RU2347020C2 - Indication of level of wear and tear with help of fibres - Google Patents

Abstract

FIELD: textiles, paper.

SUBSTANCE: invention relates to the detecting device for wear and tear of fabric for paper manufacturing and other industrial fabrics. Fibres have a core and many layers, and the core and layers are distinguishable so that it is possible to display the wear and tear of the fabric. Industrial fabric contains fibres with a display medium for its wear and tear. To detect wear and tear of the fabric passing fibres, multilayered fibres are used, they are used to form guide paths on the fabric, and single fibres, which also have contrast colours and form a guide path for the fabric. Use of the device makes it possible to have regular monitoring of the quality of the fabric ant any of its points, including the working process of the machine.

EFFECT: regular monitoring of the quality of the fabric ant any of its points, including the working process of the machine.

41 cl, 7 dwg

Description

Technical field

The present invention relates to a tool for detecting the degree of wear of fabrics for papermaking or other technical fabrics and for creating guide lines in such fabrics, in particular for multilayer and conductive fibers used as said means.

State of the art

In the papermaking process, a cellulosic fibrous web is formed by precipitating a fibrous pulp, i.e. an aqueous dispersion of cellulose fibers onto a moving forming fabric in the forming part of a paper machine. A large amount of water leaves the liquid mass through the molding fabric, and a cellulosic fibrous web remains on its surface.

The resulting cellulosic web is moved from the molding part to the press part, in which there are a number of compression zones between the press shafts. A cellulosic fibrous web carried by a press fabric or placed between two press fabrics passes through these zones, being compressed, whereby water is squeezed out of it, the cellulosic fibers in the web stick together and the web turns into a paper sheet. Water is absorbed by the press fabric or fabrics and, ideally, does not return to the paper sheet.

Finally, the paper sheet enters the drying section, comprising at least one row of rotating drying drums or cylinders, heated from the inside by steam. The resulting paper sheet is guided along a serpentine path sequentially around each drum using a drying cloth tightly pressing the paper sheet to the surface of the drums. Heated drums reduce the water content in the paper sheet to the desired level due to its evaporation.

It is known that molding, pressing and drying fabrics for a paper machine have the form of endless belts and act as conveyors. It is also known that paper making is a continuous process that proceeds at a significant speed, i.e. in the forming part, the fibrous liquid mass is continuously deposited on the forming fabric, and the resulting paper sheet, after leaving the drying part, is continuously wound into rolls.

When working in paper machines, fabrics having the form of endless ribbons, and especially their inner surfaces, undergo abrasion. This wear is mainly due to contact with the stationary elements of the paper machine. Many fabrics have to be removed from paper machines when, as a result of wear caused by such moving contact, the thickness of the fabric, at least in some places, decreases so much that the fabric weakens or some of its properties or characteristics that are important for making paper either specific application.

Typically, wear is monitored using a thickness gauge. However, it is difficult for a thickness gauge to measure the thickness of the tissue for the paper machine in areas that are more than 1-2 feet (0.3-0.6 m) from the edges of the fabric, especially during its movement in the paper machine.

Therefore, for papermaking it is highly desirable to have a means of controlling the wear of the tissue for the paper machine, especially at any point on its inner and outer surfaces, even during the operation of the machine. The present invention provides such a tool for use in industry.

SUMMARY OF THE INVENTION

The main objective of the invention is the creation of industrial fabric with a built-in mechanism to control its wear.

Another objective of the invention is to provide a fabric in which there is a detectable guide line.

These and other objectives and advantages are achieved in the tissue according to the present invention. Thus, the invention is directed to the creation of a fiber for industrial fabric and to industrial fabric containing this fiber, said fiber having a core surrounded by a plurality of respective layers and means for indicating wear of industrial fabric. The core and layers visually differ from each other by their properties, for example, color or reflection coefficient. The indicated degree of wear of the fabric is related to the degree of wear of the respective layers. This allows you to control the wear of the fabric, because as a result of abrasion, the fiber layers are gradually removed and, finally, the core is exposed.

