METHOD FOR ADAPTING AT LEAST ONE WINDING PARAMETER OF A WINDING DEVICE

Abstract

The invention relates to a method for adapting at least one winding parameter of a winding device during winding of a film web on a winding core, having the following steps:—conveying of the film web along a measuring path between a first driven roll and a second driven roll—increasing of the web tension of the film web between the first roll and the second roll—continuous detecting of the drive parameters of the first roll and of the second roll at least in the form of the torque and the circumferential speed,—determining of a stress-strain diagram from the detected drive parameters—adapting of at least one winding parameter of the winding device on the basis of the determined stress-strain diagram in order to achieve a defined elongation of the film web during winding on the winding core.

Claims

1. A method for adapting at least one winding parameter of a winding device during winding of a film web on a winding core, the method comprising: conveying of the film web along a measuring path between a first driven roll and a second driven roll; increasing of the web tension of the film web between the first roll and the second roll; continuous detecting of the drive parameters of the first roll and of the second roll at least in the form of the torque and the circumferential speed; determining of a stress-strain diagram from the detected drive parameters; adapting of at least one winding parameter of the winding device on the basis of the determined stress-strain diagram in order to achieve a defined elongation of the film web during winding on the winding core.

2. The method of claim 1, wherein the web tension is generated along the measuring path by accelerating the second roll and/or braking the first roll.

3. The method of claim 1, wherein the first roll and/or the second roll are at least one of the following drive rolls of the winding device or of a film producing machine: a cutting feed roll, a contact roll, a central drive roll, a stretching roll, and a support roll.

4. The method of claim 1, wherein at least one of the following winding parameters is at least one of web tension to the winding core, roll overfeed of winding device, and pressing forces of film web on winding core.

5. The method of claim 1, wherein the film web wraps around the first roll and/or the second roll at least during the performing of the method over an angle of more than about 90°, in particular between about 100° and 180°.

6. The method of claim 1, wherein the winding of the film web takes place at least during the detection of the drive parameters on a test core, which has a sensor device for detecting the winding pressure acting upon the test core, wherein the adaptation of the at least one winding parameter additionally considers an upper limit for the winding pressure.

7. The method of claim 6, wherein the winding pressure is used for compensation with a winding model, in order to use, verify and/or optimize this winding model for adapting the at least one winding parameter.

8. The method of claim 6, wherein the transmission of the detected winding pressure to a control unit is executed wirelessly according to at least one of the following standards: W-LAN (Wireless Local Area Network), Bluetooth, and NFC (Near Field Communication).

9. The method of claim 1, further comprising continuously cutting a measuring strip from the film web before reaching the first roll, and wherein the measuring strip passes through the measuring path.

10. An optimization device for adapting at least one winding parameter of a winding device during winding of a film web on a winding core, having a first roll and a second roll for conveying the film web along a measuring path between these two rolls, further provided with a control unit for: increasing the web tension of the film web between the first roll and the second roll; continuous detecting of the drive parameters of the first roll and of the second roll, at least in the form of the torque and circumferential speed; determining of a stress-strain diagram from the detected drive parameters; and adapting of at least one winding parameter of the winding device on the basis of the determined stress-strain diagram in order to achieve a defined elongation of the film web during winding on the winding core.

11. The optimization device of claim 10, wherein the control unit is configured for: conveying of the film web along a measuring path between a first driven roll and a second driven roll; increasing of the web tension of the film web between the first roll and the second roll; continuous detecting of the drive parameters of the first roll and of the second roll at least in the form of the torque and the circumferential speed; determining of a stress-strain diagram from the detected drive parameters; adapting of at least one winding parameter of the winding device on the basis of the determined stress-strain diagram in order to achieve a defined elongation of the film web during winding on the winding core.

12. The optimization device of claim 10, wherein the wrapping angle of the first roll and/or the wrapping angle of the second roll is greater than 90°.

13. The optimization device of claim 12, wherein the wrapping angle of the first roll and/or the wrapping angle of the second roll is between about 100° and 180°.

14. The optimization device claim 10, wherein the wrapping angle of first roll at least corresponds to the wrapping angle of the second roll.

15. The optimization device of claim 10, further comprising a test core for winding the film web, wherein the test core comprises a sensor device for detecting the winding pressure acting upon the test core.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further advantages, characteristics and details of the invention will become apparent from the following description, in which, with reference to the drawings, exemplary embodiments of the invention are explained in detail. The characteristics, which are cited in the claims and in the description, may be considered essential for the invention per se or in any suitable combination. In particular, schematically:

[0054] FIG. 1 shows an illustration of an inventive method with a corresponding optimization device,

[0055] FIG. 2 shows a further possible embodiment of an inventive method with an optimization device,

[0056] FIG. 3 shows a possible increase of the web tension,

[0057] FIG. 4 shows a further possible increase of web tension,

[0058] FIG. 5 shows a further possible increase of web tension,

[0059] FIG. 6 shows an example of a stress-strain diagram,

[0060] FIG. 7 shows an embodiment of a test core and

[0061] FIG. 8 shows a further embodiment of a test core.

