Method for evaluating an aerosol-generating article having a susceptor element for manufacturing defects - Patents.com

Abstract

The present invention relates to a method for evaluating an aerosol-generating article having susceptor elements for manufacturing defects. The method includes providing an aerosol-generating article with a substrate section comprising an aerosol-forming substrate (24) and a susceptor element (26). The method further includes the method step of providing an intersection through the substrate section and the susceptor element. Another step includes evaluating the intersection for manufacturing defects by determining one or more of the location of the susceptor elements within the substrate section, the cross-sectional length of the susceptor elements, and the cross-sectional shape of the susceptor elements. To this end, in one embodiment, a visual image of the intersection is divided into a plurality of segments (34) to create an approximate perimeter (22) of the cross-section having the susceptor elements.

Description

[Technical field]

[0001] The present invention relates to a method for evaluating an aerosol-generating article having a susceptor element for manufacturing defects.

[0002] Aerosol-generating articles, particularly non-combustion heated articles, comprise an aerosol-forming substrate and in addition a substrate section that often includes a susceptor element. The susceptor element may be configured to heat the aerosol-forming substrate by induction heating. The arrangement of the susceptor element within the aerosol-forming substrate of the substrate section and the shape of the susceptor element may affect the ability of the susceptor element to heat the aerosol-forming substrate. A long rod including multiple aerosol-generating articles with a continuous susceptor band can be cut with a cutting device such as a rotary knife to produce individual single aerosol-generating articles including the susceptor element. The cutting process may displace and deform any of the susceptor elements located within the substrate section of the aerosol-generating article. Furthermore, when assembling the aerosol-forming article, there may be a misalignment of the susceptor band relative to the adjacent aerosol-forming substrate. This may displace the susceptor element within the substrate section. This may adversely affect the ability of the susceptor element to adequately heat the aerosol-forming substrate. The manufacturing process of the aerosol-generating articles and the cutting of long rods can be a fast process that does not allow for time-consuming detailed assessment of the correct placement and shape of the aerosol-generating article.

[0003] It would be desirable to provide a more accurate method for evaluating aerosol-generating articles having susceptor elements for manufacturing defects. Summary of the Invention

[0004] According to one embodiment of the present invention, there is provided a method for evaluating an aerosol-generating article having a susceptor element for manufacturing defects. The method may include providing a substrate section in the aerosol-generating article, the substrate section comprising an aerosol-forming substrate and a susceptor element. The method may further include providing an intersection through the substrate section and the susceptor element. Furthermore, the intersection may be evaluated for manufacturing defects by determining one or more of a positioning of the susceptor element within the substrate section, a cross-sectional length of the susceptor element, and a cross-sectional shape of the susceptor element.

[0005] In another embodiment of the invention, a method is provided for evaluating an aerosol-generating article having a susceptor element for manufacturing defects. The method includes providing a substrate section in the aerosol-generating article. The substrate section comprises an aerosol-forming substrate and a susceptor element. The method includes providing an intersection through the substrate section and the susceptor element. The intersection is evaluated for manufacturing defects by determining one or more of a positioning of the susceptor element within the substrate section, a cross-sectional length of the susceptor element, and a cross-sectional shape of the susceptor element.

[0006] Such methods may allow for detection of manufacturing defects relating to one or more of the placement of the susceptor elements within the substrate section, the cross-sectional length or shape of the susceptor elements.

[0007] A visual image of the intersection may be recorded and the image may be evaluated for manufacturing defects. Specifically, a digital visual image of the intersection may be recorded.

[0008] This may allow for more reliable processing of the image. The digital visual image may allow the digital image to be evaluated via algorithmic digital image processing.

[0009] A camera system may be employed to record images of the intersection. The camera system may be a digital camera system allowing to record digital images of the intersection.

[0010] Examples of camera systems that may be employed to record digital images of the intersection include Basler's acA1300-75gc camera system, the CA-HX048M camera system, or Teledyne Dalsa's Genie Nano camera system.

[0011] The camera system may include an illumination source. The illumination source may be configured to illuminate the intersection through the substrate section and the susceptor element. This may improve the quality of the image, particularly the digital image recorded by the camera system. The illumination source may include a lamp, including, for example, an LED.

