Method and apparatus for static joining of strips of material - Patent Application 20070122997

Abstract

The present invention relates to a joining head for joining two material strips, the joining head having a process direction extending from an upstream end to a downstream end, an orthogonal direction perpendicular to the process direction, a first channel for guiding a first material strip and a second channel for guiding a second material strip, the first and second channels being arranged in parallel along the process direction, an upstream cutting plate and a downstream cutting plate, the upstream and downstream cutting plates being disposed between the first and second channels along the orthogonal direction, an upstream cutting blade and a downstream cutting blade, the upstream cutting blade and the downstream cutting blade being disposed on either side of the first and second channels in the orthogonal direction such that the upstream cutting blade is located adjacent to the second channel and the downstream cutting blade is located adjacent to the first channel, and a welding station disposed between the upstream and downstream cutting blades along the process direction, the welding station including at least one welding electrode and a welding plate, the at least one welding electrode and the welding plate being disposed on either side of the first and second channels in the orthogonal direction. The present invention also relates to a method for joining two material strips and an apparatus for joining two material strips.

Description

[Technical Field]

[0001] The present disclosure relates to a joining head for joining two strips of material.The present disclosure further relates to a method of joining two strips of material.The present disclosure further relates to an apparatus for joining two strips of material. [Background technology]

[0002] In manufacturing or production processes in which strips of material provided on bobbins are processed, it may be desirable to unwind the strip from the bobbin at a high speed so that the strip can also be processed at a high speed. For example, in the manufacture of aerosol-generating articles, the strip may be a susceptor material strip, such as a metal strip. Summary of the Invention [Problem to be solved by the invention]

[0003] If the bobbin is empty, the manufacturing or production process must be slowed or stopped to replace the empty bobbin with a new one. Similarly, if the strip is defective, the manufacturing or production process must be slowed or stopped to replace the defective strip with a new one. To avoid a complete stoppage of production, two strips wound on two different bobbins may be provided: an "old" bobbin and a "new" bobbin. The strips can be spliced ​​such that a new bobbin with a defect-free strip replaces the old one with the defective strip, or the old one is ejected. However, the joint where the old strip is spliced ​​with the new strip may be less stable and more easily prone to rupture due to physical stresses during further processing downstream of the splicing head.

[0004] It is desirable to provide a joining mechanism that may enable joining of two metal strips without removing the strips from the production line during joining. It is desirable to provide a joining mechanism that reduces or avoids production line downtime due to joining. It is desirable to provide a joining mechanism that reduces the mean time to restart equipment. It is desirable to provide a joining mechanism that avoids machine stoppages during joining. It is desirable to provide a more robust joining mechanism. It is desirable to provide a joining mechanism that provides high mechanical stability of the joined strips. It is desirable to provide a joining mechanism that reduces the risk of defects or rupture of the joined strips. It is desirable to provide a joining mechanism that reduces waste of strip material. It is desirable to provide a more economically preferable joining mechanism. It is desirable to provide a more ecologically preferable joining mechanism. [Brief explanation of the drawings]

[0005] [Figure 1] Figures 1a and 1b show the joining head. [Figure 2] 2a to 2c show the steps of the bonding method. [Figure 3] 3a to 3c show the bonding head. DETAILED DESCRIPTION OF THE INVENTION

[0006] According to one embodiment of the present invention, a joining head for joining two strips of material is provided. The joining head may have a process direction extending from an upstream end to a downstream end. The joining head may have an orthogonal direction perpendicular to the process direction. The joining head may have a first channel for guiding a first strip of material and a second channel for guiding a second strip of material. The first and second channels may be arranged in parallel along the process direction. The joining head may include an upstream cutting plate and a downstream cutting plate. The upstream and downstream cutting plates may be disposed between the first and second channels along the orthogonal direction. The joining head may include an upstream cutting blade. The joining head may include a downstream cutting blade. The upstream and downstream cutting blades may be disposed on either side of the first and second channels in the orthogonal direction such that the upstream cutting blade is positioned adjacent to the second channel and the downstream cutting blade is positioned adjacent to the first channel. The joining head may include a welding station disposed between the upstream and downstream cutting blades along the process direction. The welding station may include at least one welding electrode and a welding plate. At least one welding electrode and welding plate may be disposed orthogonally on either side of the first channel and the second channel.

[0007] According to one embodiment of the present invention, a joining head for joining two strips of material is provided. The joining head has a process direction extending from an upstream end to a downstream end. The joining head has an orthogonal direction perpendicular to the process direction. The joining head has a first channel for guiding a first strip of material and a second channel for guiding a second strip of material. The first and second channels are arranged in parallel along the process direction. The joining head has an upstream cutting plate and a downstream cutting plate. The upstream cutting plate and the downstream cutting plate are arranged between the first channel and the second channel along the orthogonal direction. The joining head has an upstream cutting blade and a downstream cutting blade. The upstream cutting blade and the downstream cutting blade are arranged in the orthogonal direction on either side of the first channel and the second channel such that the upstream cutting blade is located adjacent to the second channel and the downstream cutting blade is located adjacent to the first channel. The joining head has a welding station arranged between the upstream cutting blade and the downstream cutting blade along the process direction. The welding station has at least one welding electrode and a welding plate. At least one welding electrode and a welding plate are disposed orthogonally on opposite sides of the first and second channels.

