belt

Abstract

To provide a belt for a fiber web machine.SOLUTION: The present invention relates to a belt for use in a fiber web machine. The belt comprises an inner surface (10) and an outer surface (11). The outer surface (11) of the belt (1) comprises a belt wear indicator (20) of a length (21) and a width (22). The belt wear indicator (20) comprises a recess (24) demarcated in the depth direction of the belt from the outer surface of the belt to the bottom of the belt wear indicator and extending to the depth of at least 0.1 mm. The belt comprises an outer surface whereon a groove is not at least substantially formed. A deviation of a depth of 0.1 mm or greater constitutes not more than 10% of the surface area of the outer surface of the belt. The present invention further relates to the use of a belt wear indicator.SELECTED DRAWING: Figure 3b

Description

[Technical field]

[0001] The present invention relates to a belt for a fiber web machine. The present invention further relates to a method of using a belt wear indicator for a belt of a fiber web machine. [Background technology]

[0002] Papermaking machines, and paperboard, pulp and tissue machines typically include a forming section, a press section and a drying section. In paper, pulp and board manufacturing, a challenge is how to increase the amount of water removed from a wet fibrous web in order to improve production efficiency without degrading the physical properties of the fibrous web.

[0003] Today, these machines typically have felts and wires to remove water or support the transport of the fibrous web. Additionally, paper machines may have finishing sections to improve final product properties, such as (one or more) calenders to improve the smoothness of the dried fibrous web.

[0004] It is well known that fibrous web machines are equipped with many kinds of rolls arranged in different sections with distinguishing functions. For example, sleeve rolls can be used in the forming section to improve the removal of free water from the wet fibrous material. Shoe presses can be used in the press section to improve the removal of residual water in the fibrous web therein. Both sleeve rolls and shoe press rolls require the belt to run properly.

[0005] WO200371030 discloses examples of belts comprising polymeric materials.However, there is still a need in the industry for new belts for textile web machines. Summary of the Invention

[0006] BELT FOR A TEXTILE WEB MACHINE FIELD OF THEINVENTION The present invention relates to a belt for a fibrous web machine.One object of the present invention is to provide an improved belt for a fibrous web machine.

[0007] Aspects of the invention are characterized in that they are stated in the independent claims.Various embodiments of the invention are disclosed in the dependent claims.

[0008] The fibrous web machine can be a paper machine or it can be a board, pulp, or tissue machine.

[0009] The textile web machine may include a sleeve roll, which is typically arranged in the wire section of the textile web machine. The sleeve roll can improve the water removal of the wire section. Advantageously, the belt according to the present invention is a sleeve roll belt.

[0010] Further, the fibrous web machine may include a shoe press. The shoe press is typically arranged in the press section of the fibrous web machine. The shoe press can improve water removal in the press section. In one embodiment, the belt according to the present disclosure is a shoe press belt.

[0011] Furthermore, the fibrous web machine can include at least one calender, which can improve the smoothness of the dry fibrous web. In one embodiment, the belt according to the present invention is a roll cover of a calender roll.

[0012] Thus, the belt may be a sleeve roll belt, or a shoe press belt, or a roll cover.

[0013] The belt according to the present invention comprises a belt wear indicator. The belt wear indicator is advantageously used on belts having a non-grooved outer surface. Sleeve rolls and calender rolls are preferably equipped with belts having said non-grooved surface. Advantageously, the belt with the belt wear indicator is therefore a belt cover of a calender roll or a sleeve roll belt.

[0014] Determining the wear level of sleeve roll belts has traditionally been particularly difficult, and therefore a belt wear indicator may be particularly useful for sleeve roll belts. Thus, most advantageously, the belt having the belt wear indicator is a sleeve roll belt.

[0015] A belt according to the present disclosure has an inner surface and an outer surface. The belt may include a body including a body material. Additionally, the belt may include a reinforcing structure, which may be embedded within the body, for example. In use, the belt typically forms a closed loop. The belt may be an impermeable belt.

[0016] The outer surface of the belt includes a belt wear indicator having a length and a width. The belt wear indicator may include a recess extending from the outer surface of the belt to a predetermined depth defined in a depth direction of the belt.

[0017] The belt may have an outer surface without grooves, with deviations having a depth of more than 0.1 mm forming no more than 10% of the surface area of ​​the outer surface of the belt, preferably no more than 3%. In one embodiment, the belt does not have any deviations except for the belt wear indicators, i.e. the belt may have a smooth or at least substantially smooth outer surface.

[0018] The belt wear indicator can include at least one visually distinctive material that is visually perceptible from the color of the belt. For example, the belt wear indicator can include paint in the recess.

[0019] Alternatively or in addition to a visually distinct material, the belt wear indicator can include at least one UV-detecting material. For example, the belt wear indicator can include a UV-detecting paint within the recess.

[0020] The belt comprises at least one belt wear indicator. Preferably, the belt comprises at least two belt wear indicators. Further, the belt comprises no more than 2000 belt wear indicators.

[0021] As discussed above, the belt wear indicator extends to a depth that can be defined in the depth direction of the belt from the outer surface of the belt to the bottom of the belt wear indicator. At least the depth of the belt wear indicator can decrease as the belt wears. In one embodiment, the length of the belt wear indicator decreases as the belt wears. Alternatively or additionally, the width of the belt wear indicator can decrease as the belt wears. In one embodiment, the belt wear indicator tapers in the depth direction from the top of the belt wear indicator to the bottom of the belt wear indicator.

[0022] The width of the belt wear indicator can range between 1 mm and 10 mm, measured from a new belt before the belt is worn, so the belt wear indicator is easily visible.