[0012] The intensity variations within each segment may be detected to generate data points about the periphery of a cross-section of the susceptor element. The data points may be employed to reconstruct the cross-section of the susceptor element, preferably by fitting a cross-sectional shape through the data points of each segment.

[0013] The images, particularly the digital images, may be processed through digital imaging processing. The digital images may be processed through image approximation. Image approximation may involve processing the images through approximation algorithms that perform digital simplification on the recorded digital images of the intersections to speed up processing.

[0014] Processing via image approximation may include dividing the digital image into a number of sections. Each segment of the image may be processed separately via digital processing. The digital image may be divided into, for example, 20-50 segments. Specifically, the image may be divided into 36 segments for image processing. This may facilitate and speed up processing of the image via image approximation.

[0015] Processing through image approximation may include edge detection. Edge detection may involve detecting changes in intensity, specifically luminance intensity, within segments in the recorded image. Analysis of the luminance intensity of the image may involve detecting large changes in light and dark intensities when scanning a segment of the digital image. Large changes in light and dark intensities may indicate boundaries between objects and background. Intensity changes may be detected within a segment of the image when scanning from an outer part of the digital image towards the center of the image. Detecting these intensity changes provides one data point for each segment.

[0016] The data points may further be obtained via a blob analysis tool. Blob detection may involve detecting image points in an image that are roughly similar to one another, for example, with respect to the color or brightness of the image points. This may facilitate analysis of the approximate perimeter of one or both of the perimeter of the aerosol-generating article and the perimeter of the cross-section of the susceptor element.

[0017] The data points from the segments may be fitted, for example via a least squares method, to obtain the perimeter of the aerosol-generating article. This may indicate the outer peripheral boundary of the aerosol-generating article. Such segmented edge detection may allow for rapid imaging and approximate detection of the perimeter of the article. In particular, edge detection may allow for approximate detection of the perimeter of the aerosol-generating article and the outer boundaries of the aerosol-generating article. The perimeter of the article may be defined by tipping paper wrapped around the article.

[0018] Similarly, the perimeter of the cross-section of the susceptor element within the intersection of the article may be determined relative to the perimeter of the susceptor element within the aerosol-generating article, and in particular, the approximate perimeter of the cross-section of the susceptor element relative to the aerosol-forming substrate surrounding the susceptor element within the aerosol-generating article may be determined.

[0019] Image approximation via edge detection may enable detection of the approximate perimeter of the article and the approximate perimeter of the cross-section of the susceptor element. The approximate location of the approximate perimeter of the cross-section of the susceptor element within the approximate perimeter of the article may be determined. The approximate location may be performed by measuring the distance between the approximate perimeter of the cross-section of the susceptor element and the approximate perimeter of the cross-section of the aerosol-generating article.

[0020] Similarly, the approximate perimeter of the cross-section of the susceptor element may also provide the shape of the cross-section of the susceptor element within the intersection of the article. Similarly, the approximate length of the approximate perimeter of the cross-section of the susceptor element may be determined. The approximate length may be the longest dimension of the approximate perimeter of the cross-section of the susceptor element. For example, if the approximate perimeter has a rectangular shape, the longest dimension may be the length of the perimeter of the rectangle.

[0021] An approximate perimeter within the substrate section may be determined and compared to a reference range to obtain a first assessment result.

[0022] This may allow a reference range indicating the acceptable range of cross-sections of the susceptor elements within the article to be compared with the approximated actually determined cross-sections of the susceptor elements.

[0023] The reference range may include one or more of a reference location of a cross-section of a susceptor element within the aerosol-generating article, a reference shape of a cross-section of a susceptor element, and a reference length of a cross-section of a susceptor element.

[0024] This may allow one or more of the approximate peripheral configuration, shape or length of the susceptor element to be compared to respective reference ranges.

[0025] A method for evaluating an aerosol-generating article for manufacturing defects may include taking a reference configuration of a cross-section of a susceptor element within the aerosol-generating article, which may be compared to an approximate configuration of the susceptor element to obtain a first configuration evaluation result.

