JP3221052U - Endless belt - Google Patents

Abstract

An endless belt is provided which overcomes the disadvantage that weld seams appear as scars and which form films of qualitatively high value.
SOLUTION: With respect to an endless belt 1 having at least one welding seam 7, 9, welding seams 7, 9 extend around the endless belt 1 at least once in a helical form and / or weld The seams 7, 9 are inclined with respect to the longitudinal direction of the endless belt 1 and / or the width of the endless belt 1 is greater than 2 m. In that case at least one material which reduces the thermal conductivity of the weld seam 7, 9 is introduced into the weld seam 9, or the thermal conductivity of the endless belt 1 in at least the region directly adjacent to the weld seam 7, 9, Is increased by changes in the material composition and / or the tissue structure of the endless belt 1 in this region.
[Selected figure] Figure 1

Description

  The present invention relates to the technology for forming the endless belt described in the preamble of Reference Example 1. The invention further relates to an endless belt. Furthermore, the invention is directed to an apparatus for film casting.

  Endless belts made of steel have a wide use area. Depending on the area of use, the nature of the belt must also be established. The surface properties, thickness and length of the sheet, and also the properties and arrangement of the weld seams are also of particular importance.

  Belts of this type are described, for example, in Austrian Patent No. 283194 (B), European Patent No. 1812191 (B1), Austrian Patent No. 500488 (B1), WO 2013/177604 (A1). No. 11 or EP 1 154 290 B1). In the last mentioned print, the weld seams leave a scar and so are not suitable for forming a film, so a casting drum is used.

  Passing furnaces for baked goods are known, wherein the baked goods are arranged on an endless belt several hundred meters long and the belts are guided through the passing furnace. In that case the speed of the belt is relatively low and what is required for the surface properties is only a small adhesion capacity of the baked goods on the steel surface. The surface of the weld seam on the work surface, and hence the surface upon which the baked good portion is to be baked, may be in the work plane and have the same roughness as the work surface.

  For example, when it is intended to form a transparent plastic foil, high demands are placed on the endless belts of the belt press, in particular of the double belt press. This is because plastic foils must be optically blank. Weld seams are inhomogeneous points that leave undesirable scarring in the formed foil or film.

  In order to obtain a belt having a particularly large width, two or more belts are joined by means of longitudinal weld seams. Because these longitudinal weld seams, even very slight, result in differences in thickness at the belt, when winding up the long strip of material formed by the belt, there are no straight busbars, each for the formation of a weld seam Correspondingly, thickness maxima or thickness minima are present at these points, whereby clamping of the strip material occurs and the material can no longer be oriented flat.

  When the strip material is cut into individual pieces and they are stacked, also oblique positions of the stack occur, which can lead to obstacles in production. In order to distribute these thickness deviations along the width of the strip material, it is known to form an endless belt by only one partial belt, in which case only one longitudinal weld seam is present, which is It is disposed at an angle to the longitudinal direction of the belt. A disadvantage of this type of steel belt is that stresses occur between the weld seam and the partial belt, which results from the different lengths of the weld seam to the partial belt. This reduces the life of the endless belt.

  When forming a film, in particular a triacetate film used, for example, for LCD screens, a plurality of endless belts are used on which such films are applied. The formation of larger screens also requires the use of wider endless belts. It is also effective to use wider belts to improve productivity when forming film material. The belt width of the material belt used to form the endless belt is usually about 2 m, so in order to obtain a larger belt width, the longitudinal edges of the two or more material belts are attached to each other Welded. The weld seam differs from the remaining belt body with respect to its structural configuration based on production. From that, it is also revealed that the thermal conductivity of the welding seam of the endless belt and the remaining belt body is different, in which case the thermal conductivity of the welding seam is higher than the thermal conductivity of the remaining belt body There is.

  When forming a film, it is common for the material product to be poured onto the endless belt, partially dried and pulled off again from the endless belt. In order to dry the film, at least one inside of the endless belt, opposite to the product-supporting side of the film, is heated, for example by means of hot air and / or by means of at least one heated diverting roller. Due to the high thermal conductivity of the weld seam as compared to the remaining endless belt, the film is more rapidly dried in the area of the weld seam, resulting in an increase in surface tension in the more rapid dry area of the film. Is brought about. It also leads to the movement of film particles in the direction of the weld seam and the occurrence of local thickening of the film in the area of the weld seam. However, this has disadvantages and the weld seams appear as scars in the finished product. However, this type of scarring is undesirable and reduces the quality of the film, making it unusable in the case of optical films.

  If the weld seam is inclined with respect to the longitudinal direction of the endless belt (so that the weld seam extends in a helical shape around the endless belt), this type of scar is particularly strongly imprinted in the film. Therefore, the scarring is particularly severely impaired. Furthermore, scars which extend obliquely into the screen (as opposed to scars which extend horizontally or vertically) are more clearly visible.

Austrian Patent No. 283194 (B) European Patent No. 1812191 (B1) Austrian Patent No. 500488 (B1) Specification International Publication No. 2013/177604 (A1) European Patent No. 1154290 (B1) Austrian Patent Application Publication No. 516447 (A1)

  The object of the present invention is therefore to overcome the drawbacks mentioned above and to form films of qualitatively high value.

  According to the invention, this task is achieved by the introduction of at least one material which reduces the thermal conductivity of the welding seam into the welding seam, or at least the welding seam of an endless belt, according to the invention. The thermal conductivity in the immediately adjacent area is solved by the increase in the material composition in this area and / or the change in the structure of the endless belt. The change of the material composition can be effected, for example, by removal and / or application of the material, and the tissue structure can be changed, for example by deformation of the endless belt, in particular by thermal and / or mechanical deformation.

  The solution according to the invention reduces the difference in thermal conductivity between the weld seam and the adjacent area of the endless belt (which is a metal belt) or reduces the flow of heat through the weld seam and the area of the endless belt adjacent to it. Make it possible to minimize the difference.

  The preferred overall width of the endless belt is between 4.5 m and 6 m in order to form a foil for PVOH application.

  In order to form a foil for TAC application, the preferred overall width of the endless belt is between 2.3 m and 2.5 m.

  The thickness of the endless belt is preferably between 0.8 mm and 2 mm.

