Closed loop system and method for controlling position of susceptor in aerosol-generating article

Abstract

A closed loop system for controlling the position of a susceptor in an aerosol-generating article, the system includes a supply source for a continuous sheet material, a supply source for a continuous susceptor, a crimping device for crimping the continuous sheet material, a forming device for gathering the continuous sheet material and for forming the continuous sheet material with an inserted continuous susceptor into a continuous strip. The system further comprises a cutting device for cutting the continuous strip into aerosol-generating articles; and a control unit comprising an output control for detecting a condition of a susceptor in the aerosol-generating article and for comparing the detected condition to a quality specification. The system further comprises a positioning device for manipulating the position of the continuous susceptor, or a curl depth adjuster, where the control unit is adapted to trigger the positioning device to adjust the position of the continuous susceptor when the detected condition does not conform to the quality specification, or to adjust the curl depth of the continuous susceptor when the detected condition does not conform to the quality specification. Or is adapted to trigger the curl depth adjuster to adjust the curl depth of the sheet material in the curl device.

Description

Technical Field

[0001] The present disclosure relates to a closed-loop system and method for controlling the position of a susceptor in an aerosol-generating article, in particular a strip-shaped aerosol-generating article. In particular, the present disclosure relates to such a system and method in the manufacturing process of an aerosol-generating article. Background Art

[0002] For inductively heated tobacco consumables, inductively heatable susceptors must be provided in the aerosol-forming matrix. The susceptors should be distributed in the center of the strip product and should not be damaged or deformed. The location and integrity of the susceptors in the consumables may change the heating efficiency, temperature distribution, or may cause inconsistent performance of the consumables. Waste reduction can also be achieved by improving the quality of manufactured consumables. Summary of the invention

[0003] Therefore, there is a need for a system and method for manufacturing aerosol-generating articles that allows for consistent positioning of susceptors in aerosol-generating articles, particularly at high production volumes.

[0004] According to one aspect of the present invention, there is provided a closed-loop system for controlling the position of a susceptor in an aerosol-generating article. The system comprises:

[0005] for a supply source of continuous sheet material;

[0006] Supply source for continuous receptors;

[0007] a curling device for curling the continuous sheet material;

[0008] a forming device for gathering the continuous sheet material and for forming the continuous sheet material with the inserted continuous susceptor into a continuous strip;

[0009] cutting means for cutting the continuous strip into aerosol-generating articles;

[0010] A control unit comprising an output control for detecting a condition of a susceptor in the aerosol generating article and for comparing the detected condition with a quality specification. The system further comprises a positioning device for manipulating the position of the continuous susceptor. The control unit is adapted to trigger the positioning device to adjust the position of the continuous susceptor or to trigger the crimp depth adjuster to adjust the crimp depth of the sheet material in the crimping device when the detected condition does not meet the quality specification.

[0011] The closed-loop system according to the invention preferably measures the condition of the susceptor in the manufactured aerosol-generating article in real time. This information is used to adjust production parameters to keep the susceptor in a predetermined position in the manufactured article. Preferably, the predetermined position of the susceptor corresponds to a central position in the article.

[0012] The adjustable production parameter is the positioning of the continuous susceptor when it is inserted into the continuous sheet material when it is in strip formation, or it is the adjustment of the crimp depth of the continuous sheet material. The adjustable production parameter may be both the positioning of the continuous susceptor when it is inserted into the continuous sheet material when it is in strip formation, and the adjustment of the crimp depth of the continuous sheet material.

[0013] Thus, at least one, preferably several, physical characteristics of the produced article are measured or determined and used to adjust other production parameters to maintain the susceptor in the predetermined position.

[0014] The output control can detect, for example, the absolute position of a sensor in the product. For example, the output control can detect the displacement of the sensor away from the center of the product and in the circumferential direction of the strip product. The output control can also detect the form of the sensor, for example, if the sensor has a deformed (e.g., bent) shape. These parameters must be within a certain predetermined threshold in order to be acceptable and accepted by the output control or in the control unit, respectively. If the predetermined threshold is exceeded, it is detected that the product does not meet the predetermined quality specifications. Depending on the acceptable deviation from the threshold, such as the percentage of products exceeding the predetermined threshold, an adjustment signal can be given to the positioning unit or the curling depth adjuster, and the position of the sensor can be adjusted. Alternatively, if the threshold is exceeded, the product can be rejected as waste.

[0015] Preferably, the output control includes a reject system that rejects defective articles including susceptor conditions that do not meet at least minimum quality specifications.

[0016] Preferably, the output control is adapted to reject the aerosol-generating article as waste when the detected receptor condition exceeds a predetermined waste threshold.Thus, the waste threshold may correspond to a minimum quality specification that must be met in order for the article to be acceptable.

[0017] The detected condition of the aerosol-generating article may include any one or more of the following: the position of the susceptor in the aerosol-generating article, the form of the susceptor in the aerosol-generating article, the eccentricity of the susceptor in the aerosol-generating article, or the shape of the accumulation of sheet material around the susceptor. An absolute displacement of the susceptor from the center of the article to a more radial position in the strip, a deformation of the susceptor (particularly a deformation of the cross-section of the susceptor or a bending of the susceptor strip), or an uneven distribution of the accumulated sheet material around the susceptor may result in uneven heating of the aerosol-forming substrate of the article.

[0018] Hence, the output control is preferably adapted to capture information of a cross-section of the aerosol-generating article.

[0019] Preferably, the output control is adapted to capture information of a cross-section of at least one end of the aerosol-generating article.The output control may also be adapted to capture information of a cross-section of both ends of the aerosol-generating article.

[0020] To detect the condition of the susceptor in the article, the output control may include any detection system suitable for capturing information about the condition of the susceptor in the article, in particular the position of the susceptor in the article (e.g., about a cross section of the susceptor in the article). The output control may include, for example, an optical system, an infrared system, an X-ray system, or an inductive detection system.

[0021] Preferably, the output control comprises one or several cameras.

[0022] The output control may include a detection system to determine the orientation of the susceptor in the article for positioning the article to be controlled by the output control in a defined control position. When determining the condition of the susceptor in the article, information about the orientation of the susceptor in the article can be used as a correction factor in the output control. Alternatively, information about the orientation of the susceptor can be used to align the article, for example, before capturing information about a cross section of an end of the article.

[0023] For example, a visual system can detect the overlap of packaging materials that wrap a strip-shaped aerosol-generating product. During the manufacture of a continuous strip of an aerosol-forming substrate containing a continuous susceptor, the mutual position of the continuous packaging material relative to its contents remains substantially constant. Therefore, by visually detecting the overlap, rough information about the position of the susceptor in the product can be obtained. This can be used to adapt the detection system to the orientation of the susceptor in the product to perform output control. The orientation of the susceptor in the product can also be obtained by other means, such as by inductive means, infrared means or similar means. Therefore, the closed-loop system, in particular the control unit, may include a product rotation device for rotating the products so that they are preferably all aligned in the same orientation to pass through the output control.

[0024] In addition, a position of the susceptor (or in particular of the susceptor strip) that is defined and consistent for all articles may be advantageous or even mandatory for articles that have to be cut or otherwise processed (e.g. assembled with other segments), where a specific mutual relative position of the susceptor strip to the other segments is desired or mandatory. It has been found that a random orientation of the susceptor strip in an article may lead to irregular cuts, deformation of the susceptor, or even a shortened life of the cutting blade. It has been found that the relative position of the susceptor strip with respect to the cutting blade has a significant influence on the cutting quality.

[0025] Thus, the defined position of the article corresponds to an optimized cutting angle of the susceptor strip relative to the cutting device.It may therefore be beneficial to provide an optimized rotational positioning of the article for output control (and before cutting or otherwise further processing the article).

[0026] As described above, the position of the continuous susceptor in the sheet material can be adjusted by the positioning device or by the curling depth adjuster. In some embodiments of the closed loop system, the system comprises a positioning device and a curling depth adjuster. Therefore, in these embodiments, if the detected condition does not meet the quality specification, the control unit is adapted to trigger the positioning device to adjust the position of the continuous susceptor and to trigger the curling depth adjuster to adjust the curling depth of the sheet material in the curling device.

