Abstract:
The invention concerns a corrugating roll for producing a corrugated web, having a fluting, from a material web. The corrugating roll has a corrugating roll body, a central longitudinal axis, a peripheral direction about the central longitudinal axis and a surface fluting with at least one first corrugating tooth, which is arranged peripherally on the corrugating roll body, and at least one second corrugating tooth arranged peripherally on the corrugating roll body and which differs from the at least one first corrugating tooth for reducing corrugating roll operation-related vibrations.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the priority of German Patent Application, Serial No. 10 2016 202 099.4, filed Feb. 11, 2016, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference in its entirety as if fully set forth herein. 
       FIELD OF THE INVENTION 
       [0002]    The invention concerns a corrugfor producing a corrugated web with a fluting from a material web. Furthermore, the invention deals with a device for manufacturing a corrugated cardboard web with at least one of this type of corrugating roll. The invention also concerns a method for manufacturing a corrugating roll of this type. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known that conventional corrugated cardboard webs or corrugated cardboards have at least one corrugated web with sinusoidal fluting. The corrugated web is generally laminated with two webs, one on each side. These types of corrugated webs are formed mostly from a smooth or flat material web in a corrugating slit between two rotating corrugating rolls which have a corrugated profile like two toothed gear wheels meshing with each other. The disadvantage in this is that, as the corrugating rolls operate, they are set in vibration, the usual result of which is that the corrugated webs are not impressed optimally. 
       SUMMARY OF THE INVENTION 
       [0004]    The invention is therefore based on an object of producing a corrugating roll with particularly low vibrations when it is being used. The particular aim is to avoid even-numbered subharmonic frequencies or, respectively, the even-numbered higher harmonic frequencies occurring in the corrugating roll as it is operating. The aim also is to produce a device for manufacturing a corrugated cardboard web with particularly low vibrations as it operates. Furthermore, it is intended to provide a method for manufacturing a corrugating roll with extremely low vibrations. 
         [0005]    This object is resolved, according to the invention, by a corrugating roll for producing a corrugated web, having a fluting, from a material web, with a corrugating roll body, with a central longitudinal axis, with a peripheral direction about the central longitudinal axis, and with a surface fluting, which has at least one first corrugating tooth, arranged peripherally on the corrugating roll body, and at least one second corrugating tooth, which is arranged peripherally on the corrugating roll body and which differs from the at least one first corrugating tooth for reducing corrugating roll operation-related vibrations. 
         [0006]    The object of the invention is further resolved by a device for producing a corrugated cardboard web, comprising a corrugating device for producing a corrugated web, having a fluting, from a material web, wherein the corrugating device comprises at least one corrugating roll according to any one of the invention, an adhesive applicator to apply adhesive to tips of the fluting of the corrugated web, and a pressing device to press a liner web on to the glue-covered tips of the corrugated web. 
         [0007]    The object of the invention is further resolved by a method for producing a material web corrugating roll, comprising the steps providing of a corrugating roll basic body with basic corrugating teeth, and machining the basic corrugating teeth upon forming at least one first corrugating tooth and at least one second corrugating tooth, such that the at least one second corrugating tooth differs from the at least one first corrugating tooth for reducing corrugating roll operation-related vibrations. 
         [0008]    The essence of the concept is that the corrugating roll has corrugating teeth which differ from each other, particularly in their shape or design, to reduce operation-related vibrations, that is, vibrations while they are operating. At least one second corrugating tooth is different from the at least one first corrugating tooth or, respectively, at least one first corrugating tooth is different from the at least one second corrugating tooth. In this manner, vibrations or resonant frequencies of the corrugating roll can be minimised or suppressed. In particular, harmonic and/or subharmonic vibrations can be reduced. This is beneficial for the service life of the corrugating roll and for the device for manufacturing a corrugated cardboard web comprising at least one corrugating roll of this type. Operating noise can be minimised. Finally, the quality of the produced corrugated web or corrugated cardboard web is also increased since its fluting is impressed in a particularly clean and uniform manner. 
         [0009]    It is advantageous if the corrugating roll is driven directly or indirectly and is rotated during operation about its central longitudinal axis which then forms a rotational axis or pivot axis. 
         [0010]    Preferably, the surface fluting has corrugating teeth and corrugating tooth valleys arranged alternately. It is advantageous if a plurality of the first corrugating teeth and/or of the second corrugating teeth is present. In this, the first corrugating teeth are preferably identical. Here also, the second corrugating teeth are preferably identical. The at least one first corrugating tooth is preferably symmetrical in cross section. The at least one second corrugating tooth can be designed to be symmetrical or asymmetrical in cross section. 
         [0011]    Second corrugating teeth can be provided in a peripheral direction following directly one after the other or with at least one intermediate first corrugating tooth. First corrugating teeth can be provided in a peripheral direction following directly one after the other or with at least one intermediate second corrugating tooth. 
         [0012]    The corrugating roll may also comprise at least one further corrugating tooth which differs from the at least one first and second corrugating teeth. 
