EP3877139A1

EP3877139A1 - Method and device for changing the production of a flat film machine from an input product to a subsequent product

Info

Publication number: EP3877139A1
Application number: EP19798290.3A
Authority: EP
Inventors: Torsten Schmitz; Waldemar COLELL; Bernd-Alexander Groepper
Original assignee: Windmoeller and Hoelscher KG
Current assignee: Windmoeller and Hoelscher KG
Priority date: 2018-11-06
Filing date: 2019-11-05
Publication date: 2021-09-15
Also published as: CN112955298A; CN112955298B; DE102018127669A1; US20210323213A1; US12036718B2; WO2020094629A1

Abstract

The invention relates to a method for changing the production of a flat film machine (100) from an input product (EP) to a subsequent product (FP), having the following steps: - detecting a change request for a change from the input product (EP) to the subsequent product (FP), - determining a current input adjustment value (ES) of at least one adjustment variable (SG) of the flat film machine (100) for the input product (EP), - determining a subsequent adjustment value (FS) of the same at least one adjustment variable (SG) for the subsequent product (FP), and - generating an adjustment signal (SS) for varying in a defined manner the at least one adjustment variable (SG) of the flat film machine (100) from the input adjustment value (ES) to the subsequent adjustment value (FS).

Description

METHOD AND DEVICE FOR CHANGING THE PRODUCTION OF A FLAT FILM MACHINE FROM

AN APPLICATION PRODUCT TO A FOLLOW-UP PRODUCT

Description

The present invention relates to a method for changing the production of a flat film machine from an input product to a subsequent product and a changing device for carrying out such a method.

It is known that flat film machines are used to make products in

To produce the form of flat foils. Such flat film machines are usually equipped with a nozzle device which is capable of producing or dispensing on a wide film web. A melt flow can be passed through one or more extrusion devices

Nozzle device supplied and distributed over the entire exit width. Typical widths of such nozzle devices are in the range from one to ten or even more meters. In addition, it is also possible to coat or laminate the melt. For example, one or more flat webs can be fed to the melt for this purpose.

A disadvantage of the known solutions is that a great deal of effort has to be expended when converting different products, and at the same time there is no reproducibility of the changeover mechanism. This is based on the fact that a large number of the changeover steps which are necessary to switch from a feed product to a subsequent product are carried out manually. This can be a change in the format, for example, the exit width of the film product. However, further changes are also conceivable in combination or as an alternative, for example the composition of the film product or the layer structure of the film product. If a change is made from an input product to a follow-up product in the known solutions, manual changeover takes place, for example by changing lateral sealing swords in the form of manual insertion or extension, and manual reworking or adjusting adjusting bolts for the outlet gap of the nozzle.

It is an object of the present invention to at least partially remedy the disadvantages described above. In particular, it is an object of the present invention to stabilize the changeover between an input product and a subsequent product in a cost-effective and simple manner and to make this changeover reproducible in particular.

The above object is achieved by a method with the features of claim 1 and a changing device with the features of claim 13. Further features and details of the invention emerge from the subclaims, the description and the drawings. Features and details that are described in connection with the component according to the invention also apply, of course, in connection with the method according to the invention and vice versa, so that with respect to the disclosure of the individual aspects of the invention, reference can always be made to one another. According to the invention, a method for changing the production of a flat film machine from an input product to a subsequent product is proposed. Such a process has the following steps:

Recognition of a change request for a change from the input product to the follow-up product,

- Determining a current control input value of at least one control variable of the flat film machine for the input product,

Determining a subsequent manipulated variable of the same at least one manipulated variable for the subsequent product,

- Generating an actuating signal for a defined variation of the at least one actuating variable of the flat film machine from the actuating actuating value to the subsequent actuating value.

