Method and installation for producing a film or sheet from a slabstock foam, and method and system for retrofitting an installation for film or sheet production

Abstract

The invention relates to a method for producing a film (2) or sheet from a block material, in particular from a slabstock foam (3), in which at least the following regions are provided, as seen in a production direction (P) of the film (2) or sheet: a cutting region (I) for cutting the film (2) or sheet, wherein the film (2) or sheet is cut out, in a slitting-open manner, by means of a cutting unit (10) from the block material, which is continuously fed to the cutting region (1); also a passing-on region (II), adjoining the cutting region (I) and having a driven passing-on roller (20) for conveying the film (2) or sheet out of the cutting region (I); and also a secondary region (III), adjoining the passing-on region (II) and intended for further processing the film (2) or sheet, in particular a winding region (III) for winding the film (2) or sheet into a coil (4). In this case, there is a cutting-region stress in the film (2) or sheet in the cutting region (1) upstream of the passing-on roller (20), and there is a secondary stress in the film (2) or sheet in the passing-on region (II) upstream of the secondary region (III), in particular winding region (III). The invention also relates to an installation (1) for film or sheet production, and to a method for retrofitting an installation (1) for film or sheet production, and to a system for retrofitting an installation for film or sheet production.

Claims

1. A method for producing a film or sheet from a block material, in particular from a slabstock foam, in which at least the following regions are provided, as seen in a production direction of the film or sheet: a cutting region for cutting the film or sheet, wherein the film or sheet is cut out, in a splitting-open manner, by means of a cutting unit from the block material, which is continuously fed to the cutting region, a passing-on region adjoining the cutting region and having a driven passing-on roller for conveying the film or sheet out of the cutting region, and a secondary region adjoining the passing-on region and intended for further processing the film or sheet, in particular winding region for winding the film or sheet into a coil, wherein there is a cutting-region stress in the film or sheet in the cutting region upstream of the passing-on roller and there is a secondary stress in the film or sheet in the passing-on region upstream of the secondary region, in particular winding region, characterized in that the method is at least partially controlled in such a manner that: a) at least one parameter representing the cutting-region stress is automatically detected in the cutting region, and/or b) at least one parameter representing the secondary stress is automatically detected in the passing-on region, and in that at least one of the following process parameters is regulated on the basis of at least one of the parameters detected in step a) or b): a drive parameter (a.sub.1) of the block material, a drive parameter (a.sub.2) of the driven passing-on roller, and/or a drive parameter (a.sub.3) in the secondary region for moving the film or sheet for further processing of the film or sheet.

2. The method according to claim 1, characterized in that as a parameter representing the cutting-region stress, a sag of the film or sheet is automatically detected downstream of the cutting unit and upstream of the driven passing-on roller, as seen in the production direction of the film or sheet.

3. The method according to claim 1, characterized in that as a parameter representing the cutting-region stress, a web stress in the film or sheet is automatically detected by means of a load cell unit downstream of the cutting unit and upstream of the driven passing-on roller, as seen in the production direction of the film or sheet.

4. The method according to claim 1, characterized in that as a parameter representing the secondary stress, a sag of the film or sheet is automatically detected downstream of the driven passing-on roller and upstream of the secondary region, in particular winding region, as seen in the production direction of the film or sheet.

5. The method according to claim 1, characterized in that as a parameter representing the secondary stress, a web stress in the film or sheet is automatically detected by means of a load cell unit downstream of the driven passing-on roller and upstream of the secondary region, in particular winding region, as seen in the production direction of the film or sheet.

6. The method according to claim 1, characterized in that the sag of the film or sheet is automatically detected by means of an optical measuring device, preferably by means of a laser, more preferably by measuring to the surface of the film or sheet.

7. The method according to claim 1, characterized in that the mentioned process parameters are regulated in such a manner that: the drive parameter (a.sub.2) of the driven passing-on roller depends on the automatically detected sag of the film or sheet in the cutting region, and/or the drive parameter (a.sub.3) in the secondary region depends on the web stress in the film or sheet in the passing-on region, which is automatically detected by means of the load cell unit.