[0008] A joining mechanism is provided which may reduce the mean time to restart the equipment. A joining mechanism is provided which may avoid machine stoppages during joining. A more robust joining mechanism is provided. A joining mechanism is provided which provides greater mechanical stability of the joined strips. A joining mechanism is provided which reduces the risk of failure or rupture of the joined strips. Failure or rupture of the joined strips may lead to defective strip portions downstream of the joining head, or defective articles that have to be discarded. A joining mechanism is therefore provided which may reduce waste of strip material. An economically more favourable joining mechanism is provided. An ecologically more favourable joining mechanism is provided.

[0009] The upstream cutting blade may be located immediately downstream of the upstream cutting plate. The downstream cutting blade may be located immediately upstream of the downstream cutting plate. The upstream cutting blade may be located immediately downstream of the upstream cutting plate, and the downstream cutting blade may be located immediately upstream of the downstream cutting plate.

[0010] The at least one welding electrode may include an upstream welding electrode and a downstream welding electrode. The welding station may be configured to apply a current pulse between the upstream welding electrode and the downstream welding electrode.

[0011] The splicing head may comprise one or more guiding and aligning means for guiding and aligning one or both of the upstream and downstream cutting plates relative to the upstream and downstream cutting blades, respectively. The guiding and aligning means may guide a cutting plate to be aligned along the process direction immediately adjacent its corresponding cutting blade to effect a scissors cutting effect and avoid accidental collision of the cutting plate on the respective cutting blade.

[0012] One or both of the upstream cutting plate and the downstream cutting blade may include guide and alignment means. One or both of the upstream cutting blade and the downstream cutting blade may have an L-shape with a horizontal cutting component for cutting the strips of material and an orthogonal alignment component parallel to the orthogonal direction and functioning as a guide and alignment means for guiding and aligning the cutting plate relative to the respective cutting blade.

[0013] The bonding head may include one or more alignment means for aligning the first and second strips over one another. The bonding head may include alignment means including one or more pairs of engaging structures disposed orthogonally on opposite sides of the first and second channels such that a first structure of the pair is located adjacent to the second channel and an engaging second structure of the pair is located adjacent to the first channel. The first and second strips may be guided along the first and second channels between the pairs of engaging structures, thereby being aligned over one another. The engaging structures may be engaging tripods.

[0014] One or both of the upstream cutting plate and the downstream cutting blade may be configured to allow only limited movement of the cutting blade along the orthogonal direction. For example, the upstream cutting blade may be configured to move orthogonally beyond the edge of the upstream cutting plate facing the upstream cutting blade a distance of less than 80 percent, or less than 75 percent, or less than 50 percent of the thickness of the cutting plate. For example, the upstream cutting blade may be configured to move orthogonally beyond the edge of the upstream cutting plate facing the upstream cutting blade a distance of less than 10 millimeters, less than 5 millimeters, or less than 2 millimeters.

[0015] For example, the downstream cutting blade may be configured to move orthogonally beyond the edge of the downstream cutting plate facing the downstream cutting blade a distance of less than 80 percent, or less than 75 percent, or less than 50 percent of the thickness of the cutting plate. For example, the downstream cutting blade may be configured to move orthogonally beyond the edge of the downstream cutting plate facing the downstream cutting blade a distance of less than 10 millimeters, less than 5 millimeters, or less than 2 millimeters.

[0016] By limiting the orthogonal movement of one or both of the upstream cutting plate and the downstream cutting blade, it can be further ensured that each cutting blade only cuts one of the strips and the other strip is not accidentally cut or weakened by the respective blade.

[0017] One or both of the upstream cutting plate and the downstream cutting plate may be configured to be movable along a third direction, which may be perpendicular to both the process direction and the orthogonal direction.

[0018] The present invention further relates to a method for joining two strips of material. The method may include providing a joining head as described herein. The method may include providing a first strip of material and a second strip of material. The method may include guiding the first and second strips along first and second channels of the joining head. The method may include stopping transport of at least one segment of the first strip and at least one segment of the second strip along the process direction to provide static segments of the first and second strips at the joining head. The method may include moving at least one welding electrode and a welding plate toward each other along an orthogonal direction such that the first strip and the second strip contact each other and are positioned between the at least one welding electrode and the welding plate. The method may include applying an electric current to a welding station to weld the first strip and the second strip together. The method may include moving an upstream cutting blade toward the upstream cutting plate along the orthogonal direction to cut an upstream end of the second strip from the welded first and second strips. The method may include moving a downstream cutting blade along the orthogonal direction toward a downstream cutting plate to cut a downstream end of the first strip from the welded first and second strips.

[0019] The present invention further relates to a method for joining two strips of material. The method includes providing a joining head as described herein. The method includes a first strip of material and a second strip of material. The method includes guiding the first and second strips along first and second channels of the joining head. The method includes stopping transport of at least one segment of the first strip and at least one segment of the second strip along a process direction to provide static segments of the first and second strips at the joining head. The method includes moving at least one welding electrode and a welding plate toward each other along an orthogonal direction such that the first strip and the second strip contact each other and are positioned between the at least one welding electrode and the welding plate. The method includes applying an electric current to a welding station to weld the first strip and the second strip together. The method includes moving an upstream cutting blade toward the upstream cutting plate along the orthogonal direction to cut an upstream end of the second strip from the welded first and second strips. The method includes moving a downstream cutting blade along an orthogonal direction toward a downstream cutting plate to cut a downstream end of the first strip from the welded first and second strips.

[0020] The steps of the method may be performed sequentially according to the order described above.

[0021] One or more of the method steps may be performed simultaneously. For example, the method may include moving an upstream cutting blade along an orthogonal direction toward an upstream cutting plate to cut an upstream end of the second strip from the welded first and second strips, and simultaneously moving a downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut a downstream end of the first strip from the welded first and second strips. For example, the steps of moving at least one welding electrode and a weld plate toward each other along the orthogonal direction so that the first and second strips contact each other and are positioned between the at least one welding electrode and the weld plate, moving the upstream cutting blade along the orthogonal direction toward the upstream cutting plate, and moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate may be performed simultaneously or partially simultaneously.

