MEASURING DEVICE AND METHOD FOR MEASURING TWO OR THREE-DIMENSIONAL FILM TOPOGRAPHY AND METHOD FOR RECOGNISING IN-LINE PATTERNS IN TWO OR THREE-DIMENSIONAL FILM TOPOGRAPHY

Abstract

The invention relates to the detection and use of film topography (23) of a film web (13, 40, 51) produced in blow film or casting film methods for improving the quality of the film web (13, 40, 51). In particular, film topography (23) can be quantitatively detected using said the invention. In another aspect of the invention, the film topography (23) is analysed using a pattern recognition algorithm and is optionally allocated an error image (50). This information is used in order to improve the quality of the film web (13, 40, 51) by controlling action recommendations dependent on the error image and to quantitatively detect the flatness of a film web (13, 40, 51). The invention also relates to an influencing element (30) for influencing the properties of a film web (13, 40, 51) in the position where the film topography (23) is determined.

Claims

1. Measuring device for measuring a two- or three-dimensional film topography of a film web produced by a blown or cast film process with a radiation source, in particular a light source, a detector and a data processing and evaluation unit, characterized in that the radiation source and the detector have a different position, the radiation source is configured for projecting a radiation pattern onto a designated running section of the film web, wherein the radiation pattern is preferred a line with in particular parallel light, the detector is configured to detect the projected radiation pattern, especially to detect the projected line, the detector is focused on the projected radiation pattern, in particular the projected line, and the data processing and evaluation unit has programming, wherein the programming is configured for carrying out a triangulation method and/or a reflection method and/or a transmission method for determination of the film topography.

2. Measuring device according to claim 1, characterized in that the radiation source and the detector are positioned in a common housing. Page 4

3. Measuring device according to claim 1, characterized in that on the designated running distance of the film web projected radiation patterns runs across to the machine direction across the entire width of the designated run of the film web.

4. Measuring device according to claim 1, characterized in that the onto the designated track of the film web projected radiation pattern runs in the machine direction and has a length.

5. Measuring device according to claim 1, characterized in that the onto the designated running section of the film web projected radiation pattern runs at an angle diagonally across the designated running section of the film web.

6. Measuring device according to claim 5, characterized in that an adjusting device is provided for the angle.

7. Measuring device according to claim 1, characterized in that the device comprises a second detector, which is also connected to the data processing and evaluation unit and has a different position from the first detector and from the radiation source.

8. Plant for producing a film web, wherein the plant has an extruder for plasticizing a thermoplastic, a nozzle for the exit of the plastic, a deflection part and a winder, characterized in that the plant comprises a measuring device for inline measuring a two-dimensional o the three-dimensional film topography according to claim 1.

9. Plant according to claim 8, characterized in that the plant comprises anon a property and/or orientation of the film web acting -influencing element, wherein the influencing element may have an influencing device, the measurement of the film topography is provided within the area of influence of the influencing element, wherein the influencing element is configured to reducein particular completelyan error image of a second error, in order to conclude to the dimension of the first error via adue to the influencing process more increasingerror image of a first error compared with the error of the second error.

10. Plant for producing a film web according to claim 9, characterized in that the plant has a dancer roll for reducing tensile stress variations in the film web with the help of a regulation.

11. Plant according to claim 9, characterized in that the plant compriseswith respect to their machine direction before and/or after the film topography measurementa nip in order to isolate the tensions in the film web with the nip before and/or after the film topography measurement.

12. Plant according to claim 9, characterized in that the plant comprisesin relation to its machine direction before and/or after the film topography measurementa nip in order provide the tensions in the film web with the nip before and/or after the film topography measurement, specifically in the film web.

13. Plant according to claim 9, characterized in that the plant comprisesin relation to its machine direction before and/or after the film topography measurementa nip in order adjust the tensile stresses in the film web with the nip before and/or after the film topography measurement, targeted to the ideal tension level.

14. Plant according to claim 9, characterized in that the film topography measurement is arranged downstream of a web centre control, which forces a central run in of the film web into the film topography measuring system.