8. The method according to claim 1, characterized in that the mentioned process parameters are regulated in such a manner that: the drive parameter (a.sub.2) of the driven passing-on roller depends on the web stress in the film or sheet in the cutting region, which is automatically detected by means of the load cell unit, and/or the drive parameter (a.sub.3) in the secondary region depends on the automatically detected sag of the film or sheet in the passing-on region.

9. An installation for producing a film or sheet from a block material, in particular from a slabstock foam, wherein the installation has at least the following regions as seen in a production direction of the film or sheet: a cutting region for cutting the film or sheet, wherein a cutting unit is provided in the cutting region for cutting out, in splitting-open manner, the film or sheet from the block material which is continuously fed to the cutting region during production, a passing-on region adjoining the cutting region and having a driven passing-on roller for conveying the film or sheet out of the cutting region, and a secondary region adjoining the passing-on region and intended for further processing the film or sheet, in particular winding region for winding the film or sheet into a coil, wherein there is a cutting-region stress in the film or sheet in the cutting region upstream of the passing-on roller and there is a secondary stress in the film or sheet in the passing-on region upstream of the secondary region, in particular winding region, characterized in that at least one of the following detection units is provided: a) a cutting region detection unit in the cutting region for automatically detecting a parameter representing the cutting-region stress, and/or b) a passing-on region detection unit in the passing-on region for automatically detecting a parameter representing the secondary stress, and in that a control unit is provided for regulating at least one of the following process parameters on the basis of at least one of the parameters detected according to a) or b): a drive parameter (a.sub.1) of the block material, a drive parameter (a.sub.2) of the driven passing-on roller, and/or a drive parameter (a.sub.3) in the secondary region for moving the film or sheet for further processing of the film or sheet.

10. The installation according to claim 9, characterized in that the cutting region detection unit is configured for automatically detecting a sag of the film or sheet or sheet downstream of the cutting unit and upstream of the driven passing-on roller, as seen in the production direction of the film, and/or in that the passing-on region detection unit is configured for automatically detecting a sag of the film or sheet downstream of the driven passing-on roller and upstream of the secondary region, in particular winding region, as seen in the production direction of the film or sheet.

11. The installation according to claim 9, characterized in that the cutting region detection unit is designed as a load cell unit for automatically detecting a web stress in the film or sheet downstream of the cutting unit and upstream of the driven passing-on roller, as seen in the production direction of the film or sheet, and/or in that the passing-on region detection unit is designed as a load cell unit for automatically detecting a web stress in the film or sheet downstream of the driven passing-on roller and upstream of the secondary region, in particular winding region, as seen in the production direction of the film or sheet.

12. The installation according to claim 9, characterized in that the cutting region detection unit and/or the passing-on region detection unit for automatically detecting the sag of the film or sheet is designed as an optical measuring device, preferably as a laser, more preferably in that the optical measuring device is arranged for measuring to the surface of the film or sheet.

13. The installation according to claim 9, characterized in that, furthermore, a film thickness sensor is provided in the cutting region, which is designed as an optical measuring device, preferably as a laser, for automatically detecting the thickness of the film or sheet, more preferably in that the film thickness sensor is arranged for measuring to the surface of the film or sheet.