[0027] The closed loop system may include a positioning device that directly manipulates the position of the continuous susceptor as it is combined with the continuous sheet material. For example, the position of the continuous susceptor may be adjusted as the continuous susceptor is inserted into the partially gathered sheet material. Preferably, the insertion and positioning of the continuous susceptor occurs in the forming device simultaneously with or upstream of the strip forming process.

[0028] Preferably, the continuous susceptor is guided by a positioning device. Preferably, the position of the continuous susceptor is adjusted by moving the positioning device.

[0029] The positioning device may be movably arranged to be movable in at least two directions perpendicular to each other, for example along an x-axis and a y-axis.

[0030] Preferably, the positioning device is movable relative to the supply direction of the continuous susceptor. Thus, the x-axis may correspond to the conveying direction of the continuous material along the production line. This allows changing the insertion position of the continuous susceptor into the partially gathered sheet material. Adjusting the position of the continuous susceptor insertion into the sheet material may result in the continuous susceptor being inserted into a more densely or less densely gathered sheet material at a further upstream or downstream position along the strip forming process. Thereby, the insertion depth into the sheet material may be adjusted or the insertion resistance may be reduced. By reducing the insertion resistance, the risk of damage to the continuous susceptor when inserted into the sheet material may also be reduced.

[0031] Preferably, the positioning device is movable in three directions perpendicular to each other. This allows the position of the continuous susceptor to be adjusted in all three dimensions.

[0032] For combined strip formation and adjustment of the position of the continuous susceptor, preferably a forming device and a positioning device are combined.

[0033] Preferably, the positioning device is movably arranged in the forming device.

[0034] The positioning device may further include a rotating device for rotating the continuous susceptor in a longitudinal direction of the continuous susceptor.

[0035] Preferably, the positioning device is rotatable and thereby rotates the continuous susceptor. For example, the positioning device may include an opening through which the continuous susceptor passes. The shape of the opening of the positioning device may correspond to the shape of the cross-section of the continuous susceptor. When the positioning device is rotated or laterally displaced, the continuous susceptor automatically follows the movement of the positioning device.

[0036] Preferably, the positioning device has a conical shape.

[0037] Preferably, the shaping means has a conical shape, for example embodied as a garniture tongue.

[0038] Preferably, the positioning device is arranged in a cone of the shaping device.

[0039] In order to simplify the insertion of the continuous susceptor in the sheet material or to reduce the insertion resistance, the forming device may comprise a channel former for forming a channel in the partially gathered continuous sheet material. The continuous susceptor may then be inserted into the channel.

[0040] The curling device can provide various types of curling for the sheet material. The preferred curling extends in the longitudinal or transverse direction of the curled sheet material. Since the curling of the sheet material is usually used to support the later gathering of the sheet material, the sheet material is preferably curled in the longitudinal or conveying direction.

[0041] Preferably, the curling device is adapted to provide the continuous sheet material with a longitudinally extending curl. The longitudinally extending curl is arranged along the conveying direction of the sheet material. A further downstream arranged gathering process which gathers the flat sheet material mainly from two lateral sides can be carried out along the curl and produces a more distinct gathering and correspondingly a uniformly gathered strip.

[0042] The crimping device may comprise two interacting crimping elements. The crimping elements are arranged to allow the continuous sheet material to pass between the two interacting crimping elements, thereby crimping the continuous sheet material.

[0043] Preferably, the curl depth adjuster is adapted to change the distance between two interacting curling elements. A small distance of the curling elements enhances the curl depth of the sheet material and a large distance reduces the curl depth of the sheet material.

[0044] Preferably, the two interacting crimping elements are crimping plates or crimping rollers.

[0045] Preferably, the crimp elements are interlocking crimp elements preferably comprising interlocking crimp structures.

[0046] Preferably, the control unit further comprises a moisture sensor for measuring the moisture of the continuous sheet material. It has been found that several parameters can influence the curling depth of the sheet material. The sheet thickness has only a slight influence on the curling depth, while the moisture content of the sheet material can significantly influence the curling depth. The control unit can be adapted to trigger the curling depth adjuster to adjust the curling depth of the sheet material in the curling device depending on the moisture content of the continuous sheet material.

[0047] The control unit may include reference data stored in the control unit. The reference data may include information about the curling behavior of several sheet materials. For example, the reference data may include information about the physical properties of a particular composition of sheet material (e.g., a tobacco blend used in a sheet material containing tobacco material) at different moisture contents.

[0048] The moisture sensor can be arranged at different positions along the production line. Preferably, the moisture sensor is arranged upstream or downstream of the crimping device.

[0049] The closed loop system may further comprise a substance introducing device for introducing a substance into the continuous sheet material.

[0050] Preferably, the substance introduction means is a liquid introduction means.

[0051] The substance introduced into the continuous sheet material can be a flavoring, such as menthol, fruit flavoring or tobacco flavoring. The substance can also be, for example, water, nicotine or an aerosol-forming agent, such as glycerine. Utilizing a substance introduction device, the sheet material can be suitable for consumables to be formed. In particular, the original characteristics of the sheet material can be changed into or adapted to a desired product. For example, by increasing humidity, the manufacturing process of aerosol-forming products can be affected, such as a curling process or a receptor positioning process. The products comprising different flavorings can be made of the same basic sheet material. In addition, the initially non-aerosol-forming sheet material can be changed into an aerosol-forming sheet material by adding an aerosol-forming substance. The tobacco-based material already includes an aerosol-forming substance, while the sheet material, for example, made of a cellulose-based material, does not include an aerosol-forming substance.

[0052] The closed loop system may comprise a packaging device for wrapping the continuous strip with a wrapper. The wrapper may be made of packaging materials known in the art, such as wrapping paper or packaging plastic.

[0053] To further improve the manufacturing process, the closed loop system may include various controls, such as control sensors. The control system may in particular include measuring devices for measuring sheet material parameters before or after the sheet material is curled, susceptor parameters before the susceptor is inserted into the sheet material, device parameters (such as curling devices or liquid insertion devices), or parameters of the formed strip product.

[0054] For example, the control unit may comprise at least one further measuring device for measuring or detecting any of the following:

[0055] The thickness or width of a continuous sheet of material;

[0056] displacement of the continuous sheet material relative to a predetermined conveying position;

[0057] Defects, especially holes and gaps, in continuous sheet materials;

[0058] The curl depth of continuous sheet material;

[0059] Thickness of continuous receptors;

[0060] Width of continuous receptors;

[0061] Discoloration of continuous sheet materials;

[0062] Material flow into the device for introducing substances;

[0063] The location of the crimping element;

[0064] The electrical specifications of the sensor, particularly resistance or impedance, e.g. as part of output control;

[0065] resistance of the susceptor to insertion into a partially gathered continuous sheet of material;

[0066] Receptor splicing part;

[0067] Adhesive flow in an adhesive application device of a packaging device;

[0068] The specifications of the aerosol-generating article, in particular the diameter or ovality of the article, the presence or absence of susceptors; the porosity of the article; the aggregation in the article and the fragmentation of the curled sheet material.

[0069] According to another aspect of the present invention, there is provided a method for controlling the position of a susceptor in an aerosol-generating article, the method comprising:

[0070] Providing continuous sheet materials;

[0071] curling the continuous sheet material;

[0072] Provide continuous receptors;

[0073] gathering the continuous sheet material and inserting the continuous susceptor into the continuous sheet material to form a continuous strip;

[0074] cutting the continuous strip into aerosol-generating articles;

[0075] output control is performed to detect a condition of a susceptor in the aerosol-generating article and compare the detected condition to a quality specification; whereby, when the detected condition does not meet the quality specification of the aerosol-generating article:

[0076] Adjust the position of the continuous sensor, or

[0077] The curl depth of the continuous sheet material is adjusted.

