CAPSULE HAVING A LIQUID TRANSPORTING ELEMENT FOR USES WITH AN ELECTRONIC SMOKING DEVICE

Abstract

A capsule for use with an electronic smoking device includes a shell (105) having a lateral wall (101, 102) and an end wall (103), wherein the lateral wall (101, 102) and the end wall (103) defines a cavity (110) open at one end (111). A puncturable membrane (104) seals the open end (111) of the cavity (110). A liquid is contained within the cavity (110) by the shell (105) and the puncturable membrane (104), wherein a liquid transporting element (120) is arranged within the cavity (110) enclosed by the puncturable membrane (104) and immersed in the liquid.

Claims

1. A capsule for use with an electronic smoking device, the capsule (100) comprising: a shell (105) having a lateral wall (101, 102) and an end wall (103), the lateral wall (101, 102) and the end wall (103) defining a cavity (100) open at one end (111); a puncturable membrane (104) sealing the open end (111) of the cavity (110) defined by the end wall (103) and the lateral wall (101, 102); a liquid contained within the cavity (110) by the shell (105) and the puncturable membrane (104); and a liquid transporting element (120) arranged within the cavity (110) enclosed by the puncturable membrane (104) and immersed in the liquid, the liquid transporting element (120) comprising fibres (121) of an inorganic material defining passages (122) between the fibres (121) for transporting the liquid.

2. A capsule according to claim 1, wherein the liquid transporting element (120) comprises fibres (121) of different thickness.

3. A capsule according to claim 1, wherein the fibres are provided in groups and the groups of fibres are braided to form a rope.

4. A capsule according to claim 1, wherein the cavity has a longitudinal axis and the passages (122) between the fibres (121) are substantially oriented in a direction parallel to the longitudinal axis.

5. A capsule for use with an electronic smoking device, the capsule (100) comprising: a shell (105) having a lateral wall (101, 102) and an end wall (103), the lateral wall (101, 102) and the end wall (103) defining a cavity (110) open at one end (111); a puncturable membrane (104) sealing the open end (111) of the cavity (110) defined by the end wall (103) and the lateral wall (101, 102); a liquid contained within the cavity (110) by the shell (105) and the puncturable membrane (104); and a self-supporting liquid transporting element (120) arranged within the cavity (110) enclosed by the puncturable membrane (104) and immersed in the liquid.

6. A capsule according to claim 1, wherein the fibres (121) of the liquid transporting element (120) comprise an inorganic material based on silicon oxide.

7. A capsule according to claim 1, wherein the fibres (121) of the liquid transporting element (120) comprise a glass material.

8. (canceled)

9. A capsule according to claim 1, wherein a length of the liquid transporting element (120) in a direction from the end wall (103) of the shell to the puncturable membrane (104) enclosing the open end (111) of the cavity (110) is shorter than the distance from the end wall (103) of the shell to the puncturable membrane (104).

10. (canceled)

11. An electronic smoking device, comprising: an elongated housing (210) comprising a first hollow part (211) and a second hollow part (212) releasably connected to the first hollow part (211), the first hollow part (211) and the second hollow part (212) defining an internal space (220) of the housing (210); a replaceable capsule (240) removably inserted into the internal space (220) of the housing (210), the replaceable capsule including a shell (105) having a lateral wall (101, 102) and an end wall (103), the lateral wall (101, 102) and the end wall (103) defining a cavity (100) open at one end (111), a puncturable membrane (104) sealing the open end (111) of the cavity (110), a liquid contained within the cavity (110) by the shell (105) and the puncturable membrane (104), and a liquid transporting element (120) immersed in the liquid, the liquid transporting element (120) comprising fibres (121) of an inorganic material defining passages (122) between the fibres (121) for transporting the liquid; an electrically heatable atomizer (250) within the internal space (220) of the housing (211, 212), the atomizer (250) comprising a rupture element (251, 253) extending into the open end (241) of the cavity of the capsule (240) through a rupture of the puncturable membrane (244) of the capsule (240) when the capsule (240) is inserted into the internal space (220), wherein the rupture element comes into contact with the liquid transporting element (245) of the capsule (100).

