Patent Application
20240198554
The present invention relates to a method for producing a film or sheet from a block material according to the preamble of claim 1. The invention further relates to an installation for producing a film or sheet from a block material according to the preamble of claim 9. Furthermore, the invention relates to a method for retrofitting an installation for producing a film or sheet from a block material according to the preamble of claim 14. Finally, the invention also relates to a system for retrofitting an installation for producing a film or sheet from a block material according to the preamble of claim 15.
Installations as well as corresponding methods for operating such installations, which serve to produce films or also sheets from a generally soft block material, are in principle known from the prior art. However, the present invention allows for an improvement with regard to the automation of the known installations or methods.
This is explained below using the example of film production from a slabstock foam. In such a film production process, as is already known in principle from the prior art, a slabstock foam, which is formed as a continuous block—usually glued together—is continuously guided, for example in a circulating manner, in an installation. Alternatively, a block that is not glued together can also be guided in an installation. During circulation, the block material is guided past a cutting unit, such as a cutting wedge or a cutter bar, whereby an upper layer of the slabstock foam is cut or split off. This separated upper layer represents the product in the form of the foam film and, for example, can be wound into a coil of the foam film, as seen downstream in the process. In the aforementioned alternative example of a non-glued block, the resulting coil length of the cut film is then at maximum the total block length of the block material, since multiple passes are not carried out in succession and thus cut into a continuous film, as is the case with a glued block. In particular with larger cutting thicknesses, thus, resulting thicknesses of the cut film from about 20 mm, block material that is not glued together is also used more frequently. However, the present invention is not intended to be limited to the application of winding a cut film into a coil. It is also conceivable that a block material other than a foam material is cut, or that the cut material is not wound into a coil but is processed further in some other way. It is also conceivable that the cut film is fed out of the installation for further processing elsewhere, or that the cut material is cut directly into smaller elements which—depending on their thickness—are more likely to be regarded as sheets than as film. In the present case, on the one hand, the patent application refers to a sheet in relation to the end product of a material cut out of the block material, both initially in terms of thickness and subsequently in terms of the length of the separated sheet element cut into a separated sheet. On the other hand, in the present case, the broad term “sheet” also refers to a material web that is cut slightly thicker compared with a typical film, or a cut material web made of slightly harder or stiffer material. Consequently, according to a broad understanding, a sheet is initially also to be understood, to a certain extent, as the endless material web of material cut, in a splitting-open manner, from the block material which has not yet been shortened to an individual length of a separate sheet element. In principle, a sheet present in the form of such a material web can also be wound into a coil or roll in a process section following the cutting process and then cut to size into individual sheet elements in later steps, for example on other installations.
In the installations or methods known from the prior art for producing a film from a slabstock foam, the slabstock foam material is regularly fed at a constant feed rate to a cutting region for cutting the film. A cutting unit splits the material block at its surface in a desired thickness. As a result, the foam film of the desired thickness is created, which must be removed from the cutting region. On the one hand, the continuous feed of the circulating slabstock foam helps to push the foam film further forward and out of the cutting region as seen in the production direction. On the other hand, a passing-on region is provided which adjoins the cutting region as seen in the production direction and which can have a driven passing-on roller. This passing-on roller can thus be used to convey the cut film out of the cutting region arranged upstream in the process.
A further secondary region is regularly provided downstream of this passing-on region as seen in the production direction. Such a secondary region is basically used for further processing of the cut film to be discharged. For example, the secondary region can be a winding region in which the film is wound into a so-called coil, i.e. a wound roll of film.
Both the installations for producing the foam films and the corresponding production methods from the prior art pose a challenge in terms of setting the many process parameters that control production. Various process parameters, such as the drive parameters of the circulating foam material, for example the feed rate, or also the drive parameters such as the feed rate or drive torque of the driven roller controlling the winding process, have to be set. Each of these process parameters has an influence on the film produced and the quality thereof or, for example, on the quality of the wound coil of foam film. For example, specific requirements for the film to be produced include that it has a uniform thickness and uniform quality. In addition, the material web of the foam film should not have any cracks. Furthermore, once the film has been cut into a material web, its properties should not be negatively affected by the subsequent process steps, such as feeding the film out of the cutting region or winding the film into a coil in the winding region.