[0078] In some embodiments of the method, the method includes adjusting the position of the continuous susceptor and adjusting the curl depth of the continuous sheet material when the detected condition does not meet the quality specification. One of the two measures may be sufficient to adjust the position of the susceptor in the article, while both measures may provide even more accurate results. In particular, the adjustment of the curl depth can improve the stability of the susceptor in the article and maintain the centered position of the susceptor in the article.

[0079] The advantages and features of this method have been discussed in conjunction with the closed-loop system and apply to this method as well.

[0080] The method according to the invention allows the position of the susceptor to be adjusted in real time. Thus, the manufacture of the aerosol-generating article can be optimized or corrected continuously and on-line.

[0081] The method may comprise rejecting the aerosol-generating article as waste when a detected condition of a receptor in the aerosol-generating article exceeds a predetermined waste threshold.

[0082] Preferably, detecting the condition of the receptor in the aerosol-generating article comprises any one or more of the following:

[0083] The position of a susceptor in the aerosol-generating article, the form of a susceptor in the aerosol-generating article, the eccentricity of a susceptor in the aerosol-generating article, or the shape of a collection of sheet material around the susceptor is detected.

[0084] Preferably, the method comprises capturing information of a cross-section of the aerosol-generating article. In particular, the method may comprise capturing information of a cross-section of at least one end of the aerosol-generating article. Preferably, the method comprises capturing information of a cross-section of both ends of the aerosol-generating article.

[0085] The method may comprise detecting the condition of a susceptor in the aerosol-generating article by visual inspection of the article, by infrared measurement of the article, by X-ray measurement of the article, or by inductive measurement of the article.

[0086] Preferably, the method comprises detecting the condition of a susceptor in the aerosol-generating article by optical means, in particular using a camera.

[0087] The method according to the invention may comprise adjusting the position of the continuous susceptor prior to forming the continuous strip. For example, the method may comprise adjusting the position while gathering the continuous sheet material.

[0088] Preferably, the method comprises adjusting the position of the continuous susceptor by moving the continuous susceptor in at least two directions that are perpendicular to each other.

[0089] More preferably, the method comprises adjusting the position of the continuous susceptor by moving the continuous susceptor in three directions perpendicular to each other.

[0090] The method may include adjusting the position of the continuous susceptor by guiding the continuous susceptor in and along the movable positioning device.

[0091] The method may include adjusting the position of the continuous susceptor by rotating the continuous susceptor along a longitudinal direction of the continuous susceptor.

[0092] Curling the continuous sheet material is preferably performed in the longitudinal or transverse direction of the sheet material, thus in or perpendicular to the conveying direction of the sheet material.Preferably, the method according to the invention comprises providing a curl in the continuous sheet material in its conveying direction.

[0093] Preferably, the method comprises gathering the continuous sheet material along a curl formed in the continuous sheet material.

[0094] The method may include forming a channel in the partially gathered continuous sheet material, and inserting a continuous susceptor into the channel.

[0095] Preferably, the method comprises inserting a continuous susceptor between folds of the continuous sheet material.

[0096] The method may comprise curling the continuous sheet material by guiding the continuous sheet material between curling elements. For example, the method comprises thereby guiding the continuous sheet material between curling rollers or curling plates.

[0097] Preferably, adjusting the crimp depth is performed by varying the distance between the crimping elements.

[0098] The method may further comprise measuring the moisture content of the continuous sheet material, and adjusting the curling depth depending on the moisture content of the continuous sheet material.Measuring the moisture content of the continuous sheet material may be performed, for example, before or after curling or both before and after curling.

[0099] The method according to the invention may further comprise wrapping the continuous strip with a wrapper. Preferably, the wrapper is a continuous paper sheet or a continuous plastic sheet.

[0100] The method according to the invention may further comprise adding a substance to the continuous sheet material.

[0101] Preferably, the substance is a liquid.

[0102] Preferably, the substance comprises flavouring, nicotine or an aerosol former.

[0103] The continuous susceptor may for example be a continuous belt, a continuous wire or a thread. Preferably, the continuous susceptor is a continuous belt.

[0104] The continuous susceptor may for example comprise a metal, a magnetic material or a magnetic metal. For example, the susceptor material is stainless steel, in particular ferromagnetic stainless steel, or aluminum.

[0105] The continuous sheet material is a substantially flat sheet which is rolled and then gathered into a strip. In embodiments where the positioning device is used to adjust the position of the continuous susceptor in the sheet material, the strip manufacturing process may be supplied with already rolled sheet material.

[0106] The continuous sheet material may be provided as a non-aerosol-forming sheet material or as an aerosol-forming sheet material.

[0107] The method may comprise changing the non-aerosol-forming sheet material to an aerosol-forming sheet material by adding an aerosol-forming substance to the non-aerosol-forming sheet material prior to forming the continuous strip.

[0108] The continuous sheet material may for example be a sheet material comprising tobacco material, a plant-based sheet material, a cellulose-based sheet material, a sheet material comprising fibrous material, or a combination of these materials.

[0109] The method according to the invention may further comprise measuring or detecting any of the following:

[0110] The thickness or width of continuous sheet material,

[0111] displacement of the continuous sheet material relative to a predetermined conveying position;

[0112] Defects, especially holes and gaps, in continuous sheet materials;

[0113] The curl depth of continuous sheet material;

[0114] Thickness of continuous receptors;

[0115] Width of continuous receptors;

[0116] Discoloration of continuous sheet materials;

[0117] Material flow into the device for introducing substances;

[0118] The location of the crimping element;

[0119] The electrical specifications of the receptor, especially resistance or impedance;

[0120] resistance of the susceptor to insertion into a partially gathered continuous sheet of material;

[0121] Receptor splicing part;

[0122] Adhesive flow in an adhesive application device of a packaging device;

[0123] The specifications of the aerosol-generating article, in particular the diameter or ovality of the article, the presence or absence of susceptors; the porosity of the article; the aggregation in the article and the fragmentation of the curled sheet material.

[0124] Preferably, electrical specifications, in particular resistance or impedance, of the susceptor may be measured or detected as part of detecting the condition of the susceptor in the aerosol-generating article. In particular, such resistance or impedance measurements may be part of output control. Measurement of electrical specifications of the susceptor may also be performed on the continuous susceptor as a quality check before the continuous susceptor is used in the manufacturing process of the aerosol-forming article.

[0125] The method may also include detecting splices of susceptors in a continuous susceptor or in an aerosol generating article. Articles comprising splices will be eliminated as not meeting any quality specification.

[0126] The splices may be detected before the continuous susceptor is inserted into the continuous sheet material. They may be detected when the continuous susceptor is in a continuous strip. Alternatively or in addition, they may be detected when the susceptor is in an aerosol-forming article, for example as part of output control.

[0127] When formed into a continuous strip, the continuous sheet material is an aerosol-forming continuous sheet material.The continuous sheet may be an aerosol-forming sheet material when supplied to the manufacturing process, or may be converted to an aerosol-forming sheet material before or when being gathered into a strip.

[0128] The continuous sheet material forms the aerosol-forming matrix in the article.

[0129] Preferably, the continuous sheet material is a tobacco sheet, in particular a sheet of homogenised tobacco material.

[0130] The tobacco sheet forming the aerosol-forming substrate may comprise tobacco particles, fibre particles, an aerosol-former, a binder and, for example, also flavourants.

[0131] Preferably, the tobacco sheet is a cast leaf.Cast leaf is a form of reconstituted tobacco formed from a slurry comprising tobacco particles, fiber particles, an aerosol former (eg glycerol or propylene glycol), a binder and, for example, also flavorants.

[0132] Preferably, aerosol forms tobacco sheet material and contains volatile tobacco flavor compounds, and these compounds are discharged from tobacco matrix when heating.Aerosol forms tobacco matrix and can comprise blended tobacco shredded filler or be made up of blended tobacco shredded filler, or can comprise homogenized tobacco material.Homogenized tobacco material can be formed by condensed particle tobacco.Aerosol forms matrix and can be made up of tobacco-free material or comprise tobacco-free material in addition, for example homogenized plant-based material except tobacco.