[0023] The belt can be positioned to have a safe distance between the belt wear indicator and the reinforcing structure of the belt, such as a thread, to protect the reinforcing structure of the belt. Thus, the belt wear indicator preferably extends to a depth, defined in the depth direction of the belt, that is at least 0.01 mm less, preferably at least 0.1 mm less, than the depth of the outermost surface of the reinforcing structure of the belt.

[0024] Thus, the distance between the bottom of the belt wear indicator and the outer surface of the reinforcing structure, defined in the depth direction from the bottom of the belt wear indicator to the outermost surface of the reinforcing structure, can be at least 0.01 mm, preferably at least 0.1 mm. In this way, the belt wear indicator can be used to protect the reinforcing structure of the belt.

[0025] In order to determine the wear rate of the belt at any point before the belt becomes too worn to be safe, the distance between the belt wear indicator and the reinforcing structure of the belt is defined in the depth direction of the belt from the bottom of the belt wear indicator to the outermost surface of the reinforcing structure and can be 1.5 mm or less, preferably 1 mm or less.

[0026] The belt wear indicator may, for example, have the shape of a cylindrical plug or the shape of one or more grooves.

[0027] All belt wear indicators of a belt may cover less than 10% of the belt's outer surface area. Preferably, the belt wear indicators cover no more than 3%, more preferably no more than 1%, and most preferably no more than 0.5% of the belt's outer surface area, defined as the total area of ​​the outer surfaces of the belt wear indicators.

[0028] This novel solution has many advantages. The machine components of a textile web machine are typically arranged in a compact manner, so that inspection or maintenance has traditionally been difficult due to limited space. Belt wear should be detected early enough to have time to replace the belt in a controlled manner during a shut down. To save costs, the belt is often replaced as late as possible. However, the belt must be replaced with a new one before it breaks.

[0029] Since the belt wears over time, inspection and maintenance of the belt needs to be performed in a timely manner to avoid malfunctions.

[0030] Thanks to the belt wear indicators that can cover a very small but well-placed area of ​​the belt, it is always possible to see the wear rate of the belt, regardless of the current wear rate. Furthermore, the low coverage of the wear indicators on the outer surface of the belt does not affect the operational performance of the belt or the physical properties of the fibrous web.

[0031] Traditionally, it has been difficult and expensive to determine the wear rate of a belt. For example, WO200371030 discloses a paper machine belt comprising a polymeric material, which can have two layers with different colors. However, with this type of solution, it is not possible to know the wear rate before the entire layer is worn out, which is too late to avoid operational failures, or to determine the wear rate of the belt early enough to have time to replace the belt in a controlled manner during a selected stop period. Therefore, by using this type of solution, it is not possible to see the wear rate of the belt at any possible time. For this reason, belt maintenance cannot be prepared in advance.

[0032] Thanks to the belt according to the present disclosure, the exact wear rate of the belt can be determined cost effectively.

[0033] The novel belt wear indicator can indicate when the belt has worn so much that it may break during use, without substantially affecting other properties of the belt. Furthermore, the novel belt wear indicator can indicate how worn the belt is at any particular moment. Thanks to the novel belt, it is possible to easily indicate the wear level of a grooveless belt without using difficult or unreliable measuring devices. Furthermore, the wear rate of the belt can be detected early enough to have time to replace the belt in a controlled manner, for example during a selected stop period. [Brief description of the drawings]

[0034] In the following, the invention will be explained with reference to the drawings. [Figure 1a] FIG. 1a shows an exemplary position of the sleeve roll. [Figure 1b] FIG. 1b shows an embodiment of a sleeve roll. [Figure 2a] FIG. 2a shows an embodiment of a belt. [Figure 2b] 2b-3a show some example structures for belts. [Figure 3a] 2b-3a show some example structures for belts. [Figure 3b] FIG. 3b illustrates an exemplary location of a belt wear indicator. [Figure 4a] 4a-4f show several exemplary cross sections of belt wear indicators. [Figure 4b] 4a-4f show several exemplary cross sections of belt wear indicators. [Figure 4c] 4a-4f show several exemplary cross sections of belt wear indicators. [Figure 4d] 4a-4f show several exemplary cross sections of belt wear indicators. [Figure 4e] 4a-4f show several exemplary cross sections of belt wear indicators. [Figure 4f] 4a-4f show several exemplary cross sections of belt wear indicators.

[0035] The drawings are illustrative and may not be to scale, and in the drawings like parts are indicated with the same reference numerals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] This solution is explained in more detail below with reference to several embodiments, which should not be considered as limiting.

[0037] In this specification, reference is made to figures having the following numbers and symbols: 1 Belt 1a Belt body thickness 2 First end of belt 3 Second end of belt 5 Textile web machine fabrics, e.g. wire or felt 6 Fiber web 10 Inner surface of belt 11 Outer surface of belt 14 Belt body 20 Belt Wear Indicator 21 Belt wear indicator length 22 Belt wear indicator width 23 Belt wear indicator depth 24 Belt wear indicator recess 25 Belt wear indicator filling such as paint in recess 26 Length of belt wear indicator location area 27 Outer edge area of ​​belt 28 Distance between adjacent belt wear indicators 29 Circumference repetition of wear indicators, i.e. the distance between the first and last wear indicators as determined by the MD 30 Reinforcement structure 31 First layer of yarn in reinforcement structure 32 Second layer of reinforcement 60 Belt attachment points 100 sleeve rolls 102 Sleeve roll support shaft 110 Sleeve roll curve elements α is the angle between the belt wear indicator and the outer surface of the belt D1 Belt 1st direction D2 Belt second direction MD: Travel direction of the belt CD Belt lateral direction C1 Sleeve roll first curve C2 Sleeve roll second curve

[0038] The embodiments and examples described in the claims and the specification can be freely combined with each other unless otherwise specified.

