Method, mobile terminal, and computer program product
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-27
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026051981_13082026_PF_FP_ABST
Abstract
Description
[0001] File: 28708 “Support strip” WO / PFW - 1 -
[0002] Method, mobile device and computer program product
[0003] The invention relates to a method for adjusting a shoe press according to the preamble of claim 1, as well as a mobile terminal and an associated computer program product.
[0004] Machines for producing fibrous webs, particularly paper, cardboard, or tissue webs, typically include a press section where the fibrous web is dewatered by mechanical pressure. This press section is usually located between the forming and drying sections. A particularly efficient and gentle method of mechanical dewatering for the fibrous web can be achieved using a so-called shoe press. In this process, the fibrous web, usually together with a felt or between two felts, is guided through an extended press gap between a shoe press roller and a counter roller. The extended press gap is achieved by rotating a flexible shoe press sleeve around a pressure shoe on the shoe press roller. The pressure shoe has a concave shape that matches the radius of the counter roller.The pressure shoe can be subjected to pressure and moved radially relative to the stationary yoke of the shoe press roller. Such shoe press rollers are marketed by the applicant under the brand name "NipcoFlex" rollers and are described in more detail, for example, in publications DE 102019 104388 and DE 102019 104389.
[0005] The shoe press sleeve is subjected to very high loads from the press shoe, as it is not only stressed by the pressure in the press gap itself, but also constantly subjected to alternating bending stresses between convex and concave deformation at the entry and exit points of the press gap during rotation – viewed in the circumferential direction. To maximize the service life of the shoe press sleeve, it is important that it is not subjected to any further significant loads beyond these unavoidable ones. File: 28708 “Support strip” WO / PFW -2 -
[0006] It is therefore necessary to precisely adjust the shoe roller in general, and specifically the extended press gap between the shoe roller and the counter roller. However, since the relevant components, such as the press shoe, are located inside the shoe roller, their exact position cannot be easily determined.
[0007] Therefore, the applicant has proposed methods in documents DE 102022 108707 and DE 102022 108708 to simplify these settings for the user with the help of augmented reality. However, adjusting a shoe press roller remains difficult.
[0008] The object of the present invention is to further develop these methods and to overcome the disadvantages of the prior art.
[0009] The problem is solved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention are found in the dependent claims.
[0010] A method for adjusting a shoe press for a machine for producing a fibrous web is proposed, wherein the shoe press comprises a shoe roller and a counter roller which together form an extended press nip, and wherein the shoe roller has a fixed yoke and a movable pressure shoe, as well as a press shell which is rotatably mounted about the fixed yoke and the pressure shoe, and wherein a scraper is further provided which can be applied to the outside of the shoe press roller, as well as a support element, e.g. a support strip, which is in contact with the press shell inside the shoe press roller, characterized in that the method comprises the following steps:
[0011] A1. Image and / or video recording of the exterior of the shoe press, in particular the shoe press roller, and transmission of the recording to a processing unit. B1. Determining the position of the support element.
[0012] C1. Representation of the support element's position as metadata by overlaying it with the image and / or video recording on a display. File: 28708 "Support strip" WO / PFW - 3 -
[0013] During this procedure, the shoe press can be positioned in either the maintenance or operating position.
[0014] Before the press sleeve enters the press nip during operation of the shoe press, water must be removed from its surface to prevent potential re-wetting and overloading of the press nip. For this purpose, a scraper is applied to the outside of the sleeve. To ensure the scraper is effective, it must be pressed against the sleeve surface with a certain amount of pressure. To prevent deformation and damage to the press sleeve, a support element – usually in the form of a support strip – is provided inside the shoe press roller. This support element is positioned internally at the circumferential point where the scraper makes contact from the outside. This prevents the sleeve from being pushed inwards.
[0015] During operation, the scrapers can shift over time, leading to unfavorable settings. This can result in inefficient water removal, an uneven moisture profile, and uneven wear. Causes for this include, for example, cleaning the collection tray or loosening of the device due to alternating loads.
[0016] To resolve this problem, the operator must readjust the scraper position so that the scraper rests evenly on the casing and the support bar. An optimally adjusted scraper rests centrally on the support bar. However, this task requires knowing the position of the support bar, which is very challenging since it is not possible to see inside the shoe press roller.