[0026] The reference arrangement may indicate an acceptable area within the intersection of the aerosol-generating article that may be occupied by a cross-section of a susceptor element. The cross-section of the susceptor element may have an elongated shape. The cross-section of the susceptor element may have a rectangular shape. The reference arrangement may define an area around the elongated or rectangular shape of the cross-section of the susceptor element as the acceptable area that may be occupied by the cross-section of the susceptor element. For example, the reference arrangement may define a rectangular acceptable area around a rectangular cross-section of the susceptor element. Similarly, the reference arrangement may define an elongated acceptable area around an elongated cross-section of the susceptor element.

[0027] For example, for an aerosol-generating article having an intersection with a diameter between 7.0 and 7.2 millimeters, the acceptable area for a rectangular cross-section of the susceptor element may be within a rectangular area having a length on the order of 6 millimeters and a width on the order of 6 millimeters, with the actual cross-sectional dimensions of the susceptor element being on the order of 3.5 to 4.5 millimeters in length and 0.04 to 0.08 millimeters in width.

[0028] The acceptable area in which the cross-sections of the susceptor elements may be located may also be defined as all areas within the intersection of the article that are at least a predetermined distance from the outer periphery of the article. For example, for a tobacco rod having a diameter between 7.0 and 7.2 millimeters, the susceptor elements may be located within all areas within the intersection of the aerosol-generating article that are at least 1 millimeter from the outer periphery of the article.

[0029] A method for evaluating an aerosol-generating article for manufacturing defects may include taking a reference shape of a cross-section of a susceptor element, which may be compared to an approximate perimeter of the cross-section of the susceptor element to obtain a first shape evaluation result.

[0030] The nominal shape of the cross section of the susceptor element may define a maximum allowable bending of the cross section of the susceptor element. The maximum allowable bending of the cross section of the susceptor element may define an area that can be occupied by the shape of the cross section of the susceptor element. For a susceptor element having a rectangular cross section with a length and width of the order of 4 millimeters to 0.6 millimeters, the allowable bending may be at most 0.9 millimeters. In this case, a nominal area of ​​a shape with a width of at most 0.9 millimeters may be defined around the susceptor element.

[0031] A method for evaluating an aerosol-generating article for manufacturing defects may include taking a reference length of a cross-section of a susceptor element, which may be compared to an approximate cross-section length of the susceptor element to thereby obtain a first length evaluation.

[0032] The cross-sectional length of the susceptor element may be allowed to vary by up to 20 percent of the length of the susceptor, and preferably by up to 10 percent of the length of the susceptor.

[0033] The first evaluation result may be obtained during manufacture of the aerosol-generating article. Preferably, a manufacturing apparatus is used to manufacture the aerosol-generating article, and the manufacturing apparatus may be employed to obtain the first evaluation result.

[0034] By obtaining a first evaluation result via an approximation procedure, a quick and easy calculation method can be realized to evaluate manufacturing defects related to one or more of the positioning of the substrate section within the aerosol-generating article, the shape of the susceptor element, and the length of the susceptor element.

[0035] For example, a HAUNI CLT crimping machine, an ITM multi-segment filter combiner, or a GD cigarette making machine can be used to manufacture the aerosol-generating article. All of these manufacturing devices have operating systems for running the machines during the manufacturing process. Each of the above method steps for obtaining a first evaluation result can be rapidly performed by an approximation procedure used for digital processing of an image of the intersection of the aerosol-generating article.

[0036] This "in-line" analysis during the manufacturing process allows a rough approximation of the perimeter of the cross section of the susceptor element to be achieved. This is made possible in particular by analyzing each segment of the digital image as described above. The method for manufacturing aerosol-generating articles is a high-speed process that produces a high production volume of aerosol-generating articles per unit time. This high-speed process therefore does not allow for time-consuming, more detailed image processing of the images of the intersections of the aerosol-generating articles produced during the manufacturing process.

[0037] The method for evaluating an aerosol-generating article having a susceptor element for manufacturing defects may also include determining an enhanced perimeter of a cross-section of the susceptor element. The visual image may include a plurality of image points. The perimeter of the cross-section of the susceptor element may be determined by analyzing at least 70%, preferably at least 90%, and most preferably at least all of the image points of the visual image. This may produce an enhanced perimeter of the cross-section of the susceptor element in the visual image recorded during the manufacturing process.