A method according to the invention is in particular automated or at least partially automated. At least the last step, namely the generation of the actuating signal for a defined variation of the at least one actuating variable, is preferably automated or partially automated. A method according to the invention can, for example, proceed as follows:

If a change in format is desired in the simplest way, that is to say a reduction or an increase in the width of the film product from the input product to the subsequent product, the procedure can be as follows. The change request can be recognized either by manual input by the operating personnel, or else by recognizing the end of production of the input product and thus an automated requirement profile for the changeover. After recognizing this change request, the method according to the invention is used to determine a current set value for at least one manipulated variable of the flat film machine. If, for example, the exit width or the net width of the film web is to be changed, for example reduced from the input product to the follow-up product, the corresponding input manipulated variable is used for the manipulated variable of the net width of the input product, for example as the manipulated manipulated variable of the measured net width at the end of the film web and / or, for example, as a control value, the exit width at the Nozzle outlet gap determined. The target variable, namely the subsequent manipulated variable for the subsequent product for the exactly the same at least one manipulated variable can also be determined in the same way via a corresponding database or manual input. Thus, the starting point in the form of the control value and the target point in the form of the subsequent control value are now known to a control process or a corresponding control process. On the basis of the difference between the set control value and the subsequent control value for the at least one control variable, the desired control signal can now be made available and generated in order to achieve a defined variation of the at least one control variable. In the present example, this would mean that the control signal should ensure a variation in the net width for the film product. For example, the control signal can act on automatically operated sealing swords on the sides of the nozzle outlet gap. If the net width of the film product is to be reduced from the input product to the subsequent product, this control signal would lead to one or both sides of the nozzle outlet gap in such an exemplary case for the retraction of the sealing swords. The manipulated variable, namely the exit width from the nozzle exit slit in this case, would therefore be varied from a broad parameter according to the use manipulated variable to a narrower parameter according to the subsequent manipulated variable. A direct control loop can therefore be provided for direct influencing as a manipulated variable for the exit width. However, it is also conceivable in the sense of the present invention that an indirect influence is possible as a manipulated variable, namely in the form of the net width of the film product. The net width or possibly also the gross width can be changed, for example, by the exit width as an indirect parameter of the production machine of the flat film machine. It is now possible to automatically and directly influence the manipulated variable with a control signal, either directly or indirectly.

Based on known solutions, a number of advantages can now be achieved. The decisive factor according to the present invention is the correlation between the current control input value and the desired subsequent control value as the target value of the control. This correlation can in particular be made available in an automated manner and finally allow the control signal to be automatically controlled and / or regulated. In comparison to known solutions, automation or partial automation of this changeover from the input product to the subsequent product is now available be put. This automation or partial automation now takes the responsibility of the operating personnel of the flat film machine and transfers it to the control method according to the invention. This significantly reduces the susceptibility to errors and the possibly longer duration of the changeover process in the event of an incorrect changeover. Last but not least, it also makes it possible to make the switch from a feed product to a follow-up product reproducible. It should also be pointed out that, of course, not only a single manipulated variable, but also two or any number of manipulated variables can be taken into account during the changeover. The correlation of individual manipulated variables with one another, for example the prioritization of individual manipulated variables with one another, is of course also possible in the sense of the present invention. A method according to the invention can therefore lead to an automated or partially automated change in the production of a flat film machine. In this way, the time required, the risk of a production stop and the risk of rejects during the changeover process are reduced or even minimized.

It can be advantageous if, in a method according to the invention, the starting product differs from the subsequent product by at least one of the following product parameters:

- Width of a film web

- Thickness of a film web

- Temperature of a film web

- Composition of a film web

- Layer distribution of a film web

- Quality parameters of the film web

- Production stability of the film web

- Layer thickness ratio of the film web

- Temperature profile of the film web

Width difference of the film web - Adjustment profile of adjusting bolts of the outlet nozzle

- Machine parameters of the flat film machine

- Outlet width of the outlet nozzle

- Thickness profile of the film web

The list above is a non-exhaustive list. The above product parameters can also be understood or used as indirect manipulated variables. In particular, both usage parameters and quality parameters of the film web, but also production parameters and, accordingly, stability parameters of the film web are conceivable for the use according to the invention. The products, that is to say the input product and the subsequent product, often differ even in two or more parameters, as described above. The width of the film web can mean both the gross width and the net width after the edge sections have been cut off. The thickness of the film web can be varied by the corresponding layer distribution, number of layers and thickness of the individual layers. The temperature of the film web is aimed in particular at the quality of the film web but also the stability and the production speed. The composition and the layer distribution of the film web are geared in particular to the later intended use, for example with reference to certain barrier properties or the mechanical stability of the film product.