[0022] The static joining mechanism of the present invention may result in less mechanical friction between the electrode and the metal strip compared to a dynamic joining mechanism, where the transport of the strip is not stopped during joining, thereby resulting in less wear on the electrode and a longer lifespan of the electrode, and may provide an economically more favorable joining mechanism.

[0023] In the static joining mechanism of the present invention, the moving strips are more likely to be unintentionally deflected compared to the static strips, so there may be less misalignment of the metal strips on top of each other compared to dynamic joining mechanisms. A more robust joining strip may be provided.

[0024] The step of applying an electric current to the welding station to weld the first and second strips together may be done in different ways.

[0025] For example, the at least one welding electrode may be a single electrode and the current may be applied between the single electrode and the welding plate.

[0026] For example, the at least one welding electrode may be a first electrode and a second electrode, and current may be applied in a first pulse between the first electrode and the weld plate and then in a second pulse between the second electrode and the weld plate.

[0027] For example, the at least one welding electrode may be a first electrode and a second electrode, and current may be applied in a first pulse between the first electrode and the weld plate and simultaneously in a second pulse between the second electrode and the weld plate.

[0028] For example, the at least one welding electrode may be a first electrode and a second electrode, and current may be applied in a single pulse between the first electrode and the weld plate and between the second electrode and the weld plate.

[0029] For example, the at least one welding electrode may be a first electrode and a second electrode, and a current may be applied between the first electrode and the second electrode.

[0030] The first electrode may be located upstream of the second electrode along the process direction. The first electrode may be located downstream of the second electrode along the process direction.

[0031] The method may include, after moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to sever the downstream end of the first strip from the welded first and second strips, retracting the at least one welding electrode and weld plate along the orthogonal direction. The method may include, after moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to sever the downstream end of the first strip from the welded first and second strips, retracting the at least one welding electrode and weld plate along the orthogonal direction, and then retracting the upstream cutting plate and the downstream cutting blade along the orthogonal direction. The method may include, after moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to sever the downstream end of the first strip from the welded first and second strips, retracting the at least one welding electrode and weld plate along the orthogonal direction, and simultaneously retracting the upstream cutting blade and the downstream cutting blade along the orthogonal direction.

[0032] The method may include aligning the first and second strips of material over one another. The aligning step may be performed before the strips are welded and / or while the strips are being welded. The aligning step may be performed by one or more alignment means described herein.

[0033] The method may include guiding and aligning one or both of the upstream cutting plate and the downstream cutting blade relative to the respective upstream cutting plate and downstream cutting blade. The guiding and aligning may be performed before the strips are welded and / or while the strips are being welded. The guiding and aligning may be performed by one or more guiding and aligning means described herein.

[0034] The method may include retracting the upstream and downstream cutting plates along a third direction after moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips.

[0035] Preferably, the first and second strips of material are not pre-weakened prior to joining.

[0036] The first and second strips of material may comprise a susceptor material. The susceptor material may comprise one or more metallic materials. The susceptor material may comprise aluminum. The first and second strips of material may be configured for use as a susceptor in an aerosol-generating article. The first and second strips may be susceptor strips for use in an aerosol-generating article.

[0037] As used herein, the term "susceptor" or "susceptor element" refers to an element that heats when subjected to an alternating magnetic field. This may be the result of eddy currents induced in the susceptor element, hysteresis losses, or both eddy currents and hysteresis losses. During use, the susceptor element is positioned in thermal contact or thermal proximity with an aerosol-forming substrate received in an aerosol-generating device or cartridge. In this manner, the aerosol-forming substrate is heated by the susceptor, thereby forming an aerosol.

[0038] The susceptor element may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptor elements comprise metal or carbon.

[0039] Preferred susceptor elements may include or consist of a ferromagnetic material, such as a ferromagnetic alloy, ferritic iron, or ferromagnetic steel or stainless steel, etc. Suitable susceptor elements may be or include aluminum.

[0040] Suitable susceptor elements may include a non-metallic core having a metal layer, such as a metal band formed on the surface of the ceramic core. The susceptor element may have a protective outer layer, such as a protective ceramic or glass layer, encapsulating the susceptor element. The susceptor element may include a protective coating formed of glass, ceramic, or an inert metal formed over a core of susceptor element material.

[0041] The susceptor element may be disposed in thermal contact with the aerosol-forming substrate of the aerosol-forming substrate portion in which the susceptor element is incorporated. Thus, as the temperature of the susceptor element increases, the aerosol-forming substrate is heated and an aerosol is formed. Preferably, the susceptor element is disposed in direct physical contact with the aerosol-forming substrate, for example, within the aerosol-forming substrate.

[0042] The first and second strips of material can have widths of at least about 1 millimeter, more preferably at least about 2 millimeters. Typically, the susceptor may have a width of up to 8 millimeters, preferably about 6 millimeters or less. The first and second strips of material may have a substantially rectangular cross-section, preferably with a width of about 2 millimeters to about 8 millimeters, more preferably about 3 millimeters to about 6 millimeters. The first and second strips of material may have a width of about 4 millimeters.