[0039] In this specification, the term "comprising" may be used as an open term, but also includes the closed term "consisting of." Thus, unless otherwise indicated, the word "comprising" may be read as "comprising or consisting of."

[0040] For purposes of this specification and claims, unless otherwise indicated, all ranges include any combination of the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

[0041] "Thickness" refers to the depth of the belt.

[0042] In this application the terms "travel direction" MD and "cross direction" CD are used. The travel direction MD refers to the direction of rotation of the belt in use. The cross direction CD refers to the longitudinal direction, typically transverse to the travel direction MD of the belt 1. In use, the cross direction is substantially parallel to the axis of rotation of the belt.

[0043] In this application, the term "substantially parallel" means that a direction does not deviate from said substantially parallel direction by more than 10 degrees, and most preferably does not deviate by more than 3 degrees. Thus, for example, "substantially parallel to the travel direction" means in this application that a direction does not deviate from said travel direction by more than 10 degrees, and preferably does not deviate by more than 3 degrees.

[0044] The term "non-grooved surface" refers to such an outer surface of a belt, in which deviations with a depth of more than 0.1 mm form no more than 10% of said surface, and preferably the surface is flat or at least mainly flat. This specification does not relate to belts with a grooved surface. Conventionally, grooves have been distributed over the entire outer surface of a belt to meet certain operational requirements, for example to remove water in two directions relative to the belt. Surprisingly, some belts with a non-grooved outer surface, such as sleeve roll belts, show many advantages over belts with a grooved surface. Thus, the novel belt has a non-grooved surface, in which deviations with a depth of more than 0.1 mm form no more than 10% of said surface.

[0045] The fibrous web machine according to the present disclosure may comprise at least one of a sleeve roll, a shoe press, and a calender.

[0046] calendar The fibrous web machine may include a calender.

[0047] The function of a calender is typically to improve the smoothness of the fibrous web being treated. A calender typically has at least two rolls that close under pressure to compress and smooth the fibrous web.

[0048] The belt may be in connection with (positioned on) the calender rolls such that, in use, the belt 1 can pass through a press zone formed between the calender rolls.

[0049] Shoe press The fibrous web machine may include a shoe press.

[0050] A shoe press equipped with this belt 1 can be used for dewatering a fibrous web. A shoe press typically comprises a counter roll and a press shoe, between which a press zone is formed. Thus, an extended press zone, i.e., a so-called long nip, is formed between the press shoe and the counter roll. The function of the shoe press is typically to remove water from a fibrous web.

[0051] The belt is, or can be, positioned in relation to a shoe press such that during operation the belt passes through a press zone between a counter roll and the press shoe.

[0052] Typically, the press shoe and the counter roll are pressed against each other in the press zone such that the shoe press belt, at least one papermaker fabric, and the fibrous web to be dewatered, which pass within the nip between the press shoe and the counter roll, are all compressed.

[0053] The sleeve roll fiber web machine may include a sleeve roll. The belt may be a sleeve roll belt.

[0054] The sleeve roll belt is preferably a grooveless belt; therefore, wear of the sleeve roll belt may be difficult to notice without the belt wear indicator 20. Furthermore, as shown in FIG. 1a, the sleeve roll belt is typically difficult to access. Thus, a belt wear indicator may be particularly advantageous for the sleeve roll belt. A sleeve roll 100 having a belt according to the present disclosure may be placed in the forming section to improve moisture removal within the forming section.

[0055] 1b shows an example of a sleeve roll. The sleeve roll 100 with the belt 1 can be used to dewater the fibrous web 6 on the wire 5. The belt 1 can be arranged on the sleeve roll 100.

[0056] The sleeve roll 100 may include a support shaft 102. The belt 1 may be disposed around an outer surface of the sleeve roll 100. Thus, the belt 1 may be led to circle around the support shaft 102.

[0057] The belt 1 can be arranged relative to the sleeve roll 100 such that its outer surface 11 faces the fibrous web 6 and its inner surface 10 faces the sleeve roll 100. This allows the sleeve roll 100 to be surrounded by the belt 1 having a loop shape.

[0058] Furthermore, the sleeve roll 100 can be provided with support elements arranged at a distance from one another on the support shaft 102. The belt 1, which can run around the outer surface of the sleeve roll, can be supported by the support elements.

[0059] The sleeve roll 100 may further comprise a curved element 110. During operation, the belt typically passes through a dewatering zone on the curved element. The curved element 110 may increase the force that stretches the belt on the curved element 110. The curved element 110 may be movable, i.e., the radius of curvature of the belt on the surface of the curved element 110 may be controlled by moving the curved element 110 toward the center of the sleeve roll or outward from the outer surface of the sleeve roll. Thus, the stretching of the belt 1 may vary from normal speed to very high speed.

[0060] The circumference of the belt can be increased or decreased during the operation time of the belt by the movable curved element 110. Thus, the belt can have high elasticity so that it can handle the stretch caused by the curved element 110 of the sleeve roll. Furthermore, the belt can have good strength properties so that it does not break easily.

[0061] As mentioned above, the belt 1 can be guided to circulate around the fixed support shaft 102. Additionally, the wire(s) 5 can be guided through curvilinear dewatering zones C1, C2, which can be supported by the belt 1.

[0062] The sleeve roll 100 may include at least one curved dewatering zone C1, C2, typically including at least two partial curves C1, C2, such that the radius of curvature of the first partial curve C1 may be greater than the radius of curvature of the second partial curve C2 following the first partial curve in the belt travel direction MD, which may improve the removal of water from the fibrous web.