[0038] The precision of the refined perimeter of the cross-section of the susceptor element may be greater than the precision of the approximate perimeter of the cross-section of the susceptor element determined via the approximation procedure described above.

[0039] The refined perimeter of the susceptor element within the substrate intersection may be compared to a reference range to obtain a second evaluation result.

[0040] The second evaluation result may be more accurate than the first evaluation result because the second evaluation result employs a refined perimeter of the susceptor element, while the first evaluation result uses an approximate perimeter of the cross-section of the susceptor element.

[0041] The second evaluation result may be obtained using a computer system. The computer system may be separate from the manufacturing device for manufacturing the aerosol-generating article. Thus, the second evaluation procedure for obtaining the second evaluation result may also be referred to as an "offline" evaluation. The computer system may determine the refined perimeter of the cross-section of the susceptor element with a longer calculation time compared to the manufacturing device for the aerosol-generating article employed to determine the approximate perimeter of the cross-section of the susceptor element. The refined perimeter of the cross-section of the susceptor element at the intersection of the aerosol-generating article may be determined using special image processing software such as Vision Pro® QuickBuild Setup Cognex Designer.

[0042] Determining the refined perimeter of the cross section of the susceptor element in the visual image of the intersection of the aerosol-generating article may also include edge detection. Edge detection may involve detecting changes in intensity, specifically luminance intensity, of image points in the recorded visual image. Analyzing the luminance intensity of each pixel of the image may include detecting a large change in light-dark luminance between adjacent image points. A large change in light-dark intensity between adjacent pixels may indicate a boundary between the object and the background. Performing edge detection on at least 70 percent, preferably at least 90 percent, and most preferably all of the image points of the visual image allows for a more accurate determination of the refined perimeter of the cross section of the susceptor element. Similarly, performing edge detection on at least 70 percent, preferably at least 90 percent, and most preferably all of the image points of the visual image allows for a more accurate determination of the refined perimeter of the cross section of the aerosol-generating article. The perimeter of the article may be defined by a tipping paper wrapped around the article. Similarly, the perimeter of a cross-section of a susceptor element may be determined relative to the perimeter of the susceptor element within the aerosol-generating article. In particular, a refined perimeter of a cross-section of the susceptor element may be determined relative to an aerosol-forming substrate surrounding the susceptor element within the aerosol-generating article.

[0043] Edge detection allows for detection of the refined perimeter of the article and the refined perimeter of the cross-section of the susceptor element. An refined location of the refined perimeter of the cross-section of the susceptor element within the refined perimeter of the article may be determined. The refined location may be performed by measuring the distance between the refined perimeter of the cross-section of the susceptor element and the refined perimeter of the cross-section of the aerosol-generating article.

[0044] The refined perimeter of the aerosol-generating article and the refined perimeter of the cross-section of the susceptor element may be employed to determine one or more of a refined position of the cross-section of the susceptor element within the aerosol-generating article, a refined shape of the cross-section of the susceptor element, and a refined length of the cross-section of the susceptor element.

[0045] One or more of the refined cross-sectional position of the susceptor element within the aerosol-generating article, the refined cross-sectional shape of the susceptor element, and the refined cross-sectional length of the susceptor element can be compared to the same reference ranges as the respective approximate parameters.

[0046] Thus, a method for evaluating an aerosol-generating article for manufacturing defects may also include taking a reference configuration of a cross-section of a susceptor element within the aerosol-generating article, which may be compared to the refined configuration of the susceptor element to obtain a second configuration evaluation result.

[0047] A method for evaluating an aerosol-generating article for manufacturing defects may include taking a reference shape of a cross-section of a susceptor element, which may be compared to a refined periphery of the cross-section of the susceptor element to obtain a second shape evaluation result.

[0048] A method for evaluating an aerosol-generating article for manufacturing defects may include taking a reference length of a cross-section of a susceptor element, which may be compared to a refined length of the cross-section of the susceptor element to obtain a second length evaluation.