12. An electronic smoking device according to claim 11, wherein the first hollow part (211) has a closed first end and an open second end, and the second hollow part (212) has a first end and a second end, with the open second end of the first hollow part engaged with the first end of the second hollow part and the second end of the second hollow part (211) forms a mouth piece wherein the capsule (240) is insertable into the first hollow part (211) with the puncturable membrane adjacent to the atomizer.

13. An electronic smoking device according to claim 12, wherein an air passage is formed between an outer surface of the capsule (240) and an inner surface of the first hollow part (211) to allow an air stream from the atomizer (250) to the mouth piece.

14. A method for filling a capsule, the method comprising: feeding an empty capsule from a stock to an insertion apparatus, wherein the capsule comprises a shell (105) having a lateral wall (101, 102) and an end wall (103), the lateral wall (101, 102) and the end wall (103) defining a cavity (100) open at one end (111); feeding a liquid transport element (120) to the insertion apparatus; inserting a liquid transporting element into the cavity (110) of the capsule (100) from the one end (111) of the capsule (100); filling the cavity (110) of the capsule (100) with a liquid; and sealing the one end (111) of the cavity (110) with a puncturable membrane

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The components in the figures are not necessarily to scale, instead emphasis being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference signs designate corresponding parts. In the drawings:

[0039] FIG. 1 illustrates a capsule according to an embodiment;

[0040] FIG. 2 illustrates a liquid transporting element for a capsule according to an embodiment;

[0041] FIG. 3 illustrates a capsule according to a further embodiment;

[0042] FIG. 4 shows a REM photograph of a liquid transporting element according to an embodiment;

[0043] FIG. 5 shows another REM photograph of the liquid transporting element;

[0044] FIG. 6 illustrates an electronic smoking device having a capsule according to an embodiment;

[0045] FIGS. 7A and 7B illustrate processes of a method for manufacturing a capsule according to an embodiment; and

[0046] FIG. 8 is a flow diagram of a series of steps for manufacturing a capsule according to an embodiment.

DETAILED DESCRIPTION

[0047] In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top”, “bottom”, “front”, “back”, leading”, “trailing”, “lateral”, “vertical” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purpose of illustration and is in no way limiting. The embodiments being described use specific language, which should not be construed in a limiting sense.

[0048] FIG. 1 illustrates a capsule 100 for use with an electronic smoking device according to an embodiment.

[0049] The capsule 100 includes a shell 105 formed by a first or front shell part 101 defining a first lateral wall, a second or back shell part 102 defining a second lateral wall 102, and an end wall 103 which is integral with second shell part 102. The first shell part 101 and the second shell part 102 form together a lateral wall of the shell 105 and define together with the end wall 103 a cavity 110 of the capsule 100. The cavity 100 is open at one end 111 and closed at an opposite end 112 by the end wall 103.

[0050] The shell 105 of the capsule 100 is illustrated in FIG. 1 as a two-piece element formed by the first shell part 101, which is substantially of hollow-cylindrical shape, and the second shell part 102 which substantially a closed-bottom hollow cylinder. The second lateral wall of the second shell part 102 extends from the end wall 103. The first and second shell parts 101, 102 are connected with each other at their ends facing each other to form a common cavity with a single opened end 111. The shell 105 can also be formed as a single integral part. In this case, the first shell part 101 and the second shell part 102 are integral with each other.

[0051] In each case, the shell 105 can be an injection-moulded part made of a hydrophobic material, for example a polyolefin or PTFE such as polypropylene or any other suitable plastic material.

[0052] A puncturable membrane 104 covers and seals the open end 111 of the cavity 110 to prevent that a liquid contained within the cavity 110 leaks from the cavity 110. The puncturable membrane 104 can be an aluminium foil which is, for example, heat-sealed to the open end 111 of the cavity 111.

