Patent Publication Number: US-2023147341-A1

Title: A Method for Recycling an Aerosol Generating Article

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to aerosol generating articles, and more particularly to an aerosol generating article for use with an aerosol generating device for heating the aerosol generating article to generate an aerosol for inhalation by a user. Embodiments of the present disclosure relate in particular to a method for recycling an aerosol generating article which employs a non-liquid aerosol generating material and an inductively heatable susceptor. 
     TECHNICAL BACKGROUND 
     Devices which heat, rather than burn, a non-liquid aerosol generating material to produce an aerosol for inhalation have become popular with consumers in recent years. 
     Such devices can use one of a number of different approaches to provide heat to the aerosol generating material. One such approach is to provide an aerosol generating device which employs an induction heating system. In such a device, an induction coil is provided with the device and an inductively heatable susceptor is also provided. Electrical energy is supplied to the induction coil when a user activates the device which in turn generates an alternating electromagnetic field. The susceptor couples with the electromagnetic field and generates heat which is transferred, for example by conduction, to the non-liquid aerosol generating material and an aerosol is generated as the aerosol generating material is heated. 
     It can be convenient to provide the non-liquid aerosol generating material and the inductively heatable susceptor in the form an aerosol generating article which can be inserted by a user into an aerosol generating device. As such, there is a need to mitigate problems associated with the disposal of such aerosol generating articles after they have been used or if they are off-specification. 
     SUMMARY OF THE DISCLOSURE 
     According to a first aspect of the present disclosure, there is provided a method for recycling an aerosol generating article comprising a non-liquid aerosol generating material and an inductively heatable susceptor, the method comprising:
         (i) shredding the aerosol generating article to break up the non-liquid aerosol material and the inductively heatable susceptor; and   (ii) separating the inductively heatable susceptor and the non-liquid aerosol generating material.       

     According to a second aspect of the present disclosure, there is provided a method for manufacturing an aerosol generating article, the method comprising: 
     positioning the separated inductively heatable susceptor obtained by the method according to the first aspect proximate a further non-liquid aerosol generating material to form an aerosol generating article. 
     According to a third aspect of the present disclosure, there is provided a method for manufacturing an aerosol generating article, the method comprising: 
     separating an inductively heatable susceptor and a non-liquid aerosol generating material in a used or off-specification aerosol generating article; and 
     positioning the separated inductively heatable susceptor proximate a further non-liquid aerosol generating material to form an aerosol generating article. 
     The aerosol generating article is intended for use with an aerosol generating device for heating the non-liquid aerosol generating material, without burning the non-liquid aerosol generating material, to volatise at least one component of the aerosol generating material and thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the aerosol generating device. 
     In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms ‘aerosol’ and ‘vapour’ may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user. 
     The inductively heatable susceptor may comprise a single susceptor or may comprise a plurality of susceptor elements. 
     The inductively heatable susceptor may comprise at least one of a metal material, a metal alloy material, a ceramic material, a carbon material, and a polymeric fibre material coated with a metal material. The inductively heatable susceptor may comprise one or more, but not limited, of aluminium, iron, nickel, stainless steel and alloys thereof, e.g. Nickel Chromium or Nickel Copper. 
     The methods according to the present disclosure help to reduce the environmental impact associated with disposal of a used or off-specification aerosol generating article by enabling the inductively heatable susceptor to be separated from the non-liquid aerosol generating material and thereafter re-used or further recycled. The methods according to the present disclosure may also help to reduce the production cost associated with manufacture of an aerosol generating article through re-use of a separated inductively heatable susceptor. 
     Step (i) may include shredding the non-liquid aerosol generating material. This may facilitate separation of the inductively heatable susceptor and the non-liquid aerosol generating material. 