         [0013]    It is advantageous if the corrugating roll is configured in one piece. Preferably, the at least one first cortugating tooth and the at least one second corrugating tooth are connected with the corrugating roll body such as to form one piece therewith or they are configured in one piece therewith. 
         [0014]    Preferably, two corrugating rolls form a corrugating device to corrugate the material web and mesh with each other or engage into each other. When operating, preferably the corrugating teeth of a first corrugating roll engage in the corrugating tooth valleys of a second corrugating roll while the corrugating teeth of the second corrugating roll engage in the corrugating tooth valleys of the first corrugating roll. By doing so, the smooth or flat material web fed through a corrugating slit or roll gap delimited between the corrugating rolls is permanently formed. 
         [0015]    It is advantageous if the device to manufacture a corrugated cardboard web also comprises an adhesive applicator to apply adhesive to the tips of the fluting of the corrugated web. 
         [0016]    Furthermore, it is expedient if the device to manufacture a corrugated cardboard web has a pressing device to press a liner web on to the glue-covered tips of the corrugated web. Preferably, the pressing device has at least one pressing roll or a pressure belt module with a guided continuous pressure belt to press the liner web against the glued corrugated web. The pressure belt module preferably has a belt-tensioning and/or belt adjustment device for tensioning the pressure belt, or controlling the path or lateral position of the pressure belt. An arrangement without this type of belt-tensioning and/or belt adjustment device is possible as an alternative. 
         [0017]    It is advantageous if the machining of the basic corrugating teeth to manufacture the corrugating roll is carried out by metal removal, in particular by grinding. 
         [0018]    According to the invention, the at least one first corrugating tooth and the at least one second corrugating tooth differ from each other, at least regionally, in terms of their tooth shape or tooth geometry. Preferably, they have different cross sections. 
         [0019]    According to the invention, the at least one first and second corrugating teeth differ, at least regionally, in terms of their crest shape or crests. In particular, the at least one first and second corrugating teeth have different cross sections in their crest regions. 
         [0020]    According to the invention, the crest curvatures of the at least one first and second corrugating teeth are different, at least regionally. It is advantageous if, in its first crest region, the at least one first corrugating tooth has one first crest curvature radius, at least regionally, which is between 0.9 mm and 1.9 mm Preferably, in its second crest region, the at least one second corrugating tooth has a second crest curvature radius which is smaller or greater than the first crest curvature radius. 
         [0021]    According to the invention, the at least one first and second corrugating teeth differ in terms of their respective, particularly maximum, radial tooth height measured from the corrugating roll body, wherein preferably the radial height difference between the first tooth height and the second tooth height is respectively between 0.001 mm and 0.1 mm, wherein preferably the second radial tooth height is respectively between 0.1% and 10% smaller or greater than the first radial tooth height (H 1 ). It is advantageous if the at least one first corrugating tooth has a respectively greater or smaller, particularly maximum, radial tooth height than the at least one second corrugating tooth. 
         [0022]    According to the invention, the at least one first and second corrugating teeth differ in terms of their tooth thickness in the peripheral direction, wherein the first tooth thickness and the second tooth thickness, at least regionally, differ from each other. It is advantageous if the at least one first corrugating tooth has, at least regionally, a respectively greater or smaller tooth thickness than the at least one second corrugating tooth. The difference in the tooth thickness is preferably between 0.001 mm and 0.1 mm. 
         [0023]    According to the invention, flanks of the at least one first and second corrugating teeth run differently, at least regionally. For example, these flanks, at least regionally, have a different inclination and/or curvature than the corrugating roll body and/or the respective corrugating tooth crest. For example, the leading and/or trailing flanks of the first and second corrugating teeth run differently, at least regionally. 
         [0024]    According to the invention, the roots or root regions of the at least one first and second corrugating teeth differ, at least regionally, particularly in their shape, or geometry. The roots or root regions are arranged adjacent to the respective crest or crest region of the corrugating tooth. It is advantageous if the at least one first corrugating tooth has, in its first root region, or, in the case of its first root, a first course, or a first curvature, especially a first curvature radius, which differs from a corresponding second course, or a corresponding curvature, particularly a second curvature radius, of the second root region, or root of the at least one second corrugating tooth. For instance, the first curvature radius of the first root region is between 0.9 mm and 2.5 mm. Alternatively, the root thicknesses of the first and second root regions differ in the peripheral direction. 
         [0025]    According to the invention, the corrugating roll comprises several of the second corrugating teeth and has differently designed corrugating tooth valleys, in particular second corrugating tooth valleys, which are delimited in the peripheral direction by adjacent corrugating teeth, in particular two adjacent corrugating teeth, of the corrugating roll. The second corrugating tooth valley differs in its radial depth from the first corrugating tooth valley delimited by at least one corrugating tooth. For example, the first corrugating tooth valley is formed so that it is deeper or less deep than the second corrugating tooth valley. Preferably, the difference is between 0.001 mm and 0.1 mm. 
         [0026]    The embodiment, in which the first corrugating teeth and the second corrugating teeth are arranged periodically with respect to each other on the corrugating roll body, is extremely advantageous in terms of operation-related vibrations. Furthermore, this allows the corrugating roll(s) to run particularly quietly. Alternatively, the first corrugating teeth and second corrugating teeth, at least regionally, are arranged aperiodically. 