15. Plant according to claim 9, characterized in that the film topography measurement is arranged before or after a deflection roller.

16. Plant according to claim 9, characterized in that the film topography measurement is arranged after a width spreader element.

17. Plant according to claim 9, characterized in that the film topography measurement is arranged after a seam station.

18. Plant according to claim 9, characterized in that the film topography measurement is arranged after a slit device.

19. Plant according to claim 9, characterized in that the film topography measurement is arranged after a tension measuring roll.

20. Method for inline pattern recognition of error images in a two-dimensional or three-dimensional film topography of a film web which is produced in the blown film or cast film process, characterized in that a two-dimensional or three-dimensional film topography is determined as a measuring value, in particular with a measuring device according to claim 1, the determined film topography is transmitted to a data processing and evaluation unit, the data processing and evaluation unit classifies, systematically comparing, with the help of a film topography pattern recognition algorithm using a data base of predefined pattern properties, separates the error images contained in the pattern and identifies the error images.

21. Method according to claim 20, characterized in that the predefined pattern properties include a number of error images defects across the width of the film web.

22. Method according to claim 20, characterized in that the predefined pattern properties comprise a continuously or cyclically appearance of errors images.

23. Method according to claim 20, characterized in that the predefined pattern characteristics comprise an increasing or decreasing manifestation of error images.

24. Method according to claim 20, characterized in that the predefined pattern properties comprise a position of the error images on the film web.

25. Method according to claim 20, characterized in that the predefined pattern properties comprise a helical course of the error images on the film web.

26. Method according to claim 20, characterized in that the predefined pattern properties comprise a rectilinear course of the error images on the film web.

27. Method according to claim 20, characterized in that the predefined pattern properties comprise a position of the error images on the film web in relation to the film web width.

28. Method according to claim 20, characterized in that the predefined pattern properties comprise a position of the error images on the film web in relation to the machine direction.

29. Method according to claim 20, characterized in that the predefined pattern properties comprise an orientation of the error images in relation to an angle between 1 and 89 to the machine direction on the film web.

30. Method according to claim 20, characterized in that the causes of the error images are analyzed.

31. Method according to claim 20, characterized in that the pattern recognition algorithm is self-learning.

32. Method according to claim 20, characterized in that the pattern recognition algorithm learns by inputs of the machine operator.

33. Method according to claim 20, characterized in that the data base of the pattern properties contains causes of the individual error images.

34. Method according to claim 20, characterized in that the data base of the pattern properties contains for the individual error images actions recommendations for stopping or reducing an error image by changing a setting variable in the manufacturing process to the film web.

35. Method according to claim 20, characterized in that the setting variable in the manufacturing process contains a recipe of the thermoplastic substance.

36. Method according to any claim 20, characterized in that the setting variable in the manufacturing process contains a nozzle cross-section for the exit of the plastic.

37. Method according to claim 20, characterized in that the setting variable in the manufacturing process includes the setting of a flattening part.

38. Method according to claim 20, characterized in that the setting variable in the manufacturing process includes the setting of a lateral guide.

39. Method according to claim 20, characterized in that the setting variable in the manufacturing process includes the setting of a flatness position actuator.

40. Method according to claim 20, characterized in that the setting variables in the manufacturing process are divided into segmented control zones.

41. Method according to claim 20, characterized in that for controlling the production process of a film web for reducing or preventing of error images an action recommendation from the data base of the pattern recognition is automatically used for controlling the manufacturing process of the film web.

42. Method according to claim 20, characterized in that for regulating the manufacturing process of a film web for preventing or reducing of error images an action recommendation from the data base of the pattern recognition is automatically used for regulating the production process of the film web.

43. Use of the method according to claim 20 for the inline flatness determination of awith a blow or cast film method producedfilm web.

44. Plant for producing a film web, wherein the plant comprises an extruder for plasticizing a thermoplastic, a nozzle for the exit of the plastic, a deflection part and a winder, characterized in that the device comprises a measuring device according to, claim 1.