     The inductively heatable susceptor may be a continuous susceptor and may comprise at least one of a mesh form and a fibre cloth form. In some implementations, the continuous susceptor may comprise at least one of a metal mesh laminate and a metal fibre cloth laminate. Step (i) may include shredding the continuous susceptor. This may facilitate separation of the inductively heatable susceptor and the non-liquid aerosol generating material. 
     In embodiments in which the inductively heatable susceptor comprises a plurality of susceptor elements, the inductively heatable susceptor may comprise a particulate susceptor material. For example, the particulate susceptor material may comprise at least one of a granular form, a powder form, and a fibre form. The particulate susceptor material may be distributed throughout the non-liquid aerosol generating material. Step (i) may, therefore, involve shredding only the non-liquid aerosol generating material. 
     Step (ii) may comprise vibrating the shredded aerosol generating article to separate the inductively heatable susceptor and the non-liquid aerosol generating material. The use of vibration may provide a convenient way to separate the inductively heatable susceptor and the non-liquid aerosol generating material. Step (ii) may comprise depositing the shredded aerosol generating article on a vibrating screen unit having apertures therein to separate the inductively heatable susceptor and the non-liquid aerosol generating material. The apertures in the vibrating screen unit may be sized to allow passage therethrough of the non-liquid aerosol generating material and to retain on a retaining surface thereof the inductively heatable susceptor. 
     Step (ii) may comprise exposing the shredded aerosol generating article to a magnetic force to separate the inductively heatable susceptor from the non-liquid aerosol generating material. Since the inductively heatable susceptor comprises a magnetic material, it may be convenient to use a magnetic force to separate the inductively heatable susceptor and the non-liquid aerosol generating material. Step (ii) may comprise applying the magnetic force using a magnet, for example using an electromagnet. The magnet may be positioned above the shredded aerosol generating article so that the inductively heatable susceptor is attracted towards the magnet in a generally upwards direction. 
     The above examples are non-limiting and step (ii) may, for example, comprise the use of a robotic picking arm to remove the inductively heatable susceptor from the non-liquid aerosol generating material. 
     Step (ii) may comprise: 
     depositing the shredded aerosol generating article on a vibrating screen unit having apertures therein sized to allow passage therethrough of the non-liquid aerosol generating material and to retain on a retaining surface thereof the inductively heatable susceptor; and 
     exposing the inductively heatable susceptor retained on the surface of the vibrating screen unit to a magnetic force to remove the inductively heatable susceptor from the surface. 
     The use of both vibration and a magnetic force may help to ensure reliable separation of the inductively heatable susceptor and the non-liquid aerosol generating material. 
     The aerosol generating article may comprise one or more of a paper wrapper and a filter, and step (i) may comprise shredding the paper wrapper and/or the filter. This ensures that the aerosol generating article is opened during the shredding step to allow separation of the inductively heatable susceptor and the non-liquid aerosol generating material. The filter may comprise cellulose acetate fibres. The filter may be in abutting coaxial alignment with the non-liquid aerosol generating material. 
     The apertures in the vibrating screen unit may be sized to retain the shredded paper wrapper and/or the shredded filter on the retaining surface. This allows the paper wrapper and/or the filter to be separated from the inductively heatable susceptor and the non-liquid aerosol generating material. 
     The method may further comprise cleaning the separated inductively heatable susceptor. This may allow the separated inductively heatable susceptor to be re-used in the subsequent manufacture of an aerosol generating article or for another purpose. 
     The method may further comprise analysing the separated inductively heatable susceptor to determine one or more of the mechanical and electrical properties thereof. 
     The outcome of the analysis may advantageously be used to determine whether the separated inductively heatable susceptor is suitable for re-use in the subsequent manufacture of an aerosol generating article or whether it is better suited for another purpose. 
     The step of analysing the separated inductively heatable susceptor may be performed after the step of cleaning the separated inductively heatable susceptor. This may allow the analysis to be performed more reliably. 
