TECHNICAL ROLL, IN PARTICULAR FOR PAPER MANUFACTURING, METHOD FOR INTRODUCING A POLYMER FIBRE INTO AN EMPTY CONDUIT OF A TECHNICAL ROLL, AND USE OF A POLYMER FIBRE

Abstract

A technical roll, in particular for paper manufacturing, having an elongated roll core and at least one first covering which is provided on the roll core, wherein an empty duct or conduit is provided, which is suitable for receiving a polymer fibre and extends over the length of the roll such that the polymer fibre can be introduced at one end of the empty duct. The application also relates to a technical roll having a polymer fibre, to a method for introducing the polymer fibre into an empty duct, and to the use of a polymer-based optical waveguide as a sensor in a technical roll.

Claims

1. A technical roll, in particular for papermaking, having: an elongated roll core, at least one first cover, which is provided on the roll core, and an empty conduit, which is suitable for receiving a polymer fiber and extends over a length of the technical roll in such a way that the polymer fiber can be introduced at one end of the empty conduit.

2. The technical roll as claimed in claim 1, wherein the empty conduit is arranged outside the roll core.

3. The technical roll as claimed in claim 1, wherein a plurality of covers are provided on the roll core, wherein the first cover forms an outer cover and the empty conduit is arranged between the roll core and the outer cover.

4. The technical roll as claimed in claim 1, wherein the empty conduit is matched to the polymer fiber in such a way that the polymer fiber rests on an inner side of the empty conduit.

5. The technical roll as claimed in claim 1, wherein the empty conduit has an internal diameter of 300 μm to 600 μm.

6. The technical roll as claimed in claim 1, wherein the empty conduit extends over an entire length of the cover and both ends of the empty conduit are accessible from outside.

7. The technical roll as claimed in claim 6, wherein the empty conduit is manufactured from a plastic, in particular a co-polyester or polyamide.

8. The technical roll as claimed in claim 1, wherein a plurality of empty conduits are provided.

9. The technical roll as claimed in claim 1, wherein the empty conduit extends parallel to a longitudinal axis (L) of the roll.

10. The technical roll as claimed in claim 1, wherein the empty conduit extends at an angle to the longitudinal axis (L) of the roll.

11. The technical roll as claimed in claim 1, wherein the technical roll has a length of up to 12 m.

12. A method for introducing a polymer fiber into an empty conduit of a technical roll, the method having the following steps: providing a polymer fiber with a leading end, introducing the leading end into one end of the empty conduit, applying a vacuum to another end of the empty conduit or applying compressed air to the one end of the empty conduit, and drawing the polymer fiber through the empty conduit via the applied vacuum, or pushing the polymer fiber through the empty conduit via the applied compressed air.

13. The method as claimed in claim 12, wherein the polymer fiber is provided with an adhesive before being introduced into the empty conduit in such a way that there are no or virtually no clearances between the polymer fiber and an inner side of the empty conduit.

14. The method as claimed in claim 12, wherein plastic is injected into the empty conduit following the introduction of the polymer fiber into the empty conduit.

15. The method as claimed in claim 12, wherein the polymer fiber is introduced following a complete fabrication of the technical roll.

16. A technical roll, in particular for papermaking, having: a roll core, at least one cover, and a sensor, which is formed as a polymer-based optical waveguide, polymer fiber, and extends inside the technical roll and outside the roll core.

17. The technical roll as claimed in claim 16, wherein the polymer fiber extends over an entire length of the technical roll.

18. The technical roll as claimed in claim 16, wherein a measuring device is provided, which is designed to couple light into the polymer fiber and to detect reflected light out of the polymer fiber as a measured value.

19. The technical roll as claimed in claim 18, wherein the measuring device has an evaluation unit, which determines one or more parameters selected from the group of pressure, temperature or moisture content, from one or more detected measured values.

20. The technical roll as claimed in claim 16, wherein the polymer fiber has at least one measuring point, preferably a plurality of measuring points.

21. The technical roll as claimed in claim 16, wherein a measuring device has a transmission unit, which is designed to transmit measured values and/or determined parameters in a wire-free manner to a central unit for further processing.

22. The technical roll as claimed in claim 16, wherein an energy recovery unit is provided, which supplies the measuring device with energy.

23. The technical roll as claimed in claim 22, wherein the energy recovery unit generates energy as a result of rotation of the technical roll by way of induction.

24. The technical roll as claimed in claim 23, wherein the energy recovery unit has a rechargeable battery, which stores the recovered energy.