         [0027]    According to the invention in its peripheral direction the corrugating roll has varying pitches, in which a first pitch exists between the first corrugating teeth adjacently arranged in the peripheral direction, and a second pitch exists between a first corrugating tooth and the second corrugating tooth arranged adjacent to it in the peripheral direction, wherein the first pitch and the second pitch are different, wherein preferably the first pitch and the second pitch differ from each other by 0.005 mm to 0.1 mm in the peripheral direction. It is advantageous if the varying pitches are produced by varying tooth thicknesses of the first and second corrugating teeth. Preferably, the second corrugating teeth, at least regionally, have a smaller or greater second tooth thickness than the first corrugating teeth, which produces varying pitches. 
         [0028]    Alternatively or additionally, the radii, or courses of the at least one first corrugating tooth and of the at least one second corrugating tooth are preferably different in terms of their corrugating crests and/or roots, which preferably produces varying pitches in the corrugating roll. Alternatively or additionally, advantageously, at least one flank angle of the at least one first corrugating tooth and of the at least one second corrugating tooth, particularly the leading and/or trailing flanks, is different, which preferably produces varying pitches in the corrugating roll. 
         [0029]    The embodiment according to which the first pitch and the second pitch differ from each other by 0.005 mm to 0.1 mm in the peripheral direction produces an extremely uniformly impressed corrugated web and a particularly quiet running of the corrugating roll(s). 
         [0030]    It is advantageous if every fourth of all of the corrugating teeth is a second corrugating tooth. Preferably, every third of all of the corrugating teeth is a second corrugating tooth. Preferably, every second of all of the corrugating teeth is a second corrugating tooth. These are preferred distributions of the corrugating teeth. 
         [0031]    Alternatively for example, every fifth, sixth or seventh tooth of all of the corrugating teeth is a second corrugating tooth. 
         [0032]    The embodiment according to which every third of all of the corrugating teeth is a second corrugating tooth provides for a reduction of the ¼ (quarter) tooth frequency, or tooth meshing frequency during the operation of the corrugating roll. 
         [0033]    The method, in which the machining of the basic corrugating teeth is performed by at least one machining tool such that in a first machining step, at least two basic corrugating teeth, arranged adjacent to each other, are always being at least partially machined simultaneously as the first corrugating teeth are being formed, and in a second machining step, after a relative displacement between the at least one machining tool and the corrugating roll basic body, at least one first corrugating tooth is always being at least partially machined again as the at least one second corrugating tooth is being formed by the at least one machining tool and, during the second machining step, at least one first corrugating tooth remains completely unmachined, is extremely effective. Advantageously, always exactly two basic corrugating teeth arranged adjacent to each other are machined essentially completely and two basic corrugating teeth arranged to the side of them are approximately half-machined simultaneously in a first operation by the at least one machining tool. In doing so, the two basic corrugating teeth machined essentially completely in the first operation are advantageously located between the two lateral basic corrugating teeth which are only essentially half-machined in the first operation. 
         [0034]    After the next relative movement between the at least one machining tool and the corrugating roll basic body, in the second operation just one first corrugating tooth is again machined, at least regionally, while forming the second corrugating tooth, whereas the remaining first corrugating teeth, produced immediately before, remain unmachined this time. The doubly-machined corrugating tooth differs, therefore, from the just basically machined corrugating teeth and thus forms a second corrugating tooth. Advantageously, all basic corrugating teeth are machined in this manner to form the corrugating roll. 
         [0035]    It is advantageous if, in order to produce the relative movement between the at least one machining tool and the corrugating roll basic body, the corrugating roll basic body is pivoted correspondingly. Alternatively, the at least one machining tool is pivoted relative to the corrugating roll basic body. 
         [0036]    Advantageously, the crest and/or root of the respective corrugating tooth can be machined with the at least one machining tool. 
         [0037]    Alternatively, at least one of the basic corrugating teeth is machined singly in order to obtain differing corrugating teeth. 
         [0038]    Preferred embodiments of the invention are described below, by way of example, with reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]      FIG. 1  shows a simplified side view of a device according to the invention to produce a corrugated cardboard web, 
           [0040]      FIG. 2  shows an enlarged section of a corrugating roll according to the invention of the device shown in  FIG. 1  to produce a corrugated cardboard web, 
           [0041]      FIG. 3  shows an enlarged section of a corrugating roll according to the invention according to a second embodiment which can be used instead of the corrugating roll shown in  FIG. 2 , 
           [0042]      FIG. 4  shows an enlarged section of a corrugating roll according to the invention according to a third embodiment which can be used instead of the corrugating roll shown in  FIG. 2 , 
           [0043]      FIG. 5  shows an enlarged section of a corrugating roll according to the invention according to a fourth embodiment which can be used instead of the corrugating roll shown in  FIG. 2 , 
           [0044]      FIG. 6  shows an enlarged section of a corrugating roll according to the invention according to a fifth embodiment which can be used instead of the corrugating roll shown in  FIG. 2 , 
           [0045]      FIG. 7  shows an enlarged section of a corrugating roll according to the invention according to a sixth embodiment which can be used instead of the corrugating roll shown in  FIG. 2 , and 
           [0046]      FIG. 8  shows a simplified device for producing the corrugating rolls according to the invention which are illustrated in  FIGS. 2 to 7 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0047]    Firstly, referring to  FIG. 1 , a device for producing a corrugated cardboard web, which is a component part of a corrugated cardboard facility for producing cardboard and can also be designated as single facer, comprises a first corrugating roll  5  mounted to rotate about a first rotational axis  4  and a second corrugating roll  7  mounted to rotate about a second rotational axis  6  for producing a corrugated web  2  having a fluting  1  from a smooth or flat material web  3 . Advantageously, the designs of the corrugating rolls  5 ,  7  are identical. The designs of the corrugating rolls  5 ,  7  can also be different. The rotational axes  4 ,  6  run parallel to each other and are perpendicular to a transportation direction  8  of the material web  3 . 