  The typical length (peripheral length in the closed state) of the endless belt according to the present invention is preferably 50 m-150 m.

  Preferably, the endless belt comprises only one partial belt narrower than the endless belt, and the endless belt preferably has only one weld seam. In that case forming the endless belt from only one partial belt, which extends in a spiral shape along the endless belt, while the endless belt is formed from the same partial belt, so that the dimensional deviation or material between the belt sections It has the advantage that no deviations occur and, on the other hand, the non-uniformities caused by the welds are distributed uniformly over the width of the endless belt. On account of the measures according to the invention, the effect of this non-uniformity (scars in the film) can be made significantly less noticeable.

  Weld joints which preferably extend in a helical shape are shown, for example, in Austrian patent 283 194 (B). The weld seam here extends around the endless belt at least once. However, “extending around the endless belt in a helical shape” also has the possibility of extending the helical weld seam around only a portion of the endless belt, according to this application.

  According to a preferred variant of the invention, the material introduced into the weld seam can be a component of the alloy of the base material of the belt body of an endless belt.

  However, it is alternatively possible that the material introduced into the weld seam is not an alloy component of the base material of the endless belt belt body.

  A particularly good reduction of the thermal conductivity is obtained by the material introduced into the weld seam being selected from the group of Cr, Ni, Co.

  According to a variant of the invention, which assimilates the heat flow through the weld seam and the area continuous with it, according to a variant of the invention, on the surface of the belt relative to the weld seam in the area directly adjacent to the weld seam on the endless belt The recess can be formed, in which case the recess is filled with a material having a higher thermal conductivity than the weld seam. The recess may then be formed by mechanical or chemical removal of the material or may be the result of a welding process.

  It has been shown that the material is effective when applied by the galvanic method, in particular by tampon plating.

  Another highly efficient method of reducing the difference in heat flow through the weld seam and the area adjacent to it is obtained by deforming the area adjacent the weld seam by providing another weld seam. The welding seams directly adjacent to one another can at least partially overlap one another.

  It has been found that it is particularly effective if the depth of penetration of the other weld seams into the base material of the endless belt decreases as the distance of the other weld seams from the at least one weld seam increases. ing.

  According to a preferred development of the invention, the thickness of the at least one weld seam in the direction of the thickness of the endless belt can be reduced by removing the material, and the recess resulting from the removal has a lower thermal conductivity than the weld seam. It is filled by the material which has a rate. This variant of the invention makes it possible to adjust the flow of heat in the area of the welding seam particularly well. This is because the heat flow can be varied according to the type of material used. For example, a plastic with poor thermal conductivity can be used as the material.

  A preferred embodiment is characterized in that the weld seam forms an angle of 1 ° to 25 °, in particular 6 ° to 9 °, with the longitudinal direction of the endless belt. This has the advantage that the even distribution of the non-homogeneous points provided by the weld seam is ensured over the width of the product to be formed, and furthermore the overall length of the weld seam can be kept small.

  A preferred embodiment comprises the thermal conductivity of the belt body formed by the endless belt partial belt at the belt surface in the central region of the partial belt and the thermal conductivity of the weld seam at the belt surface in the central region of the weld seam. Is characterized in that it has a ratio of at most 1.5, preferably at most 1.3, particularly preferably at most 1.1.

  A preferred embodiment comprises the thermal conductivity of the belt body formed by the endless belt partial belt at the belt surface in the central region of the partial belt and the thermal conductivity of the weld seam at the belt surface in the central region of the weld seam. Is characterized in that when the angle is greater than 5 °, it is at most 1.5, preferably at most 1.3, particularly preferably at most 1.1.

  The formation of the welding seam / s in forming the endless belt according to the invention is for example disclosed in the welding device or the welding method disclosed in particular in the patent application EP 516 447 A1. Clamp device) can be used.

  As with all the examples mentioned above, the endless belt can preferably be post-processed after the formation of the welding seam / s, e.g.

  The problem is also solved by the endless belt which is a metal belt according to claim 1. The advantages described with respect to the method of the individual embodiment also apply to the embodiment of the endless belt, according to the meaning.

  A particularly preferred endless belt of steel, possibly consisting only of one partial belt which is thinner than the endless belt, and possibly having only one weld seam, which weld seam is around the belt , Preferably at least once, in a helical form and / or inclined with respect to the longitudinal direction of the belt, and the partial belt has compressive residual stress on the surface layer, The inner surface layer has compressive residual stress with respect to the endless belt, and the weld seam has substantially equal spacing between the inner surface and the outer surface with respect to the midplane, and thus is substantially symmetrical It is formed. In belts of this type, it is known that the outer surface, and thus the work surface, has compressive residual stress, for example to reduce wear or reduce stress crack corrosion. If the inner surface layer has compressive residual stress, the life can be surprisingly extended. This is strange as the inside of the belt is struck during the change of direction and therefore has compressive stress anyway. By forming the weld seams symmetrically, the difference in length between the weld seam and the continuous area of the partial belt can be kept much smaller, which can additionally extend the life of the belt.

  If the steel of the partial belt is precipitation hardened, the advantages of the precipitation hardened belt can be exploited, in which case the weld seam does not have to precipitation harden itself, and thus the partial belt and the weld seam The difference in length between the two can be further reduced.

  If only the surface layer of one of the partial belts, preferably the inside, has compressive residual stress, then the force against elastic stretch as the belt changes direction is smaller, which likewise leads to a belt life of It can be extended.

  If the inner surface layer of the partial belt, which is continuous with the weld seam, is mechanically removed, it is possible to avoid notched points which promote premature failure of the belt.

  When the width of the weld seam is 1.0 to 1.5 times the thickness of the partial belt, transverse contraction is prevented when a tensile load is applied, thereby providing support for the tensile strength of this weld seam. Be

  In the case where the partial belt has a thickness of 0.3 mm to 3.5 mm, in particular 0.8 mm to 1.2 mm, there is a belt with a particularly small thickness, so that, for example, the direction change in a 590 mm roller also results There is no inherent disadvantage.