[0133] The fiber particles may include tobacco stem material, stems or other tobacco plant material and other cellulose-based fibers such as wood fibers with low lignin content. The fiber particles may be selected based on the desire to produce sufficient tensile strength for cast leaves relative to low impurity rates (e.g., impurity rates between about 2% and 15%). Alternatively, fibers such as plant fibers may be used with the above fiber particles, or in an alternative, bamboo.

[0134] Can select to form the aerosol forming agent contained in the slurry of cast leaf or the aerosol forming agent that is used for other aerosol forming substrates based on one or more characteristics.Functionally, the mechanism that aerosol forming agent provides allows aerosol forming agent to volatilize and carry nicotine or flavoring agent or both in aerosol when being heated to more than the specific volatilization temperature of aerosol forming agent.Different aerosol forming agents vaporize at different temperatures usually.Aerosol forming agent can be any suitable known compound or the mixture of compound, and it promotes dense and stable aerosol formation in use, and is basically resistance to the thermal degradation under the operating temperature of the induction heating device used together with the tobacco substrate that can be inductively heated.Can be based on the ability of aerosol forming agent that for example at room temperature or near room temperature keeps stable but can volatilize at the higher temperature between for example 40 degrees Celsius and 450 degrees Celsius, select aerosol forming agent.

[0135] The aerosol-forming agent may also have humectant-type properties that help maintain a desired moisture level in the aerosol-forming substrate, particularly but not limited to when the substrate is composed of a tobacco-based product (particularly including tobacco particles). In particular, some aerosol-forming agents are hygroscopic materials that act as humectants, i.e., materials that help keep the substrate containing the humectant moist.

[0136] One or more aerosol formers can be combined to take advantage of one or more properties of the combined aerosol formers. For example, triacetin can be combined with glycerol and water to take advantage of triacetin's ability to deliver active ingredients and glycerol's humectant properties.

[0137] The aerosol former may be selected from polyols, glycol ethers, polyol esters, esters and fatty acids, and may include one or more of the following compounds: glycerol, erythritol, 1,3-butylene glycol, tetraethylene glycol, triethylene glycol, triethyl citrate, propylene carbonate, ethyl laurate, triacetin, meso-erythritol, diacetin mixture, diethyl suberate, triethyl citrate, benzyl benzoate, benzyl phenylacetate, ethyl vanillate, tributyrin, lauryl acetate, lauric acid, myristic acid and propylene glycol.

[0138] The aerosol-forming substrate may include other additives and ingredients, such as flavourings.The aerosol-forming substrate preferably comprises nicotine and at least one aerosol former.

[0139] The thickness of the rolled sheet material, in particular the rolled aerosol-forming sheet material, more particularly the rolled tobacco sheet, such as cast leaf, may be in the range of about 0.5 mm to about 2 mm, preferably about 0.8 mm to about 1.5 mm, for example 1 mm. Due to manufacturing tolerances, thickness deviations of up to about 30% may occur.

[0140] As used herein, the term "susceptor" refers to a material that is capable of converting electromagnetic energy into heat. When placed in an alternating electromagnetic field, eddy currents are typically induced and hysteresis losses occur in the susceptor, causing heating of the susceptor. Since the susceptor is in thermal contact or thermal proximity with the aerosol-forming substrate, the aerosol-forming substrate is heated by the susceptor, causing an aerosol to be formed. Preferably, the susceptor is arranged in direct physical contact with the aerosol-forming substrate.

[0141] The susceptor may be formed of any material that can be inductively heated to a temperature sufficient to release material from the aerosol-forming substrate. Preferred susceptors include metal or carbon. Preferred susceptors may include or consist of ferrous or ferromagnetic materials, such as ferritic iron, ferromagnetic alloys (such as ferromagnetic steel, stainless steel or aluminum). Preferably, the susceptor includes greater than 5%, preferably greater than 20%, more preferably greater than 50% or greater than 90% ferromagnetic or paramagnetic material. Preferred susceptors may be heated to a temperature between about 150 degrees Celsius and about 300 degrees Celsius. Preferably, the susceptor may be heated to a temperature between about 200 degrees Celsius and about 270 degrees Celsius, for example 235 degrees Celsius.

[0142] The susceptor is preferably metal, such as stainless steel, in particular ferromagnetic stainless steel, or aluminium.Preferably, the susceptor is or comprises a magnetic material.

[0143] Preferably, the continuous susceptor is a wire, strip, sheet or ribbon.If the susceptor has a constant cross-section, such as a circular cross-section, it preferably has a width or diameter of between about 1 mm and about 5 mm.

[0144] Preferably, the susceptor is a metal strip.

[0145] Preferably, the susceptor is a stainless steel strip. However, the susceptor material may also include or be made of: graphite; molybdenum; silicon carbide; aluminum; niobium; Inconel alloy (a superalloy based on austenite nickel-chromium); metallized films; ceramics such as zirconium oxide; transition metals such as iron, cobalt, nickel, or metalloid components such as boron, carbon, silicon, phosphorus, aluminum.

[0146] Preferably, the susceptor strip in the article has a substantially rectangular shape, the width of which is preferably between about 2 mm and about 8 mm, more preferably between about 3 mm and about 5 mm, such as 4 mm.

[0147] The width of the susceptor strip is smaller than the width or diameter of the strip-shaped aerosol-generating article in which the susceptor strip is arranged.

[0148] The thickness of the susceptor material is preferably between about 0.03 mm and about 1 mm, more preferably between about 0.05 mm and about 0.5 mm, such as between about 0.07 mm and about 0.2 mm.

[0149] As a general rule, whenever the term "about" is used in conjunction with a specific value throughout this application, it should be understood that the value following the term "about" does not have to be exactly the specific value due to technical considerations. However, the term "about" used in conjunction with a specific value is always understood to include and also explicitly disclose the specific value following the term "about". Preferably, the aerosol-generating article has the form of a strip, the strip diameter of which is preferably in the range of about 3 mm to about 12 mm, more preferably between about 4 mm to about 8 mm, for example 7 mm. Preferably, the strip has a circular cross-section or an elliptical cross-section. However, the strip may also have a rectangular or polygonal cross-section.

[0150] Preferably, the aerosol-forming article is a rod-shaped article, preferably having a circular cross-section.

[0151] The aerosol generating article comprises an aerosol forming substrate capable of forming an aerosol. The aerosol forming substrate is solid and can comprise a tobacco-containing material, which contains volatile tobacco flavor compounds released from the substrate when heated. Alternatively, the aerosol forming substrate can comprise a non-tobacco material. The aerosol forming substrate can also comprise an aerosol forming agent. The example of a suitable aerosol forming agent is glycerol and propylene glycol. The aerosol forming substrate is formed by a continuous sheet material.

[0152] The invention is defined in the claims. However, a non-exhaustive list of non-limiting examples is provided below. Any one or more features of these examples may be combined with any one or more features of another example, embodiment or aspect described herein.

[0153] Example Ex1: A closed-loop system for controlling the position of a susceptor in an aerosol-generating article, the system comprising:

[0154] for a supply source of continuous sheet material;

[0155] Supply source for continuous receptors;

[0156] a curling device for curling the continuous sheet material;

[0157] a forming device for gathering the continuous sheet material and for forming the continuous sheet material with the inserted continuous susceptor into a continuous strip;

[0158] cutting means for cutting the continuous strip into aerosol-generating articles;

[0159] a control unit comprising an output control for detecting a condition of a susceptor in the aerosol-generating article and for comparing the detected condition to a quality specification; wherein the system further comprises

[0160] a positioning device for manipulating the position of said continuous receptor,

[0161] or a curl depth adjuster, and wherein

[0162] When the detected condition does not meet the quality specification, the control unit is adapted to trigger the positioning device to adjust the position of the continuous susceptor, or to trigger the curling depth adjuster to adjust the curling depth of the sheet material in the curling device.

[0163] Example Ex2: A closed-loop system according to Example Ex1, wherein the output control is suitable for rejecting the aerosol-generating article as waste when the detected sensor condition exceeds a predetermined waste threshold.