In order to meet these requirements, the current prior art regularly requires the installations to be operated by experienced operators. For example, the cut material web is often checked manually or by visual inspection by experienced system operators and, if defects are detected, individual process parameters are adjusted by the system operator. The disadvantage of this is, for example, that the continuous process—which ideally should not be stopped until the block material to be cut is completely used up and then changed—requires permanent supervision by experienced system operators. This leads to high personnel cost and associated production costs. In addition, the production methods and installations are more prone to errors, as the different levels of experience of the system operators often mean that the film produced no longer has the same uniform quality after a shift change from a more experienced to a less experienced employee due to a lack of adequate adjustment. Previous attempts to automate the process have so far failed because they are usually still too dependent on the adjustment of an experienced system operator. In particular, previous approaches are mainly such that manual re-adjustments have to be made after each change in cut thickness of the cut film.
It is therefore an object of the present invention to remedy this situation and to avoid the disadvantages described. More specifically, it is an object of the invention to configure the known method for producing a film or sheet from a block material in a more cost-effective and less error-prone manner. Another object is to configure the known installation for producing a film or sheet from a block material in a more cost-effective and less error-prone manner. Furthermore, it is an object of the invention to provide a method for retrofitting known installations for producing a film or sheet from a block material, whereby the operating costs can be reduced and the production can be configured to be less error-prone. Finally, it is an object to provide a system for retrofitting an installation for producing a film or sheet from a block material, with which the installations can be improved in terms of operating costs and error-proneness.
The object is achieved with regard to the production method by a method with the features of the characterizing part of claim 1. With regard to the installation, the object is achieved by an installation for producing a film or sheet from a block material with the features of the characterizing part of claim 9. With regard to the method for retrofitting an installation, the object is achieved by a method with the features of the characterizing part of claim 14. With regard to the system, the object is achieved by a system for retrofitting an installation for producing a film or sheet from a block material with the features of the characterizing part of claim 15.
Substantial for the invention is the knowledge that the described disadvantages of the prior art can be avoided by the fact that the load on the material web can be detected in a targeted machine-based manner and automatically in the different sections, and based thereon, the global process parameters can be controlled. This does interfere with the existing process in the known installations for film and sheet production, which is accompanied by increased expenditure. However, this makes the overall process more stable due to the more uniform quality of the films and sheets produced. The present invention allows automatic control of the process parameters that determine the production process of the films or sheets, which reduces operating costs due to lower personnel costs and increases process reliability due to less frequent variations in thickness or quality in the product. Automatic detection of the parameters is therefore carried out automatically in such a manner that the corresponding parameters are detected in a machine-based manner. The detection takes place independently of the operation by an experienced system technician. Furthermore, the automatic detection is in particular such that the automatic detection is substantially independent of the film material and film thickness. Accordingly, a system operator does not have to individually adjust the detection of the parameters after a change in the material of the cut film or after a change in the cut thickness by a few millimeters, for example. The automatic detection continues to be done in a machine-based manner.
In the method according to the proposal for producing a film or sheet from a block material, which can be in particular a method for producing a film or sheet from a slabstock foam, at least the following regions are provided as seen in a production direction of the film or sheet:
According to the proposal, the film or sheet is cut in the cutting region by means of a cutting unit from the block material, which is continuously fed to the cutting region, wherein the cutting unit can in particular be a cutter bar or a cutting wedge. Accordingly, the cutting of the film or sheet in the cutting region is to be understood to mean that the block material is split in a thickness direction transverse to the conveying direction. This is not to be understood to mean that the block material or the film split off therefrom is cut into individual elements with respect to their length as seen in the conveying direction.