[0043] The first and second strips of material may have a thickness of about 10 micrometers to about 1,000 micrometers, preferably about 20 micrometers to about 500 micrometers, more preferably about 25 micrometers to about 250 micrometers, even more preferably about 30 micrometers to about 100 micrometers, and more preferably about 40 micrometers to about 80 micrometers. The first and second strips of material may have a thickness of about 57 micrometers to about 63 micrometers. Even more preferably, the first and second strips of material may have a thickness of about 58 micrometers to about 62 micrometers. Most preferably, the first and second strips of material have a thickness of about 60 micrometers.

[0044] Preferably, the first and second strips are made of the same material and have the same dimensions.

[0045] Conveying the strip of material can be carried out at a strip speed of about 50 meters / minute to about 400 meters / minute.

[0046] A buffering unit may be provided downstream of the splicing head. The method may include one of stopping a portion of the processing line downstream of the buffering unit, operating it at a slower speed, or operating it at a normal speed during the step of splicing the first strip and the second strip with the splicing head. The method may include buffering a given length of the first strip in the buffering unit prior to the splicing step.

[0047] The upstream portion of the first strip may be wound onto a first bobbin. The upstream portion of the second strip may be wound onto a second bobbin. The method may include rejecting the first bobbin after the joining step. The method may include swapping the position of the first bobbin and the position of the second bobbin after joining.

[0048] The method may include providing an aerosol-forming substrate and forming a rod comprising the joined strip and aerosol-forming substrate.

[0049] According to one embodiment of the present invention, there is provided a method of forming an aerosol-generating article, comprising forming one or more rods as described herein and incorporating the one or more rods into an aerosol-generating article.

[0050] According to another embodiment of the present invention, there is provided an apparatus for joining two strips of material. The apparatus includes a processing line. The processing line has an upstream end and a downstream end. The processing line is configured to process one or both of a first strip of material and a second strip of material. The apparatus includes a joining head as described herein. The joining head is located between the upstream end and the downstream end of the processing line.

[0051] The apparatus may include a buffer unit adapted to buffer a variable amount of the first strip or the second strip, the buffer unit being located downstream of the bonding head.

[0052] The apparatus may include a quality sensor configured to detect a value of a quality parameter at the detected portion of the first strip. The apparatus may include a controller connected to the quality sensor. The controller may be configured to evaluate whether the value of the quality parameter falls within a predetermined threshold to determine whether a joining routine is initiated. If the value does not fall within the predetermined threshold, the quality of the detected portion of the first strip may be acceptable, meaning that normal processing of the first strip continues and joining is not initiated. If the value does fall within the predetermined threshold, the quality of the detected portion of the first strip is outside an acceptable range, meaning that a joining routine is initiated by the controller.

[0053] The quality sensor may comprise one or more of an optical sensor, preferably a light sensor, a photo camera, or a video camera. The optical sensor may comprise a light source.

[0054] The quality sensor may be configured to detect one or more of a width of the first strip, a thickness of the first strip, and the presence or absence of holes or tears in the first strip. The quality sensor may be configured to detect a width of the first strip, and the quality parameter may be the width of the first strip.

[0055] The first strip defines a width. The width of the strip is the dimension of the strip in a direction substantially perpendicular to the direction of transport of the strip. The width of the strip is also substantially perpendicular to the thickness of the strip. When width is measured as the integrity parameter, a width sensor adapted to measure the width of the first material strip containing the alkaloid and transmit a signal based on the width measurement may be used. The width sensor may be a distance sensor. The width sensor may include a light barrier sensor. The width sensor may include a camera.

[0056] The bond may be made according to a measurement of the width of the first strip.

[0057] The quality sensor may be or may include a distance sensor adapted to measure the distance between the sensor and an outer surface of the bobbin holding the strip of material, and if the distance is outside a preset range, the quality sensor may indicate that the bobbin may be nearly empty.

[0058] Preferably, the evaluation of one of the more parameters of the first strip is performed before buffering of the first strip.

[0059] The apparatus may include a first holder for holding a first strip of material and a second holder for holding a second strip of material. The first holder may be a first shaft adapted to rotatably hold a first bobbin of the first strip. The second holder may be a second shaft adapted to rotatably hold a second bobbin of the second strip.

[0060] The upstream portion of the first strip may be wound onto a first bobbin. The upstream portion of the second strip may be wound onto a second bobbin. The first bobbin may be formed by a coil of the first material strip. The first bobbin may be inserted into a first shaft adapted to rotate about its axis of rotation. The second bobbin may be formed by a coil of the second material strip. The second bobbin may be inserted into a second shaft adapted to rotate about its axis of rotation. The method may include a step of rejecting the first bobbin after the joining step. The method may include a step of exchanging the position of the first bobbin with the position of the second bobbin after joining. Preferably, a new bobbin, such as a third bobbin, is inserted into the first shaft to replace the first bobbin.

[0061] The apparatus may include a bobbin holder unit including a first shaft and a second shaft. The bobbin holder unit may be adapted to exchange positions of the first shaft and the second shaft. For example, the bobbin holder unit may include a rotating disk, and the first shaft and the second shaft may extend from the same side of the disk. Rotation of the disk may allow the positions of the shafts to be exchanged.

[0062] The device may comprise a rod former, and the rod so formed may preferably be used as a component of an aerosol-generating article.

[0063] As used herein, the term "strip" refers to a laminar element having a width and length substantially greater than its thickness. The width of the material strip is preferably between about 1 millimeter and about 8 millimeters. The thickness of the material strip is preferably between about 20 micrometers and about 500 micrometers, more preferably between about 30 micrometers and about 80 micrometers, and even more preferably between about 50 micrometers and 70 micrometers.