14. A method for retrofitting an installation for producing a film or sheet from a block material, in particular from a slabstock foam, wherein the installation has at least the following regions as seen in a production direction of the film or sheet: a cutting region for cutting the film or sheet, wherein a cutting unit is provided in the cutting region for cutting out, in a splitting-open manner, the film or sheet from the block material which is continuously fed to the cutting region during production, a passing-on region adjoining the cutting region and having a driven passing-on roller for conveying the film or sheet out of the cutting region, and a secondary region adjoining the passing-on region and intended for further processing the film or sheet, in particular winding region for winding the film or sheet into a coil, wherein there is a cutting-region stress in the film or sheet in the cutting region upstream of the passing-on roller and there is a secondary stress in the film or sheet in the passing-on region upstream of the secondary region, in particular winding region, characterized in that the installation is equipped with at least one of the following detection units: a) with a cutting-region detection unit in the cutting region for automatically detecting a parameter representing the cutting-region stress, and/or b) with a passing-on region detection unit in the passing-on region for automatically detecting a parameter representing the secondary stress, and in that: the installation is equipped with a control unit in such a manner, or an existing control unit is retrofitted in such a manner that at least one of the following process parameters in the installation can be regulated on the basis of at least one of the parameters detected according to a) or b): a drive parameter (a.sub.1) of the block material, a drive parameter (a.sub.2) of the driven passing-on roller, and/or a drive parameter (a.sub.3) in the secondary region for moving the film or sheet for further processing of the film or sheet.

15. A system for retrofitting an installation for producing a film or sheet from a block material, in particular from a slabstock foam, characterized by: at least one of the following detection units: a) a cutting-region detection unit for automatically detecting a parameter representing the cutting-region stress in the cutting region, and/or b) a passing-on region detection unit for automatically detecting a parameter representing the secondary stress in the passing-on region, and characterized by: a control unit, configured in such a manner, or a communication unit configured to communicate with an existing control unit of the installation in such a manner that at least one of the following process parameters in the installation can be regulated on the basis of at least one of the parameters detected according to a) or b): a drive parameter (a.sub.1) of the block material, a drive parameter (a.sub.2) of the driven passing-on roller, and/or a drive parameter (a.sub.3) in the secondary region for moving the film or sheet for further processing of the film or sheet.

Description

[0101] Further advantageous and preferred embodiments are apparent from the following description with reference to the figures. In the drawing, which only shows an exemplary embodiment

[0102] FIG. 1 shows an entire installation for producing a film from a slabstock foam,

[0103] FIG. 2 shows a schematic partial view of an installation according to the proposal for producing a film from a slabstock foam according to a first exemplary embodiment,

[0104] FIG. 3 shows a schematic partial view of an installation according to the proposal for producing a film from a slabstock foam according to another exemplary embodiment,

[0105] FIG. 4 shows a schematic partial view of an installation according to the proposal for producing a film from a slabstock foam according to another exemplary embodiment,

[0106] FIG. 5 shows a schematic partial view of an installation according to the proposal for producing a film from a slabstock foam according to another exemplary embodiment, and

[0107] FIG. 6 shows a schematic partial view of an installation according to the proposal for producing a film from a slabstock foam according to another exemplary embodiment.

[0108] FIG. 1 shows an installation 1 for producing a film 2 from a block material, in the present case a slabstock foam 3, which is formed from a soft polyurethane (PUR) foam. Such an installation 1 is basically already known from the prior art. The slabstock foam 3 is conveyed in a circulating manner through the installation 1 at a constant feed rate v.sub.1 of approximately 120 m/min. In the view according to FIG. 1, the slabstock foam 3 is conveyed to the right in the lower level of installation 1, deflected by 180? at the right end of installation 1 and, at the top of installation 1, conveyed back in the left direction before being deflected again by 180? at the left edge of installation 1 back into the lower level of installation 1. In this manner, the slabstock foam 1 is conveyed endlessly circulating through the installation 1, essentially until it has been used up and sufficient film 2 has been produced. However, the present invention is not limited to this case. As already explained at the beginning, films can also be cut from a slabstock foam which is not formed to be continuous, i.e. is not glued together, for example. It is also conceivable that a slabstock foam is fed in a reversing manner past a cutting unit for cutting the film. This can be the case, for example, with slabstock foams that are typically 10 m to 60 m long. In such a case, no deflection of the slabstock foam 3 through an installation 1 with multiple levels would then be necessary. The length of the corresponding cut film is then limited to the length of the slabstock foam. However, the cut film can still be wound into a coil or processed further, for example as a stack of sheets.