According to the proposal, a driven passing-on roller is provided in the passing-on region for conveying the film or sheet out of the cutting region. In particular, the driven passing-on roller can have an outer contact surface with a relatively high coefficient of friction, so that the influence of the process taking place upstream of the passing-on roller on the sub-process downstream of the driven passing-on roller can be greatly reduced. The driven passing-on roller achieves a separation of the cutting process, which takes place upstream in relation to the production direction, and the secondary process, for example the winding process taking place downstream. In particular, a coefficient of friction of at least 0.4, preferably greater than 0.5, more preferably greater than 1.0, particularly preferably greater than 2.0, can be provided. For this purpose, the driven passing-on roller can have a coating on the surface to increase the coefficient of friction. The driven transfer roller is particularly preferably configured as a rubberized roller so that a desired high coefficient of friction is set.
The cutting region according to the proposal can in particular be understood to mean that it extends from the cutting unit to the driven passing-on roller, as seen in the production direction of the film or sheet. It is therefore substantially the region in which a thinner material web split off from the block material, for example in the form of a film, is present for the first time and this film is advanced in a substantially uninfluenced manner to the driven passing-on roller. In the cutting region, there is a cutting-region stress in the film or sheet upstream the passing-on roller.
The passing-on region according to the proposal can be understood in particular in such a manner that, as seen in the production direction of the film or sheet, it extends from the driven passing-on roller to a subsequent drive unit of the adjoining secondary region, for example to a driven winding roller (winding belt) in a winding region. The secondary region according to the proposal in turn can be understood in particular in such a manner that it adjoins the passing-on region as seen in the production direction of the film or sheet and extends, for example, starting from a driven winding roller (winding belt). In the passing-on region, there is a secondary stress in the film or sheet upstream of the secondary region. In particular, the cutting-region stress and the secondary stress in the film or sheet differ from each other due to the separation of the process by the driven passing-on roller arranged therebetween.
The method according to the proposal for producing the film or sheet from the block material is characterized in that the method is at least partially controlled in such a manner that:
In this manner, the production method can advantageously run in a reliable manner, even if no experienced system operator is observing the process. Advantageously, there is no need for an operator to draw conclusions about the stress values prevailing in the film by personally visually or even manually checking the material web that has been split off from the material block and transported through the installation.
The method according to the proposal for producing the film or sheet from the block material is further characterized in that at least one of the following process parameters is controlled on the basis of at least one of the parameters detected in step a) or b), thus on the basis of the parameter(s) representing the cutting-region stress and/or the secondary stress:
In this manner, the automatically detected stress values, thus, the load on the material web prevailing in the individual areas, are effectively used to control the process of producing the film or sheet. For example, if too high a load is detected on a cut film, a drive parameter of the central driven passing-on roller can be reduced, as a result of which the cut film is no longer pulled out of the cutting region as strongly. As a result, a negative influence such as a thickness variance in the film split off from the block material can be efficiently avoided.
In principle, the present invention has recognized that various drive parameters can be controlled automatically for this purpose. For example, the production process can be controlled via the feed rate of the block material fed to the cutting region. Furthermore, the drive torque or, particularly preferably, the circumferential speed of the driven passing-on roller can be considered as drive parameters of the driven passing-on roller to be controlled. The circumferential speed of the driven passing-on roller makes it particularly easy to control the feed rate of the material web in the passing-on region and thus to adjust the resulting load on the material web. Drive parameters of the secondary region, such as the winding region, when the film is wound into a coil in the secondary region, can also be used for control. The drive torque, but particularly preferably the circumferential speed of a driven winding roller or a driven winding belt can also be used to control the winding of the film or sheet into a coil.