[0064] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate capable of emitting volatile compounds capable of forming an aerosol. An "aerosol-generating article" according to the present invention may take the form of an article in which an alkaloid-containing material, such as tobacco material, is heated without combustion to form an aerosol, and an article in which an alkaloid-containing aerosol is produced from an alkaloid-containing material, for example, from a tobacco extract or other nicotine source, without combustion or heating. An aerosol-generating article according to the present invention may be a complete assembled aerosol-forming article, or may be a component of an aerosol-generating article that is combined with one or more other components to provide an assembled article for producing an aerosol, such as a consumable part of a heated smoking device. The aerosol-generating article may also include a susceptor strip surrounding an aerosol-forming substrate.

[0065] The terms "upstream" and "downstream" are used herein to refer to the process direction of the strip.

[0066] As used herein, the term "perpendicular" is not necessarily limited to an angle of exactly 90 degrees, but in some embodiments may include angles that deviate somewhat from a right angle. For example, deviations of about 15 degrees or less, or about 10 degrees or less, or about 5 degrees or less, or about 2 degrees or less, or about 1 degree or less may be acceptable. For example, the angle between the processing direction and the orthogonal direction may be 75 degrees or more and 90 degrees or less, 80 degrees or more and 90 degrees or less, 85 degrees or more and 90 degrees or less, 88 degrees or more and 90 degrees or less, or 89 degrees or more and 90 degrees or less. The term "perpendicular" may be limited to angles of about 90 degrees. The term "perpendicular" may be limited to angles of 90 degrees.

[0067] As used herein, the term "parallel" is not necessarily limited to an angle of exactly 0 degrees, but in some embodiments may include angles that deviate somewhat from strictly parallel. For example, deviations of about 15 degrees or less, or about 10 degrees or less, or about 5 degrees or less, or about 2 degrees or less, or about 1 degree or less may be acceptable. For example, the angle between the first channel and the second channel along the process direction may be between 0 degrees and 15 degrees, between 0 degrees and 10 degrees, between 0 degrees and 5 degrees, between 0 degrees and 2 degrees, or between 0 degrees and 1 degree. The term "parallel" may be limited to an angle of about 0 degrees. The term "parallel" may be limited to an angle of 0 degrees.

[0068] Below is provided a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features described above, for example, with any one or more features of other examples, embodiments, or aspects described herein.

[0069] Embodiment E1: A joining head for joining two strips of material, comprising: a process direction extending from the upstream end to the downstream end; an orthogonal direction perpendicular to the processing direction; a first channel for guiding a first strip of material and a second channel for guiding a second strip of material, the first and second channels being arranged in parallel along a processing direction; an upstream cutting plate and a downstream cutting plate, the upstream cutting plate and the downstream cutting plate being disposed between the first channel and the second channel along an orthogonal direction; an upstream cutting blade and a downstream cutting blade, the upstream cutting blade and the downstream cutting blade being positioned on opposite sides of the first channel and the second channel in an orthogonal direction such that the upstream cutting blade is positioned adjacent to the second channel and the downstream cutting blade is positioned adjacent to the first channel; a welding station disposed between the upstream cutting blade and the downstream cutting blade along the processing direction, the welding station including at least one welding electrode and a welding plate, the at least one welding electrode and the welding plate being disposed on opposite sides of the first and second channels in an orthogonal direction;

[0070] Example E2: The splicing head of example E1, wherein the upstream cutting blade is located immediately downstream of the upstream cutting plate and the downstream cutting blade is located immediately upstream of the downstream cutting plate.

[0071] Example E3: A joining head described in Example E1 or Example E2, wherein at least one welding electrode includes an upstream welding electrode and a downstream welding electrode, and preferably, the welding station is configured to apply a current pulse between the upstream welding electrode and the downstream welding electrode.

[0072] Example E4: A bonding head described in any of Examples E1 to E3, wherein the upstream cutting plate and the downstream cutting plate are configured to be movable along a third direction, and the third direction is perpendicular to both the process direction and the orthogonal direction.

[0073] Example E5: A joining head described in any of Examples E1 to E4, comprising one or more guiding and aligning means for guiding and aligning one or both of the upstream and downstream cutting plates relative to the respective upstream cutting plate and downstream cutting blade.

[0074] Example E6: The joining head of example E5, wherein one or both of the upstream cutting plate and the downstream cutting blade are provided with guiding and alignment means.

[0075] Example E7: A joining head as described in example E6, wherein one or both of the upstream cutting plate and the downstream cutting blade have an L-shape with a horizontal cutting part for cutting the material strips and an orthogonal alignment part that is parallel to the orthogonal direction and functions as a guiding and alignment means for guiding and aligning the cutting plate relative to the respective cutting blade.

[0076] Example E8: The splice head of any of Examples E1-E7, comprising one or more alignment means for aligning the first and second strips on top of each other.

[0077] Embodiment E9: A bonding head, wherein the alignment means is provided by one or more pairs of engaging structures arranged on opposite sides of the first and second channels in an orthogonal direction, the first structure of the pair being arranged adjacent to the second channel and the engaging second structure of the pair being arranged adjacent to the first channel; A bonding head as described in example E8, wherein the bonding head is configured to guide the first and second strips along the first and second channels between the engaging pair of structures to align the first and second strips on top of each other.

[0078] Example E10: The bonding head of example E9, wherein the engagement structure is configured as an engagement tripod.