[0017] By displaying the position of the support element as metadata through overlaying it with the image and / or video recording on a display, operating personnel now have the opportunity, for the first time, to know the exact position of the support element while adjusting the scraper, which enables precise adjustment of the file: 28708 “Support strip” WO / PFW - 4 -
[0018] The scraper allows for adjustment of the scraper's position so that, during operation of the press, the scraper rests on a point of the shoe press shell that is supported by the support element.
[0019] This information can be used in various ways.
[0020] • When displayed on the live image of a mobile device (e.g.
[0021] (Mobile phone or tablet) the setting can be made directly using this live image.
[0022] • However, it is also possible to determine the position using the superimposed image.
[0023] The support element on the outside of the mantle should be appropriately marked, and the scraper adjusted according to these markings. This is advantageous if, for example, a faulty scraper setting is discovered during an inspection using the described procedure, but no personnel or
[0024] A tool is available to correct the scraper position.
[0025] It can also be advantageous if the representation of the support element's position includes additional information. For example, the support element typically has a circumference width of approximately 20 mm to 50 mm. Within this width, there is an optimal area around the center of the support element that is ideal for positioning the scraper. This area can be displayed as additional metadata by overlaying it with the image and / or video recording on the screen.
[0026] This allows the operating personnel to assess whether a scraper, which may still be within the area of the support bar, should perhaps be readjusted, as it has already moved out of the optimal range.
[0027] The following presents another inventive idea that can be advantageous both on its own and in combination with existing methods. File: 28708 “Support strip” WO / PFW - 5 -
[0028] A method for adjusting a shoe press for a machine for producing a fibrous web is proposed, wherein the shoe press comprises a shoe roller and a counter roller, which together form an extended press nip. The shoe roller has a fixed yoke and a movable press shoe. It also has a press sleeve, which is rotatably mounted around the fixed yoke and the press shoe.
[0029] The shoe press has a working position and a maintenance position, whereby in the maintenance position the shoe roller and the counter roller have a greater distance between them than in the working position.
[0030] The process includes the following steps:
[0031] a. Preparing the shoe press in the maintenance position
[0032] b. Image and / or video recording of the exterior of the shoe press, in particular the counter roller, and transmission of the recording to a processing unit. c. Determination of a current actual value for the operating status of the press shoe. This actual value includes, in particular, values relating to the position of the press shoe.
[0033] d. Representation of the position of the press shoe as meta-information by superimposing it on the image and / or video recording on a display, wherein the press shoe is represented at the position it would occupy relative to the counter roller in the working position of the shoe press.
[0034] Many maintenance and optimization tasks are performed on a shoe press while it is stationary and in a maintenance position. In this position, the shoe press is opened so that the shoe roller and the counter roller are further apart than in the working position. To move from the working to the maintenance position, one of the two rollers is usually held stationary while the other is moved. Typically, the roller that is geometrically positioned at the top is moved further upwards.
[0035] Furthermore, it is not uncommon for coverings such as press felts to have been removed in this maintenance position.
[0036] Nevertheless, knowledge of the press's condition in the working position is crucial for maintenance and optimization work. File: 28708 "Support bar" WO / PFW - 6 -
[0037] Up to now, experienced operators or multiple attempts have been necessary to obtain an optimal result.
[0038] The inventors recognized that augmented reality (AR) methods can be used very advantageously to facilitate the adjustment of a press shoe. Thus, according to a further inventive idea, the relevant features, such as the position of the press shoe relative to the counter roller, are displayed in the current image or video recording of the open press in the maintenance position, as they would be in the working position. This allows the operating personnel to see at a glance whether adjustments are needed for the press, the press shoe, measuring instruments, or similar components.
[0039] Regarding the position of the press shoe relative to the counter roller, several aspects may be of interest.
[0040] In advantageous embodiments of the method, for example, it may be provided that the radial distance of the press shoe from the counter roller is displayed on the screen.
[0041] Alternatively or additionally, it may also be provided that the position of the press shoe is shown in the circumferential direction of the counter roller.
[0042] Alternatively or additionally, it may also be provided that the position of the press shoe is shown in the axial direction of the counter roller.
[0043] It may also be intended that different aspects of the position of the press shoe are displayed on the screen for different applications (see, for example, examples 1 and 2 below).