[0063] The curvilinear dewatering zones C1, C2 can be formed by curvilinear elements 110 of the sleeve roll 100. The degree of curvature of the curvilinear elements 110 can increase in the running direction of the belt 1, so that an increasing dewatering pressure is applied to the fibrous web 6 running between the wires on the at least one curvilinear dewatering zone C1, C2 on the curvilinear elements 110. The curvilinear dewatering zones C1, C2 on the curvilinear elements 110 can include several curves such that the radius of curvature preferably decreases in the running direction of the wires. This can improve the removal of water from the fibrous web.

[0064] The curved element 110 can be moved between two or more positions and therefore can be used to control the radius of curvature of the belt 1 on the curved element 110.

[0065] The first position of the curvilinear element 110 may form a first surface on the curvilinear element. The first surface may have the same radius of curvature as a nearby surface of the curvilinear element.

[0066] In the second position of the curved element 110, the outer surface of the curved element may be moved outward. Thus, the second position of the curved element 110 may form a second surface on the curved element. The second surface may have a reduced radius of curvature when compared to the surface near the curved element.

[0067] In the second position of the curved element 110, the belt 1 may need to stretch due to the curved element 110. Furthermore, if the curved element 110 is movable, the belt 1 may need to return to its original shape when the curved element returns to the first / retracted position. Therefore, the belt 1 may need to have good elasticity and suitable strength properties.

[0068] The sleeve roll 100 may further include an oil lubricant between the inner surface 10 of the belt 1 and the outer surface of the sleeve roll 100. The inner surface 10 of the belt 1 may slide against the outer surface of the sleeve roll 100. A fibrous web 6 to be treated may be guided to the belt 1, typically supported by one or more fabrics such as wires 5.

[0069] belt The belts according to the present invention can be configured to be sleeve roll belts, or the belts according to the present invention can be configured to be shoe press belts or roll covers for calender rolls.

[0070] The belt may have an inner surface 10 and an outer surface 11. The belt may include reinforcing structures 31,32.

[0071] The belt may, at least during operation, form a closed loop, i.e. the belt 1 may be shaped as an endless loop.

[0072] The belt 1 can have a length, a circumference, and a thickness. The thickness is the minimum dimension. The circumference and length can be selected to fit the belt to a sleeve roll 100, a shoe press, or a calender roll. The circumference of the belt 1 is determined so that the inside diameter of the belt 1 is suitable for the purpose in use.

[0073] The belt 1 can be an impermeable belt, so it is possible to use for example an oil layer on the inner surface 10 of the belt without affecting the outer surface 11 of the belt.

[0074] In this application, the term "elasticity" refers to the ability of the belt to return to its original shape when the force is removed. The modulus of elasticity (%) is a value indicating how much the belt can stretch elastically. The belt may be configured to elastically stretch 1.5% or more in the direction of belt travel, so that the belt returns to its original length after the force stretching the belt is removed. In one embodiment, the belt may be configured to elastically stretch in the range of 1.5% to 5.0%, more preferably 2.0% to 4.0%, in the direction of belt travel, so that the belt returns to its original length after the force stretching the belt is removed. Thus, the belt may have good stretchability and elasticity at least in the direction of belt travel. This makes the belt less susceptible to damage. The belt 1 may further be bendable, i.e., the belt may be capable of bending at least to a predetermined radius of curvature without breaking.

[0075] The length of the belt in the transverse direction is defined according to the machine width and may be, for example, in the range of 1.5 m to 13 m.

[0076] The circumferential length of the belt 1, i.e., the length of one revolution, is determined so that the inner diameter of the belt 1 is suitable for use. The circumferential lengths of the sleeve roll belt, shoe press belt, and calender roll may be different. The inner diameter of the belt may be in the range of 700 mm to 2000 mm.

[0077] The belt may have an outer edge 27 (see FIG. 3b), which is typically not in contact with the fibrous web or fabric. The outer edge 27 may have a length in the range of 200 mm to 400 mm, preferably 250 mm to 350 mm.

[0078] The thickness 1a of the belt can be at least 1.5 mm, more preferably at least 2 mm, most preferably 3 mm or more, so that it is possible to obtain an adequate strength and to place reinforcing structures, for example threads, in the belt.

[0079] The thickness 1a of the belt can be 10 mm or less, more preferably 7 mm or less, most preferably 4 mm or less, for example in the range of 2.5 mm to 5 mm. This thickness, together with the material of the belt, can provide the belt, especially the sleeve roll belt and the shoe press belt, with good strength properties. As for the roll cover of the calender roll, its thickness can be up to 40 mm depending on its operating conditions.

[0080] The belt 1 has a body 14. The body can include or consist of a body material. Preferably, the belt 1 includes an elastic body having the ability to resume an initial shape after being compressed. Thus, the belt 1 can include an elastic body to have good elasticity.

[0081] The belt 1 can be made of a material that is suitable for textile web machines, does not damage wires, felts, or textile webs, and has suitable stretch and strength properties.

[0082] The body may comprise or consist of a polymer(s). The body 14 may comprise or consist of an elastomeric material. The belt 1 may comprise an elastomeric material as its main material.

[0083] The body 14 may comprise polyurethane. The body 14 may comprise mainly polyurethane, for example, at least 50% by weight of polyurethane, calculated from the total weight of the belt. Polyurethane may improve the properties of the belt, such as elasticity and flexibility, and is particularly suitable for use in combination with the fabric 5 and the fiber web 6. Thus, polyurethane may be used to obtain good strength and elasticity properties; thus, the belt may be able to stretch and flex during the operating time without breaking. Furthermore, the belt may comprise 99.9% by weight or less, more preferably 97% by weight or less, or 95% by weight or less of polyurethane, calculated from the total weight of the belt. For example, the reinforcing structures 31, 32 may comprise (one or more) other materials. Methods for producing polyurethane are known to those skilled in the art. The manufacturing process of polyurethane may be based on the methods of the prior art.