[0109] In the present case, the film 2 produced is wound into a coil 4 in a secondary process. The cutting of the film 2 from the slabstock foam 3 and the winding of the film 2 into the coil 4 takes place in the cutting and winding process, which takes place in subregion A, which is indicated by the dotted box in FIG. 1. The present invention improves the production process of the film 2 and the entire installation 1 in a particular manner in this subregion A. Therefore, the illustrations according to FIG. 2 to FIG. 6 are based on this subregion A and the latter is essentially described below. With reference to the figures, the present invention is explained by way of example, wherein, on the one hand, the method for producing the film 2 and, on the other hand, the installation 1 for producing it are described. Furthermore, the proposed method for retrofitting an installation for producing a film, with which an existing installation can thus be retrofitted in an advantageous manner, as well as the proposed system for retrofitting an installation for producing a film, with which the method for retrofitting can be carried out, also become clear with the aid of the figures.

[0110] In this respect, like reference signs in FIG. 1 to FIG. 6 also relate to like technical features so that reference can be made to the preceding description. Explanations of technical features based on the installation 1 or system in question can be applied analogously to the methods according to the proposal and vice versa.

[0111] FIG. 2 shows a first embodiment of the installation 1 or the production process according to the proposal, focusing on the cutting and winding process previously indicated by the dotted box in FIG. 1 (subregion A in FIG. 1). FIG. 3 and FIG. 4 show corresponding further embodiments. FIG. 5 and FIG. 6 also relate to further embodiments according to the proposal, wherein only a smaller subregion is illustrated, specifically without showing the subsequent secondary process, which is the winding process in the exemplary embodiments of FIG. 2 to FIG. 4.

[0112] In FIG. 2, as well as in FIG. 3 and FIG. 4, as seen in a production direction P of the film 2, first shown is a cutting region I for cutting the film 2 from the slabstock foam 3, as well as a passing-on region II adjoining the cutting region I, and finally, adjoining the passing-on region II, a secondary region III which in the exemplary embodiments shown in FIG. 2 to FIG. 4 is a winding region III.

[0113] The slabstock foam 3 is fed to the cutting region I at the feed rate v.sub.1. In doing so, the slabstock foam 3 reaches the cutting unit 10 which in the present case is designed as a cutting wedge 11. The cutting wedge 11 can also be a cutter bar.

[0114] The cutting wedge 11 splits off a layer of material from the surface of the slabstock foam 3 so that the film 2 is cut out, in a splitting-open manner, from the slabstock foam 3 by means of the cutting unit 10.

[0115] In the cutting region I, a thickness of the cut film 2 can also be automatically detected, which is not shown here. This can be done using an optical measuring device, such as a laser, for example by measuring to the surface of the film. For this purpose, a film thickness sensor, for example in the form of a laser measuring system, can be provided in the region of the cutting unit 10. Advantageously, this optical measuring device can be arranged above the cut film 2 and thus carry out the measurement from above since in this manner, the installation space available in the entire installation 1 can be ideally utilized (see FIG. 1). The measured thickness of the film 2 can serve as an additional automatically detected control variable in order to be able to regularly or continuously check the quality of the film produced.

[0116] The cut film 2 is transported further through the cutting region I, which extends to a passing-on roller 20 arranged downstream as seen in the production direction P. The passing-on roller 20 is a driven roller, which is indicated by the curved arrow (v.sub.2). The driven passing-on roller 20 is driven by its own drive unit. A drive torque is applied, which ultimately causes the driven passing-on roller 20 to rotate at the circumferential speed v.sub.2. The circumferential speed v.sub.2 therefore represents a drive parameter a.sub.2 of the driven passing-on roller 20. The drive torque is another drive parameter a.sub.2. The drive parameter a.sub.2 ultimately has a significant influence on the flow of the production process of the film 2 and, as a result, on the quality of the film 2 produced.

