Detecting Segments for Aerosol-Generating Articles with Two Consecutive Sensors

The invention relates to providing quality control of an arrangement of segments for aerosol-generating articles.

WO 2021/121790 A1 discloses a method for optical analysis of a component of an aerosol-generating article. The component is rod-shaped and defines a first and a second end, one opposite to the other. The component includes an aerosol-forming substrate and a susceptor inserted within the aerosol-forming substrate. A first image of the first end of the component is generated by a first polarized camera to detect in the first image a position of the susceptor. A second image of the first end of the component is generated by a second polarized camera. Polarization information contained in the first image is combined with polarization information contained in the second image to obtain a single combined image of the first end of the component. A third image of the second end of the component is generated by a third polarized camera to detect in the third image a position of the susceptor. In an embodiment, an X-ray sensor is provided to irradiate the component between the first end and the second end.

During production of aerosol-generating articles, individual segments, such as rod-shaped segments, may be positioned with respect to each other to form arrangements of segments. There is a need to provide a way of conducting quality control of an arrangement of segments for aerosol-generating articles. There is a need to provide a way of determining the length of one or more individual segments in an arrangement of segments. There is a need to provide a way of determining the position of one or more segments in an arrangement of segments. There is a need for a way to conduct quality control of an arrangement of segments in an efficient manner. One or more of these needs may at least in part be satisfied by the present invention.

According to an aspect of the present invention, there is provided a method for conducting a quality control of an arrangement of segments for aerosol-generating articles. The arrangement of segments comprises at least two segments arranged consecutively along a longitudinal axis. Each segment extends along the longitudinal axis between two opposing longitudinal ends of the segment. The at least two segments comprise at least one aerosol-generating segment. The at least one aerosol-generating segment comprises an aerosol-generating material and a susceptor. The susceptor comprises a metallic material for heating the aerosol-generating material. The method comprises carrying out a first measurement comprising detecting the susceptor by magnetic interaction with the metallic material of the susceptor. The method further comprises carrying out a second measurement comprising optically detecting at least one longitudinal end of at least one of the segments.

Since the first measurement relies on detecting the susceptor by magnetic interaction with the metallic material of the susceptor, the first measurement may detect the susceptor with high reliability. The first measurement may detect the metallic material of the susceptor substantially irrespective of the appearance and the light transmission properties of the segments. The magnetic measurement may allow detecting the susceptor and, thus, the aerosol-generating segment, even in cases where the aerosol-generating segment and an adjacent segment without a susceptor are not visibly distinct.

The second measurement may rely on different optical properties of different segments of the arrangement of segments to detect the at least one longitudinal end of the at least one of the segments. The second measurement may allow distinguishing between two or more segments that do not comprises the susceptor.

The second measurement may be particularly efficient in detecting a longitudinal end of a segment that does not directly abut another longitudinal end of one of the segments.

The second measurement may comprise detecting a longitudinal end of a segment that directly abuts a longitudinal end of another segment, in particular by utilizing different optical properties of the segments.

Since the first measurement and the second measurement rely on different measurement principles, a broad range of information on the arrangement of segments may be obtained by carrying out both measurements. Combining the first magnetic measurement and the second optical measurement may allow obtaining accurate information on different kinds of segments or interfaces between segments.

The susceptor may extend in parallel to the longitudinal axis. The susceptor may extend along an entire length of the aerosol-generating segment along the longitudinal axis. The susceptor may be embedded in the aerosol-generating material of the aerosol-generating segment. The aerosol-generating material may fully surround the susceptor with respect to a circumferential direction of the susceptor. The susceptor may extend along the longitudinal axis from a first end of the susceptor to a second end of the susceptor. Along the longitudinal axis, the first end of the susceptor and the second end of the susceptor may coincide with the two opposing longitudinal ends of the aerosol-generating segment, respectively.

The first measurement may comprise detecting a position of the susceptor along the longitudinal axis. Detecting the position of the susceptor along the longitudinal axis may comprise one or more of detecting a position of the first end of the susceptor along the longitudinal axis, detecting a position of the second end of the susceptor along the longitudinal axis, and detecting a length of the susceptor along the longitudinal axis.

The position of the susceptor along the longitudinal axis may be detected as an absolute position along the longitudinal axis at the time of the first measurement, for example with respect to a specific reference point along the longitudinal axis. The position of the susceptor along the longitudinal axis may be determined as a relative position along the longitudinal axis, for example relative to a specific feature of the arrangement of segments.

The second measurement may comprise detecting a position of the at least one longitudinal end along the longitudinal axis.

The position of the at least one longitudinal end along the longitudinal axis may be detected as an absolute position along the longitudinal axis at the time of the second measurement, for example with respect to a specific reference point along the longitudinal axis. The position of the at least one longitudinal end along the longitudinal axis may be detected as a relative position along the longitudinal axis, for example relative to a specific feature of the arrangement of segments. For example, the position of the at least one longitudinal end along the longitudinal axis may be detected with respect to the position of another longitudinal end of one of the segments.