25. The technical roll as claimed in claim 16, wherein an empty conduit is provided, in which the polymer fiber extends.

26. The technical roll as claimed in claim 16, wherein a polymer-based optical waveguide is used as a sensor in the technical roll for detecting at least one parameter, wherein the optical waveguide extends within the technical roll and has at least one measuring point.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0051] Further advantages and refinements of the present application emerge from the description and the appended drawings, in which:

[0052] FIG. 1 shows a schematic illustration of a technical roll with a cover;

[0053] FIG. 2 shows a schematic illustration of the roll from FIG. 1 in a longitudinal view;

[0054] FIG. 3 shows a schematic illustration of a roll having a plurality of covers in a longitudinal view;

[0055] FIG. 4 shows a schematic illustration of the roll according to FIG. 2 with an inserted polymer fiber and attached detection device;

[0056] FIG. 5 shows a schematic block diagram of the detection device; and

[0057] FIG. 6 shows a block diagram to explain the method.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0058] A technical roll is illustrated in FIG. 1 in a highly simplified form in a front view and is identified by the reference numeral 10. The corresponding illustration in a longitudinal view is illustrated in FIG. 2.

[0059] Such technical rolls are used in an extremely wide range of application areas, for example in papermaking, in tissue manufacturing, paper or tissue further processing or film manufacturing. Technical rolls of this type are also used, among other things, as suction press rolls, press rolls, film press rolls, multi-nip rolls, soft rolls, super rolls, embossing calendar rolls, central press rolls, guide rolls, size press rolls or coater rolls, to mention only some by way of example.

[0060] In general, such a technical roll 10 has a roll core 12 made of metal and at least one coating 14, which is also designated as cover 14. In FIG. 1, the roll 10 is illustrated with a single-layer cover 14, however, multilayer covers 14 may also be used in many applications. One example of a two-layer cover having two layers 14.1 and 14.2 is illustrated by way of example in FIG. 3. It goes without saying that three or more layers can also be provided.

[0061] The cover 14 of the roll 10 can be built up from a rubber material, a composite material or a polyurethane material. Combinations of these materials in multilayer covers are also conceivable.

[0062] The roll 10 shown in FIG. 1 has at least one empty conduit 20, preferably also further empty conduits 22, which extend over the entire length of the roll 10 and are provided adjacent the roll core 12 in the region of the cover 14. The empty conduit 20 is preferably manufactured from a plastic material and has an internal diameter of 300 μm to 600 μm, preferably 425 μm. It is used to accommodate a polymer fiber 30, which will be explained further in detail below.

[0063] The empty conduit 20 has two open ends 24, which are accessible from outside at the respective ends of the roll 10. This means, in other words, that the polymer fiber can be introduced into the appropriate opening 24 in the empty conduit 20 from one of the two ends.

[0064] The empty conduit 20 can be provided in a simple way during the application of the cover 14 to the roll core 12. Particularly complicated manufacturing steps are not necessary for this purpose. Care must merely be taken that the material of the empty conduit 20 withstands the thermal conditions during the application of the cover 14. Furthermore, it is important when choosing the material for the empty conduit 20 that it is a flexible material which can deform under the compressive forces to be measured.

[0065] In FIG. 4, the technical roll 10 from FIG. 2 is now illustrated, a polymer fiber 30 being located in the empty conduit 20.

[0066] The polymer fiber 30 is used as an optical sensor 32 for measuring various parameters, such as, for example, moisture content, pressure and/or temperature. The polymer fiber 30 may be a polymer-based optical waveguide structure, which has one or more reflection structures 33 (for example in the form of interferometric reflection points) distributed in the longitudinal direction, wherein the various parameters can be detected on these lattice structures. The reflection structures consequently define the measuring points 34 along the polymer fiber.

[0067] The precise structure of an example of such a polymer-based optical waveguide structure, called polymer fiber for short, is described in the document WO 2015/181155A1. The disclosure content thereof, in particular with regard to the structure of the polymer fiber, is hereby incorporated completely by reference in the present description. Such a polymer fiber is offered by the company Shute, 3490 Kvistgaard, Denmark.

[0068] The measurement of the various aforementioned parameters is carried out by light being coupled into the polymer fiber, and by the light reflected at the lattice structures, i.e. measuring points, being detected. Depending on the aforementioned parameters, which are present at the various positions in the longitudinal direction of the lattice structures, the light is reflected differently, so that conclusions can be drawn about the parameters at the measuring points via this connection. The local resolution of the various measuring points which are predefined by the lattice structures is carried out via the different propagation times of the reflected light.