[0164] Example Ex3: A closed-loop system according to any of the preceding examples, wherein the detected condition of the aerosol-generating article comprises any one or more of the following:

[0165] The position of a susceptor in the aerosol-generating article, the form of a susceptor in the aerosol-generating article, the eccentricity of a susceptor in the aerosol-generating article, or the shape of the collection of sheet material around the susceptor.

[0166] Example Ex4: A closed-loop system according to any of the preceding examples, wherein the output control is suitable for capturing information of a cross-section of the aerosol-generating article.

[0167] Example Ex5: A closed-loop system according to Example Ex4, wherein the output control is suitable for capturing information of a cross-section of at least one end of the aerosol generating article.

[0168] Example Ex6: A closed-loop system according to any one of Examples Ex4 to Ex5, wherein the output control is suitable for capturing information of the cross-sections of the two ends of the aerosol-generating article.

[0169] Example Ex7: A closed-loop system according to any of the preceding examples, wherein the output control comprises an optical system, an infrared system, an X-ray system, or an inductive detection system.

[0170] Example Ex8: A closed-loop system according to Example Ex7, wherein the output control includes a camera.

[0171] Example Ex9: A closed-loop system according to any of the preceding examples, wherein the system includes the positioning device and the curling depth adjuster, and wherein if the detected condition does not meet the quality specification, the control unit is suitable for triggering the positioning device to adjust the position of the continuous sensor, and is suitable for triggering the curling depth adjuster to adjust the curling depth of the sheet material in the curling device.

[0172] Example Ex10: A closed-loop system according to any one of the preceding examples, wherein the positioning device is movably arranged to be movable in at least two directions that are perpendicular to each other.

[0173] Example Ex11: A closed-loop system according to Example Ex10, wherein the positioning device is movable relative to the supply direction of the continuous susceptor.

[0174] Example Ex12: A closed-loop system according to any one of Examples Ex10 to Ex11, wherein the positioning device is movable in three directions that are perpendicular to each other.

[0175] Example Ex13: A closed-loop system according to any one of Examples Ex10 to Ex12, wherein the positioning device is movably arranged in the forming device.

[0176] Example Ex14: A closed-loop system according to any one of the preceding examples, wherein the positioning device comprises a rotating device for rotating the continuous susceptor along the longitudinal direction of the continuous susceptor.

[0177] Example Ex15: A closed-loop system according to Example Ex14, wherein the positioning device is rotatable to rotate the continuous sensor.

[0178] Example Ex16: A closed-loop system according to any one of Examples Ex10 to Ex15, wherein the positioning device has a conical shape.

[0179] Example Ex17: A closed-loop system according to any of the preceding examples, wherein the forming device has a conical shape.

[0180] Example Ex18: A closed-loop system according to Example Ex17, wherein the positioning device is arranged in a cone of the forming device.

[0181] Example Ex19: A closed-loop system according to any of the preceding examples, wherein the forming device comprises a channel former for forming a channel in a partially gathered continuous sheet material.

[0182] Example Ex20: A closed-loop system according to any of the preceding examples, wherein the curling device is suitable for providing a longitudinally extending curl to the continuous sheet material.

[0183] Example Ex21: A closed-loop system according to any of the preceding examples, wherein the curling device comprises two interacting curling elements, the two interacting curling elements being arranged to allow the continuous sheet material to pass between the two interacting curling elements, thereby curling the continuous sheet material.

[0184] Example Ex22: A closed-loop system according to Example Ex21, wherein the curl depth adjuster is suitable for changing the distance between the two interacting curling elements.

[0185] Example Ex23: A closed-loop system according to any one of Examples Ex21 to Ex22, wherein the two interacting curling elements are curling plates or curling rollers.

[0186] Example Ex24: A closed-loop system according to any of the preceding examples, wherein the control unit further comprises a moisture sensor for measuring the moisture content of the continuous sheet material.

[0187] Example Ex25: A closed-loop system according to Example Ex24, wherein the control unit is suitable for triggering the curling depth adjuster depending on the moisture content of the continuous sheet material to adjust the curling depth of the sheet material in the curling device.

[0188] Example Ex26: A closed-loop system according to any one of Examples Ex24 to Ex25, wherein the moisture sensor is arranged upstream or downstream of the curling device.

[0189] Example Ex27: A closed-loop system according to any of the preceding examples, further comprising a substance introduction device for introducing a substance into the continuous sheet material.

[0190] Example Ex28: A closed-loop system according to Example Ex27, wherein the substance introduction device is a liquid introduction device.

[0191] Example Ex29: A closed-loop system according to any of the preceding examples, further comprising a packaging device for wrapping the continuous strip with a packaging material.

[0192] Example Ex30: A closed-loop system according to any of the preceding examples, wherein the control unit comprises at least one further measuring device for measuring or detecting any of the following:

[0193] the thickness or width of the continuous sheet material,

[0194] displacement of the continuous sheet material relative to a predetermined conveying position;

[0195] defects, particularly holes and gaps, in the continuous sheet material;

[0196] the curl depth of the continuous sheet material;

[0197] the thickness of the continuous susceptor;

[0198] the width of the continuous susceptor;

[0199] discoloration of the continuous sheet material;

[0200] Material flow into the device for introducing substances;

[0201] The location of the crimping element;

[0202] the electrical specifications of the receptor, in particular resistance or impedance;

[0203] resistance of the susceptor to insertion into a partially gathered continuous sheet of material;

[0204] Receptor splicing part;

[0205] Adhesive flow in an adhesive application device of a packaging device;

[0206] The specifications of the aerosol-generating article, in particular the diameter or ovality of the article, the presence or absence of susceptors; the porosity of the article; the aggregation in the article and the fragmentation of the curled sheet material.

[0207] Example Ex31: A method for controlling the position of a susceptor in an aerosol-generating article, the method comprising:

[0208] Providing continuous sheet materials;

[0209] curling the continuous sheet material;

[0210] Provide continuous receptors;

[0211] gathering the continuous sheet material and inserting the continuous susceptor into the continuous sheet material to form a continuous strip;

[0212] cutting the continuous strip into aerosol-generating articles;

[0213] performing output control to detect a condition of a susceptor in the aerosol-generating article and compare the detected condition to a quality specification; whereby, when the detected condition does not meet the quality specification of the aerosol-generating article, adjusting the position of the continuous susceptor, or

[0214] The curl depth of the continuous sheet material is adjusted.

[0215] Example Ex32: The method according to Example Ex31 includes adjusting the position of the continuous sensor and adjusting the curling depth of the continuous sheet material when the detected condition does not meet the quality specification.

[0216] Example Ex33: A method according to any one of Examples Ex31 to Ex32, wherein the aerosol-generating article is rejected as waste when the condition detected by the sensor in the aerosol-generating article exceeds a predetermined waste threshold.

[0217] Example Ex34: A method according to any one of Examples Ex31 to Ex33, wherein detecting the condition of the receptor in the aerosol-generating article comprises any one or more of the following:

[0218] The position of a susceptor in the aerosol-generating article, the form of a susceptor in the aerosol-generating article, the eccentricity of a susceptor in the aerosol-generating article, or the shape of a collection of sheet material around the susceptor is detected.

[0219] Example Ex35: A method according to any one of Examples Ex31 to Ex34, wherein information of a cross-section of the aerosol generating article is captured.

[0220] Example Ex36: A method according to Example Ex35, wherein information of a cross-section of at least one end of the aerosol generating article is captured.

[0221] Example Ex37: A method according to any one of Examples Ex35 to Ex36, wherein information of the cross-sections of the two ends of the aerosol-generating article is captured.

[0222] Example Ex38: A method according to any one of Examples Ex31 to Ex37, wherein the condition of the receptor in the aerosol-generating article is detected by visual inspection of the article, by infrared measurement of the article, by X-ray measurement of the article, or by inductive measurement of the article.

[0223] Example Ex39: A method according to Example Ex38, wherein the condition of the receptor in the aerosol-generating article is detected by an optical device, in particular a camera.

[0224] Example Ex40: A method according to any one of Examples Ex31 to Ex39, comprising adjusting the position of the continuous susceptor before forming the continuous strip.