  The point of view of the present invention also relates to a metal belt, in particular a stainless steel belt, having an outer surface and an inner surface, in which case at least one of the surfaces is particularly characterized in order to determine the content of nonmetallic inclusions. Multiple measurement planes can be defined according to DIN EN 10247-July 2007, and in that case a complete scan of each measurement plane is performed at a magnification of 200: 1.

In a preferred embodiment, the endless belt has an outer surface and an inner surface, and a plurality of measurement surfaces of 625 mm ² on one side or both sides, respectively, of 2 μm and less than 5 μm. Between 0 to 25 non-metallic inclusions, between 0 and 6 non-metallic inclusions between 5 μm and less than 10 μm, and between 0 to 4 non-metallic inclusions between 10 μm and less than 15 μm . As a result, metal belts of very high purity and associated therewith very high surface quality are formed.

  The advantage produced by the above embodiment is that this low inclusion number results in the formation of a very high surface quality of the metal belt with a substantially consistent and uniform metal surface, so that it is a support for forming the foil material It is suitable to use a metal belt as a belt (process belt). In this application, the concepts "support belt" and "process belt" are used interchangeably. Not only does the belt support the film or foil, but the film or foil on the belt passes through the process, which is controlled or supported by the belt. That is, the belt can be heated, in particular from below, and is thus used to transfer heat to the film or foil.

  Furthermore, along with that, much better surface quality can also be obtained in the next polishing step. The reason is that the size and number of non-metallic inclusions has been reduced to an acceptable level, and the surface defects are substantially avoided accordingly. Therefore, copying of the metal surface in the foil material to be formed is not an obstacle. In that case, in particular, polymer films can be formed which are later used as optical films or in LCD screens. This high purity and defect-free surface quality of the metal belt, coupled with the use of the metal belt as a support or support for the foil material to be formed, makes it possible to further improve its quality when it is formed. Therefore, very few copies of inclusions are transferred from the surface of the metal belt onto the foil material, so that high-value products can be formed.

  Preferred embodiments of endless belts feature 0 to 3 inclusions between 15 μm and less than 20 μm and / or 0 to 3 inclusions each between 20 μm and less than 25 μm per measurement surface, respectively. And

  As a result, the number of inclusions which are larger in area or volume can likewise be kept very low, so that the surface of the metal belt has only a very small number of defective surfaces in its entirety. In this way, it is possible to substantially avoid damage due to popping inclusions even during the polishing process. Because these inclusions are only a very small percentage of the overall surface of the metal belt in area or volume.

  Preferably, at least one outer surface of the endless belt has a mirror gloss without structure having a roughness depth Ra ≦ 0.02 μm or Rz ≦ 0.1. That is, it allows precise matching of the corresponding materials to form the metal belt with respect to the product to be formed. This is especially true for the surface quality to be obtained in the polishing method.

  The metal material forming the endless belt or one or more partial belts is X10CrNi18-8, X5CrNi18-10, X5CrNiMo17-12-2, X3CrNiMo13-4, CrNiCuTi15-7, Ck67, Ti-II, X1NiCrMoCu25-20- It is selected from 5 groups. Thereby a consistent material quality is consistently provided across the width of the metal belt. Thus, the tolerances in material quality that are allowed in forming the pre-product or pre-material are not confused with one another. Thus, consistent and uniform material quality is provided to support the product to be formed, using a metal belt as the mounting material or support material.

  The problem is solved by an apparatus for forming a film, in particular a triacetylcellulose (TAC) film, a polyvinyl alcohol (PVOH) film, a polyimide (PI) film or an acrylic film, which apparatus comprises an endless belt according to the invention. It is characterized by

  The problem is likewise solved by using the endless belt according to the invention for forming a film, in particular a triacetylcellulose (TAC) film, a polyvinyl alcohol (PVOH) film, a polyimide (PI) film or an acrylic film. Ru.

  As foil material, for example, a polymer film as a wide film can be formed. A base material is applied onto the surface of the endless belt and cast, in particular, from which a high-value optical film or foil is then formed. A possible material is cellulose triacetate (CTA), also known as triacetate or TAC film, which is a plastic obtained from cellulose reacted with acetic acid. In a continuous process, a CTA film to which a solvent such as, for example, dichloromethane is added is then applied on the surface of the metal belt and then moved through a drying oven with the endless belt. In that case, the dried film is pulled off the metal belt when the solvent evaporates and a sufficient strength is reached. This CTA foil material can be used in particular to form an LCD screen. In that case, a CTA film as protective film on both sides is applied onto the polarizer. This is done at least in the laminating process.

In order to better understand the invention, it will be described in detail using the following figures.
The figures are diagrammatic representations, each of which is greatly simplified.

It is a perspective view showing an endless belt concerning the present invention. It is sectional drawing which shows the 1st modification of the endless belt which concerns on this invention. It is sectional drawing which shows the 2nd modification of the endless belt which concerns on this invention. It is sectional drawing which shows the 3rd modification of the endless belt which concerns on this invention. It is sectional drawing which shows the 4th modification of the endless belt which concerns on this invention. Fig. 1 shows a device according to the invention. It is a perspective view showing the modification of the endless belt concerning the present invention. Fig. 7 shows a portion of an endless belt having weld seams extending in a helical shape. FIG. 5 is a cross-sectional view of an endless belt in the area of a weld seam; The modification of welding seam formation is shown.

  In the embodiment described as being different from the first, the same reference numerals or the same component names are provided in the same parts, in which case the disclosure contained in the entire description is It can be transferred according to the meaning to the same part having the same reference symbol or the same component part name. Also, the position descriptions selected within the description, such as, for example, above, below, sides etc. relate to the figures described and shown directly and this position description is meant in case of position change Transfer to new position according to.

  All the descriptions for the value area in the specific description include both the arbitrary partial area and all the partial areas, for example, the descriptions 1 to 10 are all starting from the lower limit 1 and the upper limit 10 Subregions, ie all ones beginning with one or more of the lower limit and ending with the upper limit of 10 or less, eg 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10 The region shall be included together.

  In FIG. 1, an endless belt 1, in particular an endless steel belt, is schematically shown in a simplified manner, which has a total width 2 transversely to its longitudinal extension. The width of the endless belt 1 is then greater than 2 m, preferably greater than 4 m.