[0044] In advantageous embodiments of the method, at least one marker element may be attached to the outside of the shoe press, whereby the marker element is also captured during image and / or video recording. File number: 28708 “Support strip” WO / PFW - 7 -
[0045] The marker element could, for example, be a specially shaped geometric object that is reliably detected by image analysis. This marker element can advantageously be positioned on the roller, which remains stationary when the press is opened, i.e., when transitioning from the operating position to the maintenance position.
[0046] The position(s) where a marker element is placed are well-defined and known in advance. In particular, the position of the drum relative to these marker elements is also known. This improves the accuracy of projecting the metadata onto the image of the drum compared to designs where the drum's position is determined solely from the image of the drum.
[0047] Furthermore, it can be advantageous to have a database system in place, allowing the processing unit to access the database system to determine the position of the press shoe or other metadata. This can facilitate the determination of the positional data for displaying the press shoe.
[0048] It is particularly advantageous if the position of the press shoe on the display can be changed virtually, and the calculation unit is set up to determine a suggestion for a setting of the shoe press with which the virtual change can be implemented.
[0049] In particular, it can be provided that the radial distance of the press shoe from the counter roller is virtually variable, and the processing unit is configured to generate a proposal for changing the center-to-center distance between the press shoe and the counter roller. This virtual change can be achieved, for example, by operating a slider on the display or by other suitable means.
[0050] Example 1: Variation of axle spacing
[0051] The advantages of such a virtual modification can be clearly illustrated by the example of changing the axle spacing and, consequently, the press nip. File: 28708 “Support strip” WO / PFW - 8 -
[0052] Counter rollers in shoe presses often have a polymer covering, typically made of polyurethane. Wear during operation, as well as re-grinding of the covering during roller maintenance, reduces the thickness of the covering and thus the diameter of the counter roller. This reduction in diameter can amount to several millimeters. Although this may seem small compared to the diameter of the counter rollers, it has a significant impact on the press nip and the pressure conditions within it. To maintain constant pressure in the press nip with a reduced roller diameter, the travel distance of the press shoe must be increased. However, this leads to overstretching of the rotating press shell, thereby reducing its service life.
[0053] Overstretching also causes coverings such as press felts to be guided over smaller radii during nip passage, which also leads to increased wear of these coverings.
[0054] Therefore, for the efficient operation of a shoe press, the most precise possible distance between the two rollers is very important.
[0055] Therefore, for example, after a roller service or at specific service intervals, the distance between the two rollers must be adjusted to the changed diameter. This can be done in various ways. Nowadays, it is common practice to reduce the center distance by inserting so-called positioning shims, or to increase it by removing them. However, adjusting the number of positioning shims depends on the operator's experience and is done through trial and error. This method is both inaccurate and time-consuming.
[0056] The illustration of the press shoe's position relative to the counter roller in the working position of the shoe press is already very helpful. An even more advantageous design can now be provided in file 28708 "Support strip" WO / PFW - 9 -
[0057] The operator can virtually change the position of the press shoe displayed on the screen. The processing unit then provides a suggestion on how to achieve this changed position. This suggestion can be in the form of a change to the center distance ("Reduce distance by 2 mm"). Even more efficiently, the suggestion can include direct instructions on the necessary actions ("Insert an additional positioning disc"). This prevents incorrect settings and the need for repeated readjustment of the center distance.
[0058] Alternatively or additionally, it may also be provided that the calculation unit is given a suggestion for a planned setting of the shoe press ("Insert three additional positioning discs"), and the position of the press shoe is virtually changed on the display to visualize the effect of the planned setting.
[0059] In a further advantageous embodiment, the procedure may include the following step:
[0060] e.) Positioning a measuring device, in particular a measuring film, to determine a pressure profile in the press nip.
[0061] Example 2: Positioning of the measuring device during nip pressure measurement
[0062] Knowledge of the pressure profile in the press nip is of great importance to the operator of a shoe press. Therefore, this profile is measured regularly. This measurement is usually carried out by positioning a measuring strip, a pressure-sensitive measuring film, or similar device on the counter roller when the press is open, and then determining the pressure profile in the working position with the press nip closed. File: 28708 “Support strip” WO / PFW - 10 -
[0063] In order to obtain a complete measurement of the pressure profile, the measuring device must be positioned as precisely as possible at the point on the counter roller where the press nip is formed by the pressure shoe in the working position.