[0225] Example Ex41: A method according to Example Ex40, which includes adjusting the position while gathering the continuous sheet material.

[0226] Example Ex42: The method according to any one of Examples Ex31 to Ex41, comprising adjusting the position of the continuous receptor by moving the continuous receptor along at least two directions perpendicular to each other.

[0227] Example Ex43: According to the method of Example Ex42, the position of the continuous sensor is adjusted by moving the continuous sensor along three directions perpendicular to each other.

[0228] Example Ex44: The method according to any one of Examples Ex31 to Ex43, comprising adjusting the position of the continuous receptor by guiding the continuous receptor in and along a movable positioning device.

[0229] Example Ex45: The method according to any one of Examples Ex31 to 44, comprising adjusting the position of the continuous susceptor by rotating the continuous susceptor along the longitudinal direction of the continuous susceptor.

[0230] Example Ex46: A method according to any one of Examples Ex31 to Ex45, wherein the continuous sheet material is curled in the longitudinal direction.

[0231] Example Ex47: The method according to Example Ex46 includes gathering the continuous sheet material along the curl formed in the continuous sheet material.

[0232] Example Ex48: A method according to any one of Examples Ex31 to Ex47, wherein a channel is formed in the partially gathered continuous sheet material, and the continuous susceptor is inserted into the channel.

[0233] Example Ex49: A method according to any one of Examples Ex31 to Ex48, wherein the continuous susceptor is inserted between folds of the continuous sheet material.

[0234] Example Ex50: A method according to any one of Examples Ex31 to Ex49, wherein the continuous sheet material is curled by guiding the continuous sheet material between curling elements.

[0235] Example Ex51: According to the method of Example Ex50, the continuous sheet material is guided between curling rollers or curling plates.

[0236] Example Ex52: A method according to any one of Examples Ex50 to Ex51, wherein adjusting the curling depth is performed by changing the distance between the curling elements.

[0237] Example Ex53: A method according to any one of Examples Ex31 to Ex52, wherein the moisture content of the continuous sheet material is measured and the curl depth is adjusted depending on the moisture content of the continuous sheet material.

[0238] Example Ex54: A method according to Example Ex53, wherein the moisture content of the continuous sheet material is measured before or after curling or before and after curling.

[0239] Example Ex55: According to the method of any one of Examples Ex31 to Ex54, the method also includes wrapping the continuous strip with a packaging material.

[0240] Example Ex56: A method according to Example Ex55, wherein the packaging material is a continuous paper sheet or a continuous plastic sheet.

[0241] Example Ex57: A method according to any one of Examples Ex31 to Ex56, which also includes adding a substance to the continuous sheet material.

[0242] Example Ex58: A method according to Example Ex57, wherein the substance is a liquid.

[0243] Example Ex59: A method according to any one of Examples Ex56 to Ex58, wherein the substance comprises a flavoring, nicotine or an aerosol former.

[0244] Example Ex60: A method according to any one of Examples Ex31 to Ex59, wherein the continuous susceptor is a continuous belt, continuous wire or thread.

[0245] Example Ex61: A method according to any one of Examples Ex31 to Ex60, wherein the continuous susceptor comprises a metal, a magnetic material, or a magnetic metal.

[0246] Example Ex62: A method according to Example Ex61, wherein the sensor material is stainless steel, in particular ferromagnetic stainless steel, or aluminum.

[0247] Example Ex63: A method according to any one of Examples Ex31 to Ex62, wherein the continuous sheet material is a substantially flat sheet that is curled and then gathered into a strip.

[0248] Example Ex64: A method according to any one of Examples Ex31 to Ex63, wherein the continuous sheet material is provided as a non-aerosol-forming sheet material or as an aerosol-forming sheet material.

[0249] Example Ex65: A method according to Example Ex64, wherein the non-aerosol-forming sheet material is changed into an aerosol-forming sheet material by adding an aerosol-forming substance to the non-aerosol-forming sheet material before forming the continuous strip.

[0250] Example Ex66: A method according to any one of Examples Ex31 to Ex65, wherein the continuous sheet material is a sheet material containing tobacco material, a plant-based sheet material, a cellulose-based sheet material, a sheet material containing fiber material, or a combination of these materials.

[0251] Example Ex67: According to the method of any one of Examples Ex31 to Ex66, it further measures or detects any of the following:

[0252] the thickness or width of the continuous sheet material,

[0253] displacement of the continuous sheet material relative to a predetermined conveying position;

[0254] defects, particularly holes and gaps, in the continuous sheet material;

[0255] the curl depth of the continuous sheet material;

[0256] the thickness of the continuous susceptor;

[0257] the width of the continuous susceptor;

[0258] discoloration of the continuous sheet material;

[0259] Material flow into the device for introducing substances;

[0260] The location of the crimping element;

[0261] the electrical specifications of the receptor, in particular resistance or impedance;

[0262] resistance of the susceptor to insertion into a partially gathered continuous sheet of material;

[0263] Receptor splicing part;

[0264] Adhesive flow in an adhesive application device of a packaging device;

[0265] The specifications of the aerosol-generating article, in particular the diameter or ovality of the article, the presence or absence of susceptors; the porosity of the article; the aggregation in the article and the fragmentation of the curled sheet material.

[0266] Example Ex68: A method according to Example Ex67, wherein the electrical specifications of the receptor, in particular the resistance or impedance, are measured or detected as part of detecting the condition of the receptor in the aerosol-generating article.

[0267] Example Ex69: A method according to any one of Examples Ex67 to Ex68, wherein a sensor splicing portion in the continuous sensor or in the aerosol generating article is detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0268] Several examples will now be further described with reference to the accompanying drawings, in which:

[0269] Figure 1 A schematic closed-loop control system is shown;

[0270] Figure 2 shows a schematic cross section along a forming device with a positioning device;

[0271] Figure 3 A curling closed-loop control system is shown;

[0272] Figure 4 Output controls are shown;

[0273] Figure 5 shows a cross section of a strip product with position control; and

[0274] Figure 6 A cross section of a strip product with eccentricity and deformation control is shown. DETAILED DESCRIPTION

[0275] Figure 1 A production line for an aerosol-generating article and a closed-loop control system for position control of a susceptor in a crimped and gathered sheet material forming the aerosol-generating article are shown.

[0276] exist Figure 1In the figure, the black arrows 77 indicate the physical flow of the product. The dashed arrows 88 indicate the information flow from the various measuring devices 81, 82, 83, 84, 85, 86, 89 including sensors to the control unit 8. The two dashed arrows 99 indicate the information flow from the control unit 8 to the actuator of the curling device 4 or to the positioning device 6 in the forming device 5 which may be embodied as a cone forming module.

[0277] In the supply unit 7, a continuous sheet material, such as a tobacco-containing sheet material, in particular a cast leaf, is unwound from a bobbin. In the optional flavor module 78, flavorants, as well as nicotine, aerosol formers or other substances may be applied to the continuous sheet material. For example, using the flavor module 78, an original non-aerosol-forming sheet material may be changed into an aerosol-forming sheet material, and this becomes the aerosol-forming substrate.

[0278] The sheet material is further conveyed to a curling device 4, wherein the sheet material is curled. The sheet material is preferably provided with a longitudinal curl along the length of the sheet material and the conveying direction. Further downstream in the production line, a susceptor strip insertion module 76 is arranged. The susceptor strip insertion module 76 is preferably integrated in a forming device 5, which further comprises a positioning device 6 for the susceptor strip in the partially gathered sheet material. With the positioning device 6, the position of the continuous susceptor relative to the sheet material can be adjusted. In the forming device 5, the aerosol-forming sheet material is mainly gathered along the curl and the aerosol-forming sheet material, and the susceptor is formed into a continuous strip. The continuous strip is further cut downstream in a cutting device 79 into individual strip-shaped products. The products may for example be single or double strips of aerosol-generating products, thus having a single or double length.

[0279] The cut strips are subjected to output control 86. Output control 86 is preferably a visual inspection of the cross section of the strip. Output control 86 preferably controls the condition of the susceptor in the strip product primarily by controlling the position of the susceptor in the product. The measured and determined susceptor condition is compared with the quality specification in output control 86 or control unit 8.