The core and the corresponding layers may differ visually from each other. The fiber may have a light-absorbing core and transparent layers with a varying refractive index. In this case, the light reflected from the core may change color depending on the degree of wear of the transparent layers.

The fiber may contain a light transmitting core and transparent layers with a varying refractive index. In this case, the light transmitted through the core may change color depending on the degree of wear of the transparent layers.

The core and / or one or more of the corresponding layers can be doped with a dye, which can be detected by a sensor when excited by an external energy source.

The fiber may be one of the fibers of a multi-fiber yarn.

According to a second aspect of the invention, there is provided an industrial fabric fiber and industrial fabric comprising one or more conductive monofilaments and means for indicating the degree of wear of the fabric. Conductive monofilaments are woven into the fabric from the side subject to wear, which allows you to create other means of indicating the degree of wear, another mechanism for detecting wear. The degree of wear of the fabric is related to the degree of wear of the conductive monofilaments and can be determined, for example, by measuring the resistance in the transverse direction of the fabric. The fiber or all or some of the conductive monofilaments may be round or non-circular.

According to a third aspect of the invention, there is provided a fiber for industrial fabric having a core surrounded by a plurality of layers and forming a visible guide line in a fabric containing this fiber. This visible guide line may be located in the direction across the paper path in the machine and / or along the paper path in the machine. The guide line is not erased by high-pressure jets or dry cleaning and is used to determine tape alignment, to measure speed, or as a trigger for an electronic guide system. The fiber may have a round or non-circular shape and be at least one of the fibers of a multi-fiber yarn.

According to a fourth aspect of the invention, there is provided a conductive monofilament having a contrasting color and used as a constant guide line on industrial fabric. The color contrast or electrical properties of the filaments can be used as a trigger for measuring speed in real time or as a trigger for an electronic guiding system.

Brief Description of the Drawings

The objectives and advantages of the invention will become apparent from its description with reference to the accompanying drawings, where

figure 1 shows a sectional example of a multilayer fiber according to the invention;

figure 2 shows a side and top view of the multilayer fiber depicted in figure 1, which shows the wear defined according to the invention;

figure 3 shows a sectional view of an example of a multilayer optical fiber according to another aspect of the invention;

figure 4 shows a top view of the fabric containing the multilayer fibers depicted in figures 1, 2 and 3;

in Fig.5 shows a top view of the depicted in Fig.4 fabric having wear;

6 and 7 show examples of fabrics with guide lines in the direction transverse to the paper path in the machine and along the paper path in the machine, respectively, according to the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A preferred embodiment of the invention will be described in the context of fibers and woven fabrics used in papermaking. However, the invention is applicable to fabrics used in other industrial plants where wear detection and direction are an important factor.

The fabrics may be spiral wound fabrics, knitted fabrics, extruded cellular fabrics, fabrics having spiral coils and other non-woven fabrics. These fabrics may also include monofilament yarns, twisted monofilament yarns, multifilament or twisted multifilament yarns, and may have a single-layer weave, multi-layer weave, or may be laminated. When the fabric is made with spiral coils, the fiber can form coils, serve as threads connecting the coils, or as inserts (packing), which can be provided in the space inside the coils. The yarns are usually obtained by molding synthetic polymer resins by extrusion, such as polyamide and polyester resins, the use of which for this purpose is known to specialists in industrial fabrics.

An example of a multilayer fiber 10 according to the invention is shown in section in figure 1. The fiber 10 may comprise, for example, a core thread 12 surrounded by a plurality of outer layers 14, 16, 18.

Preferably, the core 12 and its surrounding layers 14, 16, 18 are visually distinguishable, for example, have contrasting colors or different reflectance. This allows you to control the wear of fabrics, which include such fibers 10, as gradually, one after another, the layers 14, 16, 18 of the fibers 10 are erased, eventually exposing the core filaments 12. An example of a multilayer fiber 10 with such wear shown in figure 2 (in section and from above).