  In order to obtain the desired overall width 2, the endless belt 1 is preferably formed in its longitudinal extension from a plurality of arranged partial belts 3,4. The partial belts 3, 4 are then welded to one another at the longitudinal edges. This is done by means of a weld seam 9 which is shown simply as a longitudinal weld seam. The partial belts 3, 4 are formed from preformed sheet sections, in which case prior to welding the longitudinal edges are each subjected to a pretreatment method suitable for the selected welding method.

  Furthermore, in order to form the endless belt 1, the mutually facing front ends 5, 6 of the endless belt are joined by a welding seam 7, which is referred to as a transverse welding seam.

  The two partial belts 3, 4 are first of all generally welded together in their longitudinal extension, and then a transverse weld seam 7 is formed. In the embodiment shown here, the transverse weld seam 7 is arranged to extend at an angle with respect to the longitudinal edges 9, 10 located on the outside of the endless belt 1. However, it is also possible to select the right-angled orientation of the transverse weld seam 7 with respect to the longitudinal edges 9, 10.

  According to the endless belt 1 and the belt thickness of the material used in that case, the radius of deflection of the endless belt 1 is matched thereto. If the transition of the endless belt 1 extends linearly between the turning points which are spaced apart from one another, then a spacing 11 occurs between them. If another direction change of the endless belt 1 is provided, the spacing 11 is reduced accordingly.

  The two partial belts 3, 4 can be formed with substantially the same width. In total, the overall width 2 of the endless belt 1 is caused by the belt widths of the partial belts 3, 4. In order to connect the partial belts 3, 4, the longitudinal edges to be connected to one another are butted on the front side and welded to one another at this point. The welding can be performed by laser welding, WIG welding, plasma welding, MIG / MAG welding, ultrasonic welding, or friction stir welding, for example, with or without a protective gas.

  FIG. 7 shows a modification of the endless belt according to the present invention. The endless belt 1 here has at least one welding seam 9 which extends helically around the endless belt 1 and is inclined with respect to the longitudinal direction of the endless belt 1. A preferred weld seam extending in a helical shape is also shown, for example, in Austrian patent 283194 (B). The weld seam here extends around the endless belt at least once. The method steps or features of the endless belt described below are equally applicable to the endless belt shown in FIG. 1 as well as to the endless belt shown in FIG. 7 or in the specification of Austrian patent 283194 (B).

  According to FIG. 2, during the formation of the weld seam 9, a material 12 for reducing the thermal conductivity of the weld seam 9 is introduced into the weld bath.

  The material 12 introduced into the welding fluid tank can be an alloy component of the base material of the belt body 13 of the endless belt 1. Alternatively, a material 12 which is not a component of the base material of the belt body 13 is also selected.

  Examples of possible materials for the belt body 13 described below relate to the standard designations described in EN 1 0027 sheet 1 and sheet 2. By way of example, here, material X10CrNi18-8 with material number 1.4310, X5CrNi18-10 with material number 1.4301, X5CrNiMo17-12-2 with material number 1.4401, X3CrNiMo13- with material number 1.4313 4, CrNiCuTi15-7 or similar materials, Ck67 with material number 1.1231 and Ti-II with material number 3.7035, X1 NiCrMoCu25-20-5. Material Ck6 is also referred to as protected workpiece designation "Ti994-Ti-grade 2".

In the materials for the belt body 13 which will be described in detail below, these are formed in the respective material by means of the individual alloying elements. In that case, the descriptions in Table 1 are carried out in weight percent, unless different units are listed.

  For example, if material X5CrNi18-10 (1.4301) or material X5CrNiMo17-12-2 (1.4401) is used for the belt body 13, it is already in the alloy of the base material of the belt body 13 into the welding bath. The thermal conductivity of the weld seam 9 can be reduced by adding Cr or Ni contained therein. In that case, preferably, an amount of Cr or Ni is added to the welding fluid tank such that the content of Cr or Ni in the weld seam 9 is at least 5% -20% higher than in the base material of the belt body 13 Ru. When Cr is added as material 12 to the weld seam 9, the Cr content of the weld seam 9, according to the example above, is, for example, more than 18% and 24% depending on the base material used respectively Less than.

  By adding Co into the weld bath, the thermal conductivity of the weld seam 9 can be reduced by elements not included in the base material alloy of the belt body 13 in the above example. In this case, the amount of Co added to the weld seam 9 is preferably such that the content of Co in the weld seam is between 5% and 20%.

  By the addition of the material 12, the thermal conductivity of the weld seam 9 can be adapted to the thermal conductivity of the area of the belt body 13 immediately adjacent to the weld seam 9.

  According to FIG. 2, the thermal conductivity in the area 14 immediately adjacent to the weld seam 9 of the endless belt 1 can be increased by a change in the material composition in this area. That is, in the area 14 directly adjacent to the weld seam 9 on the endless belt 1, a recess 15 of the belt surface can be formed relative to the weld seam 9. This can be done, for example, by removing the material in region 14. The recess 15 can be filled with a material 16 having a higher thermal conductivity than the weld seam 9. In this way, the thermal conductivity of the area 14 is increased and thus approaches the thermal conductivity of the weld seam 9. For example, Cu can be used as the material 16. Galvanic methods, such as tampon galvanization, can be used to apply the material 16.

  As shown in FIG. 4, the area 14 adjacent to the weld seam 9 can be deformed by providing other weld seams 17, 18, 19. The further welding seams 17, 18, 19 are then provided above and to the side of the welding seam 9, in which case the directly adjacent areas 17, 18, 19 at least partially overlap. Since the weld seams 17, 18, 19 have a higher thermal conductivity than the base material of the belt body 13, the thermal conductivity in the area 14 can be achieved by arranging the additional weld seams 17, 18, 19. The difference between the thermal conductivity of the area 14 and the thermal conductivity of the welding seam 9 is reduced.

  According to FIG. 5, the thickness of the at least one weld seam 9 can be reduced by the removal of material, viewed in the direction of the thickness of the belt body 13 of the endless belt 1. The recess 21 resulting from the removal can be filled with a material 20 having a lower thermal conductivity than the weld seam 9. As material 20, for example, plastic, in particular Teflon (registered trademark) can be used.