[0049] For any aerosol-generating article, if one or more of the approximate position of the cross-section of the susceptor element, the approximate shape of the cross-section of the susceptor element, and the approximate length of the cross-section of the susceptor element within the aerosol-generating article are entirely within their respective reference ranges, then either of the first evaluation results is passed.

[0050] Similarly, for any aerosol-generating article, if one or more of the approximate location of the cross-section of the susceptor element within the aerosol-generating article, the approximate shape of the cross-section of the susceptor element, and the approximate length of the cross-section of the susceptor element can be at least partially outside the respective reference ranges, any of the first evaluation results will be unsatisfactory.

[0051] The substrate section of the aerosol-generating article having the susceptor element may be covered with a wrapper. A first positioning assessment result may be obtained by determining the distance between the wrapper and an approximate periphery of a cross section of the susceptor element. The distance may be determined by determining the distance between a portion of the approximate periphery closest to the wrapper. In particular, an upper end of the approximate periphery of the susceptor element may be the portion closest to the wrapper.

[0052] Similarly, a second positioning assessment result may be obtained by determining the distance between the wrapper and the refined periphery of the susceptor element, which may also be determined by determining the distance between the refined periphery and a portion of the wrapper that is closest to the wrapper.

[0053] When the reference placement range is a predetermined minimum distance between the wrapper of the base section of the article and the cross-section of the susceptor element, it may be particularly advantageous to determine the first placement evaluation result and the second placement evaluation result in the manner described above.

[0054] Additionally, an aerosol-generating article may be rejected if any portion of the approximate perimeter deviates from the reference placement range by more than 10 percent, or if any portion of the refined perimeter deviates from the reference placement range by more than 10 percent.

[0055] Aerosol-generating articles that are determined to be unacceptable may be discarded after manufacture.

[0056] During the manufacture of the aerosol-generating article, the first evaluation result, specifically one or more of the first placement evaluation result, the first shape evaluation result, and the first length evaluation result, may be determined continuously.

[0057] If the aerosol-generating article is detected as having susceptor elements that fail the first evaluation, the location of the susceptor band within the aerosol-forming substrate may be altered during the manufacturing process, thereby altering the location of the susceptor elements within the aerosol-generating article to reposition the susceptor elements within an acceptable range of location.

[0058] Similarly, the force or momentum of any cutting device, such as a rotating knife, may be varied to change one or both of the deformation of the susceptor element and the shape of the susceptor element within the aerosol-generating article. Similarly, the length of the susceptor element within the aerosol-generating article may be varied. This may change one or more of the shape and length of the susceptor element within the aerosol-generating article to allow repositioning of the susceptor element within acceptable standard ranges of shape and length.

[0059] The second evaluation result may be more accurate than the first evaluation result. This may be due to the approximate perimeter of the cross section of the susceptor element determined during the first evaluation employing fewer data points than the refined perimeter determined during the second evaluation. Thus, the second evaluation result may be employed to correct the first evaluation result. In particular, the second evaluation result may be used to confirm or refute the first evaluation result. The second evaluation result may be determined at a shorter time interval than the first evaluation result.

[0060] For example, the first assessment may be performed continuously throughout the manufacturing process of the aerosol-generating article, and the second assessment may be performed monthly or every six months.

[0061] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing one or more volatile compounds capable of forming an aerosol. Such volatile compounds may be released by heating the aerosol-forming substrate. The aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoking article.

[0062] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may include both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material that contains volatile tobacco flavor compounds that are released from the substrate upon heating. The aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may include an aerosol former that facilitates the formation of a dense and stable aerosol. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols such as triethylene glycol, 1,3-butanediol, glycerin, esters of polyhydric alcohols such as glycerol monoacetate, diacetate, or triacetate, and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate, dimethyl tetradecanedioate. The aerosol former may be a polyhydric alcohol or a mixture thereof, such as triethylene glycol, 1,3-butanediol, and glycerin. The aerosol former may be propylene glycol. The aerosol former may include both glycerin and propylene glycol.