     The non-liquid aerosol generating material may be any type of solid or semi-solid material. Example types of aerosol generating solids include powder, granules, pellets, shreds, strands, particles, gel, strips, loose leaves, cut leaves, cut filler, porous material, foam material or sheets. The non-liquid aerosol generating material may comprise plant derived material and in particular, may comprise tobacco. It may advantageously comprise reconstituted tobacco. 
     The non-liquid aerosol generating material may comprise an aerosol-former. Examples of aerosol-formers include polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. Typically, the non-liquid aerosol generating material may comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. In some embodiments, the non-liquid aerosol generating material may comprise an aerosol-former content of between approximately 10% and approximately 20% on a dry weight basis, and possibly approximately 15% on a dry weight basis. 
     Upon heating, the non-liquid aerosol generating material may release volatile compounds. The volatile compounds may include nicotine or flavour compounds such as tobacco flavouring. 
     The aerosol generating article may be elongate and may be substantially cylindrical. The aerosol generating article may be formed substantially in the shape of a stick. The cylindrical shape of the aerosol generating article with its circular cross-section may advantageously facilitate insertion of the aerosol generating article into a heating compartment of an induction heating assembly of an aerosol generating device, for example in which the induction heating assembly includes a helical induction coil having a circular cross-section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is diagrammatic cross-sectional view of an example of an aerosol generating system comprising an aerosol generating device and an aerosol generating article; 
         FIG.  2    is a flowchart illustrating an example of a method for recycling an aerosol generating article such as that illustrated in  FIG.  1   ; and 
         FIG.  3    is a diagrammatic side view of an example of an apparatus for recycling an aerosol generating article and suitable for performing the example of the method illustrated in  FIG.  2   . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings. 
     Referring initially to  FIG.  1   , there is shown diagrammatically an example of an aerosol generating system  1 . The aerosol generating system  1  comprises an aerosol generating device  10  and an aerosol generating article  24 . The aerosol generating device  10  has a proximal end  12  and a distal end  14  and comprises a device body  16  which includes a power source  18  and a controller  20  which may be configured to operate at high frequency. The power source  18  typically comprises one or more batteries which could, for example, be inductively rechargeable. 
     The aerosol generating device  10  is generally cylindrical and comprises a generally cylindrical cavity  22 , for example in the form of a heating compartment, accessible from the proximal end  12  of the aerosol generating device  10 . The cylindrical cavity  22  is arranged to receive a correspondingly shaped generally cylindrical or rod-shaped aerosol generating article  24  containing a non-liquid aerosol generating material  26  and an inductively heatable susceptor  28 . The inductively heatable susceptor  28  is a single continuous susceptor, but in other (non-illustrated) embodiments, the inductively heatable susceptor  28  may comprise a plurality of susceptor elements and could, for example, comprise a particulate susceptor material. 
     The aerosol generating article  24  is a disposable article and the non-liquid aerosol generating material  26  is typically a solid or semi-solid material. Examples of suitable aerosol forming solids include powder, granules, particles, gel, strips, loose leaves, cut filler, pellets, powder, shreds, strands, foam material and sheets. The aerosol generating material  26  typically comprises plant derived material and, in particular, comprises tobacco. 
     The aerosol generating material  26  typically comprises an aerosol-former such as glycerine or propylene glycol. Typically, the aerosol generating material  26  may comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. Upon heating, the aerosol generating material  26  releases volatile compounds possibly including nicotine or flavour compounds such as tobacco flavouring. 
     The aerosol generating article  24  has first and second ends  30 ,  32  and comprises a paper wrapper  34  surrounding the aerosol generating material  26 . The aerosol generating article  24  also comprises a filter  36  at the first end  30  which projects from the device body  16  at the proximal end  12 . The filter  36  acts as a mouthpiece and comprises an air-permeable plug, for example comprising cellulose acetate fibres. The aerosol generating article  24  also comprises a vapour cooling region  38  positioned between the aerosol generating material  26  and the filter  36 . 
