, with a system controller comprising an output unit and with a controller unit;

(4) FIG. 2 schematically shows of a further partial view of the system shown in FIG. 1;

(5) FIG. 3 schematically shows a sectional view through a coextruded multilayer film produced by means of the system shown in FIGS. 1 and 2, with a central layer and three further layers extruded thereon;

(6) FIG. 4 schematically shows a sectional view of the coextrusion adapter of the line shown in FIGS. 1 and 2;

(7) FIG. 5 schematically shows a partial perspective view of the coextrusion adapter shown in FIG. 4 with the drive unit partially shown flanged thereto; and

(8) FIG. 6 schematically shows a representation of an alternative coextrusion adapter and an alternative drive unit with a manipulator.

(9) The system 1 shown in particular in FIGS. 1 and 2 as a first possible embodiment is set up for producing a coextruded multilayer film 2, which is produced from a multilayer coextrusion composite 3 (cf. for example FIG. 4).

(10) While the coextruded multilayer film 2 shown by way of example in FIGS. 1 and 3 consists of an extruded central layer 5 and three further coextruded layers 6, the multilayer coextruded composite 3 shown by way of example in FIG. 4 shows an extruded central layer 5 with a total of four additional coextruded layers 6.

(11) The line 1 has a machine direction 7 in which the multilayer coextrusion composite 3 or the coextruded multilayer film 2 is conveyed along a processing section 8 through the line 1.

(12) According to the illustrations according to FIGS. 1 and 2, in particular a coextrusion device 10 for coextruding the multilayer coextrusion composite 3 with a frame 11, on which a coextrusion adapter 12 with its block base body 13 is arranged, a drive unit 15, a system controller 17, which in particular comprises a controller unit 18, a memory unit 19, an output unit 20 as well as a digital network connection 21, which has a plurality of digital interfaces 22, 23 (only shown and referenced by way of example) for a data connection of all data-processing-relevant system components (not referenced again), and a measuring device 24, the latter being equipped in this embodiment with an infrared apparatus 25, are shown.

(13) In particular in the representation according to FIG. 4, the coextrusion device 10 is shown more clearly with the coextrusion adapter 12, to which a channel package part 30 with a distributor plate 31 attached thereto is fixed on the head side for flanging on extruder devices not shown here, in order to melt different materials 32 (only numbered by way of example). On the base side of the coextrusion adapter 12, a nozzle part 33 is attached, which is flanged to the coextrusion adapter 12 by means of a nozzle connection flange 34 for supporting the nozzle part 33. The nozzle part 33 is configured as a slot die 35.

(14) In any case, the measuring device 24 already mentioned above is arranged in particular downstream of the slot die or the nozzle part 33, as viewed in the machine direction, that is to say downstream of this nozzle part 33.

(15) The coextrusion adapter 12 shown here by way of example has a central channel 40 for producing the central layer 5 of the multilayer coextrusion composite 3 and a total of four further coextrusion channels 42 (numbered only by way of example) for producing four further layers 6 of the coextrusion composite 3, namely two further layers 6 lying further inwards, which interact directly with the central layer 5, and two further layers 6 lying further outwards, which interact or are connected indirectly with the central layer 5 via the additional layers 6 lying further inwards.

(16) Furthermore, the coextrusion adapter 12 has a plurality of adjusting elements 47 (numbered only by way of example) by means of which not only different layer thicknesses 50 (see FIG. 3) but also different layer thickness profiles (not shown) can be individually set over the width of the multilayer coextrusion composite 3. Since such adjusting elements 47 are already known from the prior art, they are not described in more detail here. In any case, several such adjusting elements 47 per channel 40 or 42 are arranged next to each other in the direction 52 of width of the coextrusion adapter 12, so that in particular in this embodiment with regard to the four further coextrusion channels 42 not only their channel cross-sections (not separately numbered) and thus also layer thicknesses 50 as a whole can be individually manipulated, but in addition also channel cross-section profiles (not shown) and consequently also layer thickness profiles can be individually set.

(17) For actuating the adjusting elements 47 located deep in the coextrusion adapter 12, the coextrusion adapter 12 also has a corresponding number of adjusting devices 53, which project with their input-side drive elements 55 beyond the outside 56 of the coextrusion adapter 12 or are at least accessible from the outside, so that the drive unit 15 can drive the adjusting devices 53, whereby ultimately the adjusting elements 47 can in turn be actuated by the drive unit 15. The adjusting devices 53 also have index pin elements 57, by means of which the relative positions (not numbered) of the adjusting elements 47 arranged in the coextrusion adapter 12 can be determined and checked. For this purpose, the index pin elements 57 and the respective input-side drive elements 55 associated with them are fixedly connected to one another, so that each movement of an input-side drive element 55 is synchronized with the movement of the associated index pin element 57.