[0084] The belt body may have a layer(s) of polyurethane having a particular composition and hardness, and having good physical properties of crack resistance, abrasion resistance, and flex fatigue resistance.

[0085] The belt may comprise reinforcing structures 30, 31, 32. The reinforcing structure 30 may be a support structure that supports the body 14. The elasticity of the belt must be substantially high, and therefore the reinforcing structure 30 should not excessively reduce the elasticity of the belt.

[0086] The reinforcing structures 30, 31, 32 can include yarns. The term "yarn" refers to a long structure having a relatively small cross section. A yarn can be composed of fibers and / or filaments, with or without twist. The term "filament" refers to a very long fiber.

[0087] The yarn may be a multi-ply yarn. The yarn may be based on a synthetic polymer.

[0088] The belt may have some threads arranged in at least two directions, a first direction D1 and a second direction D2. The first direction D1 may be parallel or substantially parallel to the belt running direction MD. The second direction D2 may be parallel or substantially parallel to the belt rotation axis.

[0089] Adjacent yarns within each layer can either be in contact with each other or bonded to each other, or spaced apart from each other.

[0090] The yarns in the different layers 31, 32 can either be in contact with or bonded to the yarns of the next layer, or they can be spaced apart from each other. Preferably, the reinforcing yarn layers 31, 32 on top of each other are separated from each other. Thus, the yarn layers do not need to be fixed or bonded to each other in any way. However, if the yarns of the different layers are in contact with or bonded to the yarns of the next layer, the strength properties of the reinforcing structure can be improved.

[0091] The threads can be embedded in the elastic body, and therefore can be completely surrounded by the body material.

[0092] The yarns can include synthetic fibers with high strength, high modulus, and high elasticity. The yarns can include or consist of at least one of polyamide (PA), such as nylon, polypropylene (PP), polyethylene (PE), rayon, viscose, polyester, such as polyethylene terephthalate (PET), polyvinyl alcohol (PVA), polyaramid, polyphenylene sulfide (PPS), liquid crystal plastic (LCP), polyimide, and polyether ether ketone (PEEK). Yarns including or consisting of the above-mentioned materials can strengthen the belt while still allowing the belt to flex and stretch at the required level.

[0093] With reference to Figures 2a-b and 3a, the belt may have a non-grooved outer surface 11. As mentioned above, the term "non-grooved surface" refers to an outer surface of the belt in which deviations with a depth of more than 0.1 mm form less than 10% of the surface. Thus, preferably, the outer surface 11 of the belt does not include many parallel grooves. The belt may have a smooth outer surface. In particular, the outer surface of a sleeve roll belt is preferably smooth or substantially smooth. A belt 1 with a smooth outer surface may have no grooves or patterns with a depth of more than 0.1 mm, except for belt wear indicators.

[0094] The outer surface 11 of the belt may comprise a slight patterning, i.e. a so-called buffing. The depth of the buffing on the outer surface 11 of the belt 1 may be for example 0-50 μm or 3-30 μm. A suitable roughness of the outer surface of the belt may have an advantageous effect on the cooperation with a fibrous web machine fabric.

[0095] Belt Wear Indicator The belt 1 comprises one or more belt wear indicators 20. Some examples of belt wear indicators are shown in figures 2b to 4f. The belt wear indicators 20 can be used to warn the user when the belt is so worn that it may soon break. Thanks to the belt wear indicators the wear of the belt can be easily checked during stops and the belt can be controllably replaced with a new one during a given stop.

[0096] The belt wear indicator 20 may comprise or consist of a recess 24. The wear of the belt may be recorded, for example by a camera, and / or measured, for example, as the depth, width and / or length of the belt wear indicator 20.

[0097] Thus, the belt wear indicator may have the form of a (blind) hole.

[0098] The belt wear indicator 20 can include or consist of a recess 24 that has no filling, or the belt wear indicator 20 can include or consist of a recess 24 that has a filling 25. Thus, the recess 24 may be at least partially filled with the filling 25.

[0099] The filling may comprise or consist of paint.

[0100] Preferably, the recesses are not completely filled with the filling and there is only a layer of paint on at least some surfaces of the recesses. The recesses may have paint on all or substantially all surfaces of the recesses.

[0101] The color(s) of the belt wear indicator can be different from the color(s) of the belt. The belt wear indicator 20 can have a color that is visually perceptible from the color of the belt. Thus, the filling 25, such as a paint, preferably has a color that is visually perceptible from the color of the belt. Thus, the recesses 24 may be painted to improve visibility.

[0102] Alternatively or in addition to a visually perceptible color(s) from the color of the belt, the belt wear indicator can include a UV detectable component, such as a UV detectable paint. Thus, the belt wear indicator can have a UV detectable paint.

[0103] The UV detectable paint may have the same color as the belt, or the color of the UV detectable paint may be visually perceptible from the color of the belt.

[0104] If the belt wear indicator has a UV detectable component, such as paint, the belt wear indicator can have the same color as the belt and still be easily detectable from the outer surface of the belt during a stop.

[0105] In one embodiment, the color of the belt wear indicator 20 is the same as the color of the belt. If the color of the belt wear indicator is the same as the color of the belt and the belt wear indicator does not have a UV detectable component, it may be difficult to see the location of the belt wear indicator. However, the wear of the belt can still be recorded by a camera and / or measured, for example, as the depth of the belt wear indicator 20.