  As is the case for all the embodiments described above, the endless belt 1 can be post-processed, for example polished, in particular with high brightness after the formation of the weld seams 7, 9. Also, the weld seams 7, 9 can themselves be further processed, for example polished and / or polished. In addition, since the thickness of the endless belt 1 can be matched, the endless belt has a substantially constant thickness over the entire circumferential length.

  Thermal conductivity of the belt body 13 formed by the partial belt 31 of the endless belt 1 on the surface of the belt in the central area of the partial belt 31 and thermal conductivity of the weld seam 9 on the surface of the belt in the central area of the weld seam 9 It is effective if the ratio between is at most 1.5, preferably at most 1.3 and particularly preferably at most 1.1. This is particularly effective if the angle α (the angle of inclination of the weld seam 9 extending in a helical shape with respect to the longitudinal extension a of the endless belt) is greater than 5 °.

  In the exemplary embodiment, the endless belt 1 is constituted by a partial belt 31 having a width 2 of 2,200 mm and having a width b2 of 1,400 mm. The partial belt 31, which is shown elongated in FIG. 8, is connected only via one welding seam 9 which passes around. Multiple partial belts can also be welded together. The weld seam 9 forms an angle α of 6.1 ° with the longitudinal direction a of the endless belt 1.

  FIG. 9 shows in cross-section the area of the partial belt 31 with which the welding seam 9 abuts. The weld seam 9 has a width b3 of 3.3 mm at the outer surface 33, which is preferably 1.15 times the thickness d1 of the partial belt 31 of 2.9 mm. A virtual central plane 34 is shown in dashed lines symmetrically between the outer surface 33 and the inner surface 32. The weld seam 9 is formed substantially symmetrically with respect to the central plane 34, and in some cases there are notched points which occur during welding. Both the outer surface layer and the inner surface layer can be removed mechanically. The inner surface layer can, for example, have a compressive residual stress in the region of 400 MPa. The weld seam shown in FIG. 9 can be implemented electrically (WIG) with a tungsten electrode and an inert gas.

  The cross section shown in FIG. 10 corresponds to that of FIG. 9, but differs in cross section only by the rectangular weld seam 9, which was implemented with a Nd: YAG laser.

Example 1:
A partial belt section having a width of 800 mm and a thickness of 0.8 mm was welded by WIG welding with a voltage of 10 V, a current strength of 29 A and helium as inert gas. The width of the weld seam was 2.1 mm. The weld seam is V-shaped. The sheet was then turned 180 ° in a test fixture through a roller having a radius of 590 mm. After 2 × 10 ⁶ cycles, cracking occurred in the area of the weld seam.

Example 2:
A partial belt section having a width of 1,211 mm and a thickness of 0.8 mm, which is part of a partial belt, is welded by WIG welding with a voltage of 8.7 V, a current strength of 16 A and helium as an inert gas It was done. The width of the weld seam was 1.25 mm. The weld seams were double V-shaped. Additionally, as one side is shot blasted, a compressive residual stress of 400 MPa could be built. The sheet was then turned 180 ° through a roller having a radius of 590 mm so that the shot-blasted surface abuts the roller in a test fixture. Only after the 2.8 × 10 ⁷ cycles was cracking in the area of the weld seam.

Example 3:
The formation of the welding seam / s is carried out by means of the welding device or the welding method disclosed in Austrian patent application EP 516 447 A1, in particular by means of the clamping device disclosed there. To be done.

  It should be pointed out for completeness, but each of the embodiments listed above and shown in FIGS. 1-10 can each be combined with one or more other of these embodiments. That is, for example, the welding seam 9 shown in FIG. 1 or FIG. 7 is additionally combined with providing further welding seams 17, 18, 19 or injecting an additional material 20 as shown in FIG. be able to. The combination of the method shown and described has advantages with regard to a particularly precise adjustment of the thermal conductivity in the welding seam 9 and / or in the area 14.

  According to FIG. 6, the device 22 according to the invention for forming the film 23 or foil has a pouring area 24. This film 23 can be a solvent based film, such as, for example, a so-called TAC film, a PVOH film or the like. As solvent, for example, dichloromethane can be used in the case of TAC films (methylene chloride) or water in the case of PVOH films.

  The injection area 24, which is also referred to in the prior art as a casting chamber, can be surrounded by a covering, for example of a sheet. Furthermore, an injection device 25 for applying the material 26 onto the endless belt 1 and the endless belt 1 is arranged in the injection area 24. The endless belt 1 orbits between two rollers 29 and 30. One of these rollers 29, 30 can be driven and can be used as a drive roller for the endless belt 1.

  The application of the material 26 onto the endless belt 1 can be carried out by pouring, for example by curtain coating, extrusion, spraying or the like. The poured material 26 forms a film-shaped layer on the endless belt 1 and passes through the process on the endless belt 1, which results in at least partial drying and / or curing of the material 26. In order to peel off the (partially) dried film 23 from the endless belt 1, a peeling device 27, for example in the form of a roller, can be provided.

  In order to obtain a high production rate, the film 23 is pulled off from the belt in a "wet" state which has not yet been almost completely dried. The term "wet" relates, in solvent-based films, to the proportion of solvent still contained in the film 23. Thus, for example, if the film is completely dry, the solvent fraction is zero.

  In order to partially dry the material 26 or the film 23, a heating device 28 can be provided, which heats the inside of the endless belt 1 opposite to the product 26 or the product side which supports the film 23. The heating device 28 can have, for example, a nozzle box, through which the hot air is blown out towards the inside of the endless belt 1.

  In addition to the heating device 28, one or both of the rollers 29, 30 can be heated.

  By using the endless belt 1 according to the present invention, it is well avoided that the weld seams of the endless belt 1 in the film 23 stand out.

  Finally, it should be pointed out that, in order to better understand the structure of the endless belt 1, the endless belt or parts thereof are partially out of scale and / or enlarged and / or reduced. Shown.

  In the following, preferred forming variants and materials for endless belts are described. In forming the endless belt 1, which is a metal belt, generally, the material provided for it is cast to be a metal block in a casting process, which in turn is an appropriate sheet in a rolling process In particular, it is rolled and rolled. Depending on the width of the installation provided for sheet rolling, the maximum width of the sheet formed thereby is also defined or limited. In currently known and conventional rolling equipment for such high value sheets, sheet widths of about 2000 mm can be formed.