It can also be advantageous if, in a method according to the invention, a stored flow behavior of the flat film machine, in particular a nozzle device of the flat film machine, is taken into account when generating the actuating signal. When producing with the flat film machine or even during the manufacture of the flat film machine, in particular the nozzle device, the flow behavior within the flat film machine can be measured or simulated directly or indirectly, for example by reading out an adjusting pin profile. The flow behavior can be stored by measurement or simulation model, so that it can serve as the basis for the changeover method according to the present invention. For example, this stored flow behavior can be used for stability during the changeover process, but also for desired quality changes between the input product and the subsequent product Flat film machine are used to achieve appropriate optimization steps when changing in terms of quality and stability or the time required for the changeover. Such a stored flow behavior can be specific to the respective product, that is to say the input product or the subsequent product. An adaptation to such a profile is now possible in the flat film machine. This flow behavior can be determined and stored once, but can also be adapted and adapted by constant monitoring or regular remeasurement. In particular, it is conceivable that after a method according to the invention has been completed, there is a feedback into the stored flow behavior in order to include the result of the change process in the stored data of the stored flow behavior. In this way, framework conditions of the machine, in particular the nozzle device, can also be taken into account during the changeover process.

Further advantages can be achieved if, in a method according to the invention, at least one stored production parameter of the flat film machine of a production database is taken into account when generating the actuating signal. Such a production database is designed in particular with specific product parameters of each individual different film product. For example, the stretch ratio, but also production parameters such as temperature, width ratios or thickness compositions, can be stored in the production database. Further information, such as an adjusting profile of adjusting bolts, positions of pinning devices or the like, can also be stored in the production database. Depending on the film recipe, as much individual information and product and production parameters as possible are stored in this production database. These can contain the control values and / or subsequent control values directly or indirectly, so that one or more control signals can correlate with the content of such a production database both directly and indirectly. Such a production database is preferably directly part of a corresponding changing device.

Further advantages can be achieved if, in a method according to the invention, at least one production parameter and / or a stored control signal from the changeover database is taken into account when generating the control signal. In addition to the production parameter, which in particular can also be part of the production database according to the preceding paragraph, conversion data are also conceivable which can be taken into account. In particular, the changeover database contains information about changes that have already occurred between input products and secondary products. In principle, the changeover based on the respective follow-up product, on the basis of the outgoing input product in each case, but also the explicit pairing between the input product and the follow-up product can form the basis for storage in the changeover database. In the changeover database there are, as it were, changeover recipes, in what way and with which control signals the changeover can take place. This leads to a significant simplification, since during the redistribution and in particular for the generation of the control signal, a significantly lower computational effort is required in an associated changing device. On the contrary, such a recipe for conversion can be processed simply and quickly, since complex calculations and calculations are no longer necessary. By adopting, but also adapting, stored actuating signals, feedback can also take place in such a changeover database. For example, successful, but also error-prone conversion attempts and switching between the input product and the subsequent product can be written back to the conversion database in order to be able to provide a learning system in the conversion database with quality-enhancing recipes.

There are also advantages if, in a method according to the invention, a melt flow distribution of the flat film machine is varied by the control signal. The melt flow distribution can be used, for example, with reference to the flow distribution, as has already been explained. Direct, but also indirect positioning is possible here via the inflow to the nozzle outlet gap, but also for the nozzle outlet gap itself. A global adjustment of a manipulated variable is just as conceivable as a local adjustment to individual sections of the nozzle outlet gap. An adaptation of the entire delivery rate in the flow direction upstream of the nozzle device is also conceivable in the sense of this embodiment.

There are further advantages if, in a method according to the invention, the manipulated variable is formed by the working width of the flat film machine. This working width is in particular the exit width from the nozzle exit gap Nozzle device. It can correlate with the gross width, but also with the net width of the film web of the input product or the subsequent product. A change in this working width can be provided, for example, by side sealing swords. This working width is in particular one of the stored parameters in a conversion database or a production database in accordance with the paragraphs explained above.