[0079] Example E11: A method of joining two strips of material, comprising: Providing a bonding head according to any one of embodiments E1 to E10; Providing a first strip of material and a second strip of material; Guiding the first and second strips along the first and second channels of the bonding head; stopping transport of at least one segment of the first strip and at least one segment of the second strip along the process direction to provide static segments of the first and second strips at the bonding head; moving the at least one welding electrode and the weld plate toward each other along an orthogonal direction such that the first and second strips contact each other and are positioned between the at least one welding electrode and the weld plate; applying an electric current to the welding station to weld the first strip and the second strip together; moving the upstream cutting blade along the orthogonal direction toward the upstream cutting plate to cut the upstream end of the second strip from the welded first and second strips; and moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips.

[0080] Example E12: The method described in Example E11, further comprising, after the step of moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips, the step of retracting at least one welding electrode and welding plate along the orthogonal direction, and optionally the step of retracting the upstream cutting plate and downstream cutting blade along the orthogonal direction.

[0081] Example E13: A method described in Example E11 or Example E12, comprising providing a joining head described in Example E4, and further comprising a step of retracting the upstream cutting plate and the downstream cutting plate along a third direction after the step of moving the downstream cutting blade in a perpendicular direction toward the downstream cutting plate to separate the downstream end of the first strip from the welded first and second strips.

[0082] Example E14: A method of joining two strips of material, comprising: providing a processing line for conveying strips of material from an upstream end toward a downstream end of the processing line; providing a splice head positioned between an upstream end and a downstream end of the processing line; providing a first strip of material and a second strip of material to a processing line; stopping the transport of at least one segment of the first strip and at least one segment of the second strip to provide static segments of the first and second strips at the bond head; and joining the static segment of the first strip and the static segment of the second strip with a joining head.

[0083] Example E15: The method of example E14, wherein the joining head comprises a welding station, and the step of joining the stationary segment of the first strip and the stationary segment of the second strip with the joining head comprises welding the first strip to the second strip.

[0084] Example E16: A method described in example E14 or example E15, wherein the joining station includes an upstream cutting blade and a downstream cutting blade, and the step of joining the stationary segment of the first strip and the stationary segment of the second strip at the joining head includes cutting the upstream portion of the second strip with the upstream cutting blade and cutting the downstream portion of the first strip with the downstream cutting blade.

[0085] Example E17: The method of any of Examples E11-E16, wherein the first and second strips of material are not pre-weakened prior to joining.

[0086] Example E18: The method of any of Examples E11-E17, wherein the first and second strips of material comprise a susceptor material, preferably the susceptor material comprises one or more metals, more preferably the susceptor material comprises aluminum.

[0087] Example E19: The method of example E18, wherein the first and second strips are susceptor strips for use in an aerosol-generating article comprising an aerosol-forming substrate.

[0088] Embodiment E20: The method of any of embodiments E11-E19, further comprising a buffer unit provided downstream of the bonding head.

[0089] Example E21: The method described in example E20, wherein a portion of the processing line downstream of the buffer unit is either stopped, operated at a lower speed, or operated at normal speed during the step of joining the first strip and the second strip at the joining head.

[0090] Example E22: The method of example E20 or example E21, comprising buffering the length of the first strip in a buffer unit prior to the bonding step.

[0091] Example E23: The method of any of Examples E11-E22, wherein the upstream portion of the first strip is wound onto a first bobbin and the upstream portion of the second strip is wound onto a second bobbin.

[0092] Example E24: The method of example E23, further comprising the step of rejecting the first bobbin after the joining step.

[0093] Example E25: The method of example E23 or example E24, further comprising exchanging the position of the first bobbin and the position of the second bobbin after joining.

[0094] Example E26: The method of any of examples E11-E25, further comprising providing an aerosol-forming substrate and forming a rod comprising the joined strip and aerosol-forming substrate.

[0095] Example E27: A method of forming an aerosol-generating article, the method comprising forming one or more rods according to the method of example E26, and incorporating the one or more rods into an aerosol-generating article.

[0096] Example E28: A device for joining two strips of material, comprising: a processing line having an upstream end and a downstream end and configured to process the first strip of material and the second strip of material; and a bonding head according to any one of embodiments E1-E10, positioned between an upstream end and a downstream end of a processing line.

[0097] Example E29: The apparatus according to example E28, comprising a buffering unit adapted to buffer a variable amount of the first strip or the second strip, the buffering unit being located downstream of the bonding head.

[0098] Example E30: An apparatus according to example E28 or example E29, comprising a quality sensor configured to detect a value of a quality parameter at the detected portion of the first strip.

[0099] Example E31: The device of any of Examples E28 to E30, comprising a rod former.

[0100] Features described with respect to one embodiment may be equally applied to other embodiments of the invention.

[0101] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0102] FIG. 1a schematically illustrates a splicing head for joining two strips of material. The splicing head has a process direction 10 extending from an upstream end 12 to a downstream end 14. The splicing head has an orthogonal direction 16 perpendicular to the process direction 10. The splicing head has a first channel 18 (see FIG. 1b) for guiding a first strip of material 20 and a second channel 22 (see FIG. 1b) for guiding a second strip of material 24. The first and second channels 18, 22 are arranged parallel to the process direction 10. The splicing head includes an upstream cutting plate 26 and a downstream cutting plate 28. The upstream and downstream cutting plates 26, 28 are disposed between the first channel 18 and the second channel 22 along the orthogonal direction 16. The splicing head includes an upstream cutting blade 30 located immediately downstream of the upstream cutting plate 26 and a downstream cutting blade 32 located immediately upstream of the downstream cutting plate 28. The upstream cutting blade 30 and the downstream cutting blade 32 are positioned on either side of the first channel 18 and the second channel 22 in the orthogonal direction 16, such that the upstream cutting blade 30 is positioned adjacent to the second channel 22 and the downstream cutting blade 32 is positioned adjacent to the first channel 18. The joining head includes a welding station disposed between the upstream cutting blade 30 and the downstream cutting blade 32 along the process direction 10. The welding station includes an upstream welding electrode 34, a downstream welding electrode 36, and a welding plate 38. The welding electrodes 34, 36 and the welding plate 38 are positioned on either side of the first channel 18 and the second channel 22 in the orthogonal direction 16.