[0280] The information of the output control 86 is fed to the control unit 8. Depending on the result of the quality control, the control unit 8 sends a corresponding signal to the positioning device 6 or the crimping device 4, or to both the positioning device 6 and the crimping device 4, in order to adjust the position of the continuous susceptor into the sheet material when the strip is formed, or to adjust the crimping depth of the sheet material in the crimping device 4.

[0281] Next to the output control 86, various measuring devices 81, 82, 83, 84, 85, 89 arranged along the production line can provide input to the control unit 8. This information can be used to adjust the individual devices 7, 78, 4, 5, 6, 76, 79 arranged along the production line. The various measuring devices 81, 82, 83, 84, 85, 89 are:

[0282] - a measuring device 81 for detecting the running position of the sheet material (e.g. a left or right deviation from a central conveying direction). Deviations in the running position of the sheet material can be corrected by repositioning the sheet material to a more central conveying direction. Information on the deviations in the running position of the sheet material can also be input to other further downstream arranged devices, such as the flavor module 78.

[0283] - Measuring means 82 for measuring the width and thickness of the sheet material. This information can be used, for example, in the crimping device 4 and the susceptor strip insertion module 76. Exemplary values ​​for the casting leaf are a width of 125 mm and a thickness of 200 μm.

[0284] - a color change measuring device 83, for example after the flavor module 78;

[0285] - a measuring device 84 for measuring the curling depth and a moisture sensor 87 for measuring the moisture content of the sheet material. Information on the moisture content of the sheet material may have a significant influence on the curling process, while information on the curling depth can be used directly to adjust the distance of the curling elements in the curling device 4. An exemplary value for the curling depth of the casting leaf at a moisture content of 8% water is 250 μm (average peak; thickness 200 μm).

[0286] - An impedance measuring device 89 may be provided to control the susceptor before it is inserted into the sheet material. By this measure, defective susceptors or susceptors of substandard quality for the manufacture of articles may be avoided. An exemplary value for the metal susceptor sheet impedance and resistance is 600 mOhm.

[0287] A resistance measuring device 85 is provided at the location of the susceptor strip insertion module 76. The resistance measuring device 85 measures the insertion resistance of the susceptor into the sheet material. A high insertion resistance may deform the susceptor during the insertion process or may result in the susceptor having an insufficient insertion depth in the sheet material. For example, adjusting the location of the susceptor insertion into the sheet material may reduce the risk that the sheet material is more or less densely gathered in a location further upstream or further downstream.

[0288] Figure 1The system shown in comprises several measuring devices arranged along the production line of aerosol generating articles. These devices may be present to enhance the accuracy and reliability of the system, but may also be optional and may be located at other process stages of the production line or control system, or may be, for example, replicated to be also available at other process stages in the production line. By way of example only, the moisture sensor 87 may be arranged before or when the sheet material is supplied, shortly before the sheet material is curled, or after the sheet material is curled but before the strip is formed. The moisture sensor may also be arranged at some or all of these locations. It has also been found that the width and thickness of the sheet material have a slight effect on the curling process of the sheet material, so that the measuring device 82 may be omitted. In addition, for example, the insertion module 76 for sensor insertion also includes a positioning device. Preferably, a reference deviation within a distance range of about 0.2 mm from a reference travel distance is detected.

[0289] Figure 2 is a schematic diagram of a forming device 5 in the form of a forming cone 51. In the forming cone 51, a continuous curled sheet material 70 is gathered and a continuous susceptor 72 is inserted into the partially gathered continuous sheet material 70. The two materials are formed into a continuous strip 71. The continuous susceptor 72 is preferably centrally arranged in the strip 71 along the central longitudinal axis of the strip and is completely surrounded by the sheet material 70. Preferably, the continuous susceptor 72 is arranged between the curls or folds of the partially gathered aerosol-forming sheet material 70.

[0290] The continuous crimped sheet material 70 may, for example, be an aerosol-forming sheet, such as a cast leaf comprising homogenised tobacco material and an aerosol-forming agent.The continuous susceptor 72 may be a continuous metal strip, such as a ferromagnetic stainless steel strip.

[0291] The positioning device 6 in the form of a movable cone 61 is arranged in the forming cone 51. The outlet 52 of the forming cone 51 of the forming device 5 is arranged concentrically with the outlet 63 of the movable cone 61 of the positioning device 6. The two outlets 52, 63 can (but usually are not) be arranged at the same position along the X axis, which corresponds to Figure 2 The sheet material 70 and the susceptor 72 in the direction of travel. Generally, the outlet 63 of the movable cone 61 is arranged upstream of the outlet 52 of the forming cone 52.

[0292] The movable cone 61 guides the continuous susceptor 72 during its insertion into the sheet material 70 and thereby defines the position of the susceptor in the strip 71 .

[0293] The positioning device 6 preferably comprises a linear guide which allows the position of the movable cone 61 to be adjusted along the X, Y, Z directions (whose axes are perpendicular to each other). Preferably, by adjusting the position of the movable cone 61, the direction and orientation of the susceptor can be changed in real time. For example, the outlet 63 of the movable cone 61 has a form corresponding to the form of the cross section of the continuous susceptor. Thereby, the susceptor is tightly guided and any movement of the movable cone is directly transmitted to the continuous susceptor.

[0294] The positioning device 6 is movable in the X direction and it is also possible to vary the inclination angle 62 between the positioning device 6 and the forming device 5 .

[0295] The positioning device 6 , in particular the movable cone 61 , may also be rotatable, preferably about the longitudinal middle axis of the cone 61 .

[0296] exist Figure 2 , the X direction is parallel to the travel direction of the sheet material 70. The Y direction points to the lateral side of the travel direction of the sheet material 70 and is perpendicular to the travel direction. The Z direction points to the top / bottom direction compared to the travel direction of the sheet material and is perpendicular to the travel direction.

[0297] Figure 3 An example of a control loop for the curling process of a continuous sheet material 70 is shown. Figure 1 The same reference numerals are used for the same or similar elements.

[0298] Before curling the sheet material 70 , the measurement of the humidity, and possibly also the width and thickness, is performed in a corresponding measuring device indicated by the moisture sensor 87 .

[0299] The sheet material 70 is then curled in the curling device 4 by passing between two curling rollers 41. The distance 40 between the curling rollers 41 is measured and can be adjusted to adjust the curling depth 42 of the sheet material 70.

[0300] The information from the moisture sensor 87 is compared with reference data stored in the control unit 8. The reference data comprises the settings of the crimping device 4, i.e. the crimping roller distance 40 for a specific sheet material, e.g. a specific composition of the sheet material, e.g. a tobacco blend for a sheet material containing tobacco material at a specific moisture content.

[0301] Figure 3 The graph indicated as control unit 8 in the upper right square in FIG. 4 shows the curl depth value d for the moisture content M. For example, a low, medium or high moisture content M corresponds to a target curl depth value 43 between 0.20 mm and 0.23 mm. A low moisture content refers to a moisture content M below 7.6% water, and a high moisture content refers to a value M above 8.5% water in the sheet material (e.g., cast leaf).

[0302] In a crimp depth measuring device 84, such as a depth profiler, arranged downstream of the crimping device 4, the crimp depth 42 is measured. A target crimp depth 43 is compared with the measured crimp depth 42. Information about the deviation 44 of these values ​​is provided to the control unit 8, which can give a corresponding signal 99 to the actuator of the crimping device 4 to adjust the distance 40 of the crimping rollers 41. The distance 40 of the crimping rollers 41 can be measured, for example, with a laser sensor.

[0303] In the example shown, the measured moisture content M gives a target crimp depth value 43 of 0.204 mm. The measured crimp depth 42 in the measuring device 84 gives a measured crimp depth 42 of 0.173 mm. Therefore, using this information, the distance 40 of the crimping rollers 41 in the crimping device 4 can be set to 0.2 mm.