[0117] The driven passing-on roller 20 serves to convey the film 2 out of the cutting region I. In this respect, the driven passing-on roller 20 also represents the starting point of the passing-on region II. The driven passing-on roller 20 is a rubberized roller, which thus has a contact surface with the passed-on film 2 with an increased coefficient of friction. In this manner, a good separation of the sub-processes can advantageously take place, namely between the cutting region I and the passing-on region II.

[0118] As seen upstream in the process, the feed rate v.sub.1 as the drive parameter a.sub.1 of the slabstock foam 3 also substantially determines the production process of the film 2. The film 2 cut in the cutting region I is also advanced further in the production direction P by the slabstock foam 3, which is continuously moved forwards at the feed rate v.sub.1. Because the driven passing-on roller 20, which is designed as a rubberized roller, has a contact surface with a high coefficient of friction, the drive parameter a.sub.2 can be set in a desired optimum ratio to the drive parameter a.sub.1, or specifically the circumferential speed v.sub.2 to the feed rate v.sub.1. In this manner, the sub-process taking place downstream of the driven passing-on roller 20, thus taking place starting from the passing-on region II and in particular in the adjoining winding region III (or secondary region III in general), has no or only a very slight influence on the sub-process in cutting region I. In a particularly advantageous manner, the film 2 can thus be left sagging in cutting region I with virtually no stress. Accordingly, the driven passing-on roller 20 does not pull so strongly on the film 2 in the cutting region I in which the film 2 is just being separated from the block material. As a result, a falsification of the cutting result, for example a thinning of the film 2 actually cut to a desired thickness or even an undesired tearing of the film 2, can be successfully avoided.

[0119] As an alternative to the exemplary embodiments shown in FIG. 2 to FIG. 4, the driven passing-on roller 20 can also be part of a pair of rollers which also comprises an auxiliary roller 21. This can be seen in the further exemplary embodiments shown in FIG. 5 and FIG. 6. The film 2 can then be transported further along a longer, circulating conveyor belt 22 and conveyed out of the cutting region I in this manner. The conveyor belt 22 can also optionally have a contact surface with an increased coefficient of friction in order to optimize the separation of the cutting region I from the subsequent regions (passing-on region II, secondary region III).

[0120] The secondary region III is basically configured for further processing of the film 2. Specifically, in the exemplary embodiments shown in FIG. 2 to FIG. 4, the secondary region III is designed as winding region III for winding the film 2 into the coil 4. The winding unit can be designed as a center winder or also as a surface winder.

[0121] In the present case, the winding region III has a driven winding roller 30, which is indicated by the curved arrow (v.sub.3). In this respect, the winding roller 30 is driven and provides the circumferential speed v.sub.3 as a further drive parameter a.sub.3 in the secondary region III or winding region III, wherein the circumferential speed v.sub.3 controls in particular the winding process. In general, the secondary process is controlled by the drive parameter a.sub.3 in the secondary region III, wherein the drive parameter a.sub.3 in the secondary region III serves on the one hand to move the film 2 and on the other hand to further process the film 2.

[0122] As an alternative to winding the film 2 into the coil 4, other secondary processes are also possible, for example cutting the continuous film 2 into individual film elements or sheets. It is also conceivable for the film 2 to be fed out of the entire installation 1, for example laterally at right angles to the conveying direction corresponding to the direction of the feed rate v.sub.1 (see FIG. 1). FIG. 5 and FIG. 6 therefore show exemplary embodiments in which the film 2 is shown broken off at the end of the passing-on region II in order to indicate that various subsequent secondary processes and thus secondary regions III are possible.

[0123] In the exemplary embodiment according to FIG. 2 to FIG. 4, an auxiliary roller 31 is provided in addition to the driven winding roller 30. It is also possible that a winding belt with a driven winding roller is used to implement the winding process.