45. Plant according to the claim 44, characterized in that the plant for producing a film web comprises an influencing element according to claim 9.

46. Plant according to claim 44, characterized in that the plant for producing a film web is configured in the form of a blown film or cast film.

47. (disturbance free error determination method) Method for inline determination of a first error, in particular flatness position error, of ain the blown or cast film producedfilm web by means of a two- or multi-dimensional film topography measurement method, wherein the film web has the first and a second error, characterized in that the method useson a property and/or orientation of the film web actingan influence, in particular an influencing element according to claim 9, in order to reducein particular completelyan error image of the second error, in order to conclude to the dimension of the first error, via adue to the influencing process more increasingerror image of a first error compared with the error of the second error.

48. Method according to claim 47, characterized in that the tensile stress variations in the film web are reduced in the area of the film topography measurement with help of a regulation of the dancer roller.

49. Method according to claim 47, characterized in that the tensions in the film web are isolated with a nip before and/or after the film topography measurement.

50. Method according to claim 47, characterized in that tensions in the film web are specifically generated in the film web with a nip before and/or after the film topography measurement.

51. Method according to claim 47, characterized in that the tensile stresses in the film web are set targeted with a nip before and/or after the film topography measurement to the ideal tension level.

52. Method according to claim 47, characterized in that the film topography measurement is performed after a web centre control, which forces a centrically run of the film web into the film topography measuring system.

53. Method according to claim 47, characterized in that the film topography measurement takes place before or after a deflection roller.

54. Method according to claim 47, characterized in that the film topography measurement is performed after a width spreader element (German: Breitstreckenelement).

55. Method according to claim 47, characterized in that the film topography measurement is carried out after a seam station.

56. Method according to claim 47, characterized in that the film topography measurement is performed after a slit device.

57. Method according to claim 47, characterized in that the film topography measurement takes place after a tension measuring roller.

58. (canceled)

Description

[0298] The invention will be described below with reference to an exemplary embodiment

explained in detail on the drawing. It is shown there:

[0299] FIG. 1 shows schematically a plant for producing a film web, in particular a blown film plant, with a measuring device for measuring a film topography, in particular a blown film plant,

[0300] FIG. 2 shows schematically an influencing element in the area of the film topography measurement and

[0301] FIG. 3 shows schematically an error image.

[0302] The blown film plant 1 in FIG. 1 consists essentially of an extruder 2, a blow head 3, a reversing turn out 4, a treatment section 5 and a winder 6.

[0303] The extruder 2 conveys and plasticizes a plastic melt, which exits through a ring

gap nozzle (not numbered) in the blow head 3. The exiting plastic melt forms a film bubble 7, which is laid together in a flattening part 8 to a double laid flat film web 13.

[0304] The doubly flattened film web 13 is pulled from a turn-out roller pair 9, 10 and further passed into the reversing turn-out 4.

[0305] The reversing turn-out is driven by a motor 11 and carries out a reversing movement 12, by which deviations in the film thickness profile of the double flat laid film web 13 are moved away.

[0306] Behind the reversing turn out 4, the double flattened film web is fed to the

treatment section 5, which stretches the doubly flattened film web 13 in this embodiment monoaxially in the machine direction.

[0307] Behind the treatment section 5, the double flattened film web 13 is transmitted to the winding 6 and is wound there to a film roll.

[0308] Between the treatment section 5 and the winder 6 passes the double flattened

film web 13 to a film thickness profile measuring device 14, which determines a film thickness profile 15 of the doubly flattened film web 13.

[0309] The film thickness profile 15 of the doubly flattened film web 13 is supplied together with a reversing angle 16 of the reversing turn-out 4 of a data processing and evaluation unit 17.

[0310] The data processing and evaluation unit 17 is adapted to carry out a method for

determining a thickness distribution systematic and a method for adjusting the film thickness profile and to control the annular nozzle of the blow head 3.

[0311] Likewise, the doubly flattened film web 13 passes between the treatment section 5 and the winder 6 a film topography measuring system 18 consisting of a radiation source 19 and a detector 20.