[0064] Precise positioning is particularly important because commercially available pressure-sensitive measuring films (e.g., "Prescale" from Fujifilm) have a width only slightly greater than the length of the press nip. If the operator mispositions the measuring film by just 1-2 cm, the pressure profile will be incompletely captured, and the measurement must be repeated. This is not only time-consuming but also costly, as the frequently used measuring films are quite expensive and can only be used once.
[0065] According to one embodiment of the proposed method, a live image of the shoe press can now be captured using a mobile device such as a mobile phone or tablet, and in particular, the position of the press shoe in the circumferential direction of the counter roller can be displayed as a superimposition on the live image. The current position of the measuring device is visible on the live image, and the superimposed position of the press shoe in its working position allows the measuring device – e.g., the measuring film – to be positioned very precisely at the location of the future press nip.
[0066] It can be particularly advantageous if the operator's mobile device (e.g., a mobile phone, a tablet, smart glasses, etc.) is configured so that, after a corresponding selection by the operator, various of the procedures described here can be carried out using augmented reality, e.g.
[0067] • Variation axle spacing and / or
[0068] • Positioning of the measuring device during nipple pressure measurement and / or
[0069] • Adjusting the position of the scraper
[0070] In this way, the user has a very versatile tool at hand, which simplifies a wide variety of maintenance and adjustment tasks on a shoe press. File: 28708 “Support strip” WO / PFW - 11 -
[0071] It is further proposed that a computer program product can be loaded directly into the internal memory of a computing unit or is stored on a medium and comprises software code sections with which the steps according to a method according to an aspect of the invention or further inventive idea are carried out when the product is running on a computing unit.
[0072] The computer program product can, in particular, be loaded into or be stored in the internal memory of a mobile device according to one aspect of the invention.
[0073] The invention will be explained below with the aid of figures. The figures show, in detail:
[0074] Figures 1a and 1b schematically show a shoe press in working position and in maintenance position.
[0075] Figure 2 shows a section of a process according to one aspect of the further inventive idea
[0076] Figure 3 shows a section of a process according to a further aspect of the further inventive idea
[0077] Figure 4 shows an embodiment according to the invention.
[0078] Figure 1a schematically shows a shoe press 1 in a working position 10. The shoe press 1 has a shoe roller 2 and a counter roller 3, which together form an extended press pin 4. The shoe roller 2 comprises a fixed yoke 6 and a press shoe 5, as well as a press sleeve 7, which is rotatably mounted about the fixed yoke 6 and the press shoe 5. The press shoe 5 is movable, so that at least the radial distance of the press shoe 5 from the counter roller 3 can be changed. Inside the shoe roller 2, support elements 13 in the form of support strips 13 are also provided, over which the press sleeve 7 is guided. Figure 1b shows the same shoe press 2 in a maintenance position 20, in which the shoe roller 2 and the counter roller 3 have a greater distance from each other than in the working position. File: 28708 “Support strip” WO / PFW - 12 -
[0079] 10. In this example, the transition from working position 10 to maintenance position 20 and back is achieved by a movement of the shoe roller 2, while the counter roller 3 remains stationary.
[0080] The internal components such as the press shoe 5 or the support elements 7 are not visible from the outside, as they are covered by the end cover of the shoe roller or the press jacket 7.
[0081] This situation is illustrated in Figure 2. Here, the press shoe 5 and its current operating state are not readily apparent. In the embodiment shown, at least one marker element 8 is attached to the outside of the shoe press 1, and this marker element 8 is captured during image and / or video recording.
[0082] The plan is to take an image and / or video recording of the exterior of the shoe press 1, in particular the counter roller 3, and to transmit the recording to a processing unit. In the example shown, the recording is made with a mobile phone or tablet, which can also additionally serve as the processing unit. Then, a current actual value for the operating state of the press shoe 5 is determined. This actual value includes, in particular, values relating to the position of the press shoe 5.
[0083] Finally, the position of the press shoe 5 is displayed as metadata 5a by superimposing it on the image and / or video recording on a display 9, whereby the press shoe 5a is displayed at the position it would occupy relative to the counter roller 3 in the working position 10 of the shoe press 1. Optionally, a database system can be provided, and the processing unit can access the database system to determine the position of the press shoe 5 or other metadata.