[0103] FIG. 1b shows the joining head of FIG. 1a together with a first strip of material 20 and a second strip of material 24. FIG.

[0104] 2a illustrates a first step of the joining method after the first and second material strips 20 and 24 have been guided through the first and second channels 18 and 22, respectively, of the joining head, as shown in FIGS. 1a and 1b. After stopping the transport of the first and second strips 20 and 24 along the process direction 10 (see FIG. 1a) to provide stationary segments of the first and second strips 20 and 24 at the joining head, in the configuration of FIG. 2a, the upstream and downstream welding electrodes 34, 36 and welding plate 38 are moving toward each other along the orthogonal direction 16, as indicated by the arrows in FIG. 2a. Thus, the first and second strips 20, 24 are positioned so that they contact each other and are sandwiched between the welding electrodes 34, 36 and the welding plate 38.

[0105] In this configuration, shown in Figure 2a, an electric current is applied to the welding station to weld the first strip 20 and the second strip 24 together.

[0106] FIG. 2b illustrates a second step after the first strip 20 and the second strip 24 have been welded together as shown in FIG. 2a. In the configuration of FIG. 2b, the upstream cutting blade 30 is moved toward the upstream cutting plate 26 along the orthogonal direction 16 to sever the upstream end of the second strip 25 from the welded first and second strips. The severance of the upstream end of the second strip 25 is facilitated by a scissors effect applied to the second strip 24 located between the upstream scissors formed by the upstream cutting blade 30 and the upstream cutting plate 26. The upstream scissors do not apply a scissors effect to the first strip 20. The first strip 20 is pushed only upward along the orthogonal direction 16 by the moving upstream cutting blade 30 because there is no opposing plate to cut.

[0107] Simultaneously, downstream cutting blade 32 is moved along transverse direction 16 toward downstream cutting plate 28 to sever the downstream end of first strip 21 from welded first strip 20 and second strip 24. Severing of the downstream end of first strip 21 is facilitated by a scissors effect applied to first strip 20 located between downstream scissors formed by downstream cutting blade 32 and downstream cutting plate 28. The downstream scissors do not apply a scissors effect to second strip 24. Second strip 24 is pushed only downward along transverse direction 16 by the moving downstream cutting blade 32 because there is no opposing plate to cut.

[0108] The movement of the cutting blades 30, 32 is indicated by the arrows in Figure 2b.

[0109] FIG. 2c illustrates a third step after portions of first strip 21 and second strip 25 have been cut as shown in FIG. 2b. In the configuration of FIG. 2c, welding electrodes 34, 36 and welding plate 38 are retracted away from the joined strips along orthogonal direction 16. The movement of welding electrodes 34, 36 and welding plate 38 is indicated by the arrows in FIG. 2c. In a subsequent fourth step (not shown), the upstream cutting plate and downstream cutting blades 30, 32 are also retracted away from the joined strips along orthogonal direction 16. In another subsequent step (not shown) that occurs after the third step and before, simultaneously with, or after the fourth step, the upstream cutting plate 26 and downstream cutting plate 28 are retracted away from the joined strips along a third direction, which is orthogonal to both process direction 10 and orthogonal direction 16.

[0110] Figure 3 shows in perspective views a joining head for joining two material strips in three different configurations (Figures 3a-3c) with respect to the orthogonal direction 16. The process direction 10 and the orthogonal direction 16 are shown in Figure 3c. Also shown in Figure 3c is a third direction 17 that is perpendicular to both the process direction 10 and the orthogonal direction 16. Thus, the third direction 17 is directed out of the image plane of Figures 3a-3c.

[0111] FIG. 3 a shows the joining head's first and second channels 18, 22 for guiding the material strips, upstream and downstream cutting plates 26, 28, upstream and downstream cutting blades 30, 32, and upstream and downstream welding electrodes 34, 36. The upstream cutting blade 30 is mounted on a first movable module 40. The downstream cutting blade 32 is mounted on a second movable module 42. In the sequence of FIGS. 3 a-3 c, the movable modules 40 and 42 are configured as shown in FIG. 3 c, with the upstream cutting blade 30 moving toward the upstream cutting plate 26 along the orthogonal direction 16 to cut the upstream end of the second strip (not shown in FIG. 3 ), and the downstream cutting blade 32 moving toward the downstream cutting plate 28 along the orthogonal direction 16 to cut the downstream end of the first strip (not shown in FIG. 3 ). The welding electrodes 34, 36 move together with and simultaneously with the movable module 40.

[0112] The upstream cutting plate 30 and downstream cutting blade 32 of the splicing head of Figures 3a-3c provide dual functionality: a cutting function for cutting the respective strips, and a guiding and aligning function for guiding and aligning the corresponding cutting plates 26, 28 with the cutting blades 30, 32 to achieve a scissors-cutting effect and avoid accidental protrusion of the cutting plates 26, 28 over the respective cutting blades 30, 32. Figure 3b shows that the upstream cutting blade 30 includes a horizontal cutting component 30a for cutting the second strip 20 (not shown in Figure 3) as it passes along the second channel 22, and an orthogonal alignment component 30b that functions as a guide and alignment means for guiding and aligning the cutting plate 26 with the horizontal cutting component 30a of the cutting blade 30 to achieve the scissors-cutting effect. The downstream cutting blade 32 also includes respective horizontal cutting and orthogonal alignment components.