In principle, a driven roller is to be understood to mean that it is actively driven via a drive unit. Thus, a drive torque is applied, which causes the driven roller to rotate and effects a generally constant circumferential speed on the circumferential surface of the roller. The film is passed on as a material web on this outer circumferential surface. In this respect, driven rollers are distinguished in the process from passive rollers, which only serve to deflect or as a kind of roller for the passive forwarding of the material web.
The automated regulation of the various process parameters can be carried out according to the invention by automatically regulating and controlling only a single one of the exemplary process parameters, or preferably also by automatically regulating multiple process parameters. The present invention has recognized the advantages of actively intervening in the usual production process and automatically and mechanically detecting the prevailing stress in the material web or parameters representing this stress. This additional machine- or measurement-related effort has the advantage that the overall operating costs can be successfully reduced if the detected parameters are used to regulate the process parameters controlling the production process. For this purpose, for example, drive parameters such as the circumferential speed of the driven passing-on roller of the passing-on region are set in relation to the automatically detected parameter representing the cutting-region stress for the purpose of control. In an advantageous manner, the control of the production process by experienced system operators can be reduced considerably.
In principle, the thickness of the film or sheet cut or split from the block material can range from 0.8 mm to 200.0 mm. Preferably, the thickness of the cut film is between 1.5 mm and 30.0 mm. The preferred material for the block material is a foam, in particular flexible polyurethane (PUR) foam. Alternatively, it is also possible to provide harder porous/foamed materials as block material and cut them into films or sheets. For example, polyethylene (PE) or various rubber-like materials can also be used as block material.
Preferably, the feed rate of the block material, for example the circulating slabstock foam, can be between 50 m/min and 350 m/min, particularly preferably around 120 m/min.
In particular, it is advantageous if the method is regulated in such a manner that the cutting-region stress is considerably lower than the secondary stress in the film or sheet. Preferably, the ratio of cutting-region stress to secondary stress can be 0.75 or less, more preferably 0.5 or less, particularly preferably 0.25 or less. In this context, it is also possible to speak of a substantially stress-free state of the film or material web in the cutting region compared with the passing-on region. This advantageously ensures that the material web sags in the cutting region between the cutting unit and the passing-on roller, i.e. adjacent to the cutting wedge or cutter bar. In this manner, it is successfully prevented that the downstream components of the installation pull too strong on the cut film or sheet and thus negatively affect the uniform cut thickness of the film or sheet or, in general, the uniform quality of the product. In addition, material necking is successfully avoided, which can be caused, for example, by excessive stress in the cut film and thus cause an undesirable reduction in the film width or irregularities in the film width.
In principle, the present invention makes it advantageously possible to precisely control and also adjust the two stress regions, i.e. the cutting-region stress and the secondary stress. In principle, it is also conceivable that the ratio of cutting-region stress to secondary stress is 1:1. It is particularly advantageous if the cutting-region stress is substantially constant. In contrast, the secondary stress, which is usually higher, can vary more widely depending on the secondary process.
A first preferred embodiment of the method for producing the film or sheet (claim 2) is 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.
A further preferred embodiment of the method for producing the film or sheet (claim 4) is 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 the winding region, as seen in the production direction of the film or sheet.
The sag of the film represents a qualitative measure, which is particularly easy to detect visually, of how high the cutting-region stress or secondary stress is, in particular whether it is too high, for example, and if the corresponding process parameters should be adjusted in order to reduce the corresponding stress.
A further preferred embodiment of the method for producing the film or sheet (claim 3) is 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 viewed in the production direction of the film or sheet.
A further preferred embodiment of the method for producing the film or sheet (claim 5) is characterized in that, as a parameter representing the secondary tension, 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 the winding region, as viewed in the production direction of the film or sheet.
In this case, a load cell can precisely and numerically measure the parameter to be detected in the form of the cutting-region stress or secondary stress. The load cell preferably detects only the stress prevailing in the material web, thus in the cut film or sheet. In this manner, precise conclusions and exact control and adjustment of the production process are advantageously possible.