[0084] In the example shown in Figure 2, the position of the press shoe 5a in the circumferential direction and in the axial direction of the counter roller 3 is shown as a superimposition 5a on the live image. File: 28708 “Support strip” WO / PFW - 13 -
[0085] This represents the position upon which the press shoe 5 presses in working position 10. This essentially corresponds to the dimensions of the extended press nip 4.
[0086] Knowledge of the pressure profile in the press nip 4 is of great importance to the operator of a shoe press 1. Therefore, this profile is measured regularly. This measurement is usually carried out by positioning a measuring strip, a pressure-sensitive measuring film, or similar device on the counter roller 3 with the press open (maintenance position 20), and then determining the pressure profile with the press nip 4 closed in the working position 10.
[0087] The live image will show the current positioning of the measuring device, and the measuring device - e.g. the measuring film - can be brought very precisely to the position of the later press nip via the superimposed position 5a of the press shoe 5 in working position 10.
[0088] Precise positioning is particularly important because commercially available pressure-sensitive measuring films (e.g., "Prescale" from Fujifilm) have a width only slightly greater than the length of the press nip. If the operator mispositions the measuring film by just 1-2 cm, the pressure profile will be incompletely captured, and the measurement must be repeated. This is not only time-consuming but also costly, as the frequently used measuring films are quite expensive and can only be used once.
[0089] Figure 3 again shows the display 9 of a mobile device (phone / laptop) with an image and / or video recording of the exterior of the shoe press 1 in a maintenance position 20. A marker element 8 is also attached to this shoe press 1, which is captured during the image and / or video recording. For illustrative purposes, the marker element 8 is attached to the exterior of the shoe press. In this example, the radial distance of the press shoe 5 from the counter roller 3 is displayed as meta-information 5a on the display 9, which the press shoe 5 would assume relative to the counter roller 3 in the working position 10 of the shoe press 1. File: 28708 “Support strip” WO / PFW - 14 -
[0090] Furthermore, the metadata for the position of the press shoe 5a on the display 9 is designed to be virtually modifiable, and the processing unit is configured to determine a suggested setting 12 for the shoe press 1 that can be implemented. A slider 11 is shown as an example of a means 11 for this virtual modification in Figure 3. This slider 11 allows the displayed metadata for the press shoe position 5a to be changed by increasing or decreasing the radial distance of the (virtual) press shoe 5a to the (real) counter roller 3. The display 9 then shows a suggested setting 12 for how the center-to-center distance between the shoe press roller 2 and the counter roller 3 should be changed to implement this virtual change in reality. This suggested setting 12 can be given in absolute distance values, as shown in Figure 3.Alternatively or additionally, proposal 12 can also contain specific instructions for the necessary modification of the press (e.g., "insert 3 additional shimps").
[0091] Figure 4 shows an embodiment according to the invention. The focus here is less on the press shoe 5 than on the support strips 13 inside the shoe press roller 2. In this embodiment, an image and / or video recording of the exterior of the shoe press 1, in particular of the shoe press roller 2, is again created and this recording is transmitted to a processing unit. Subsequently, the position of at least one support strip 13 is determined and this position of the support element is displayed as metadata 13a on a display 9 by superimposing it with the image and / or video recording.