[0124] The winding region III generally starts with the driven winding roller 30, as seen in the production direction P. In general, the secondary region III always has a unit providing a drive parameter a.sub.3, so that with respect to the secondary region III, this secondary region III starts with the arrangement of the unit exerting the drive parameter as on the film 2, as seen in the production direction P of the film 2.

[0125] The present invention can ensure a consistent quality of the produced film 2. In doing so, the operating costs can be reduced by automating the production process and, in particular, by automating the quality control. Thus, on the one hand, it is decisive for the quality of the produced film 2 that the thickness of the film 2 is constant and that no thickness variance occurs or cracks occur in the cut film 2 due to further processing steps, such as the further transport of the film 2 through the installation and ultimately the winding into the coil 4.

[0126] The web stress that prevails in the material web in the form of the cut film 2 is of decisive importance here. The cutting-region stress, which corresponds to the web stress in the cutting region I, is therefore very important. It must not be too high in order to successfully avoid cracks in the film 2, for example.

[0127] According to the proposal, the production process can therefore be controlled by automatically detecting at least one parameter representing the cutting-region stress in the cutting region I (method step a)).

[0128] Furthermore, the web stress in the passing-on region II is of decisive importance, for example for winding the film 2 into the coil 4, this web stress generally being referred to as secondary stress. As an alternative or in addition to the aforementioned control of the production process (method step a)), the method can therefore also be controlled by automatically detecting at least one parameter representing the secondary stress in the passing-on region II (method step b)).

[0129] For this purpose, in the present case, a cutting-region detection unit 12 is provided in the cutting region I for automatically detecting a parameter representing the cutting-region stress.

[0130] In the exemplary embodiment according to FIG. 2, the cutting region detection unit 12 is configured to automatically detect a sag of the film 2 downstream of the cutting unit 10 and upstream of the driven passing-on roller 20, as seen in the production direction P of the film 2. This sag of the film 2 in the cutting region I serves as a parameter representing the cutting-region stress. The same applies in this respect to the exemplary embodiments according to FIG. 4 and FIG. 5.

[0131] The cutting region detection unit 12 according to FIG. 2 (and also according to FIG. 4 and FIG. 5) is designed as an optical measuring device 13, for example as a laser. The optical measuring device 13 detects the sag of the film 2 in the cutting region I from above to the surface of the film 2 as a qualitative measure of how great the web stress acting on the film 2 is in this region.

[0132] Similarly, a passing-on region detection unit 23 is also provided in the passing-on region II for automatically detecting a parameter representing the secondary stress.

[0133] In principle, the passing-on region detection unit 23 can also be configured for automatically detecting a sag of the film 2 downstream of the driven passing-on roller 20 and upstream of the secondary region III or winding region III, as seen in the production direction P of the film 2, as shown by way of example in the exemplary embodiment according to FIG. 4. For this purpose, the passing-on region detection unit 23 is designed as an optical measuring device 24, for example as a laser. The optical measuring device 24 can also detect the sag of the film in the passing-on region II by measuring to the surface of the film 2 as a representative qualitative measure of the secondary stress.

[0134] The automatic determination of the sag of the film 2 can be carried out in a simple manner by the optical measuring devices 13 and 24, respectively, since the sag of the film 2 is ultimately represented by the current vertical position of the film 2.

[0135] The optical measuring devices 13 and 24, respectively, are advantageously arranged above the film 2 and carry out an optical measurement from above to the surface of the film 2, so that the installation space available in the entire installation 1 (see FIG. 1) is effectively utilized.

[0136] Alternative detection units can also be used to detect the parameters representing the cutting-region stress or secondary stress. For example, load cell units can advantageously be used to more accurately numerically detect the corresponding value of the web stress.

[0137] In FIG. 2, the passing-on region detection unit 23 is designed as such a load cell unit 25. This also applies to the exemplary embodiments in FIG. 3, FIG. 5 and FIG. 6.