A further preferred embodiment of the method for producing the film or sheet (claim 6) is characterized in that the sag of the film or sheet is automatically detected by means of an optical measuring device. Here, the sag is preferably detected by means of a laser, more preferably by measuring to the surface of the film or sheet. In principle, lateral measurement is possible; however, measurement to the material web is preferably carried out from above so that the space available there can be advantageously utilized with regard to the installation of the measuring device.
A further preferred embodiment of the method for producing the film or sheet is characterized in that a thickness of the film or sheet is automatically detected in the cutting region. Preferably, the thickness 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. In principle, lateral measurement is possible; however, measuring to the material web is preferably carried out from above so that the space available there can be advantageously utilized with regard to the installation of the measuring device. Measuring the thickness of the cut film provides another parameter that can be used to assess the quality of the film produced during the process. In this manner, a uniform quality of the produced film can be guaranteed.
A further preferred embodiment of the method for producing the film or sheet (claim 7) is characterized in that the mentioned process parameters are controlled in such a manner that:
In particular, the circumferential speed of the driven passing-on roller and/or also the circumferential speed of a driven winding roller can advantageously be set directly as a function of the detected sag of the film or sheet in the cutting region or of the numerically detected web stress in the passing-on region.
In doing so, it is particularly advantageous if the circumferential speed of the driven passing-on roller is in the range from 98% to 110%, in particular 101% to 105%, of the feed rate of the block material. Furthermore, it is advantageous if the feed rate in the secondary region, or specifically as an example, the circumferential speed of the driven winding roller, is in the range of 95% to 115%, in particular 103% to 107%, of the feed rate of the block material. In this manner, a simple regulation of the overall process in the forward production direction can be carried out. The production process is stable and ensures a uniform quality of the film produced.
A further preferred embodiment of the method for producing the film or sheet (claim 8) is characterized in that the mentioned process parameters are regulated in such a manner that:
In particular, the circumferential speed of the driven passing-on roller and/or also the circumferential speed of a driven winding roller can advantageously be set directly as a function of the numerically detected web stress in the film or sheet in the cutting region or of the detected sag of the film or sheet in the passing-on region.
According to another independent aspect of the invention, an installation for producing a film or sheet from a block material is proposed (claim 9). This can in particular be an installation for producing a film or sheet from a slabstock foam. Furthermore, the installation is preferably designed to carry out a production method as described above. As seen in a production direction of the film or sheet, the installation according to the proposal has at least the following regions:
In this case, a cutting-region stress prevails in the film or sheet in the cutting region upstream of the passing-on roller, and a secondary stress prevails in the film or sheet in the passing-on region upstream of the secondary region, in particular the winding region. The installation according to the proposal is characterized in that at least one of the following detection units is provided:
Furthermore, the installation according to the proposal is characterized 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):
Furthermore, according to a further independent aspect of the invention, a method is proposed for retrofitting an installation for producing a film or sheet from a block material, in particular from a slabstock foam (claim 14). Preferably, the retrofitted installation can be an installation as described above. In any case, the installation has at least the following regions as seen in a production direction of the film or sheet:
In this case, a cutting-region stress prevails in the film or sheet in the cutting region upstream of the passing-on roller, and a secondary stress prevails in the film or sheet in the passing-on region upstream of the secondary region, in particular the winding region. The method for retrofitting according to the proposal is characterized in that the installation is equipped with at least one of the following detection units:
In addition, the method for retrofitting according to the proposal is characterized in that:
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 in accordance with a) or b):
According to a further independent aspect of the invention, there is also proposed a system for retrofitting an installation for producing a film or sheet from a block material (claim 15). In particular, this can be a system for retrofitting an installation for producing a film or sheet from a slabstock foam. The system according to the proposal is designed to carry out a method for retrofitting as described above. The system according to the proposal is characterized by at least one of the following detection units:
Furthermore, the system is characterized by:
Both with regard to individual technical features and with regard to the resulting advantages with respect to the proposed installation for producing the film or sheet, as well as with regard to the proposed method for retrofitting an installation for producing a film or sheet, as well as with regard to the proposed system for retrofitting an installation for producing a film or sheet, reference can be made to the preceding detailed explanations of the proposed method for producing a film or sheet from a block material. The individual technical aspects are transferable between the different claims and preferred embodiments in a technically meaningful manner—also across categories.