The at least one longitudinal end detected in the second measurement may be a longitudinal end of a segment different from the at least one aerosol-generating segment. The at least one longitudinal end detected in the second measurement may be a longitudinal end of a segment without a susceptor.

The at least two segments may comprise at least one segment without a susceptor. The at least two segments may comprise at least one segment without metallic material.

The at least two segments may comprise at least one of a filter segment, or a segment with a hollow acetate tube, or a mouthpiece segment. One or more of the filter segment, the segment with a hollow acetate tube, or the mouthpiece segment may be metal-free. The filter segment may comprise a filter for filtering aerosol released by the aerosol-generating material. The hollow acetate tube may be configured to provide a path through which aerosol generated by the aerosol-generating segment may flow. The aerosol may cool down while flowing through the hollow acetate tube. The mouthpiece segment may be configured to form a mouthpiece of an aerosol-generating article to be engaged by the mouth of a user.

The at least two segments may be fixed relative to each other.

The at least two segments may be provided in an end-to-end arrangement along the longitudinal axis. Consecutive segments of the at least two segments may abut each other. A spacing along the longitudinal axis between consecutive segments may be smaller than 10 millimeters, or smaller than 5 millimeters, or smaller than 3 millimeters, or smaller than 1 millimeter, or smaller than 0.5 millimeter.

The arrangement of segments may further comprise a wrapper wrapped around the at least two segments. The wrapper may fix the at least two segments with respect to each other. The wrapper may be wrapped around the at least two segments along a circumferential direction with respect to the longitudinal axis. The wrapper may comprise a paper material, for example. The wrapper may define an outer appearance of the arrangement of segments. The wrapper may have the same color along its entire surface. The wrapper may be wrapped around the at least two segments along the entire length of the arrangement of segments. Preferably, the wrapper is translucent.

Optically detecting the at least one longitudinal end of the at least one of the segments in the second measurement may comprise optically detecting at least two longitudinal ends of the segments, or detecting more than two longitudinal ends of the segments.

The second measurement may comprise detecting the at least one longitudinal end by an optical transmission measurement. An optical transmission measurement may allow distinguishing neighboring segments based on different optical transmittances of the segments. Different optical transmittances of the segments may result from different compositions of the segments.

The second measurement may comprise emitting light from a light source such that the light travels through the arrangement of segments, and detecting an intensity of the light that exits the arrangement of segments on the opposing side with an optical detector. The light source and the optical detector may be provided on opposing sides of the arrangement of segments. The arrangement of segments may be provided between the light source and the optical detector. The light source, the arrangement of segments, and the optical detector may be arranged one after the other along a direction that is at least substantially perpendicular to the longitudinal axis. The light may traverse the arrangement of segments along a direction that is at least substantially perpendicular to the longitudinal axis.

The second measurement may comprise obtaining a picture of the arrangement of segments. The picture may be comprised in a video. The method may comprise analyzing the picture to detect interfaces between adjacent segments. The method may comprise analyzing the picture to detect a length or a position of at least one of the segments. Analyzing the picture may comprise analyzing light intensities in different regions of the picture. Analyzing the picture may comprise analyzing a light intensity distribution along the longitudinal axis.

The second measurement may comprise detecting an interface of adjacent segments. An interface of adjacent segments may be determined as a position along the longitudinal axis where a transmittance of the arrangement of segments changes.

The first measurement may comprise detecting an electric current in an electric coil. The electric current may be indicative of a metallic material in a measurement region. The metallic material may be the metallic material of the susceptor. The electric coil may be part of a metal detector. A winding direction of the electric coil may be around the longitudinal axis. A winding direction of the electric coil may be perpendicular to the longitudinal axis. The electric coil may be a detector coil.

The first measurement may comprise inducing electric currents in the susceptor by magnetic interaction with the susceptor. The electric currents may be induced in the susceptor by subjecting the susceptor to an electromagnetic field. The electromagnetic field may be generated by an electric coil, in particular an excitation coil.

The method may further comprise conveying the arrangement of segments. One or both of the first measurement and the second measurement may be carried out while the arrangement of segments is conveyed. One or both of the first measurement and the second measurement may be carried out in-line during a running production process involving the arrangement of segments. The arrangement of segments may be conveyed along a transport path. At least a section of the transport path may be parallel to the longitudinal axis. A first measurement station configured for carrying out the first measurement may be provided along the transport path. A second measurement station configured for carrying out the second measurement may be provided along the transport path. The second measurement station may be provided downstream of the first measurement station with respect to the transport path. One or both of the first measurement station and the second measurement station may be stationary. The arrangement of segments may be conveyed through the first measurement station in parallel to the axial direction.