[0138] In FIG. 3, in turn, the cutting region detection unit 12 is designed as such a load cell unit 14 (also in FIG. 6). In FIG. 3 and FIG. 6, in addition to the load cell unit 14, a deflection roller 15 is also provided in the cutting region I, which is arranged upstream of the load cell unit 14 as seen in the production direction P.

[0139] In any case, by means of the load cell units 14 in the cutting region I, the prevailing cutting-region stresses can be precisely measured. In turn, the secondary stresses can be precisely measured by means of the load cell units 25 in the passing-on region II.

[0140] Whether by precisely determining the prevailing cutting-region stress or secondary stress or also by indirect qualitative measurement by means of detecting the sag of the film 2, these measured values can advantageously serve as control variables for the overall process in the proposed installation 1.

[0141] Both values, i.e. both a parameter representing the cutting-region stress and additionally a parameter representing the secondary stress, can be measured, wherein it is not absolutely necessary to measure both values in order to achieve the advantages of the invention, but one of the two values can also be sufficient.

[0142] The measured values then serve as a control variable for controlling the entire production process of the film 2. Thus, at least one of the drive parameters a.sub.1, a.sub.2, a.sub.3 is controlled as a process parameter on the basis of at least one or even both of the measured values (cutting-region stress and parameters representing secondary stress).

[0143] Specifically, with regard to the exemplary embodiment according to FIG. 2, it is particularly advantageous if the aforementioned process parameters are controlled in such a manner that the drive parameter a.sub.2 of the driven passing-on roller 20 depends the automatically detected sag of the film 2 in the cutting region I. Advantageously, the circumferential speed v.sub.2 of the driven passing-on roller 20 can depend on the detected sag. This dependency can be implemented directly. For example, the circumferential speed v.sub.2 can be increased if an increase in the detected sag of the film 3 is measured, i.e. if the film 2 sinks in the cutting region I in relation to its vertical position. Conversely, the control is advantageously carried out in such a manner that when the sag decreases, i.e. when the film 2 rises with respect to its vertical position, the circumferential speed v.sub.2 is reduced.

[0144] Furthermore, with regard to the exemplary embodiment according to FIG. 2, it is particularly advantageous if the aforementioned process parameters are controlled in such a manner that the drive parameter a.sub.3 in the secondary region III depends on the web stress in the film 2 in the passing-on region II, which is automatically detected by means of the load cell unit 25. Advantageously, the circumferential speed v.sub.3 of the driven winding roller 30 can depend on the detected secondary stress, i.e. web stress in the film 2 in the passing-on region II. This dependency can be implemented directly, in particular since the web stress is detected numerically via the load cell unit 25. For example, the circumferential speed v.sub.3 can be increased if an increase in the secondary stress value is measured. Conversely, the control is advantageously carried out in such a manner that when the secondary stress value decreases, the circumferential speed v.sub.3 is increased.

[0145] In this manner, on the one hand, a uniform quality of the cut film 2, in particular without thickness variance and without tears, is ensured, and, on the other hand, a wound coil 4 of the desired quality is ensured. A time-consuming permanent inspection, whether by visual inspection or manual inspection of the material web, for which experienced system operators are required, is therefore no longer necessary.

[0146] It is particularly advantageous if the unit arranged downstream of the cutting unit 10 as seen in the production direction P of the film 2, such as the driven passing-on roller 20 or the deflection roller 15, is offset upwards with respect to its vertical position relative to the cutting unit 10, as can be seen in all the exemplary embodiments shown (FIG. 2 to FIG. 6).

[0147] In addition, when optically detecting the sagging of the film 2 in the passing-on region II, as shown in FIG. 4, it is advantageous if, as seen in the production direction P, a deflection roller 26, which is offset downwards, in particular with respect to the vertical position, relative to the driven passing-on roller 20, is also provided downstream of the driven passing-on roller 20.