         [0048]    There is a roll slit  9  between the corrugating rolls  5 ,  7  to transport and corrugate the material web  3 . Together, they form a corrugating arrangement. 
         [0049]    In order to join the corrugated web  2  with a liner web  10  to a corrugated cardboard web  11 , laminated on one side, the device for producing a corrugated cardboard web has an adhesive applicator  12  downstream from the corrugating rolls  5 ,  7 , said adhesive applicator comprising in turn an adhesive container  13 , an adhesive applying roll  14  dipping into the adhesive container  13  and an adhesive metering roll  15  abutting the adhesive adhesive applying roll  14 . There is adhesive  16  in the adhesive container  13 . 
         [0050]    In order to transport and to apply adhesive to the corrugated web  2 , the adhesive applying roll  14  forms an adhesive applying gap  17  with the first corrugating roll  5 . The adhesive  16  located in the adhesive container  13  is applied, by means of the adhesive applying roll  14 , dipped in said container and rotating about a third rotational axis  18  during operation, to the open tips of the fluting  1  of the corrugated web  2  transported in the transportation direction  8  and where it abuts the first corrugating roll  5 . The adhesive metering roll  15  is arranged essentially opposite the first corrugating roll  5  and serves to form a uniform coating of adhesive on the adhesive applying roll  14 . The adhesive metering roll  15  rotates during operation about its fourth rotational axis  19  which runs parallel to the third rotational axis  18 , or to the rotational axes  4 ,  6 . 
         [0051]    The corrugated web  2  provided with the adhesive  16  together with the liner web  10  transported in a transportation device  20  are then jointly fed through the device for producing a corrugated cardboard web to obtain the corrugated cardboard web  11  laminated on one side. 
         [0052]    In order to press the liner web  10  against the corrugated web  2  provided with the adhesive  16 , where it abuts, at least regionally, the first corrugating roll  5 , the device for producing a corrugated cardboard web has a pressing device  21 , designed here as a pressing module and arranged downstream from the gluing gap  17  relative to the corrugated web  2 . 
         [0053]    The pressing device  21  is arranged above the first corrugating roll  5 . It has a diverting roll  23  mounted to rotate about a fifth rotational axis  22  and a web tensioning- and/or web regulating roll  25  mounted to rotate about a sixth rotational axis  24  as well as a continuous pressure belt  27  fed around the diverting roll  23  and the web tensioning- and/or web regulating roll  25 . The rotational axes  22 ,  24  run parallel to each other. They also extend parallel to the rotational axes  18 ,  19 . 
         [0054]    The web tensioning- and/or web regulating roll  25  is adjustable in terms of its distance from the diverting roll  23  to change the tensioning of the pressure belt  27  and/or in terms of its inclination to the diverting roll  23  to change the course of the pressure belt  27 , or its lateral course. An appropriate web tensioning- and/or web regulation device  26  is present for this purpose, wherein said device engages directly or indirectly with the web tensioning- and/or web regulating roll  25  and comprises, for example, at least one adjusting cylinder unit whose length can be changed. 
         [0055]    The first corrugating roll  5  engages from below, at least regionally, in a space existing between the diverting roll  23  and the web tensioning- and/or web regulating roll  25 . The pressure belt  27  in this arrangement is diverted by the first corrugating roll  5 . It presses against the liner web  10 , which, in turn, is forced against the corrugated web  2  provided with the adhesive  16  and abuts the first corrugating roll  5 . 
         [0056]    A first splicing device (not shown) is advantageously provided for the device for producing a corrugated cardboard web to supply the material web  3  and a second splicing device (not shown) is provided to supply the liner web  10 . Hence, the material web  3  is advantageously a continuous material web. It follows that the liner web  10  preferably also involves a continuous liner web, therefore. The corrugated cardboard web  11  laminated on one side is also continuous, therefore. 
         [0057]    Also, a smooth laminating web/liner web (not shown) and/or at least one further corrugated cardboard web (not shown) laminated on one side can be applied to the corrugated web  2  in the cardboard device opposite the liner web  10 . These are then glued together to form a lamination. 