[0106] If the belt wear indicator 20 comprises a filling, the filling can be designed to wear simultaneously with the belt. It is thus possible to avoid markings in the fiber web. The filling can be, for example, a paint in the recess, which covers at least some of the surfaces of the recess. This embodiment can be a particularly cost-effective solution that can significantly improve the ease of visual inspection. Furthermore, thanks to the filling, such as a paint, the wear of the belt can be easily measured and / or recorded, for example by a camera.

[0107] After installation, the belt can typically only be visually checked on a small area of ​​the belt. The access difficulties are mainly due to several frames, guard-type sheeting, and dewatering elements surrounding the roll, as shown in FIG. 1a. To obtain easy visual inspection, the belt preferably has several belt wear indicators spaced apart from each other and positioned over the entire circumference of the belt, as shown in FIG. 3b. Thus, no matter where the roll stops for maintenance, at least one of the wear indicators can be observed or accessed.

[0108] The belt may be provided with one or more belt wear indicators, preferably at least 10 belt wear indicators.

[0109] Thus, the total amount of belt wear indicators can be at least 2 pcs / belt and not more than 2000 pcs / belt, preferably at least 30 pcs / belt, more preferably at least 40 pcs / belt and not more than 500 pcs / belt. Thus, it is possible to provide at any time, at any position of the belt, at least one belt wear indicator 20 that can be seen at the installation location of the belt stop position. Furthermore, it is possible to obtain a cost-effective solution that does not affect the belt properties too much. This kind of wear indicator can be easily and quickly manufactured without installing external sensors or the like. Furthermore, it may be advantageous not to have too many wear indicators in order not to affect the strength properties of the belt.

[0110] If the belt includes multiple belt wear indicators, the belt wear indicators may be spaced apart from one another.

[0111] The belt wear indicator 20 may have, for example, a rectangular shape, a cylindrical shape such as a plug shape, a conical shape, a frusto-conical shape, or a strip shape such as a groove shape.

[0112] In one embodiment, the belt wear indicator 20 has the shape of a cylindrical plug, which may be advantageous for durability, especially for belts having deep recesses.

[0113] In one embodiment, the belt wear indicator 20 has a groove shape having a length of at least 10 mm. The groove shape(s) can provide the technical effect of improving the ease of detecting the exact wear rate of the belt. The use of cross-oriented grooves can improve the ease of indicating the exact location of local wear in the CD direction. Additionally, MD-oriented grooves can help locate local MD discontinuities, such as support yarn problems.

[0114] In one embodiment, the belt wear indicator 20 has a shape of several parallel grooves, each having a length of at least 1 mm, preferably at least 10 mm, preferably less than 100 mm. This type of shape containing several parallel grooves may be used to reveal a matrix like information of belt wear. The distance between adjacent grooves forming the shape can be, for example, 5 mm to 50 mm.

[0115] The belt wear indicator 20 may have a circular cross-section as shown in Figure 2b, or a strip-like cross-section as shown in Figure 3a, or any other configuration. The belt wear indicator 20 may have at least one of a circular, elliptical, square, rectangular, triangular, pentagonal, and polygonal cross-section, for example.

[0116] The belt wear indicator 20 can have a suitable width 22 and length 21 to be easily measured. Additionally, the belt wear indicator 20 can extend to a suitable depth 23 to be able to indicate the level of wear in the belt.

[0117] In one embodiment, all, or at least substantially all, of the belt wear indicators have a width 22 between 1 mm and 10 mm.

[0118] The belt wear indicator 20 may have a width 22 between 1 mm and 10 mm, preferably between 2 mm and 6 mm. This kind of belt wear indicator can be used to determine the wear rate of the belt without affecting the operational performance of the belt. Thus, the belt wear indicator 20 may have a width 22 of 1 mm or more, preferably 1.5 mm or more, most preferably 2 mm or more. Furthermore, the belt wear indicator 20 may have a width 22 of 10 mm or less, preferably 8 mm or less, more preferably 7 mm or less, most preferably 6 mm or less. The width of the belt wear indicator may be used to code and / or mark different depths of indicators adjacent to each other. The width 22 may be measured as the maximum width 22 of the belt wear indicator 20 determined from a new belt.

[0119] The belt wear indicator can have a length 21 of 1 mm or more, preferably 2 mm or more, most preferably 3 mm or more. Furthermore, the belt wear indicator 20 can have a length 22 of 100 mm or less, preferably 40 mm or less, more preferably 20 mm or less, most preferably 10 mm or less, such as 6 mm or less. The length 21 can be measured as the maximum measurement of the belt wear indicator 20 along the outer surface of the belt, determined from a new belt. The length of the belt wear indicator can be used to code and / or mark different depths of indicators adjacent to each other. This type of belt wear indicator can be used to determine the wear rate of the belt without affecting the operational performance of the belt.

[0120] The depth 23 of the belt wear indicator 20 can be determined from the location of the belt wear indicator into the depth of the belt (from a new belt). The depth 23 of the belt wear indicator 20 typically decreases as the belt wears.

[0121] The belt wear indicator 20 can be positioned to extend to a depth 23 of 6 mm or less, determined in the depth direction of the belt, before the belt is worn. The belt wear indicator 20 can be positioned, for example, to extend to a depth 23 of 0.1 mm to 4.2 mm, determined in the depth direction from the outer surface of the belt, before the belt is worn. Preferably, the belt wear indicator 20 extends to a depth 23 of at least 0.3 mm, more preferably at least 0.5 mm, determined in the depth direction from the outer surface of the belt, before the belt is worn.

[0122] The belt may have a safe distance between the belt wear indicator and the reinforcing structure (such as a thread).