[0148] In general, it is particularly advantageous that the roller adjoining the driven passing-on roller 20, as seen in the production direction P, is offset downwards with respect to the vertical position, so that greater wrapping of the driven passing-on roller 20 by the film 2 is achieved. Increased wrapping can result in increased friction, whereby better separation of the two regions, namely the cutting region I and the passing-on region II, is achieved. The entire production process of the film 2 is advantageously more decoupled from each other with regard to the different sub-processes of cutting and the subsequent secondary process, so that the sub-processes have less influence on each other.

[0149] Furthermore, it is advantageous that, as seen in the production direction P, a roller is arranged upstream of a load cell unit, be it the load cell unit 14 in FIG. 3 or FIG. 6 and/or the load cell unit 25 in FIG. 2, 3, 5 or 6, which is offset upwards with respect to the vertical position. As can be seen in FIG. 2, the driven passing-on roller 20 is arranged above the load cell unit 25 with respect to the vertical position. In FIG. 3, the deflection roller 15 is arranged above the load cell unit 14 with respect to the vertical position, and furthermore, the driven passing-on roller 20 is arranged above the load cell unit 25 with respect to the vertical position. In FIG. 5, and also in FIG. 6, the auxiliary roller 21 is arranged above the load cell unit 25 with respect to the vertical position. Furthermore, in FIG. 6 the deflection roller 15 is arranged above the load cell unit 14 with respect to the vertical position. In this manner, an increased wrapping of the respective load cell unit 14 or 25 by the film 2 is achieved. This results in an increased force transmission between the film 2 and the respective wrapped roller of the load cell unit 14 or 25, which in turn results in a more sensitive detection of the web stresses by the load cell unit 14 or 25. The control and, in particular, regulation of the entire production process of the film 2 can thus be significantly improved.

[0150] If the secondary process in the secondary region III is characterized by a roller which transports the film 2 further, as in the present exemplary embodiments according to FIGS. 2, 4 and 4 in which the winding region III has a driven passing-on roller 30, then it is particularly advantageous if the (middle) driven passing-on roller 20 is offset upwards with respect to the vertical position relative to a connecting line running between this roller of the secondary region III and the cutting unit 10. As can be seen in FIGS. 2, 3 and 4, the driven passing-on roller 20 is arranged above the connecting line between the cutting unit 10 and the driven winding roller 30 with respect to the vertical position.

[0151] This can be particularly advantageous if further units arranged between the driven passing-on roller 20 and the rear roller of the secondary region III, for example the driven winding roller 30, should ever be omitted. For example, it can be desirable or necessary to form a bypass for bypassing these further units of the passing-on region II in order to guide the film 2 directly from the driven passing-on roller 20 to the secondary region III or the winding region III. The proposed installation 1 is flexible in that it is designed to be adaptable for such a case.

REFERENCE LIST

[0152] 1 Installation for the production of a film or sheet from a block material [0153] 2 film [0154] 3 slabstock foam [0155] 4 coil [0156] 10 cutting unit [0157] 11 cutting wedge [0158] 12 cutting region detection unit [0159] 13 optical measuring device [0160] 14 load cell unit [0161] 15 deflection roller [0162] 20 driven passing-on roller [0163] 21 auxiliary roller [0164] 22 conveyor belt [0165] 23 passing-on region detection unit 23 [0166] 24 optical measuring device [0167] 25 load cell unit [0168] 26 deflection roller [0169] 30 driven winding roller [0170] 31 auxiliary roller [0171] I cutting region [0172] II passing-on region [0173] III winding region [0174] III secondary region [0175] A cutting and winding process [0176] P production direction of the film 2 [0177] v.sub.1 Feed rate of the slabstock foam 3 [0178] v.sub.2 circumferential speed of the driven passing-on roller 20 [0179] v.sub.3 circumferential speed of the driven winding roller 30 [0180] a.sub.1 drive parameter of the slabstock foam 3 [0181] a.sub.2 drive parameter of the driven passing-on roller 20 [0182] a.sub.3 drive parameter in the secondary region III