         [0058]    The fluting of the material web  3 , or production of the corrugated web  2  is described in more detail below. During operation, the corrugating rolls  5 ,  7  rotate about their rotational axis  4 ,  6  in respectively opposite peripheral directions  28 ,  29 . In doing so, the corrugating rolls  5 ,  7  mesh with each other, or engage into each other and thus form the material web  3  so that there is a corrugated web  2  downstream from the roll slit  9 . 
         [0059]    The first corrugating roll  5  is described below in more detail also with reference to  FIG. 2 . Since in this case the second corrugating roll  7  is designed in the same manner as the first corrugating roll  5 , a detailed description of the second corrugating roll  7  is dispensed with for the sake of brevity. The following description of the first corrugating roll  5  applies essentially analogously for the second corrugating roll  7 . Alternatively, the designs of the corrugating rolls  5 ,  7  are different. For example, the second corrugating roll  7  simply has identical corrugating teeth. 
         [0060]    The first corrugating roll  5  has a corrugated first surface fluting  30  with alternately arranged corrugating teeth and corrugating tooth valleys  32 . The corrugating teeth and the corrugating tooth valleys  32  run parallel to the first rotational axis  4 . They are arranged alternately. 
         [0061]    Each corrugating tooth valley  32  is delimited by the adjacent corrugating teeth both in the peripheral direction  28 ,  29  as well as radially inwards. Each corrugating tooth valley  32  is delimited radially inwards by a radially inner valley base face  33  of the corrugating teeth, which is concave relative to the first rotational axis  4 . The corrugating tooth valleys  32  are essentially identical. 
         [0062]    Each corrugating tooth has a radially outer corrugating tooth crest, which is convex relative to the first rotational axis  4 . Furthermore, each corrugating tooth has a radially inner corrugating tooth root. The corrugating tooth crests can be directly adjacent to the neighbouring corrugating tooth roots. Alternatively, a corrugating tooth neck is arranged between each corrugating tooth crest and the associated corrugating tooth root. 
         [0063]    Each corrugating tooth extends between two adjacent corrugating tooth valleys  32 . In each corrugating tooth valley  32 , a half of the valley base face  33  still belongs to the corrugating tooth, in fact the part adjacent to this corrugating tooth. Hence, as can be seen from  FIG. 2 , each corrugating tooth extends between planes EZ which divide the corrugating tooth valleys  32 , or valley base faces  33  centrally in the radial direction. 
         [0064]    Relative to the first peripheral direction  28 , each corrugating tooth has a leading flank  35  and a trailing flank  36 . Hence, the flanks  35 ,  36  extend from the corrugating tooth crest to the adjacent valley base face  33 , or, respectively, the flanks  35 ,  36  form it. Hence, they extend from the radially outermost point A of each corrugating tooth to the radially innermost point I of each corrugating tooth. The radially innermost points I lie in the planes EZ, whereas the radially outermost points A are located centrally between adjacent planes EZ. 
         [0065]    The corrugating teeth extend outwards from a cylindrical corrugating roll body  37 . Each corrugating tooth has a radial tooth height with respect to the first rotational axis  4  and extending out from the corrugating roll body  37 . The radial tooth height of the corrugating tooth is maximal at points A, whereas it is minimal at points I, or is 0, respectively. 
         [0066]    In the first peripheral direction  28 , the corrugating teeth are essentially identical with respect to their tooth thickness. The corrugating teeth taper radially outwards. 
         [0067]    The first corrugating roll  5  has a constant pitch T between adjacent corrugating teeth in the first peripheral direction  28 . 
         [0068]    The first corrugating roll  5  has constant gap widths LW in the first peripheral direction  28 , or identical corrugating tooth valleys  32 , between adjacent corrugating teeth. 
         [0069]    The first corrugating roll  5  has different corrugating teeth. The first surface fluting  30  is formed, therefore, by differing corrugating teeth. 
         [0070]    The first corrugating roll  5  has a multiplicity of first corrugating teeth  31  and several second corrugating teeth  38  which differ in their respective maximum radial heights from the first corrugating teeth  31 . Measured from the corrugating roll body  37 , the first corrugating teeth  31  each have a maximum radial height H 1 , whereas the second corrugating teeth  38 , measured from the corrugating roll body  37 , each have a maximum radial height H 2 . The respective maximum radial height H 2  is smaller than the respective maximum radial height H 1 . As a comparison, in  FIG. 2  in the case of the illustrated second corrugating tooth  38 , the shape of a higher first corrugating tooth  31  is also illustrated at the same time with a dotted line. 
         [0071]    Both the first corrugating teeth  31  as well as the second corrugating teeth  38  have a convex corrugating crest. The first corrugating teeth  31  have a first corrugating crest  34  with a first crest curvature, whereas the second corrugating teeth  38  have a second corrugating crest  48  with a second crest curvature. In the case of the first crest curvature, a first crest curvature radius is present which is smaller than a second crest curvature radius of the second crest curvature. 