[0069] The inventors have surprisingly established that the compressive forces acting on the roll surface can be detected very well via the polymer fiber 30, although the polymer fiber is not located in the immediate vicinity of the roll surface but at a certain distance from the roll surface.

[0070] A measurement of the parameters is thus possible during operation of the roll, wherein, in the best case, one or more measured values can be supplied during each revolution depending on the reflection structure (or the number of reflection points). Usually, however, the measured values are not detected during each revolution but at an interval of a plurality of revolutions, if appropriate also staggered over time in the longitudinal direction of the roll. This means, in other words, that the measured values at the various measuring points of the polymer fiber are detected at different revolution times. Of course, it is also possible for all the measured values from the various measuring points to be detected per revolution.

[0071] To couple the light in and to detect the reflected light, a detection device 40 is provided at one end of the roll 10, as shown in FIG. 4.

[0072] As illustrated in FIG. 5, the detection device 40 has a measuring unit 42 which, for example, comprises an optical lens 44, by which the light generated by an optical emitter 48, for example an LED, is coupled into the polymer fiber 30 and the reflected light is fed to an optical sensor 46, for example in the form of a photodiode or a phototransistor or an optical spectrometer. However, it should be mentioned at this point that an optical lens is not necessarily required to couple the light in. The optical sensor 46 and the optical emitter 48 can also be provided in the form of a laser diode unit 50. In recent times, laser diodes which can carry out both functions, namely of emitting light and detecting reflected light, have been obtainable.

[0073] The laser diode unit 50 is connected to an evaluation unit 52, which performs the control of the laser diode unit and evaluates the corresponding received measured signals. The evaluated measured signals are transported from the evaluation unit 52 to a transmission unit 54, which transmits the data in a wire-free manner, for example via Wi-Fi or Bluetooth technology, to a computer 60. There, the measured data are then available for further evaluation.

[0074] The energy supply of the measuring unit 42 is preferably provided autonomously via an energy recovery unit 56.

[0075] The energy recovery unit 56 contains a rechargeable battery, which is used to temporarily store recovered electrical energy. Electrical energy can be recovered through the rotation of the roll 10 during operation for example inductively. With this solution, cables to the detection device 40 for the energy supply can be avoided.

[0076] By equipping the roll 10 with one or more polymer fibers 30, different parameters can be detected and evaluated during the operation of the roll. These parameters have various uses. Thus, for example, as a result of the evaluation of the measured parameters, the nip can be adjusted very well. In addition, conclusions about the wear of the cover 14 can be derived from the measured parameters.

[0077] The sensors described, comprising the detection device and polymer fiber 30, can be retrofitted at any time in a roll 10 with an existing empty conduit 20. This has the potential advantage that the customer can initially acquire a technical roll without any sensors and can then retrofit the sensors later. The outlay for the retrofitting is low, since it is merely necessary to introduce the polymer fiber 30 into the empty conduit 20 and to attach the corresponding detection device 40 to the end of the roll.

[0078] To introduce the polymer fiber 30 into the empty conduit 20, firstly the polymer fiber is supplied and provided with an adhesive, steps 82 and 84 in FIG. 6.

[0079] The leading end of the polymer fiber is then introduced into the opening 24 of the empty conduit at one end, step 86.

[0080] At the opposite end of the roll 10, a suction device is attached in the region of the opening 24 of the empty conduit 20, in order to produce a vacuum in the empty conduit 20. Since, on the opposite side, the polymer fiber 30 together with the applied adhesive seals off the corresponding opening 24, the vacuum in the empty conduit 20 ensures that the polymer fiber 30 is drawn through the empty conduit 20, steps 88 and 90. Alternatively, a compressed air device is attached to the end of the roll 10 in order, so to speak, to “blow” the polymer fiber 30 through the empty conduit.

[0081] It can be seen that this process of introducing the polymer fiber 30 is possible without great effort. It is preferable that the polymer fiber 30 together with the adhesive achieves the greatest full-area contact with the inner side of the empty conduit, so that, in subsequent operation, it is also ensured that the compressive forces acting on the empty conduit are transferred directly to the polymer fiber.

[0082] Overall, it is evident that the present application permits a considerably improved technical roll which can very easily be equipped or retrofitted with very flexibly insertable sensors.

[0083] It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

[0084] As used in this specification and claims, the terms “for example,” “e.g.,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.