It is also advantageous if, in a method according to the invention, a change in the position of at least one lateral sealing blade in a nozzle exit gap of the flat film machine is generated as a control signal from the set control value to the subsequent control value. Such a movement will take place, in particular, in an automated or partially automated manner, so that the actuating signal causes a motor drive to move the respective lateral sealing sword laterally into or out of the nozzle outlet gap. The working width of the flat film machine and, accordingly, the exit width at the nozzle exit gap can thus be changed automatically or partially automatically. In order to prepare the sealing swords for the movement, for example an active loosening of adjusting bolts, which clamp the sealing swords in the edge area, can take place. If the adjusting bolts are, for example, thermal bolts, active cooling, for example by means of air outlets for cooling air on these adjusting bolts, is also conceivable. Delayed or at the same time, it is also possible to adjust pinning devices, in particular analogously to adjusting the sealing swords.

Further advantages can be achieved if at least one quality parameter of the subsequent product is selected as the manipulated variable in a method according to the invention. A quality parameter can be geared in particular to the use of the later film product. For example, the stretch ratio, the temperature, the production speed or similar quality parameters can influence the quality level in which the subsequent product can later be used. However, the quality can also relate to the stability of the production, so that the quality parameter is designed as the stability parameter of the subsequent product. This leads to a stabilization of the production, so that the change production can be carried out at a relatively high production speed, so that the time for the change can be reduced. Increasing the stability also has the advantage that there is a high probability that the film web will not tear, so that the switch between the input product and Follow-up product can be carried out with essentially ongoing production. In particular, the quality parameters will be monitored in the form of a quality threshold, which must not be exceeded or undershot.

It is a further advantage if, in a method according to the invention, a local and / or a global gap size of a nozzle exit gap of the flat film machine is selected as the manipulated variable. A previous measurement can be carried out to determine the gap size with regard to the starting position. Gap sizes can be changed locally or globally, for example using adjusting bolts. Such adjusting bolts are arranged directly next to one another in a plurality and can exert force from above on an upper nozzle lip of the nozzle outlet gap. Local influencing means that only one or more adjacent adjusting bolts provide a corresponding influence for closing or opening the nozzle outlet gap. The global variation of the gap size requires a significantly larger number, in particular a movement of all or essentially all of the adjusting bolts for the global variation of the nozzle outlet gap. This allows both readjustment during operation and an essentially sudden adjustment between the input product and the subsequent product.

It can have further advantages if, in a method according to the invention, an edge stability of the input product and / or the subsequent product is selected as the manipulated variable. The edge stability is particularly crucial for the stability of the production process itself. The edge stability can be monitored separately and locally, and relates, for example, to the monitoring of the thickness or the thickness distribution in the edge area. The displacement of an edge groove or an edge bead can lead to a flattening of the edge bead and to a filling of a corresponding edge groove, so that a compensation and, in particular, an increase in the edge stability is possible due to the compensation between the thick point and the thin point. This stability is later reflected in the quality of the product, since a defined longitudinal stretch ratio can be achieved.

A further advantage is if, in a method according to the invention, at least two use control values in at least two subsequent control values are at least partially at the same time can be varied. The fact that the change step is now carried out in an automated or partially automated manner according to the invention means that it is no longer necessary to work purely sequentially, as in the manual changeover according to the prior art. Rather, it is also possible to adjust the set control values to the subsequent control values partially in parallel and thus simultaneously and / or symmetrically in time. This enables the desired changeover to be carried out significantly faster, so that a further time saving with the same or even increased quality is possible. This parallel changeover can be applied, for example, to two different edge sections of the film web.

The present invention also relates to a changing device for changing the production of a flat film machine from an input product to a subsequent product. Such a changing device has a recognition module for recognizing a change request for a change from the input product to the subsequent product. Furthermore, a determination module is provided for determining a current manipulated variable of at least one manipulated variable of the flat film machine for the insert product and for determining a subsequent manipulated variable of the same at least one manipulated variable for the subsequent product. In addition, the changing device is equipped with a generation module for generating an actuating signal for a defined variation of the at least one actuating variable of the flat film machine from the actuating actuating value to the subsequent actuating value. In particular, the recognition module, the determination module and / or the generation module is designed to carry out a method according to the invention.