[0063] The susceptor element may have an elongated, flat shape. In particular, the susceptor element may comprise a band having opposing ends. The susceptor element may have a width and a length. The length to width ratio of an individual susceptor element may be between 1.5 and 4.5, preferably between 1.8 and 3.5, more preferably between 1.9 and 2.5. In an embodiment, the length of the susceptor element may be between 9 mm and 12 mm, the width may be between 3 mm and 6 mm, preferably the length may be between 10 and 12 mm, and the width may be between 4 and 5 mm. The length of the substrate section may be between 10 and 15 mm, preferably 12 mm.

[0064] Generally, the susceptor element includes or is made of a material that can generate heat when an alternating magnetic field penetrates it. If the susceptor element is conductive, typically eddy currents are induced by the alternating magnetic field. If the susceptor element is magnetic, typically another effect that contributes to heating is generally called hysteresis loss. Hysteresis loss occurs mainly due to the movement of magnetic domain blocks in the material of the susceptor element. This is because their magnetic field orientation aligns with the alternating magnetic induction field. Another effect that contributes to hysteresis loss is when magnetic domains expand or contract in the material of the susceptor element. Generally, all these changes that occur in the material of the susceptor element at nanoscale or below generate heat in the material of the susceptor element, and are therefore called "hysteresis loss". Thus, if the susceptor is both magnetic and conductive, both hysteresis loss and the generation of eddy currents will contribute to the heating of the susceptor element. If the material of the susceptor element is magnetic but not conductive, hysteresis losses will be the only means by which the susceptor element will heat up when penetrated by an alternating magnetic field. According to the present invention, the material of the susceptor element may be both magnetic and conductive.

[0065] The susceptor material may for example comprise a ferromagnetic material. Preferably, the susceptor material may comprise a ferromagnetic alloy. More preferably, the susceptor material may comprise ferritic iron, in particular ferromagnetic steel, or stainless steel.

[0066] A susceptor element comprising a susceptor material may heat an aerosol-forming substrate surrounding the susceptor element.

[0067] The step of providing the intersections through the substrate sections and susceptor elements may be performed by cutting a continuous rod into individual aerosol-generating articles with a cutting device. Alternatively, an aerosol-generating article may be cut within its substrate section to provide the intersections. A rotating knife may be employed as the cutting device.

[0068] Features described with respect to one embodiment may be equally applied to other embodiments of the invention.

[0069] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0070] [Figure 1] FIG. 1 shows a flow chart of one embodiment of a method for performing an assessment on manufacturing defects according to the present invention. [Diagram 2] FIG. 2 shows the intersection of an article having susceptor elements and the reference range for the placement of the susceptor elements. [Diagram 3] FIG. 3 illustrates another scope for the placement of cross-sections of susceptor elements within an intersection of an aerosol-generating article. [Figure 4] FIG. 4 shows an intersection of an aerosol-generating article having a cross-sectional periphery of a susceptor element obtainable through either the refinement procedures or approximations disclosed herein. [Diagram 5] FIG. 5 illustrates the parameter ranges for the cross-sectional shape of the susceptor elements within the intersection of the article. [Figure 6] FIG. 6 shows a comparison of the nominal location and shape regions with the actually determined positions and shapes of the cross sections of the susceptor elements. [Figure 7] FIG. 7 shows an example of an approximation procedure for dividing a visual image into segments to obtain the outer perimeter of an aerosol-generating article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] In the following, like elements are designated by like reference numerals throughout the figures.

[0072] FIG. 1 illustrates a flow chart of one embodiment of a method for evaluating an aerosol-generating article having susceptor elements for manufacturing defects according to the present invention. The method employs criteria ranges 10, as indicated by the box labeled "Product Specification Settings." The criteria ranges 10 include acceptable criteria ranges for one or more of the cross-sectional arrangement, shape, and length of the susceptor elements within the aerosol-generating article. The camera system of the manufacturing equipment can record a visual image of the intersection of the aerosol-generating article having a susceptor, as indicated by the box labeled "IPC Image" 18. The camera may be the manufacturing equipment's camera, and therefore an "internal process camera (IPC)." The manufacturing equipment initiates its own analysis of the visual image based on the manufacturing equipment's operating software, as indicated by the box labeled "In-line Image Analysis" 20. This "in-line image analysis" allows checking the visual image, shown in box 16, to evaluate whether the metal susceptor (MS) is correctly positioned within the reference range in the aerosol-generating article, as shown in box 14, labeled "MS Centered or Not." This results in a first evaluation result of the manufacturing device. For the first evaluation result, an approximation algorithm is employed to quickly evaluate the placement of the susceptor elements in the aerosol-generating article. Furthermore, the computer system employs a more detailed image processing procedure on the recorded visual image. This can be achieved by an image processing procedure that covers all image points of the visual image. This can provide a more refined and more accurate image processing of the visual image compared to the first evaluation result. This provides further input for the image analysis and evaluation of the correct placement of the susceptor elements, as indicated by the arrow labeled "offline software input" in the flow chart.