(18) In this case, the respective relative position of an adjusting element 47 is determined by means of an index dimension X.sub.1, X.sub.2 or X.sub.3 (cf. FIG. 6) drawn in by way of example, wherein such an index dimension X.sub.1, X.sub.2 or X.sub.3 can be measured, for example, in relation to a reference surface (not separately numbered), for example the outer face 56 of the coextrusion adapter 12. Alternatively, such a measurement can also be carried out by means of an eddy current sensor, an inductive, capacitive or optical distance or path sensor, a measuring probe or the like.

(19) According to the illustration in FIG. 5, the coextrusion adapter 12 and the drive unit 15 are shown at least partially without a housing, and it can be clearly seen that a plurality of actuators 58 (numbered only by way of example) are on the one hand combined very closely together to form an actuator package 59 and on the other hand are arranged at a distance 62 from the coextrusion adapter 13 or its block base body 13 by means of a heat shield device 60. Thus, the individual actuators 58 are better protected from heat emanating from the coextrusion adapter 13 not only by the gap 63 resulting from the distance 62, but also by a heat shield 64 of the heat shield device 60, wherein, in the sense of the invention, a simple metal sheet is already considered to be heat shield 64.

(20) In order to be able to bridge the gap 63 between the actuators 58 or, in particular, their output-side drive elements 65 and the input-side drive elements 55 of the adjusting devices 53 in terms of drive technology, a bridging element 66 in the form of a flexible cardan shaft 67 is arranged in each case between each output-side drive element 65 of an actuator 58 and each input-side drive element 55 of an associated adjusting device 53.

(21) This means that such a flexibly designed bridging element 66 can also be used to compensate for an offset between an output-side drive element 65 of an actuator 58 and an associated input-side drive element 55 of an adjusting device 53.

(22) In this respect, the output elements 65 on the output side and an associated drive element 55 on the input side can have different or offset axes of rotation (not referenced), whereby it is possible, in particular, to arrange the input side drive elements 55 closer together than can be the case with the output drive elements 65 of the actuators 58 due to the dimensions of the actuators 58.

(23) According to the illustration in FIG. 6, another alternative embodiment of a different coextrusion adapter 12 in combination with a different drive unit 15 for the system 1 for producing a coextruded multilayer film 2 or for its device 10 for coextruding a multilayer coextrusion composite 3 is shown, whereby in the following only the differences to the first embodiment shown in FIGS. 1 to 5 are described in order to avoid repetitions. While the other coextrusion adapter 12 of FIG. 6 is essentially identical in construction with the coextrusion adapter 12 of the first embodiment, the other drive unit 15 of FIG. 6 differs by having a manipulator 70, on which a single actuator 58 is arranged.

(24) By means of the manipulator 70, each individual actuator 58 can be moved spatially in such a way that each adjusting device 53 on the same side of the coextrusion adapter 12 can be approached individually one after the other.

(25) For this purpose, the output element 65 of the actuator 58 on the output side is in each case brought into operative contact with the drive element 55 on the input side, so that the respective adjusting device 53 is driven, and thus the associated adjusting element 47 can be manipulated accordingly with regard to its relative position on or in the respective extrusion channel 5, 6.

(26) In this case, the respective associated index pin element 57 is also displaced accordingly. With a sensor device 71 additionally arranged on the actuator 58, the respective index dimension X.sub.1, X.sub.2 or X.sub.3 can be determined, with which the relative position of the respective adjusting element 47 can be determined. In this alternative example of embodiment, the sensor device 71 has a laser displacement sensor. However, confocal displacement measurements with optical sensors or laser sensors for 2D and/or 3D measurements are also possible.

(27) At this point, it should be explicitly pointed out that features of the solutions described above or in the claims and/or figures can also be combined, if necessary, in order to be able to implement or achieve the explained features, effects and advantages in a correspondingly cumulative manner.

(28) It is understood that the embodiments explained above are merely first embodiments of the invention. Consequently, the implementation of the invention is not limited to these embodiments.

(29) All features disclosed in the application documents are claimed to be essential to the invention insofar as they are new, individually or in combination, compared to the prior art.

LIST OF REFERENCE SIGNS USED

(30) 1 system 2 coextruded multilayer film 3 multilayer coextrusion composite 5 extruded central layer 6 further coextruded layers 7 machine direction 8 processing section 10 coextrusion device 11 frame 12 coextrusion adapter 13 block base body 15 drive unit 17 system controller 18 controller unit 19 storage unit 20 output unit 21 network connection 22 digital interface of the drive unit 23 digital interface of the measuring unit 24 measuring unit 25 infrared apparatus 30 channel package part 31 distributor plate 32 material melts 33 nozzle part 34 nozzle connection flange 35 slot die 40 central channel 42 other coextrusion channels 47 adjusting elements 50 layer thicknesses 52 width direction 53 adjusting elements 55 input-side drive elements 56 outer face 57 index pin elements 58 actuators 59 actuator package 60 heat shield device 62 distance 63 gap 64 heat shield 65 output-side output elements 66 bridging element 67 flexible cardan shaft 70 manipulator 71 sensor device X.sub.1 first index dimension X.sub.2 second index dimension X.sub.3 third index dimension