         [0072]    The flanks  35 ,  36  of the first and second corrugating teeth  31 ,  38  run, irrespective of the corrugating crests  38 ,  48 , identically relative to the corrugating roll body  37 , or relative to the rotational axis  4 . The tooth thickness d, d 2  of the first and second corrugating teeth  31 ,  38  is essentially identical. It only differs with the corrugating crests  38 ,  48 . The pitches T between first corrugating teeth  31  and between first and second corrugating teeth  31 ,  38  are identical. 
         [0073]    The first corrugating teeth  31  each have cross sections which are designed symmetrically relative to a first corrugating tooth plane E 1 . The second corrugating teeth  38  each have cross sections which are designed symmetrically relative to a second corrugating tooth plane E 2 . The corrugating tooth planes E 1 , E 2  pass through points A. 
         [0074]    Advantageously, every third tooth of all of the corrugating teeth involves a second corrugating tooth  38 . The remaining corrugating teeth are preferably first corrugating teeth  31 . Therefore, more first corrugating teeth  31  than second corrugating teeth  38  are present in the case of the first corrugating roll  5 . The arrangement of the first and second corrugating teeth  31 ,  38  is periodic or regular. 
         [0075]    A description of a second embodiment of the first corrugating roll  5   a  follows below with reference to  FIG. 3 . Identical elements or regions carry the same identifying symbols as the previous embodiment to whose description reference will be made. Functionally identical elements, but with different designs, carry the same identifying symbols with “a” placed after them. 
         [0076]    The first corrugating roll  5   a  in this case has second corrugating teeth  38   a , which differ in their tooth thickness d 2   a  from the tooth thickness d of the first corrugating teeth  31 . The respective tooth thickness d 2  is smaller than the tooth thickness d. Alternatively, the tooth thickness d 2  is greater than the tooth thickness d. 
         [0077]    The result of the different thicknesses of the first and second corrugating teeth  31 ,  38   a  is that the gap width LW 2  between a second corrugating tooth  38   a  and an adjacent first corrugating tooth  31  respectively associated with it is greater than the gap width LW between two adjacently arranged first corrugating teeth  31 . 
         [0078]    Furthermore, the pitch T 2  between a first corrugating tooth  31  and a second corrugating tooth  38   a  respectively arranged adjacent to it is smaller than the pitch T between two adjacently arranged first corrugating teeth  31 . 
         [0079]    The maximum radial tooth heights H 1 , H 2  of the first and second corrugating teeth  31 ,  38   a  are identical in each case. 
         [0080]    The respective reduced tooth thickness d 2  of the second corrugating teeth  38   a  results also from a narrower corrugating tooth crest  48   a  compared with the first corrugating teeth  31 . The flanks  35   a ,  36   a  of the second corrugating teeth  38   a  each enclose a flank angle FW 2  which is smaller than the respective flank angle FW of flanks  35 ,  36  of the first corrugating teeth  31 . 
         [0081]    The second corrugating tooth valley  32   a , delimited by a second corrugating tooth  38   a , thus differs respectively in its width in a peripheral direction  28 ,  29  from a corrugating tooth valley  32  which is delimited only by first corrugating teeth  31 . 
         [0082]    The first corrugating teeth  31  each have cross sections which are designed symmetrically relative to a first corrugating tooth plane E 1 . The second corrugating teeth  38   a  each have cross sections which are designed symmetrically relative to a second corrugating tooth plane E 2 . 
         [0083]    As in the case of the previous embodiment, every third of all of the corrugating teeth involves a second corrugating tooth  38   a.    
         [0084]    A description of a third embodiment of the first corrugating roll  5   b  follows below with reference to  FIG. 4 . Identical elements or regions carry the same identifying symbols as the previous embodiments to whose description reference will be made. Functionally identical elements, but with different designs, carry the same identifying symbols with “b” placed after them. 
         [0085]    Compared with the first corrugating teeth  31 , the second corrugating teeth  38   b  each have a reduced maximum radial, second tooth height H 2   b  and a reduced second tooth thickness d 2   b . The flank angle FW 2   b  of the second corrugating teeth  38   b  is smaller than the respective flank angle FW of the first corrugating teeth  31 . 
         [0086]    The course of the leading flanks  35  of the second corrugating teeth  38   b  correspond essentially to that of the leading flanks  35  of the first corrugating teeth  31 . They have an identical inclination to the corrugating roll body  37  or to the rotational axis  4 . 
         [0087]    The reduced tooth thickness d 2   b  and the changed flank angle FW 2   b  are each produced simply by the changed course of the trailing flank  36   b  of the second corrugating teeth  38   b . The tooth crest  48   b  of the second corrugating teeth  38   b  is narrower in each case compared with the tooth crest  34  of the first corrugating teeth  31 . 
         [0088]    The pitch T 21  between the second corrugating teeth  38   b  and the respective trailing first corrugating tooth  31 , relative to the respective trailing flanks  36 ,  36   b , is respectively greater than the corresponding pitch T between the adjacently arranged first corrugating teeth  31 . 
         [0089]    The pitch T 22  between the second corrugating teeth  38   b  and the respective leading first corrugating tooth  31 , relative to the trailing flanks  36 ,  36   b , is respectively smaller than the corresponding pitch T between the adjacently arranged first corrugating teeth  31 . 