[0073] FIG. 2 shows a schematic of an intersection 30 of an aerosol-generating article. The intersection 30 shows the outer periphery 22 of the aerosol-generating article, which may include a wrapper. The wrapper is wrapped around an aerosol-forming substrate 24. The aerosol-forming substrate 24 is outside the acceptable standard range for the placement of the cross-section of the susceptor element, as shown by the box line 28. The optimally placed cross-section 26 of the susceptor element is entirely within the acceptable standard range 28. The cross-section of the aerosol-generating article may have an overall dimension of 7.05 (±0.15) millimeters in diameter. The susceptor cross-section 26 may have a length of 4 (±0.15) millimeters and a width of 0.06 (±0.005) millimeters. X and y coordinates are shown in FIG. 2. The acceptable standard range shown by region 28 allows for an optimally positioned cross section of a susceptor element to be positioned within a region of ±3 millimeters of the x coordinate of the optimally positioned susceptor element, and within a region of ±1 millimeter of the y coordinate of the optimally positioned susceptor element.

[0074] 3 illustrates an alternative reference area for the placement of cross-sections of susceptor elements within an intersection of an aerosol-generating article. Reference area 28 includes the entire intersection of the aerosol-generating article that is spaced at least a predetermined distance from the outer periphery 22 of the article. In this case, reference area 28 may include the entire area of ​​intersection 30 of the aerosol-generating article that is spaced at least 1 millimeter from the outer periphery 22.

[0075] 4 shows the perimeter of a cross-section of a susceptor element that has been approximated or refined as described herein. The actual cross-section of the susceptor element is indicated by reference numeral 26, and dashed line 27 shows the perimeter of the cross-section of the susceptor element as determined via image processing. Evaluating the location of the perimeter 27 of the susceptor element within the intersection 30 of the aerosol-generating article may include determining a distance 29 from an end of the perimeter of the susceptor element to the outer perimeter 22 of the aerosol-generating article.

[0076] FIG. 5 shows the nominal range of shapes of susceptor elements. The left part of FIG. 5 shows different shapes 26A-26C of the cross-section of the susceptor element. The shape 26A of the cross-section of the susceptor element perfectly fits the allowable nominal range 32 and lies in the center of this range. In contrast, shapes 26B and 26C have one and two bends in the susceptor, respectively. Nevertheless, as shown in the left part of FIG. 5, both shapes 26B and 26C are within the allowable nominal range 32. In particular, the allowable nominal range 32 allows the plane of the cross-section of the susceptor element to bend up to ±0.9 millimeters relative to the plane of a perfectly fitting susceptor element having the shape 26A. The right part of FIG. 5 shows the intersection 30 together with the cross-section 26 of the susceptor element.

[0077] 6 shows a comparison of the cross section 26 of the susceptor element within the intersection 30 of the aerosol-generating article with the reference placement range 28 and the reference shape range indicated by the dashed line 32. It can be seen that the cross section 26 of the susceptor element is entirely located within the reference placement range 28. Therefore, the actually determined cross section 26 of the susceptor element can pass the evaluation for the placement of the susceptor element. However, as indicated by the dashed box 32, the highly curved cross section 26 of the susceptor element is partially located outside the acceptable reference range 32 for the shape of the susceptor element. As a result, the aerosol-generating article cannot pass the evaluation test for the acceptable shape of the susceptor element within the intersection 30.