Further advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. It shows schematically:

FIG. 1 shows an embodiment of a changing device according to the invention,

FIG. 2 shows the embodiment in FIG. 1 after the changeover to the subsequent product, FIG. 3 shows an embodiment of a flat film machine in plan view,

Figure 4 is a detailed representation of the nozzle outlet gap in the feed product and Figure 5 shows the embodiment of the figure in the subsequent product.

Figures 1 and 2 show schematically how a flat film machine 100 can be constructed. Via a nozzle device 100, it is possible to dispense a film web 200 while it is still in the liquid state and to apply it to a large cooling roll, not specified. The film web 200 now runs over several roll-shaped rollers and can either be reworked, cut and / or wound up.

FIG. 1 shows the production of an insert product EP, in which, for example, a defined net width and / or a defined exit width from the nozzle device 110 is specified. If a changeover to a follow-up product FP is now desired, the changeover device 10 in accordance with this embodiment detects a manipulated variable SG as a set manipulated variable ES at one or more points. For example, the determination module 30 at the bottom right can be the determination of the thickness. The middle determination module can, for example, record the manipulated variable SG in the form of the temperature on the chill roll, while the left-hand determination module 30 detects the nozzle outlet gap 1 12 of the nozzle device 1 10 as the manipulated variable SG. The associated parameters can now be returned to the changeover device 10 as control values ES. After the change request has now been output via the detection module 20 and the set control values ES could be collected, a control signal SS is generated in the generation module 40 and here, for example, transmitted to the nozzle device 110. When generating in the generation module 40, further data can be used, for example. For this purpose, a production database 120 is provided in the embodiment of FIGS. 1 and 2, for example, in which corresponding changeover parameters, but also corresponding usage parameters for the usage product EP or the follow-up product FP are stored. Conversion recipes can be stored in a conversion database 130, which have the control signal SS directly or as a template. Of course, after the changeover, a feedback regarding the success or with regard to Recorded errors occur in order to develop a learning system for the changeover database 130 and / or the production database 120.

FIG. 2 shows the same configuration as FIG. 1, but after the variation has been carried out with the control signal SS. Here, for example, in order to control and feed back the production state for the follow-up product FP to the three determination modules 30, the respective manipulated variable SG can be detected further, so that reaching the follow-up manipulated variable FS based on the actuated manipulated variable ES of FIG. 1 is also recognizable . Thus, within the changing device, the end of the change can be clearly assigned by reaching the subsequent control values FS and the good production of the film web 200 can be defined accordingly.

FIG. 3 schematically shows a top view, the flat nozzle device 110 having a corresponding width for the nozzle outlet gap 112 being provided in this flat film machine 100. Also shown are a wide product EP and a narrower follow-up product FP. This is the gross width, ie the exit directly from the nozzle gap 1 12. The corresponding manipulated variables SG relate to the width with regard to the actuating manipulated variable ES and the subsequent manipulated variable FS. For the changeover from the input product EP to the follow-up product FP, the actuating signal SS according to FIGS. 1 and 2 will now automatically or partially automatically move the lateral sealing swords 140 inwards along the arrow directions, so that the exit width at the nozzle outlet gap 1 12 is reduced accordingly. The exit width of the film web 200 can thus be varied directly as the manipulated variable SG. Indirectly, of course, this has an influence on a net width that can also be used as manipulated variable SG after trimming this film web 200.

FIGS. 4 and 5 show an additional or alternative possibility of influencing corresponding manipulated variables SG. Here, the manipulated variable SG is the local thickness or the exit thickness from the nozzle outlet gap 1 12. With corresponding adjusting bolts 150, which can be designed, for example, as thermal bolts, a wide or thick local nozzle outlet gap 1 12 can now be used in accordance with an actuating value ES FIG. 4 can be changed over, that is, closed further, in order to be able to achieve a narrower nozzle outlet gap 1 12 with a subsequent actuating value FS in FIG. 5. Of course, a wide variety of manipulated variables SG with a wide variety of use manipulated values ES, only subsequent manipulated values FS can also be combined with one another in order to be able to achieve an acceleration and improvement of the changeover behavior in parallel. In addition to local adjustment, global adjustment is also conceivable. A multiple adjustment can also take place in parallel and / or symmetrically.