[0123] The distance between the belt wear indicator and the outermost surface of the reinforcing structure, determined in the depth direction of the belt from the bottom of the belt wear indicator to the outer surface of the reinforcing structure, may be at least 0.01 mm, preferably at least 0.05 mm, more preferably at least 0.08 mm, and most preferably at least 0.1 mm. Thus, the belt wear indicator 20 can warn the user when the belt is worn, before causing damage to the yarns.

[0124] The distance between the belt wear indicator and the outermost surface of the reinforcing structure, defined in the depth direction of the belt from the bottom of the belt wear indicator to the outer surface of the reinforcing structure, may be 1.5 mm or less, preferably 1 mm or less, more preferably 0.8 mm or less, and most preferably 0.5 mm or less. Thus, the belt wear indicator 20 can warn the user at any time before the belt becomes too worn to be safe.

[0125] The shape of the belt wear indicator 20 can be tapered from the top of the indicator to the bottom of the indicator. Thus, the belt wear indicator 20 can have a tapered shape that tapers in a depth direction from the outer surface of the belt to the bottom of the belt wear indicator 20. Thus, the length 21 and / or width 22 of the belt wear indicator 20 can decrease with the depth 23 of the belt wear indicator 20. Thus, as the belt wears, the belt wear indicator 20 can become shorter and / or thinner. This can improve the ease of detecting wear of the belt since the wear level can be measured from the outer surface of the belt as the length 21 and / or width 22 of the belt wear indicator 20.

[0126] The belt wear indicators may cover 10% or less of the total outer surface area of ​​the belt. Preferably, the belt wear indicators cover 3% or less of the total outer surface area of ​​the belt, preferably 2% or less, more preferably 1% or less, and most preferably 0.5% or less. Thus, belt wear can be easily determined in a cost-effective manner without affecting the operational performance of the belt.

[0127] In order to easily find at least one belt wear indicator at the belt stop position, the distance between the two nearest belt wear indicators, determined in the machine direction of the belt, can be 50 cm or less, preferably 40 cm or less, and most preferably 30 cm or less. Alternatively or additionally, the distance 28 between two adjacent belt wear indicators may be at least 10 mm, for example between 10 mm and 300 mm, preferably between 30 mm and 200 mm, and most preferably between 50 mm and 100 mm.

[0128] As shown in FIG. 3b, the belt wear indicators can be arranged diagonally to facilitate visual inspection. Thus, the ease of checking the wear level of the belt can be improved at any position of the belt, despite the difficult position of, for example, a sleeve roll. Furthermore, the helically arranged belt wear indicators give the advantage of seeing the difference in wear in areas with forming fabric and in areas without forming fabric. Furthermore, thanks to the helically arranged belt wear indicators, different widths of forming fabrics can be used so that some belt wear indicators are always located under the forming fabric, but the belt wear can be measured as close as possible to the end of the roll.

[0129] The circumferential repeat 29 of the wear indicators may depend on the circumference of the belt. The circumferential repeat 29 of the wear indicators, defined in the MD from the first belt wear indicator to the last belt wear indicator, can be, for example, 400 mm to 1300 mm, such as 500 mm to 1000 mm. The belt wear indicators are preferably distributed over the entire circumference so that whenever a shutdown is performed, the wear of the belt can be observed in that shutdown position. Otherwise it is not easy to rotate the roll to see the (one or more) wear indicators.

[0130] The belt wear indicator may be located within a location area(s) 26 of the belt wear indicator. The belt 1 may have a first location area of ​​the belt wear indicator, the length of the first location area extending from the first end 2 of the belt towards the centre of the belt. The belt 1 may have a second location area of ​​the belt wear indicator, the length of the second location area extending from the second end 3 of the belt towards the centre of the belt. Thus, in one embodiment, the location of the belt wear indicator does not exceed the first location area 26 and / or the second location area of ​​the belt wear indicator. The length of the first and / or second location area(s) of the belt wear indicator may be, for example, in the range of 20 cm to 1.5 m, preferably in the range of 30 cm to 1.2 m, most preferably at least 40 cm, defined from the end(s) 2, 3 of the belt towards the centre of the belt, excluding the outer edge area 27 of the belt.

[0131] In one embodiment, the central area of ​​the outer surface of the belt is free of belt wear indicators, which can reduce the manufacturing costs of the belt. Additionally, belt wear indicators may not be needed in the center of the belt since it is typically easier to determine the wear rate of the belt from the side areas of the belt.

[0132] A belt should wear evenly. However, in some cases, the center of the belt may wear faster or slower than other parts of the belt. Therefore, in one embodiment, the belt also comprises a wear indicator in the central area of ​​the outer surface of the belt. In this embodiment, it is possible to determine whether the belt has worn evenly over the entire outer surface area of ​​the belt. Thus, in one embodiment, at least one belt wear indicator 20 may be located in the center or substantially in the center of the belt. Thus, after replacing the belt, the wear level of the belt can be inspected throughout the entire outer surface of the belt.

[0133] Referring to FIG. 4f, the belt wear indicator 20 may form an angle α of 70-110 degrees, preferably 80-100 degrees, with respect to the outer surface of the belt at the location of the belt wear indicator 20. The angle α may improve the ease of the manufacturing process. Moreover, a belt wear indicator having an angle α may not substantially affect the characteristics of the belt. Moreover, thanks to this angle, a user of the belt wear indicator 20 may more easily interpret the wear of the belt compared to other angles.

[0134] Belt manufacturing method The belt can be manufactured using methods known to those skilled in the art, for example: - providing a number of support yarns; - forming a body for the belt by casting an elastomeric material; - optionally curing said material; - providing a belt wear indicator(s) on said outer surface of said belt; The belt can be manufactured by the above method.