         [0090]    Thus the second corrugating tooth valley  32   b  delimited by the trailing tooth flank  36   b  of the second corrugating teeth  38   b  and a first corrugating tooth  31  differs respectively in its width in the peripheral direction  28 ,  29  from a corrugating tooth valley  32 , which is delimited by two first corrugating teeth  31 , or by a first corrugating tooth  31  and the leading flank  35  of the second corrugating teeth  38   b . The second corrugating tooth valley  32   b  is wider than the first corrugating tooth valley  32 . 
         [0091]    The first corrugating teeth  31  each have cross sections which are designed symmetrically relative to a first corrugating tooth plane E 1 . The second corrugating teeth  38   b  each have cross sections which are designed symmetrically relative to a second corrugating tooth plane E 2 . 
         [0092]    As in the case of the previous embodiment, every third tooth of all of the corrugating teeth is a second corrugating tooth  38   b.    
         [0093]    A description of a fourth embodiment of the first corrugating roll  5   c  follows below with reference to  FIG. 5 . Identical elements or regions carry the same identifying symbols as the previous embodiment to whose description reference will be made. Functionally identical elements, but with different designs, carry the same identifying symbols with “c” placed after them. 
         [0094]    The first corrugating roll  5   c  in this case has second corrugating teeth  38   c , which are arranged immediately next to each other in the peripheral direction  28 ,  29  and differ in their root region from the first corrugating teeth  31 . In each case, two second corrugating teeth  38   c  are arranged immediately following one another in the peripheral direction  28 ,  29 . 
         [0095]    The radially inner, second valley base face  33   c  respectively between two second corrugating teeth  38   c  is displaced radially outwards compared with the first valley base faces  33  of two adjacently arranged, first corrugating teeth  38 . The second corrugating tooth valley  32   c  delimited by the radially outwardly displaced, second valley base face  33   c  in this case has a second radial, in particular maximum, valley depth which is smaller than the first radial, in particular maximum, valley depth, which is defined by at least one first corrugating tooth  31 . The respective second valley base face  33   c  is advantageously radially outwardly displaced between 0.001 mm and 0.1 mm compared with the first valley base faces  33 . Thus, the second corrugating teeth  38   c  have a corrugating tooth root which differs from the first corrugating teeth  31 . 
         [0096]    Relative to the radially outwardly displaced, second valley base face  33   c  the second corrugating teeth  38   c  have a smaller radial maximum height than the first corrugating teeth  31 . Relative to the corrugating roll body  37 , the first and second corrugating teeth  31 ,  38   c  have an identical maximum radial height. 
         [0097]    The flanks  35   c ,  36   c  of the respective second corrugating teeth  38   c  delimiting a second corrugating tooth valley  32   c  are shortened compared with the flanks  35 ,  36  of the respective first corrugating teeth  31  which delimit a first corrugating tooth valley  32 . The flanks  35   c ,  36   c  of every second corrugating tooth  38   c  each have the same length. 
         [0098]    The curvature radius of the second valley base face  33   c  is greater than the curvature radius of a first valley base face  33 . 
         [0099]    The tooth thickness d 2 , d 2   c  of the first and second corrugating teeth  31 ,  38   d  is essentially identical. It differs only in the roots. 
         [0100]    The second corrugating tooth valleys  32   c  differ in their shape, or radial depth, from the first corrugating tooth valleys  32 . 
         [0101]    A description of a fifth embodiment of the first corrugating roll  5   d  follows below with reference to  FIG. 6 . Identical elements or regions carry the same identifying symbols as the previous embodiment to whose description reference will be made. Functionally identical elements, but with different designs, carry the same identifying symbols with “d” placed after them. 
         [0102]    Compared with the embodiment according to  FIG. 5 , in this case the second valley base faces  33   d  of two second corrugating teeth  38   d  following one another in the peripheral direction  28 ,  29  are radially inwardly displaced compared with the first valley base faces  33 . Thus, the second corrugating teeth  38   d  have a different corrugating tooth root than the first corrugating teeth  31 . 
         [0103]    The flanks  35   d ,  36   d  of every second corrugating tooth  38   d  are each longer than the flanks  35 ,  36  of every first corrugating tooth  31 . The second corrugating tooth valleys  32   d  differ in their shape from the first corrugating tooth valleys  32 . They are deeper than the first corrugating tooth valleys  32 . Advantageously, the second corrugating tooth valleys  32   d  are each deeper than the first corrugating tooth valleys  32  by 0.001 mm to 0.1 mm. 
         [0104]    The tooth thickness d, d 2   d  of the first and second corrugating teeth  31 ,  38   d  is different in the roots. 
         [0105]    A description of a sixth embodiment of the first corrugating roll  5   e  follows below with reference to  FIG. 7 . Identical elements or regions carry the same identifying symbols as the previous embodiment to whose description reference will be made. Functionally identical elements, but with different designs, carry the same identifying symbols with “e” placed after them. 