The method may further comprise separating the arrangement of segments from at least a further arrangement of segments between the first measurement and the second measurement. If the arrangement of segments is separated from the further arrangement of segments before the second measurement, the second measurement may detect defects resulting from the separation step. For example, the second measurement may be configured to determine whether the arrangement of segments has been separated from the further arrangement of segments at the correct position or whether the arrangement of segments has the correct length after the separation step.

The method may comprise evaluating data from the first measurement to determine the length of at least one individual segment of the arrangement of segments. The method may comprise evaluating data from the second measurement to determine the length of at least one individual segment of the arrangement of segments. The method may comprise evaluating data from the first measurement and data from the second measurement to determine the length of at least one individual segment of the arrangement of segments. The method may comprise evaluating data from the first measurement and data from the second measurement to determine lengths of the individual segments of the arrangement of segments. The data from the first measurement and the data from the second measurement may be combined to determine the length of one or more individual segments of the arrangement of segments.

According to another aspect of the present invention, there is provided a system for conducting a quality control of an arrangement of segments for aerosol-generating articles. The arrangement of segments comprises at least two segments. The at least two segments are arranged consecutively along a longitudinal axis. Each segment extends along the longitudinal axis between two opposing longitudinal ends of the segment. The at least two segments comprise at least one aerosol-generating segment. The at least one aerosol-generating segment comprises an aerosol-generating material and a susceptor. The susceptor comprises a metallic material for heating the aerosol-generating material. The system comprises a first measurement station, a second measurement station, and a conveying system. The first measurement station comprises a magnetic detector configured to detect the susceptor by magnetic interaction with the metallic material of the susceptor. The second measurement station comprises an optical detector configured to optically detect at least one longitudinal end of at least one of the segments. The conveying system is configured to convey the arrangement of segments along a transport path through the first measurement station and the second measurement station.

Preferably, at least a section of the transport path is parallel to the longitudinal axis. Preferably, the transport path is parallel to the longitudinal axis at the first measurement station.

Preferably, the second measurement station is downstream of the first measurement station with respect to the transport path.

The magnetic detector may comprise at least one detection coil. The magnetic detector may comprise a measurement device for measuring a current flowing through the detection coil.

The magnetic detector may comprise an excitation coil configured to induce electrical currents in the susceptor.

The magnetic detector may be configured to detect a position of the susceptor along the longitudinal axis.

The magnetic detector may be configured to detect a position of the susceptor in a radial direction perpendicular to the longitudinal direction. The magnetic detector may be configured to detect a displacement of the susceptor from a target susceptor orientation. The target susceptor orientation may correspond to the susceptor extending in parallel to the longitudinal axis. The magnetic detector may be configured to detect a deviation of the susceptor from a target radial susceptor position. The target radial susceptor position may correspond to the susceptor being centrally positioned in the aerosol-generating segment.

The at least one detection coil may comprise two or more detection coils, in particular four detection coils. The detection coils may be arranged such that their respective winding axes extend perpendicular to the longitudinal axis. The detection coils may be arranged circumferentially around the transport path at 90 degrees intervals. The measurement device may be configured to separately detect the currents flowing through the individual detection coils.

The optical detector may be configured to detect a position of the at least one longitudinal end along the longitudinal axis.

The optical detector may be configured to detect an interface of adjacent segments.

The optical detector may comprise a light source. The optical detector may comprise a light detector. The light source and the light detector may be arranged on opposing sides of the transport path. The light source may be optional, and natural light may instead be used, for example.

The light detector may comprise a camera. The camera may be a monochromatic camera. The camera may be color sensitive camera. The light detector may be configured to record a light intensity in a detection region. The light detector may be configured to record a light intensity distribution along the axial direction.

The system may further comprise a cutting station. The cutting station may be configured to separate the arrangement of segments from at least a further arrangement of segments. The arrangement of segments and the further arrangement of segments may be of the same or similar configuration. The cutting station may be arranged between the first measurement station and the second measurement station with respect to the transport path.

The system may further comprise a computing device. The computing device may be configured to determine lengths of the individual segments of the arrangement of segments by combining measurement data from the first measurement station with measurement data from the second measurement station.

According to another aspect of the present invention, there is provided a use of a magnetic detector for determining at least one of the position and length of an aerosol-generating segment in an arrangement of segments for aerosol-generating articles. The arrangement of segments comprises at least two segments consecutively arranged along a longitudinal axis.

The aerosol-generating segment may comprise an aerosol-generating material and a susceptor comprising a metallic material for heating the aerosol-generating material.

The measurement data from the magnetic detector may be combined with measurement data from an optical detector optically detecting at least one longitudinal end of at least one of the segments.

Optically detecting the at least one longitudinal end may comprise detecting a position of the at least one longitudinal end along the longitudinal axis.

Optically detecting the at least one longitudinal end may comprise detecting an interface of adjacent segments.

The arrangement of segments may be separated from at least a further arrangement of segments between the magnetic detector and the optical detector.