  Instead of aligning the two partial belts together as shown in FIG. 1, the wider central belt section can be supplemented by the two side belt sections, as shown for example in WO 2013/177604 A1. . It is also possible to weld more than two partial belts together, depending on the length of the belt to be formed respectively.

  Depending on the intended use of the endless belt 1 respectively, the endless belt or the partial belts of which it is made can be made from different stainless steel materials, carbon steel or titanium with different qualities. The metal belt can be applied as a process belt or a conveyor belt.

  The examples of materials described below for the belt body relate to the standard designations shown in EN 1 0027 sheet 1 and sheet 2. By way of example, here, material X10CrNi18-8 with material number 1.4310, X5CrNi18-10 with material number 1.4301, X5CrNiMo17-12-2 with material number 1.4401, X3CrNiMo13- with material number 1.4313 4, CrNiCuTi 15-7 or similar materials, Ck 67 with material number 1.1231 and Ti-II with a material number 3.7035, X1 NiCrMoCu 25-20-5. Material Ck6 is also referred to as protected workpiece designation "Ti994-Ti-grade 2".

  In the various materials listed above and listed in Table 2, tissue architecture is also considered. In terms of particle size, in particular for particle size numbers according to standard ASTM E 112-84 (particle size characteristics), the characteristic value “G” is ((greater / equal) 9.0. In that case, the particle size number (particle size characteristic) is determined according to the "lineal Intercept Procedure" described in Sections 11.6, 11.6.1 and 11.6.2 of the standard. It is defined with an accuracy of at least 1/2 ASTM number, while maintaining all important provisions. The textural state is full austenite without delta ferrite in the cold rolled initial material of the metal belt 1. Deformed martensite is only allowed to a slight extent, not exceeding the allowed permeability, when cold rolled to rigid stage 1 according to Table 2 below. The next brightened surface should not have an orange skin-like structure or row structure.

  The permeability of the belt rolled to the stiffness stage described in Table 2 is measured according to ASTM A-342. That is, for example, when exciting with the material X5CrNi18-10 (1.4301) and stiffness step 1: 200 oersted (Oe), relative permeability μr ≦ 1.15 is satisfied.

This value, which is described in Oersted (Oe), can be expressed in SI units of A / m (amperes / m) in the following equation:

1Oe = 1000 / (4π)

  The individual sheets can undergo various and possibly multiple quality checks starting from that state as pre-material to the finished metal belt 1. One of the tests is the "metallographic examination of the content of non-metallic inclusions in the steel by means of image sequences", which is carried out in accordance with the standard DIN EN 10247-July 2007-. In a variant of this standard, a more detailed test or test implementation is performed which differs from that described below.

According to sections 4.1.4 and 6.3 relating to the measuring surface, the standard states that the measuring surface must have a size of at least 200 mm ² . On the contrary, the measuring surface is enlarged to the dimensions of 625 mm ² and in that case the complete scanning is carried out in this surface dimension on the basis of the high purity of the material used, the inclusions sought in that case Is completely counted. This face dimension of 652 mm ² can be obtained, for example, by a square having a side length of 25 mm. In that case, the respective measuring surfaces or their measuring surfaces are always oriented parallel to the rolling surface or the sheet surface, in which case multiple arrangements of the measuring surfaces distributed over the entire surface of the belt also apply. The sheets to be tested in that case have a material thickness of between 1.0 and 3.0 mm, preferably between 1.5 and 2.0 mm.

The entire endless belt 1 or the partial belts forming the endless belt 1 each form a connected component, so that the measuring surface here is distributed over the surface. In the case of evaluation, a 200 × magnification is chosen, in which case the magnification should not be changed during the evaluation process. This is defined in section 7.1 "Enlargement" in standard EN 10247. The evaluation of the measuring surface and the complete scanning described above are performed regardless of the magnification factor. Due to the high quality requirements, all found inclusions are divided into different size classes for the measurement field respectively. In that case, the following class divisions are selected: 2 μm to less than 5 μm, 5 μm to less than 10 μm, 10 μm to less than 15 μm, 15 μm to less than 20 μm, 20 μm to less than 25 μm. In the following, an example of the counting of inclusions in the sheet table is shown, in which case the measuring surface has the dimensions of 625 mm ² and X5CrNi18-10 (1.4301) as material for forming the metal belt 1 It is used.

  Based on Table 3, it can be seen that a relatively large number of inclusions were sought only within the first magnitude class between 2 μm and less than 5 μm.

  In that case, the number of inclusions in this first size class between 2 μm and less than 5 μm is within the lower limit from no inclusions to the inclusions 15 and the upper limit to inclusions 25. In the next second size class between 5 μm and less than 10 μm, the number of non-metallic inclusions is much less, where the lower limit is no inclusions and the upper limit is inclusions 6. Within a third size class between 10 μm and less than 15 μm, the number of inclusions is within the lower limit of no inclusions and the upper limit of inclusions 4. In the other fourth size class between 15 μm and less than 20 μm and in the other fifth size class between 20 μm and less than 25 μm, the lower limit is no inclusion and the upper limit is inclusion 3 is there.

  From the number of inclusions determined at different measurement points 1 to 6, respectively, different medians or mean values are obtained for each size class, which are intercalated in a first size class between 2 μm and less than 5 μm. 19.16, with inclusions 2.23 in the second size class (5 μm to less than 10 μm), inclusion 1 in the third size class (10 μm to less than 15 μm), In the size class of 4 (15 μm to less than 20 μm) the inclusion is 0.16, and in the fifth size class (20 μm to less than 25 μm) the inclusion is 0.33.

In many applications for endless belts 1 of this type, very high surface quality is also required, so that the material has an asperity depth Ra (arithmetic center asperity value) or Rz (average asperity depth) Ra ≦ 0. It should be suitable to provide a mirror gloss without structure having 02 μm; R z ≦ 0.1. This is not only in the area of the surface of the endless belt 1, but also in the area of the connection between the individual partial belts. The surface dimensions of the larger belt case can also be a few 100 m ^2.