     The aerosol generating device  10  comprises a helical induction coil  40  which has a circular cross-section and which extends around the cylindrical cavity  22 . The induction coil  40  can be energised by the power source  18  and controller  20 . The controller  20  includes, amongst other electronic components, an inverter which is arranged to convert a direct current from the power source  18  into an alternating high-frequency current for the induction coil  40 . The aerosol generating device  10  also includes one or more air inlets  42  in the device body  16  which allow ambient air to flow into the cavity  22 . 
     As will be understood by one of ordinary skill in the art, when the induction coil  40  is energised during use of the aerosol generating system  1 , an alternating and time-varying electromagnetic field is produced. This couples with the inductively heatable susceptor  28  and generates eddy currents and/or magnetic hysteresis losses in the inductively heatable susceptor  28  causing it to heat up. The heat is then transferred from the inductively heatable susceptor  28  to the aerosol generating material  26 , for example by conduction, radiation and convection. 
     The inductively heatable susceptor  28  can be in direct or indirect contact with the aerosol generating material  26 , such that when the susceptor  28  is inductively heated by the induction coil  40 , heat is transferred from the susceptor  28  to the aerosol generating material  26 , to heat the aerosol generating material  26  and thereby produce a vapour. The vaporisation of the aerosol generating material  26  is facilitated by the addition of air from the surrounding environment through the air inlets  42 . The vapour generated by heating the aerosol generating material  26  flows through the vapour cooling region  38  where it cools and condenses to form an aerosol which can be inhaled by a user of the device  10  through the filter  36 . The flow of air and vapour/aerosol through the aerosol generating article  24  is aided by negative pressure created by a user drawing air through the filter  36 . 
     Referring now to  FIG.  2   , there is provided a method for recycling the aerosol generating article  24  illustrated in  FIG.  1    or any other example of an aerosol generating article comprising a non-liquid aerosol generating material  26  and an inductively heatable susceptor  28 . As noted above, it may be desirable to recycle a used aerosol generating article  24  in which the aerosol generating material  26  has been depleted through use or to recycle an off-specification aerosol generating article  24 . 
     In a first step S 1 , the method comprises shredding the aerosol generating article  24  to break up the non-liquid aerosol generating material  26  and the inductively heatable susceptor  28 . In a second step S 2 , the method comprises separating the inductively heatable susceptor  28  and the non-liquid aerosol generating material  26 . 
     In more detail and referring to  FIG.  3    which shows an example of an apparatus for performing the recycling method illustrated in  FIG.  2   , a plurality of used and/or off-specification aerosol generating articles  24  may be collected and deposited on a first conveyor  50 . The apparatus may comprise a shredding unit  52  positioned above first conveyor  50  which may be arranged to perform step S 1  of the method described above with reference to  FIG.  2   , namely to shred the aerosol generating articles  24  positioned on the first conveyor  50  to break up the non-liquid aerosol generating material  26  and the inductively heatable susceptor  28 . 
     In the illustrated and non-limiting example, the shredding unit  52  comprises a shredding roller  54  which may include a plurality of circumferentially arranged shredding formations  56  configured to cut open and shred the aerosol generating articles  24  positioned on the first conveyor  50 . The shredding formations  56  may be configured to shred at least the aerosol generating material  26 , and possibly to shred the paper wrappers  34  and the filters  36 . In the illustrated embodiment in which the inductively heatable susceptors  28  are continuous susceptors, the inductively heatable susceptors  28  are not shredded by the shredding formations  56  and remain intact. In other (non-illustrated) embodiments in which the inductively heatable susceptors  28  are continuous susceptors, the shredding formations  56  may also be configured to shred the inductively heatable susceptors  28 . Alternatively, and as noted above, each of the inductively heatable susceptors  28  may comprise a particulate susceptor material distributed throughout the aerosol generating material  26  which is not subjected to shredding by the shredding formations  56 . 