[0304] In the output control 86, the cross section of the gathered strip is also measured. In addition to the information about the position of the sensor in the strip, information about the gathering of the sheet material can also be determined. For example, a uniform or non-uniform gathering on the cross section of the strip can be detected. In the exemplary figure shown on the left in the square indicating the output control 86, an acceptable result 91 showing the uniform gathering of the sheet material on the cross section of the strip can be seen. In the exemplary figure shown in the middle of the square indicating the output control 86, an unacceptable result 92 is shown. The unacceptable result shows a cross section of the product including an area 921 that does not include sheet material. Products that bring unacceptable results 92 may be rejected. Rejection can be actuated by a corresponding signal from the control unit 8 that actuates a rejection device (not shown). Information about acceptable or unacceptable results 91, 92 is also used in the control unit 8 for curling depth adjustment.

[0305] Figure 4 An example of an output control 86 comprising an image sensor 2, such as a camera, is shown. The camera takes a photograph of a cross-section of an end 730 of a strip-shaped article 73, such as a double strip of an aerosol-forming article. From this, the position of the susceptor 74 in the double strip can be measured and compared to a quality specification in order to detect or determine the condition of the susceptor.

[0306] exist Figure 4In the embodiment of the present invention, a strip-shaped article 73 is conveyed in the grooves of a grooved conveyor drum 30 and preferably continuously passes a camera for position measurement. The article 73 can be precisely positioned on the conveyor drum 30 so that the susceptors 74 in the article 73 have a specific and predetermined orientation relative to the camera on the conveyor drum 30 and when passing the camera. This can simplify quality control. In particular, it can increase the speed of comparison of measurements with quality specifications, in particular with predetermined thresholds for accepting or rejecting the article 73. The predetermined and consistent orientation of the susceptors in the article may also be advantageous for further processes further downstream in the production line, such as cutting of the article or assembly of the article with further sections of an aerosol generating product or device.

[0307] exist Figure 5 and Figure 6 , examples of different measurements of the condition of a susceptor 74 in a strip product 73 are shown.

[0308] exist Figure 5 and Figure 6 , a picture of a cross-section of a strip-shaped aerosol-forming article 73 is shown, comprising a susceptor strip 74 surrounded by a rolled and gathered aerosol-forming sheet material 75 (e.g., a cast leaf). The susceptor strip 74 is not perfectly straight and is not exactly on the central longitudinal axis of the article 73. Figure 5 In FIG. 7 , two rectangles 201 , 202 indicate the limits of the quality specification. The two rectangles 201 , 202 are arranged symmetrically around the central axis of the strip and indicate the boundary distances of the susceptor strip locations in the article 73 .

[0309] The inner rectangle 201 may, for example, indicate a warning threshold indicating measured articles 73 that include susceptor positions outside the inner rectangle 201. These articles are still considered acceptable. However, if a certain percentage of articles 73 (e.g., 5% to 20%) are outside the inner rectangle 201 and thus exceed the warning threshold, the control unit 8 may activate the positioning device 5 to adjust the position of the susceptor 74 when inserted into the sheet material 75. Alternatively or in addition, the control unit 8 may activate the curling device 4 to adjust the curling depth 40 of the sheet material 75 before inserting the continuous susceptor strip into the sheet material 75.

[0310] The outer rectangle 200 may be, for example, a reject threshold. If the controlled article provides a sensor position outside the outer rectangle 200, thereby exceeding the reject threshold, the article 73 is rejected.

[0311] Preferably, the position of the susceptor 73 is adjusted or the curl depth 40 is adjusted before the waste threshold increases.

[0312] exist Figure 6In FIG. 7 , the susceptor strip 74 is bent and displaced out of the central axis of the article 73 .

[0313] The output control 8 may include an eccentricity measurement or deformation measurement of the susceptor 74. For example, the center 202 and lateral ends 203 (lateral with respect to the cross-sectional view) of the susceptor 74 may be detected. Based on these measurements, the general displacement and bending range of the susceptor 74 may be detected and compared to an acceptable range for a predetermined quality specification. Several measurements along the susceptor 74 may enhance the accuracy of the susceptor location on a cross-section of the article.

[0314] For the purpose of this specification and the appended claims, unless otherwise indicated, all numbers representing amounts, quantities, percentages, etc. should be understood to be modified by the term "about" in all cases. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically listed herein. Therefore, in this context, the number A is understood to be A±5%A. In this context, the number A can be regarded as including a value within the general standard error for the measurement of the attribute modified by the number A. In certain cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of A deviation does not substantially affect the basic features and novel features of the invention claimed for protection. Moreover, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein that may or may not be specifically listed herein.

Claims

1. A closed-loop system for controlling the position of a susceptor in an aerosol-generating article, the system comprising: for a supply source of continuous sheet material; Supply source for continuous receptors; a curling device for curling the continuous sheet material; a forming device for gathering the continuous sheet material and for forming the continuous sheet material with the inserted continuous susceptor into a continuous strip; cutting means for cutting the continuous strip into aerosol-generating articles; a control unit comprising an output control for detecting a condition of a susceptor in the aerosol-generating article and for comparing the detected condition to a quality specification; wherein the system further comprises a positioning device for manipulating the position of the continuous sensor, or a curl depth adjuster, and wherein When the detected condition does not meet the quality specification, the control unit is adapted to trigger the positioning device to adjust the position of the continuous susceptor, or to trigger the curling depth adjuster to adjust the curling depth of the sheet material in the curling device.

2. A closed-loop system according to claim 1, wherein the detected condition of the aerosol-generating article comprises any one or more of the following: The position of a susceptor in the aerosol-generating article, the form of a susceptor in the aerosol-generating article, the eccentricity of a susceptor in the aerosol-generating article, or the shape of the collection of sheet material around the susceptor.

3. A closed-loop system according to any one of the preceding claims, wherein the output control is adapted to capture information of a cross-section of at least one end of the aerosol-generating article.

4. A closed loop system according to any one of the preceding claims, wherein the positioning device is movably arranged to be movable in at least two directions which are perpendicular to each other.

5. A closed loop system according to claim 4, wherein the positioning device is movable relative to the supply direction of the continuous susceptor.

6. A closed-loop system according to any one of claims 4 to 5, wherein the positioning device is movably arranged in the forming device.

7. A closed loop system according to any one of the preceding claims, wherein the positioning device has a conical shape.

8. A closed loop system according to any one of the preceding claims, wherein the crimp depth adjuster is adapted to vary the distance between two interacting crimping elements of the crimping device.

9. A closed-loop system according to any one of the preceding claims, wherein the control unit further comprises a moisture sensor for measuring the moisture content of the continuous sheet material, and wherein the control unit is adapted to trigger the curling depth adjuster to adjust the curling depth of the sheet material in the curling device depending on the measured moisture content of the continuous sheet material.

10. A method for controlling the position of a susceptor in an aerosol-generating article, the method comprising: Providing continuous sheet materials; curling the continuous sheet material; Provide continuous receptors; gathering the continuous sheet material and inserting the continuous susceptor into the continuous sheet material to form a continuous strip; cutting the continuous strip into aerosol-generating articles; performing output control to detect a condition of a susceptor in the aerosol-generating article and comparing the detected condition to a quality specification; Thus, when the detected condition does not meet the quality specifications of the aerosol-generating article: Adjust the position of the continuous sensor, or The curl depth of the continuous sheet material is adjusted. The method of claim 10 , wherein information of a cross-section of the aerosol-generating article is captured.

12. A method according to any one of claims 10 to 11, comprising adjusting the position of the continuous susceptor whilst gathering the continuous sheet material.

13. A method according to any one of claims 10 to 12, comprising adjusting the position of the continuous susceptor by guiding the continuous susceptor in and along a movable positioning device.

14. A method according to any one of claims 10 to 13, wherein the moisture content of the continuous sheet material is measured and the curl depth is adjusted depending on the moisture content of the continuous sheet material.

15. A method according to any one of claims 10 to 14, wherein a continuous sheet material is provided in the form of a non-aerosol forming sheet material, and the non-aerosol forming sheet material is changed into an aerosol forming sheet material by adding an aerosol forming substance to the non-aerosol forming sheet material before forming the continuous strip.

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