[0092] To optimally position a scraper 14, the operator sees the current position of the scraper 14 in the image, as well as the position of the support bar as meta-information 13a. The operator can easily position the scraper 14 so that it rests precisely on the press jacket 7 at the point supported by the support element 13. File: 28708 “Support bar” WO / PFW
[0093] - 15 -
[0094] Reference symbol list
[0095] 1 shoe press
[0096] 2 shoe roller
[0097] 3 Counter roller
[0098] 4 Pressnip
[0099] 5 Press shoe
[0100] 5a Press shoe in working position of the press (meta-information) 6 Yoke
[0101] 7 Pressed jacket
[0102] 8 Marker element
[0103] 9 Display
[0104] 10 work positions
[0105] 11 means of virtual modification / sliders
[0106] 12. Proposal for changing the axle spacing
[0107] 13 Support element; support strip
[0108] 13a Support element / support strip (Meta-information)
[0109] 14 scrapers
[0110] 20 Maintenance position
Claims
File: 28708 “Support strip” WO / PFW - 16 - Patent claims 1. Method for adjusting a shoe press (1) for a machine for producing a fibrous web, wherein the shoe press (1) comprises a shoe roller (2) and a counter roller (3) which together form an extended press nip (4), and wherein the shoe roller (2) has a stationary yoke (6) and a movable pressure shoe (5), as well as a press jacket (7) which is rotatably mounted about the stationary yoke (6) and the pressure shoe (5), and wherein a scraper (14) is further provided which can be applied to the outside of the shoe press roller (2), as well as a support element (13), e.g. a support strip (13), which is in contact with the press jacket (7) inside the shoe press roller (2), characterized in that the method comprises the following steps: A1 Image and / or video recording of the exterior of the shoe press (1), in particular the shoe press roller (2), and transmission of the recording to a processing unit. B1 Determining the position of the support element (13) C1 Representation of the position of the support element as meta-information (13a) by superimposing it on the image and / or video recording on a display (9) 2. The method according to claim 1, further comprising the step D1 Adjusting the position of the scraper (14) so that, during operation of the press (1), the scraper (14) rests against a point on the shoe press shell (7) which is supported by the support element (13).
3. Method for setting up a shoe press (1) for a machine for producing a fibrous web, wherein the shoe press (1) is a File: 28708 “Support strip” WO / PFW - 17 - The shoe press (1) comprises a shoe roller (2) and a counter roller (3) which together form an extended press pin (4), wherein the shoe roller (2) has a fixed yoke (6) and a movable press shoe (5), and the shoe roller (2) also has a press sleeve (7) which is rotatably mounted about the fixed yoke (6) and the press shoe (6), and wherein the shoe press (1) has a working position (10) and a maintenance position (20), wherein in the maintenance position (20) the shoe roller (2) and the counter roller (3) have a greater distance from each other than in the working position (10). characterized by the fact that the procedure comprises the following steps: a. Providing the shoe press (1) in the maintenance position (20) b. Taking an image and / or video recording of the exterior of the shoe press (1), in particular the counter roller (3) and transmitting the recording to a calculation unit. c. Determining a current actual value for the operating state of the press shoe (5). d. Representation of the position of the press shoe as meta-information (5a) by superimposing it on the image and / or video recording on a display (9), wherein the press shoe (5) is represented at the position it would occupy relative to the counter roller (3) in the working position (10) of the shoe press (1).
4. Method according to claim 1, characterized in that at least one marker element (8) is attached to the outside of the shoe press (1), wherein the marker element (8) is also captured during the image and / or video recording.
5. Method according to one of the preceding claims, characterized in that a database system is provided and the file: 28708 “Support strip” WO / PFW - 18 - The calculation unit accesses the database system to determine the position of the press shoe (5) or other meta-information.
6. Method according to one of the preceding claims, characterized in that the position (5a) of the press shoe (5) on the display can be changed virtually, and the calculation unit is configured to determine a suggestion for a setting of the shoe press (1) with which the virtual change can be realized.
7. Method according to claim 6, characterized in that the radial distance of the press shoe (5) from the counter roller (3) is virtually variable, and the calculation unit is configured to determine a proposal for changing the axial distance of the shoe press roller (2) and the counter roller (3).
8. Method according to one of the preceding claims, characterized in that a proposal for a planned setting of the shoe press (1) is transmitted to the calculation unit, and the position (5a) of the press shoe (5) is virtually changed on the display (9) in order to visualize the effect of the planned setting.
9. A method according to any of the preceding claims, distinguished in that the method comprises the steps e. Positioning a measuring device, in particular a measuring film, for determining a pressure profile in the press nip (4) 10. Mobile device, in particular mobile phone, tablet or smart glasses, comprising a display 9 and a processing unit, which is configured to perform one or preferably several methods according to one of the preceding claims, in particular Variation axle spacing and / or file: 28708 “Support strip” WO / PFW - 19 - • Positioning of the measuring device during nipple pressure measurement and / or • Adjusting the position of the scraper 11. Computer program product that can be directly loaded into the internal memory of a computing unit or is stored on a medium and comprises software code sections with which the steps according to one of the preceding claims are performed when the product is running on a computing unit.