[0078] FIG. 7 shows an example of image processing by approximation. A visual image of an intersection 30 of an aerosol-generating article is shown, the outer periphery 22 of which is made of a wrapping paper. In this example, the approximate outer periphery of the article is determined by dividing the visual image into segments 34. Each segment is then scanned from the periphery of the image to the center of the visual image to obtain the change in brightness of the segment. The change in brightness of the segment may indicate the boundary of an object, in this example the outer periphery of the aerosol-generating article. For each segment 34 where such an abrupt change in brightness can be detected, one image point 34A is generated at the location of the change in brightness. An approximate periphery, which is the outer periphery 22 of the aerosol-generating article, is then generated by fitting a curve through these various image points 34A, for example by a least squares method.

Claims

1. 1. A method for evaluating an aerosol-generating article having a susceptor element for manufacturing defects, comprising: - providing an aerosol-generating article with a substrate section, said substrate section comprising an aerosol-forming substrate and a susceptor element; - providing an intersection through said substrate section and said susceptor element; by determining one or more of the location of the susceptor elements within the substrate section, the cross-sectional length of the susceptor elements, and the cross-sectional shape of the susceptor elements; - evaluating said intersections for manufacturing defects.

2. The method of claim 1 , wherein a visual image of the intersection is recorded and the image is evaluated for the manufacturing defects.

3. The method of claim 2 , wherein a camera system is employed to record images of the intersection.

4. The method of claim 2 or 3, wherein the visual image is divided into a plurality of segments and the perimeter of the cross-section of the susceptor element is approximated by analyzing the segments in the visual image, thereby creating an approximate perimeter of the cross-section of the susceptor element.

5. 5. The method of claim 4, wherein detecting brightness changes within the segment creates data points around the periphery of the cross-section of the susceptor element, and the data points are employed to reconstruct the cross-section of the susceptor element, preferably by fitting a cross-sectional shape through the data points of the segment.

6. The method of claim 5 , wherein the approximate perimeter within the substrate section is determined and compared to a reference range, thereby obtaining a first assessment result.

7. the reference range includes one or more of a reference location of the cross section of the susceptor element within the aerosol-generating article, a reference shape of the cross section of the susceptor element, and a reference length of the cross section of the susceptor element; comparing the reference location of the cross-section of the susceptor element within the aerosol-generating article with the approximate peripheral location of the cross-section of the susceptor element to obtain a first location assessment; comparing the reference shape of the cross-section of the susceptor element with the approximate peripheral shape of the cross-section of the susceptor element to obtain a first shape evaluation result; 7. The method of claim 6, wherein one or more of the method steps of: comparing the reference length of the cross-section of the susceptor element to the approximate perimeter length of the cross-section of the susceptor element to obtain a first length evaluation result are preformed.

8. A method according to any of claims 6 or 7, wherein the first evaluation result is obtained during the manufacture of the aerosol-generating article, preferably wherein a manufacturing device is used in the manufacture of the aerosol-generating article, and the manufacturing device is employed to obtain the first evaluation result.

9. A method according to any one of claims 4 to 8, wherein the perimeter of the cross-section of the susceptor element is determined by analyzing at least 70 percent, preferably at least 90 percent, and most preferably all, of the image points of the visual image by fitting a cross-sectional shape through the image points, thereby creating an improved perimeter of the cross-section of the susceptor element.

10. The method of claims 6 and 9, wherein the refined perimeter of the substrate section is compared to the reference range, thereby obtaining a second assessment result.

11. The method of claim 10 , wherein the second evaluation result is obtained using a computer system, preferably the computer system being separate from the manufacturing apparatus for manufacturing the aerosol-generating article.

12. - if any portion of the approximate perimeter deviates from the reference configuration by more than 10 percent; or A method according to claim 6 or 10, wherein the aerosol-generating article is rejected if any portion of the refined periphery deviates from the reference configuration by more than 10 percent.

13. the substrate section is covered with a wrapper; - the first position assessment result is obtained by determining the distance between the wrapper and the approximate perimeter, or The method according to claim 6 or 10, wherein the second positioning assessment result is obtained by determining the distance between the wrapper and the refined periphery.

14. The method according to claims 6 and 10, wherein the second evaluation result is employed to correct the first evaluation result.

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