In alternative embodiments of the invention (not shown), core 12 and layers 14, 16, 18 can be doped with dyes or other substances that change their appearance. The dye can be detected by a sensor when excited by an external energy source, such as light (e.g., laser or ultraviolet) or ultrasound.

In yet another embodiment, each fiber 10 comprises a light-absorbing / light-transmitting core 12 and several transparent layers 14, 16, 18 with different refractive indices n ₁ , n ₂ , n ₃ . An example of such a multilayer optical fiber 10 is shown in FIG. In this case, the light transmitted through the fiber 10 / reflected from the fiber 10 changes color depending on the degree of wear of the layers 14, 16, 18.

Figure 4 shows a top view of the fabric 20, which was not used, from the side exposed to wear. The fabric contains at least several multilayer fibers 10 made according to the invention. The fabric 20 may be a structure woven from threads 10 located in the direction across the paper path in the machine and threads 22 located in the direction along the paper path in the machine, although according to the invention, the fabric does not have to be woven and may have a non-woven structure. In Fig. 4, the filaments 10 extending across the paper path in the machine are any multilayer fibers of those shown in Figs. 1, 2 and 3 and form a smooth weave with the filaments 22 passing along the paper path in the machine. In this example, the kinks 24 on the surface of the fabric 20 are most susceptible to wear, since they are formed where the thread located in one direction of the fabric 20 intersects the thread located in the other direction, or passes over this thread. Therefore, these bends 24 form bulges on the surface of the fabric 20.

Figure 5 shows what the fabric 20 looks like after being used for some time. As can be seen in FIG. 5, at least one or more of the outer layers 16, 18 of the multilayer fibers 10 extending across the paper path in the machine are erased to such an extent that the inner layer 14 or the core 12 is visible. Because they have a different color or reflection coefficient, for example, than the outer layers 16, 18, the inner layer 14 or the core 12 are an indicator of wear of the fabric 20.

Alternatively, the yarns 10 extending across the paper path in the machine may be conductive monofilaments woven into the fabric 20 on its wear side to provide another means of indicating the degree of wear. By measuring the conductivity of the fabric 20 in the direction across the paper path in the machine during use, it is possible to determine the degree of wear of the fabric, namely: reducing the cross-sectional area of the conductive monofilaments corresponds to a lower conductivity of the fabric 20 in the direction transverse of the paper path in the machine.

According to another aspect of the invention shown in FIGS. 6 and 7, multilayer fibers 10 are used to create a visible guide line 30 on the fabric in the direction across and / or along the paper in the machine. This guide line 30 is used to determine tape alignment, real-time speed measurement, or as a trigger for an electronic guide system. Preferably, the guide line 30 is not destroyed by high pressure jets or dry cleaning. Alternatively, a conductive monofilament having a contrasting color can be used to create a guide line 30 on the fabric. In this case, the color contrast and / or electrical properties of the monofilaments can be used as a trigger in real-time measurement of tape speed or as a trigger for an electronic guide system. In all cases, the fiber used may have a circular or non-circular cross section. If the thread is multi-fiber, i.e. contains more than one fiber, then each fiber can be made according to the invention, or at least one fiber can have properties according to the invention (for example, be conductive). However, for all aspects of the invention, the multifilament yarn should have enough fibers made according to the invention to achieve the desired results.

Thus, the invention ensures the achievement of goals and has advantages. Although the description describes in detail preferred embodiments of the invention, its scope is not limited to these options and is determined by the attached claims.