  The premise for this is the very high purity of the previous material (low phosphorus-sulfur-aluminium content), the very dense material without holes and the stabilizing elements or elements which increase the hardness (eg titanium, cobalt, tantalum, nitrogen) There is no hard phase that may be brought about by

  Another quality criterion may be the final thickness or thickness of the endless belt 1. To that end, many measurements are required to obtain a convincing measurement of the entire belt surface. A predetermined distance of the longitudinal extension of the metal belt 1 in the lateral direction from its longitudinal edge is then maintained for this measurement. This spacing can be, for example, between 5 mm and 15 mm. In the longitudinal direction of the metal belt 1 a number of measurements are likewise carried out. Thus, a grid of measuring points distributed over the surface is obtained.

  If the overall width 2 of the endless belt 1 is described in cm, at least half the value of the overall width 2 is in cm and is chosen as the number of measurement points in the transverse direction, in particular in the vertical direction with respect to the longitudinal side edge. For example, if the overall width 2 is 200 cm, the thickness is measured at a number of at least 100 measuring points in the transverse direction. The wider the respective metal belts, the more the number of measuring points can be selected transversely to the longitudinal extension. In this case, this number of measuring points corresponds to an overall width 2 in cm or even larger. In that case, preferably, the transverse spacing between the individual measuring points is chosen to be equal to one another, so that the measuring points are distributed uniformly over the measuring width.

  That is, the deviation from the average thickness of the endless belt 1 is, for example, between ± 5% in the edge area of the endless belt 1 and between ± 5% in the central area of the endless belt 1. Therefore, high accuracy can be obtained with regard to the undulation and uniformity of the endless belt 1 as well.

  As already mentioned at the outset, for the foil formation very high demands are placed on the surface quality of the endless belt 1 and the purity of the material. The low inclusions in the material result in a substantially consistent, uniform surface quality, whereby the foil material formed thereon has a similarly high quality.

The present invention includes the following reference examples in addition to those described in the claims.
[Reference Example 1]
A method of forming an endless belt (1), wherein the endless belt has weld seams (7, 9), in which case the weld seams (7, 9) spiral around the endless belt (1), Extending at least once and / or the welding seams (7, 9) are arranged at an angle to the longitudinal direction of the endless belt (1) and / or the width of the endless belt (1) In those wherein (2) is greater than 2 m, preferably greater than 2.5 m, particularly preferably greater than 4 m,
At least one material (12) to reduce the thermal conductivity of the weld seam (7, 9) is introduced into the weld seam (9) or at least directly adjacent to the weld seam (7, 9) of the endless belt (1) The thermal conductivity in the area is increased by changes in the material composition and / or structure of the endless belt (1) in this area (14),
A method of forming an endless belt characterized by
[Reference Example 2]
The endless belt is constructed only from a partial belt (31) thinner than the endless belt (1), and the endless belt (1) preferably has only one weld seam (9).
The method according to Reference Example 1, characterized in that
[Reference Example 3]
Reference Example 1 or 2 characterized in that the material (12) introduced into the welding seam (7, 9) is a component alloy of the base material of the belt body (14) of the endless belt (1). The method described in.
[Reference Example 4]
The material (12) introduced into the welded joint (9) is not a component of the alloy of the base material of the belt body (13) of the endless belt (1), as described in Reference Example 1 or 2. the method of.
[Reference Example 5]
4. A method according to any one of the preceding claims, characterized in that the material (12) introduced into the weld seam (9) is selected from the group Cr, Ni, Co.
[Reference Example 6]
In the region (14) directly adjacent to the weld seam (9) on the endless belt (1), a recess (15) on the belt surface is formed opposite the weld seam (9), in which case the recess (15) The method according to any one of the preceding claims, characterized in that is filled with a material (16) having a higher thermal conductivity than the weld seam (9).
[Reference Example 7]
The method according to Reference Example 6, characterized in that the material (16) is applied by a galvanic method, in particular by tampon galvanization.
[Reference Example 8]
The area (14) adjacent to the weld seam (9) is deformed by providing another weld seam (17, 18, 19), in which case the directly adjacent weld seam (17, 18, 19) is at least partially The method according to any one of reference examples 1 to 7, characterized in that they overlap one another.
[Reference Example 9]
The depth at which the other weld seams (17, 18, 19) penetrate into the base material of the belt body (13) of the endless belt (1) is the other weld seam (from at least one weld seam (9) The method according to Reference Example 8, which decreases as the distance 17, 18, 19) increases.
[Reference Example 10]
The thickness of the at least one weld seam (9) is reduced by removal of material, viewed in the direction of the thickness of the belt body (13) of the endless belt (1), and the recess (21) created by removal is welded The method according to any one of reference examples 1 to 9, characterized in that it is filled with a material (20) having a lower thermal conductivity than the seam (9).
[Reference Example 11]
Reference Example 1 characterized in that the weld seam (9) forms an angle (α) of 1 ° to 25 °, preferably 6 ° to 9 ° with the longitudinal direction (a) of the endless belt (1) The method according to any one of 10.
[Reference Example 12]
The thermal conductivity of the belt body (13) formed by the at least one partial belt (3, 4, 31) of the endless belt (1) at the belt surface in the central region of the partial belt (3, 4, 31) The ratio between the thermal conductivity of the weld seam (7, 9) at the belt surface in the central region of the weld seam (7, 9) is at most 1.5, preferably at most 1.3, particularly preferred Is at most 1.1, The method as described in any one of Reference Examples 1 to 11.
[Reference Example 13]
The thermal conductivity of the belt body (13) formed by the at least one partial belt (3, 4, 31) of the endless belt (1) at the belt surface in the central region of the partial belt (3, 4, 31) The ratio between the thermal conductivity of the weld seam (7, 9) at the belt surface in the central region of the weld seam (7, 9) is at most 1. If the angle (α) is greater than 5 °. 5. The method according to Reference Example 11 or 12, characterized in that it is 5, preferably at most 1.3, particularly preferably at most 1.1.
[Reference Example 15]
The endless belt according to claim 1, wherein the endless belt is constructed from at least one partial belt (3, 4, 31) narrower than the endless belt (1) and has at least one weld seam (7, 9). An endless belt according to 1), wherein the endless belt (1) is formed by the method described in any one of Reference Examples 1 to 13.
[Reference Example 30]
The endless belt (1) according to any one of claims 1 to 14 or Reference Example 15, a film (23), particularly a triacetylcellulose (TAC) film, a polyvinyl alcohol (PVOH) film, a polyimide (PI) film Or use to form an acrylic film.