[0135] Thus, a method for producing a belt for a textile web machine comprises the steps of: - casting a body material to form a body 14; - providing reinforcing structures 31, 32 for the belt; - optionally curing the body material; - providing several belt wear indicators on an outer surface; may include.

[0136] The belt wear indicator 20, and in particular the recesses in the belt wear indicator, may be formed, for example, by micro-drilling techniques or by a laser or melting tool.

[0137] A grooved type indicator may be made using a groove making tool, such as, for example, a fixed diameter round blade. Additionally, filling, if used, may be added, for example, by applying paint.

[0138] The belt may be intended to be installed on a sleeve roll, or a shoe press, or a calender roll of a textile web machine. With reference to Figures 2b and 3b, the belt may further comprise a number of belt attachment points 60, for example for installation of the belt.

[0139] Thanks to the belt wear indicator, the wear of the belt can be easily determined. Furthermore, during experimental tests, it was shown that the belt wear indicator according to the present disclosure does not affect other properties of the belt, such as the strength properties of the belt. Furthermore, the belt wear indicator does not cause markings on the surface of the fiber web.

[0140] The invention has been described with the aid of illustrations and examples. The invention is not limited solely to the above-described embodiments, but it can be modified within the scope of the appended claims.

Claims

1. A belt for a textile web machine, comprising: The belt has an inner surface and an outer surface; the outer surface of the belt comprises a belt wear indicator having a length and a width, the length extending in a direction of belt travel and the width extending transversely to the length; the belt wear indicator comprises a recess defined in a depth direction of the belt from the outer surface of the belt to a bottom of the belt wear indicator and extending to a depth of at least 0.1 mm; the outer surface of the belt is at least partially non-grooved; A belt, wherein recesses having a depth of 0.1 mm or more cover 10% or less, or 3% or less of the surface area of ​​the outer surface of the belt.

2. A belt for a textile web machine, comprising: The belt has an inner surface and an outer surface; the outer surface of the belt comprises a belt wear indicator having a length and a width, the length extending in a direction of belt travel and the width extending transversely to the length; the belt wear indicator comprises a recess defined in a depth direction of the belt from the outer surface of the belt to a bottom of the belt wear indicator and extending to a depth of at least 0.1 mm; the outer surface of the belt is at least partially non-grooved; recesses having a depth of 0.1 mm or more cover 10% or less, or 3% or less of the surface area of ​​the entire outer surface of the belt; A belt, wherein as the belt wears, the belt wear indicator decreases in the length and / or the width.

3. A belt for a textile web machine, comprising: The belt has an inner surface and an outer surface; the outer surface of the belt comprises a belt wear indicator having a length and a width, the length extending in a direction of belt travel and the width extending transversely to the length; the belt wear indicator comprises a recess defined in a depth direction of the belt from the outer surface of the belt to a bottom of the belt wear indicator and extending to a depth of at least 0.1 mm; the outer surface of the belt is at least partially non-grooved; recesses having a depth of 0.1 mm or more cover 10% or less, or 3% or less of the surface area of ​​the entire outer surface of the belt; The recess is at least partially filled with a filling.

4. the belt wear indicator includes paint in the recess; The paint is visually perceptible from the color of the belt. A belt according to any one of claims 1 to 3.

5. the belt wear indicator includes a UV detectable paint in the recess; A belt according to any one of claims 1 to 3.

6. - said belt has at least two of said belt wear indicators; and / or - said belt having 2000 or less said belt wear indicators; A belt according to any one of claims 1 to 3.

7. the belt wear indicator tapers in the depth direction from a top of the belt wear indicator to a bottom of the belt wear indicator. A belt according to any one of claims 1 to 3.

8. - the width of the belt wear indicator is in the range between 1 mm and 10 mm; A belt according to any one of claims 1 to 3.

9. - the length of the belt wear indicator is in the range between 1 mm and 50 mm A belt according to any one of claims 1 to 3.

10. the distance between the bottom of the belt wear indicator and the outer surface of the reinforcing structure, defined in the depth direction from the bottom of the belt wear indicator to the outermost surface of the reinforcing structure, is at least 0.01 mm, preferably at least 0.1 mm; A belt according to any one of claims 1 to 3.

11. the distance between the bottom of the belt wear indicator and the outer surface of the reinforcing structure, defined in the depth direction from the bottom of the belt wear indicator to the outermost surface of the reinforcing structure, is less than or equal to 1 mm, preferably at least 0.5 mm; A belt according to any one of claims 1 to 3.

12. The belt wear indicator has the shape of a cylindrical plug. A belt according to any one of claims 1 to 3.

13. the belt wear indicator having a shape including one or more grooves; A belt according to any one of claims 1 to 3.

14. the total outer surface area of ​​all of said belt wear indicators of said belt covers no more than 1%, preferably no more than 0.5% of the outer surface area of ​​said belt; A belt according to any one of claims 1 to 3.

15. The belt is a sleeve roll belt.

5. The belt according to claim 4.

16. The belt is a shoe press belt.

5. The belt according to claim 4.

17. The belt is a roll cover, such as a roll cover for a calender roll.

5. The belt according to claim 4.

18. 4. A method of using the belt wear indicator of the belt of any one of claims 1 to 3 in a textile web machine, comprising: the belt wear indicators are distributed around a circumference of the belt such that at least one belt wear indicator is observable at any stop position of the belt; each belt wear indicator comprises a recess, the recess being defined in a depth direction of the belt from an outer surface of the belt to a bottom of the belt wear indicator and extending to a depth of at least 0.1 mm; method.

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