[0312] The radiation source 19 projects a radiation pattern 21 onto the double flattened film web 13 at the position 22.

[0313] The detector 20 is adapted to detect the radiation pattern 21 on the double flattened foil web 13. In particular, the detector 20 is focused at the position 22 of film web 13.

[0314] The detected film topography 23 is electronically transmitted from the film topography measurement system 18 to the data processing and evaluation unit 17.

[0315] The data processing and evaluation unit 17 is adapted to carry out a method for inline pattern recognition of error images (not numbered) based on the measured

film topography 23.

[0316] In addition, the data processing and evaluation unit 17 is adapted to perform a process for controlling the blown film plant 1, which aims to reduce or to prevent completely error images (not numbered) in the film topography 23 in their manifestation (not numbered).

[0317] For this purpose, the data processing and evaluation unit 17 can transmit corresponding control commands to the setting variables (not quantified) and thus influences the blown film process.

[0318] In this embodiment are available as setting variables (not numbered), the gap thickness (not numbered) of the blowing head 3, the reversing movement 12 of the reversing turn out 4 and the setting variable 24 of the treatment section 5.

[0319] For this purpose, the setting variable 24 of the treatment section 5 is electronically transmitted to the control unit 25 of the treatment section 5.

[0320] The influencing element 30 in FIG. 2 consists essentially of a first nip 31 and a second nip 32 and a film topography measuring system 33.

[0321] The first nip 31 consists of a first squeeze roll 34 and a second squeeze roll 35. The second nip 32 consists of a first squeeze roll 36 and a second squeeze roll 37.

[0322] The film topography measuring system 33 essentially consists of a radiation source

38 and a detector 39. The radiation source 38 projects a radiation pattern 42 on the film web 40 at the position 43. The detector 39 is adapted to detect the radiation pattern 42 on the film web 40. In particular, the detector 39 is focused on the position 43 of the film web 40.

[0323] The film web 40 runs in the machine direction 41 into the influencing element 30, passes to the first nip 31, the radiation pattern 42, continues to the second nip 32 and

leaves the influencing element 30 again.

[0324] The influencing element 30 is adapted to affect the web tension 44 at the position

43 of the film topography measurement with the film topography measurement system 33.

[0325] The defect image 50 of the film web 51 consists essentially of folds 53, 54, 55, 56,

57, 58, 59, 60, 62, 63, 66 extending substantially in the machine direction 52.

LIST OF REFERENCE NUMBERS USED

[0326] 1 blown film plant [0327] 2 extruder [0328] 3 blow head [0329] 4 reversing turn-out [0330] 5 treatment section [0331] 6 winder [0332] 7 foil bubble [0333] 8 flattening part [0334] 9 take-out roll [0335] 10 take-out roll [0336] 11 motor [0337] 12 reversing movement [0338] 13 double flat laid film web [0339] 14 film thickness profile measuring device [0340] 15 film thickness profile [0341] 16 reversing angle [0342] 17 data processing and evaluation unit [0343] 18 film topography measuring system [0344] 19 radiation source [0345] 20 detector [0346] 21 radiation pattern [0347] 22 position [0348] 23 film topography [0349] 24 setting variable [0350] 25 setting unit [0351] 30 influencing element [0352] 31 nip [0353] 32 nip [0354] 33 film topography measuring system [0355] 34 squeeze roll [0356] 35 squeeze roll [0357] 36 squeeze roll [0358] 37 squeeze roll [0359] 38 radiation source [0360] 39 detector [0361] 40 film web [0362] 41 machine direction [0363] 42 radiation pattern [0364] 43 position [0365] 44 web tension [0366] 50 error image [0367] 51 film web [0368] 52 machine direction [0369] 53 fold [0370] 54 fold [0371] 55 fold [0372] 56 fold [0373] 57 fold [0374] 58 fold [0375] 59 fold [0376] 60 fold [0377] 62 fold [0378] 63 fold [0379] 66 fold