DESCRIPTION OF SYMBOLS 1 endless belt 2 whole width 3 partial belt 4 partial belt 5 front end 6 front end 7 welding seam 8 longitudinal side edge 9 welding seam 10 longitudinal side edge 11 interval front end 12 material 13 belt body 14 area 15 recess 16 material 17 Weld seam 18 weld seam 19 weld seam 20 material 21 recess 22 device 23 film 24 injection area 25 injection device 26 material 27 peel device 28 heating device 29 roller 30 roller 31 partial belt 32 inner surface 33 outer surface 34 midplane

Claims (27)

Endless belt (1) constructed from at least one partial belt (3, 4, 31) narrower than endless belt (1) and having at least one weld seam (7, 9) The welding seams (7, 9) extend around the endless belt (1) in a helical shape and / or the welding seams (7, 9) are inclined relative to the longitudinal direction of the endless belt (1) And / or the width (2) of the endless belt (1) is greater than 2 m,
At least one material (12) to reduce the thermal conductivity of the weld seam (7, 9) is introduced into the weld seam (9) or directly adjacent to the weld seam (7, 9) of the endless belt (1) An endless belt, characterized in that the thermal conductivity in at least one area (14) is increased by a change in the material composition in this area (14) and / or the structure of the endless belt (1).   The endless belt according to claim 1, characterized in that the welding seams (7, 9) extend around the endless belt (1) at least once in a helical form.   The endless belt according to claim 1 or 2, characterized in that the width (2) of the endless belt (1) is greater than 2.5 m.   The endless belt according to claim 1 or 2, characterized in that the width (2) of the endless belt (1) is greater than 4 m.   The endless belt according to any of the preceding claims, characterized in that the endless belt (1) is constructed solely from a partial belt (31) narrower than the endless belt (1).   The endless belt according to claim 5, characterized in that the endless belt (1) has only one welding seam (9).   The welding seam (9) is characterized in that it has an angle (α) of 1 ° to 25 ° with the longitudinal direction (a) of the endless belt (1). The endless belt described in the section.   Endless belt according to claim 7, characterized in that the weld seam (9) has an angle (α) of 6 ° to 9 ° with the longitudinal direction (a) of the endless belt (1).   The thermal conductivity of the belt body (13) formed by the at least one partial belt (3, 4, 31) of the endless belt (1) at the belt surface in the central region of the partial belt (3, 4, 31) 4. The method as claimed in claim 1, wherein the ratio between the thermal conductivity of the weld seam (7, 9) at the belt surface in the central region of the weld seam (7, 9) is at most 1.5. The endless belt according to any one of to 8.   10. The endless belt according to claim 9, wherein the ratio is at most 1.3.   10. The endless belt according to claim 9, wherein the ratio is at most 1.1.   The thermal conductivity of the belt body (13) formed by the at least one partial belt (3, 4, 31) of the endless belt (1) at the belt surface in the central region of the partial belt (3, 4, 31) The ratio between the thermal conductivity of the weld seam (7, 9) at the belt surface in the central region of the weld seam (7, 9) is at most 1 if the angle (α) is greater than 5 ° The endless belt according to any one of claims 7 to 9, characterized in that   The endless belt according to claim 12, wherein the ratio is at most 1.3.   The endless belt according to claim 12, wherein the ratio is at most 1.1.   The partial belts (3, 4, 31) have compressive residual stress on the surface layer (32, 33), in which case the inner surface layer (32) has compressive residual stress with respect to the endless belt (1) And that the weld seams (7, 9) have the same spacing and thus be formed symmetrically with respect to the central plane (34) between the inner (32) and the outer surface (33) The endless belt according to any one of claims 1 to 14, characterized in that:   The endless belt according to any of the preceding claims, characterized in that the steel of at least one partial belt (3, 4, 31) is precipitation hardened.   17. The endless belt according to any one of the preceding claims, characterized in that only one surface layer of the endless belt (1) has a compressive residual stress.   The endless belt according to claim 17, characterized in that the inner surface layer (32) of the endless belt (1) has a compressive residual stress.   The area of the inner surface layer (32) of the partial belt (31), which is continuous with the weld seam (7, 9), is mechanically removed. The endless belt described in the section.   20. A method according to any of the preceding claims, characterized in that the width (b3) of the weld seam (7, 9) is 1.0 to 1.5 times the thickness (d1) of the partial belt (31). The endless belt described in the section.   21. The endless belt according to any of the preceding claims, characterized in that the partial belt (31) has a thickness (d1) of 0.3 mm to 3.5 mm.   22. The endless belt according to claim 21, characterized in that the partial belt (31) has a thickness (d1) of 0.8 mm to 1.2 mm. A plurality of measuring surfaces of 625 mm ² each having an outer surface (33) and an inner surface (32) on one or both of said surfaces, respectively, from 0 to between 2 μm and less than 5 μm With 25 non-metallic inclusions, with 0 to 6 non-metallic inclusions between 5 μm and less than 10 μm, and 0 to 4 non-metallic inclusions between 10 μm and less than 15 μm The endless belt according to any one of claims 1 to 22, comprising:   Each of the measurement planes is characterized by 0 to 3 inclusions between 15 μm and less than 20 μm and / or each measurement plane is characterized by 0 to 3 inclusions between 20 μm and less than 25 μm, The endless belt according to claim 23.   The at least outer surface (33) of the endless belt (1) is characterized in that it has a mirror gloss without structure having a roughness depth Ra ≦ 0.02 μm or Rz ≦ 0.1 μm. 24. The endless belt according to any one of to 24. In an apparatus (22) for forming a film (23),
26. An apparatus for forming a film, characterized in that the apparatus (22) comprises the endless belt according to any one of the preceding claims.   The apparatus for forming a film according to claim 26, wherein the film (23) is a triacetylcellulose (TAC) film, a polyvinyl alcohol (PVOH) film, a polyimide (PI) film or an acrylic film.

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