DETAILED DESCRIPTION

[0062] The simplest embodiment of an inventive optimization device 10 is shown in FIG. 2. Here, a winding device 100 with a winding core 110 is provided, on which a film web 200 is wound. The film web 200 comes from a film machine 400 and is deflected inside about various rolls. In this case a first roll 20 and a second roll 30 are explicitly shown, wherein a measuring path M for the film web 200 is provided in-between. According to the invention, this measuring path M may be used to increase, by corresponding modification of the drive condition, a web tension in the film web 200 in the measuring path M, as explained in the following.

[0063] A control unit 40 of the optimization device 10 is connected, by communicating signals, with both driven rolls 20 and 30, and determines there continuously the corresponding drive parameters AP, which are the torque and the circumferential speed and optionally further additional drive parameters AP. Moreover, in a control device 40, the inventive method is executed, i.e. in particular, the stress-strain diagram is determined and then, for achieving a defined elongation, at least one winding parameter WP is adapted. The adaptation may here, for example, result in a variation of the rotational speed of the winding device 100.

[0064] FIG. 1 shows an elaboration of FIG. 2. In this case, the film web 200 is contacted by a cutting device, which performs a cutting or a plurality of cuttings after a roll. An entire film web 200 is represented coming from the upper right side along the direction of the arrow. A corresponding cutting device cuts measuring strips 200, in this case three pieces, and separates these from the rest of the film web 200. While the rest of the film web 200 is wound around the already described roll of FIG. 2, the measuring strips 210 are conveyed to the left. Here, one or more of these measuring strips 210 may also run along a measuring path M between two rolls 20 and 30. Here, also, a variation of the web tension and the same detection of drive parameters AP takes place by the control unit 40. Here, also, a stress-strain diagram is determined and correspondingly at least one of the winding parameters WP is adapted.

[0065] FIGS. 3 to 5 show possibilities and definitions of the web tension of the film web 200. Here, both rolls 20 and 30 are provided with wrapping angles 22 and 32>90°. Both wrapping angles 22 and 32 are essentially identical in this case. The film web 200 runs along the measuring path M, wherein in FIG. 3, web tension is absent or very low, since the circumferential speed of both rolls 20 and 30 is identical or essentially identical. As shown by the increase or reduction of rotation arrows in FIGS. 4 and 5, a change of circumferential speed now takes place. According to FIG. 4, the circumferential speed of second roll 30 is increased, whereby the web tension in the film web 200 increases along the measuring path M. Thereafter, or as an alternative, a braking and therefore a reduction of the circumferential speed of the first roll 20 of FIG. 5 has taken place, which leads to a further increase of the web tension in the film web 200.

[0066] Through continuous monitoring of the drive parameters AP, i.e. torque and circumferential speed of both rolls 20 and 30, the control unit 40 may determine a stress-strain diagram 300 according to FIG. 6. In this case, the vertical dotted line clearly shows the transition between an elastic behavior and a plastic behavior for the measuring result. Here a defined value is set along the elongation 310, which corresponds to a corresponding tension 320, and this defined elongation has to be achieved. To this end, the control unit 40 adapts at least one winding parameter WP, for example the web tension or the circumferential speed of the winding core 110.

[0067] FIGS. 7 and 8 show different solutions for the test cores 120, which are here both provided with sensor devices 122. According to the embodiment of FIG. 7, the sensor device 122 is a pressure sensor, positioned on the surface of the test core 102. According to FIG. 8, a corresponding sensor device 122 is positioned in a longitudinal slit of the hollow test core 120. In both cases, the communication with the control unit 40, shown by a dotted line, takes place by wireless transmission, in particular by means of a Wi-Fi or Bluetooth module.

[0068] The preceding explanation of embodiments describes the present invention exclusively in the context of examples. It is apparent that individual characteristics of these embodiments, as long as they are technically feasible, may be freely combined with each other, without departing from the scope of the present invention.

REFERENCE LIST

[0069] 10 optimization device [0070] 20 first roll [0071] 22 wrapping angle [0072] 30 second roll [0073] 32 wrapping angle [0074] 40 control unit [0075] 100 winding device [0076] 110 winding core [0077] 120 test core [0078] 122 sensor device [0079] 200 film web [0080] 210 measuring strip [0081] 300 stress-strain diagram [0082] 310 elongation [0083] 320 tension [0084] 400 film machine [0085] AP drive parameters [0086] WP winding parameters [0087] M measuring path