The dependent claims relate to preferred embodiments, namely claims 11 to 13 in relation to the installation according to the proposal for producing the film or sheet.
A further embodiment of a method for retrofitting an installation for producing a film or sheet from a block material is characterized in that the cutting region detection unit and/or the passing-on region detection unit for automatically detecting a sag of the film or sheet is configured as an optical measuring device, preferably as a laser, more preferably in that the optical measuring device is configured for measuring to the surface of the film or sheet.
A further embodiment of a method for retrofitting is characterized in that the cutting region detection unit and/or the passing-on region detection unit is configured as a load cell unit for automatically detecting a web stress in the film or sheet.
A further embodiment of a method for retrofitting is characterized in that, furthermore, a film thickness sensor is configured in the cutting region, which is designed as an optical measuring device, preferably as a laser, for automatically detecting a thickness of the film or sheet, more preferably in that the film thickness sensor is configured for measuring to the surface of the film or sheet.
Another embodiment of a method for retrofitting is characterized in that the control of the mentioned process parameters is set in such a manner that:
Another embodiment of a method for retrofitting is characterized in that the control of the mentioned process parameters is set in such a manner that:
Another embodiment of a system for retrofitting an installation for producing a film or sheet from a block material is characterized in that the cutting region detection unit and/or the passing-on region detection unit for automatically detecting a sag in the film or sheet is designed as an optical measuring device, preferably as a laser.
Another embodiment of a system is characterized in that the cutting region detection unit and/or the passing-on region detection unit is designed as a load cell unit for automatically detecting a web stress in the film or sheet.
Another embodiment of a system is characterized in that, furthermore, a film thickness sensor for automatically detecting a thickness of the film or sheet is provided as an optical measuring device, preferably as a laser, and more preferably in that the film thickness sensor is configured for measuring to the surface of the film or sheet.
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
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
In this respect, like reference signs in
In
The slabstock foam 3 is fed to the cutting region I at the feed rate v1. 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.
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.
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
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 (v2). 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 v2. The circumferential speed v2 therefore represents a drive parameter a2 of the driven passing-on roller 20. The drive torque is another drive parameter a2. The drive parameter a2 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.
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.
As seen upstream in the process, the feed rate v1 as the drive parameter a1 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 v1. 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 a2 can be set in a desired optimum ratio to the drive parameter a1, or specifically the circumferential speed v2 to the feed rate v1. 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.
As an alternative to the exemplary embodiments shown in
The secondary region III′ is basically configured for further processing of the film 2. Specifically, in the exemplary embodiments shown in
In the present case, the winding region III has a driven winding roller 30, which is indicated by the curved arrow (v3). In this respect, the winding roller 30 is driven and provides the circumferential speed v3 as a further drive parameter a3 in the secondary region III′ or winding region III, wherein the circumferential speed v3 controls in particular the winding process. In general, the secondary process is controlled by the drive parameter a3 in the secondary region III′, wherein the drive parameter a3 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.
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 v1 (see
In the exemplary embodiment according to
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 a3, 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.
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.
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.
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)).
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)).
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.
In the exemplary embodiment according to
The cutting region detection unit 12 according to
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.
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
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.
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
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.
In
In
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.
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.
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.
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 a1, a2, a3 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).
Specifically, with regard to the exemplary embodiment according to
Furthermore, with regard to the exemplary embodiment according to
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.
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 (
In addition, when optically detecting the sagging of the film 2 in the passing-on region II, as shown in
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.
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
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
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 104 239.9 | Feb 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/054417 | 2/22/2022 | WO |