         [0106]    Compared with the first corrugating teeth  31 , the second corrugating teeth  38   e  have a leading flank  35   e  which runs differently. The inclination, or gradient of flank  35   e  differs, particularly in each root region, from the leading flanks  35  of the first corrugating teeth  31 . The flanks  35   e  of the second corrugating teeth  38   e  run less steeply than the flanks  35  of the first corrugating teeth  31  relative to the corrugating roll body  37 . The flanks  35   e  of the second corrugating teeth  38   e  run less steeply than the trailing flanks  36  of the second corrugating teeth  38   e  relative to the corrugating roll body  37 . Starting from point I, the first flanks  35   e  run more quickly upwards than the first flanks  35  of the first corrugating teeth  31 . The tooth thickness d, d 2   e  of the first and second corrugating teeth  31 ,  38   e  differs in the roots. 
         [0107]    By having different roots for the first and second corrugating teeth  31 ,  38   e  the first and second corrugating tooth valleys  32 ,  32   e  differ also in their radial depth or width from each other. 
         [0108]    First corrugating teeth  31  are arranged to be adjacent to the second corrugating teeth  38   e . The pitch T 21  between the second corrugating teeth  38   e  and the respectively following first corrugating tooth  31 , with respect to the respective leading flanks  35 ,  35   e , is, in each case, greater than the corresponding pitch T between the adjacently arranged first corrugating teeth  31 . 
         [0109]    The pitch T 22  between the second corrugating teeth  38   e  and the respectively leading first corrugating tooth  31 , with respect to the leading flanks  35 ,  35   e , is, in each case, smaller than the corresponding pitch T between the adjacently arranged first corrugating teeth  31 . 
         [0110]    A device for producing a corrugating roll  5 ,  7  and the manufacturing method associated with it is described below with reference to  FIG. 8 . 
         [0111]    The device comprises a mounting facility  39  for mounting a corrugating roll basic body  40  requiring machining which has a basic surface fluting  41  with basic corrugating teeth  47 . The mounting facility  39  allows the corrugating roll basic body  40  to pivot about its central axis. 
         [0112]    In order to machine the basic surface fluting  41 , the device has a grinding wheel  42 , which can be displaced relative to the corrugating roll basic body  40  between a machining position to machine the corrugating roll basic body  40  and a non-machining position at a distance from the corrugating roll basic body  40 . The grinding wheel  42  is designed in the shape of a disc with a pivot axis  49 . It can be driven rotationally. In operation, the grinding wheel  42  rotates about its pivot axis  49 . 
         [0113]    On its open peripheral region  43 , the grinding wheel  42  has three identical grinding projections  44  arranged adjacent to each other, each of which is peripheral and runs about the pivot axis  49 . The grinding projections  44  are arranged with uniform axial gaps between each other looking towards the pivot axis  49 . In cross section, each of them is essentially triangular in shape and each has a rounded grinding tip  45 . Each grinding tip  45  is convex with respect to the pivot axis  49 . 
         [0114]    The grinding wheel  42  has peripheral grinding grooves  50 , each with a rounded root  46  and each between said adjacently arranged grinding projections  44 . The grinding grooves  50  narrow down to their root  46 . Each root  46  is concave relative to the pivot axis  49 . 
         [0115]    The grinding projections  44 , or grinding grooves  50 , are arranged, in size and shape, such that they are suitable for forming the first corrugating teeth  31 . 
         [0116]    When the grinding wheel  42  is located in its machining position shown in  FIG. 8 , in a first grinding step, the three grinding projections  44  of the rotating grinding wheel  42  engage simultaneously in three adjacent valleys of the corrugating roll basic body  40  and engage in a grinding action on flanks of the corrugating roll basic body  40  while the two grinding grooves  50  abut the basic corrugating teeth  47  while grinding. By machining material from the basic corrugating teeth  47 , the first corrugating teeth  31 , or the corrugating tooth valleys  32 , are produced. 
         [0117]    After this first grinding step, the corrugating roll basic body  40  is pivoted in its peripheral direction by two basic corrugating teeth  47 , or two first corrugating teeth  31  relative to the grinding wheel  42  with the grinding wheel  42  lifted away from the corrugating roll basic body  40 . 
         [0118]    Then the rotating grinding wheel  42  is placed again in its machining position. In doing so, two new corrugating roll basic teeth  47  are newly machined resulting in more first corrugating teeth  31 . In doing so, a first corrugating tooth  31  is again machined resulting in further removal of material to produce the second corrugating tooth  38 ,  38   a ,  38   b ,  38   c ,  38   d ,  38   e . The grinding projections  44  are shaped corresponding to the various second corrugating teeth  38 ,  38   a ,  38   b ,  38   c ,  38   d ,  38   e . The second corrugating teeth  38 ,  38   a ,  38   b ,  38   c ,  38   d ,  38   e  are produced, therefore, from the first corrugating teeth  31 , or in the machining of the corrugating roll basic body  40 . 
         [0119]    Alternatively, the corrugating roll basic body  40  is pivoted in its peripheral direction by more than two basic corrugating teeth  47 , or two first corrugating teeth  31 , relative to the grinding wheel. This takes place particularly when the grinding wheel has more than the stated, that is, more than three grinding projections  44 . 
         [0120]    Combinations of the disclosed embodiments are possible.