[0113] The splice head of FIG. 3 further includes alignment means for aligning the first and second strips along the third direction 17. The alignment means includes an upstream top tripod 44, an upstream bottom tripod 46, a downstream top tripod 48, and a downstream bottom tripod 50. The bottom tripods 46, 50 are mounted on the first movable module 40, and the top tripods 44, 48 are mounted on the second movable module 42. The top tripods 44, 48 are each oriented oppositely relative to the respective bottom tripods 46, 50 so as to be engageable when the first and second movable modules 40, 42 move toward each other. The first and second strips are guided along the first and second channels between the mating tripod pairs 44, 46 and 48, 50, thereby being aligned along the third direction 17.

Claims

1. 1. A joining head for joining two strips of material, comprising: a process direction extending from the upstream end to the downstream end; an orthogonal direction perpendicular to the processing direction; a first channel for guiding a first strip of material and a second channel for guiding a second strip of material, the first and second channels being arranged in parallel along the processing direction; an upstream cutting plate and a downstream cutting plate, the upstream cutting plate and the downstream cutting plate being disposed between the first channel and the second channel along the orthogonal direction; an upstream cutting blade and a downstream cutting blade disposed on either side of the first channel and the second channel in the orthogonal direction such that the upstream cutting blade is located adjacent to the second channel and the downstream cutting blade is located adjacent to the first channel; a welding station disposed between the upstream cutting blade and the downstream cutting blade along the process direction, the welding station including at least one welding electrode and a welding plate, the at least one welding electrode and the welding plate being disposed on opposite sides of the first and second channels in the orthogonal direction.

2. The bondhead of claim 1 , wherein the upstream cutting blade is located immediately downstream of the upstream cutting plate and the downstream cutting blade is located immediately upstream of the downstream cutting plate.

3. 3. The joining head of claim 1, wherein the at least one welding electrode comprises an upstream welding electrode and a downstream welding electrode, and preferably the welding station is configured to apply a current pulse between the upstream welding electrode and the downstream welding electrode.

4. 4. The bonding head of claim 1, wherein the upstream cutting plate and the downstream cutting plate are configured to be movable along a third direction, the third direction being perpendicular to both the process direction and the orthogonal direction.

5. 5. The joining head according to claim 1, wherein one or both of the upstream cutting plate and downstream cutting blade have an L-shape with a horizontal cutting part for cutting strips of material and an orthogonal alignment part parallel to the orthogonal direction and acting as a guiding and alignment means for guiding and aligning the cutting plate relative to the respective cutting blade.

6. alignment means for aligning the first and second strips over one another, the alignment means being provided by one or more pairs of engaging structures disposed on opposite sides of the first and second channels in an orthogonal direction, such that a first structure of the pair is disposed adjacent to the second channel and a second engaging structure of the pair is disposed adjacent to the first channel; A bonding head as claimed in any one of claims 1 to 5, wherein the bonding head is configured to guide the first and second strips along the first and second channels between an engaging pair of structures to align the first and second strips on top of each other, preferably the engaging structures are configured as engaging tripods.

7. 1. A method for joining two strips of material, comprising: Providing a bonding head according to any one of claims 1 to 6; Providing a first strip of material and a second strip of material; guiding the first and second strips along the first and second channels of the bonding head; stopping transport of at least one segment of the first strip and at least one segment of the second strip along the process direction to provide static segments of the first and second strips at the position of the bonding head; moving the at least one welding electrode and the weld plate toward each other along the orthogonal direction such that the first and second strips contact each other and are positioned between the at least one welding electrode and the weld plate; applying an electric current to the welding station to weld the first strip and the second strip together; moving the upstream cutting blade along the orthogonal direction toward the upstream cutting plate to cut the upstream end of the second strip from the welded first and second strips; and moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips.

8. 8. The method of claim 7, further comprising the steps of: retracting the at least one welding electrode and the welding plate along the orthogonal direction after the step of moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips; and optionally retracting the upstream cutting plate and downstream cutting blade along the orthogonal direction.

9. 9. The method of claim 7 or 8, comprising the step of providing a joining head as defined in claim 4, and further comprising the step of retracting the upstream cutting plate and the downstream cutting plate along the third direction after the step of moving the downstream cutting blade along the orthogonal direction toward the downstream cutting plate to cut the downstream end of the first strip from the welded first and second strips.

10. 10. The method of any one of claims 7 to 9, wherein the first and second strips of material comprise a susceptor material, preferably comprising one or more metals, more preferably comprising aluminium.

11. 11. The method of claim 10, wherein the first and second strips are susceptor strips for use in an aerosol-generating article comprising an aerosol-forming substrate.

12. 12. The method according to any one of claims 7 to 11, further comprising a buffering unit provided downstream of the bonding head, preferably the method comprising the step of buffering a given length of the first strip in the buffering unit before the bonding step.

13. 13. The method of claim 12, wherein a portion of the processing line downstream of the buffer unit is either stopped, operated at a slower speed, or operated at normal speed during the step of joining the first strip and the second strip with the joining head.

14. 1. An apparatus for joining two strips of material, comprising: a processing line having an upstream end and a downstream end and configured to process the first strip of material and the second strip of material; A processing apparatus comprising: a bonding head according to any one of claims 1 to 6, located between the upstream end and the downstream end of the processing line.

15. 15. The apparatus of claim 14, comprising a buffering unit adapted to buffer a variable amount of the first strip or the second strip, the buffering unit being located downstream of the bonding head.

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