     The apparatus further comprises a vibrating screen unit  60  in the form of a vibrating screen conveyor  62  (second conveyor) which may be arranged to perform step S 2  of the method described with reference to  FIG.  2   , namely to separate the inductively heatable susceptors  28  and the aerosol generating material  26 . In more detail, the vibrating screen conveyor  62  is arranged to receive the separated components of the shredded aerosol generating articles  24  from the first conveyor  50 , namely the shredded aerosol generating material  26 , the inductively heatable susceptors  28 , the paper wrappers  34  and the filters  36 . In the illustrated example, the vibrating screen conveyor  62  includes a plurality of apertures (not shown) which are sized to allow passage therethrough of some of the non-liquid aerosol generating material  26  and to retain on an upper retaining surface  64  the remainder of the aerosol generating material  26  along with the inductively heatable susceptors  28 , the paper wrappers  34  and the filters  36 . As will be understood by one of ordinary skill in the art, the vibration applied to the vibrating screen conveyor  62  promotes the passage of appropriately sized non-liquid aerosol generating material  26  through the apertures and into a collector (not shown) which may be positioned below the vibrating screen conveyor  62 . 
     The apparatus includes a third conveyor  70  which is arranged above the vibrating screen conveyor  62  to partially overlap it and which may be arranged to perform step S 2  of the method described above with reference to  FIG.  2   , namely to separate the inductively heatable susceptors  28  and the aerosol generating material  26 . In more detail, the third conveyor  70  includes a plurality of electromagnets  72  which can be individually and selectively activated or deactivated. When an individual electromagnet  72  is activated, it is placed in a magnetised state and generates an attractive magnetic force. Conversely, when an individual electromagnet  72  is deactivated, it is placed in a demagnetised state and does not generate an attractive magnetic force. The activated (magnetised) electromagnets  72  are identified in  FIG.  3    by the presence of cross-hatching, whereas the deactivated (demagnetised) electromagnets  72  are identified by the absence of cross-hatching. 
     The apparatus is configured so that the electromagnets  72  positioned directly above the vibrating screen conveyor  62  are activated and placed in the magnetised state. This causes the inductively heatable susceptors  28  on the upper retaining surface  64  of the vibrating screen conveyor  62  to be attracted in an upwards direction towards the magnetised electromagnets  72 . The shredded inductively heatable susceptors  28  are then carried by the third conveyor  70  and deposited onto a fourth conveyor  80  which is positioned beneath, and which partially overlaps, the third conveyor  70 . In order to deposit the separated inductively heatable susceptors  28  on the fourth conveyor  40 , the electromagnets  72  are simply deactivated to place them into the demagnetised state so that the inductively heatable susceptors  28  can fall from the third conveyor  70  onto the surface of the fourth conveyor  80 . 
     After the inductively heatable susceptors  28  have been removed from the upper retaining surface  64  of the vibrating screen conveyor  62  by the electromagnets  72  on the third conveyor  70 , the aerosol generating material  26 , along with the paper wrappers  34  and filters  36 , remaining on the upper retaining surface  64  are ejected from the end of the vibrating screen conveyor  62  and can be collected for disposal and/or further processing. 
     Similarly, the inductively heatable susceptors  28  that have been deposited on the surface of the fourth conveyor  80  can be ejected from the end of the fourth conveyor  80 . Referring again to  FIG.  2   , in some embodiments, the inductively heatable susceptors  28  may be cleaned in step S 3 , for example washed to remove deposits and/or other contaminants. Thereafter, the inductively heatable susceptors  28  may be analysed in step S 4  to determine their mechanical and/or electrical properties. Depending on the outcome of the analysis, one or more of the inductively heatable susceptors  28  could be re-used in an optional step S 5  to manufacture further aerosol generating articles or could be further processed and/or subjected to further recycling operations. 
     Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments. 
     Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.