The above explanation of the embodiments describes the present invention exclusively in the context of examples. Of course, if technically meaningful, individual features of the embodiments can be freely combined with one another without departing from the scope of the present invention.

With respect to the list

10 changing device

20 detection module

30 determination module

40 generation module

100 flat film machine

110 nozzle device

112 nozzle outlet gap

120 production database

130 conversion database

140 sealed sword

150 adjusting bolts

200 film web

EP insert product

FP follow-up product

SG manipulated variable

SS control signal

ES control value

FS subsequent manipulated variable

Claims

Patent claims

1. A method for changing the production of a flat film machine (100) from a feed product (EP) to a follow-up product (FP), comprising the following steps:

Recognition of a change request for a change from the input product (EP) to the follow-up product (FP),

Determining a current manipulated variable (ES) at least one manipulated variable (SG) of the flat film machine (100) for the insert product (EP), - determining a subsequent manipulated variable (FS) of the same at least one

Manipulated variable (SG) for the subsequent product (FP),

Generating an actuating signal (SS) for a defined variation of the at least one manipulated variable (SG) of the flat film machine (100) from the set manipulated variable (ES) to the subsequent manipulated variable (FS).

2. The method according to claim 1, characterized in that the feed product (EP) differs from the follow-up product (FP) by at least one of the following product parameters:

Width of a film web (200)

Thickness of a film web (200)

- temperature of a film web (200)

- Composition of a film web (200)

- Layer distribution of a film web (200)

- Quality parameters of the film web

- Production stability of the film web

Layer thickness ratio of the film web

- Temperature profile of the film web

Width difference of the film web

- Adjustment profile of adjusting bolts of the outlet nozzle

Machine parameters of the flat film machine

- Outlet width of the outlet nozzle

Thickness profile of the film web

3. The method according to any one of the preceding claims, characterized in that a stored flow behavior of the flat film machine (100), in particular a nozzle device (1 10) of the flat film machine (100), is taken into account when generating the control signal (SS).

4. The method according to any one of the preceding claims, characterized in that at least one stored production parameter of the flat film machine (100) of a production database (120) is taken into account when generating the control signal (SS).

5. The method according to any one of the preceding claims, characterized in that when generating the control signal (SS) at least one production parameter and / or a stored control signal (SS) from a changeover database (130) is taken into account.

6. The method according to any one of the preceding claims, characterized in that a melt flow distribution of the flat film machine (100) is varied by the control signal (SS).

7. The method according to any one of the preceding claims, characterized in that the manipulated variable (SG) is formed by the working width of the flat film machine (100).

8. The method according to claim 7, characterized in that as a control signal (SG) a change in the position of at least one side sealing sword (140) in a nozzle outlet gap (1 12) of the flat film machine (100) from the use control value (ES) to the result Control value (FS) is generated.

9. The method according to any one of the preceding claims, characterized in that at least one quality parameter of the subsequent product (FP) is selected as the manipulated variable (SG).

10. The method according to any one of the preceding claims, characterized in that a local and / or a global gap size of a nozzle outlet gap (1 12) of the flat film machine (1 10) is selected as the manipulated variable (SG).

1 1. The method according to any one of the preceding claims, characterized in that an edge stability of the feed product (EP) and / or the subsequent product (DP) is selected as the manipulated variable (SG).

12. The method according to any one of the preceding claims, characterized in that at least two use control values (ES) in at least two subsequent control values (FS) are varied at least partially at the same time.

13. Change device (10) for changing the production of a flat film machine (100) from an insert product (EP) to a follow-up product (FP), comprising a recognition module (20) for recognizing a change request for a change from the insert product (EP) to the follow-up product ( FP), a determination module (30) for

Determining a current manipulated variable (ES) at least one manipulated variable (SG) of the flat film machine (100) for the insert product (EP) and for determining a subsequent manipulated variable (FS) of the same at least one manipulated variable (SG) for the subsequent product (FP) and a generation module (40) for generating an actuating signal (SS) for a defined variation of the at least one actuating variable (SG)

Flat film machine (100) from the set manipulated variable (ES) to the subsequent manipulated variable (FS).