Claims (41)

1. Fiber for industrial fabric used in paper production and related industries, having a core surrounded by many appropriate layers, and means for indicating the degree of wear of industrial fabric containing this fiber. 2. The fiber according to claim 1, in which the core and the corresponding layers differ from each other in their properties. 3. The fiber according to claim 1, in which the indicated degree of wear of the fabric is associated with the degree of wear of the respective layers. 4. The fiber according to claim 2, in which one of the distinctive properties is color. 5. The fiber according to claim 2, in which one of the distinctive properties is the reflection coefficient. 6. The fiber according to claim 1, in which the core and the corresponding layers visually differ from each other. 7. The fiber according to claim 1, containing a light-absorbing core and transparent layers with a varying refractive index. 8. The fiber according to claim 7, in which the light reflected from the core changes color depending on the degree of wear of the transparent layers. 9. The fiber according to claim 1, containing a light transmitting core and transparent layers with a varying refractive index. 10. The fiber according to claim 9, in which the light transmitted through the core changes color depending on the degree of wear of the transparent layers. 11. The fiber according to claim 1, in which the core and / or one or more of the corresponding layers are doped with dyes. 12. The fiber according to claim 11, in which the dye can be detected by the sensor when excited by an external energy source. 13. The fiber according to claim 1, which is at least one of the fibers of a multi-fiber yarn. 14. Industrial fabric used in paper production and related industries, containing one or more fibers, each of which has a core surrounded by many corresponding layers, and means for indicating the degree of wear of the fabric. 15. Industrial fabric according to 14, in which the core and the corresponding layers differ from each other in their properties. 16. The industrial fabric of claim 14, wherein the indicated degree of wear of the fabric is related to the degree of wear of the respective layers. 17. The industrial fabric of Claim 15, wherein one of the distinguishing features is color. 18. Industrial fabric according to clause 15, in which one of the distinctive properties is the reflection coefficient. 19. Industrial fabric according to 14, in which the core and the corresponding layers visually differ from each other. 20. The industrial fabric of claim 14, wherein each fiber comprises a light-absorbing core and transparent layers with a varying refractive index. 21. The industrial fabric of claim 20, wherein the light reflected from the core changes color depending on the degree of wear of the transparent layers. 22. The industrial fabric of claim 14, wherein each fiber comprises a light transmitting core and transparent layers with a varying refractive index. 23. The industrial fabric according to item 22, in which the light transmitted through the core changes color depending on the degree of wear of the transparent layers. 24. The industrial fabric of claim 14, wherein the core and / or one or more of the corresponding layers are doped with dyes. 25. Industrial fabric according to paragraph 24, in which the dye can be detected by the sensor when excited by an external energy source. 26. The industrial fabric of claim 14, wherein the fiber is at least one of the fibers of a multifilament yarn. 27. Fiber for industrial fabric used in paper production and related industries, having means for indicating the degree of wear of industrial fabric and containing one or more conductive monofilaments. 28. The fiber according to item 27, in which the displayed degree of wear of the fabric is associated with the degree of wear of the conductive monofilaments. 29. The fiber according to item 27, having a round or non-circular shape. 30. Industrial fabric used in paper production and related industries, containing one or more conductive monofilaments having means for indicating the degree of wear of the fabric. 31. The industrial fabric according to claim 30, wherein the indicated degree of wear of the fabric is related to the degree of wear of the conductive monofilaments. 32. The industrial fabric of claim 30, wherein some or all of the conductive monofilaments are round or non-circular. 33. The industrial fabric of claim 30, wherein the conductive monofilament is at least one of the fibers of a multifilament yarn. 34. Fiber for industrial fabric used in papermaking and related industries, having a core surrounded by many layers and forming a visible guide line in the fabric containing this fiber. 35. The fiber according to clause 34, in which when the specified fabric is used in a paper machine, the guide line is used to determine the alignment of the tape or to change the speed in real time or as a trigger for the guide system. 36. The fiber according to clause 35, in which the guide line runs in the direction along the paper in the machine. 37. The fiber according to clause 35, in which the guide line runs in the direction across the paper path in the machine. 38. The fiber according to clause 34, in which the guide line is resistant to jets under high pressure or to dry cleaning. 39. The fiber according to clause 34, having a round or non-circular shape. 40. The fiber according to clause 34, which is at least one of the fibers of a multi-fiber yarn. 41. A conductive monofilament having a contrasting color and used as a guide line on industrial fabric used in papermaking and containing this monofilament.

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