[0053] The liquid contained in the cavity 110 typically contains a solvent or carrier for a tobacco compound such as nicotine, a flavour, an ethereal oil, or a mixture thereof. The solvent is typically a hydrophilic and can include constituents like water and polyoles. For example, propylene glycol and/or glycerol can be used which are water-soluble, chemically inert, and non-toxic which renders these compounds attractive as solvent. Typically, the liquid contains water in a range of from 0% to 20% (more preferably of from to 1% to 10%, most preferably of from to 2% to 7%) and polyoles, e.g. glycerol (preferably of from 0% to 90% or even 100%, more preferably of from 10% to 50%, most preferably of from 15% to 25%) and/or propylene glycol (preferably of from 50% to 100%, more preferably of from 60% to 90%, most preferably of from 70% to 80%). All percentages are by weight, related to the total weight of the liquid.

[0054] A liquid transporting element 120, which is referred to as wick, is arranged within the cavity 110 enclosed by the puncturable membrane 104 and immersed in the liquid. The wick 120, as best shown in FIG. 2, includes a plurality of individual fibres 121 extending substantially along the longitudinal direction of the wick 120. The individual fibres 120 do not necessarily need to be parallel to each other but may have an orientation slightly deviating from the longitudinal direction. Therefore, when referring to fibres oriented or extending in the longitudinal direction, this orientation also encompasses slight deviations from the strict longitudinal direction. Furthermore, as the fibres 121, or groups of fibres, can be braided, the fibres may be slightly coiled or winded.

[0055] The fibres 121 define, and confine, small passages or cavities 122 between the individual fibres 121. The size and shape of the passages 122 may depend on the size of the fibres 121 and the packing density of the fibres 121. As the fibres 121 extend in longitudinal direction, the passages 122 also have a preferred longitudinal extension so that a plurality of longitudinal capillary spaces is formed by the passages 122 in the wick 120.

[0056] To provide the wick 120 with a sufficient stiffness, the thickness of the individual fibres 121 can be appropriately selected. For example, the fibres 121 can have a mean thickness of between 5 μm and 20 μm. A specific example is shown in FIG. 3 which is a REM (raster electron microscopy) photograph showing fibres of various thickness in an exemplary range between 8 μm and 10 μm. When describing the wick to include fibres 121 of the same size, this should be construed as referring to the same mean size as the plurality of fibres 121 has a given thickness distribution. The same size means a unimodal thickness distribution, i.e. a distribution with one distinct peak.

[0057] In further modifications, fibres 121 having a different thickness can also be used. In this case, the thickness distribution of the fibres 121 corresponds to a bimodal distribution, i.e. a distribution having two distinct peaks. Using a plurality of fibres 121 with a multimodal thickness distribution is also possible.

[0058] The thickness of the fibres 121 also depends on the material used for the fibres 121. For stiff materials, such as inorganic materials based on silicon oxide, the fibre thickness is typically in the above mentioned ranged between 5 μm and 20 μm to avoid that the individual fibres 121 become too stiff and may break upon handling. The individual fibres 121 should therefore be sufficiently flexible to allow, for example, braiding or slight twisting or coiling.

[0059] When other material are used, such as polymeric materials, the thickness of the individual fibres 121 can be higher as polymeric materials are typically more flexible than inorganic materials. However, the flexibility and stiffness of organic material can be adjusted in a wide range, for example by changing the cross-linking rate or chain size.

[0060] To provide the wick 120 with sufficient liquid transporting properties, the individual fibres 121 should not be too thick as thick fibres 121 form larger but less passage 122. As the liquid transport is mainly based on capillary action, a large internal surface formed by the plurality of passages and cavities 122 is desired which is obtainable using comparably thin fibres.

[0061] The strength of the capillary action of the liquid transporting element may be quantified as follows: When the liquid transporting element (e.g. such as a wick), is brought in a dry condition into contact with a liquid, it will start absorbing the liquid at a rate which decreases over time. For a bar of material with constant cross-section S that is wetted on one end, the penetration depth of the absorbed liquid along the length of the bar after a time t is

x=B√{square root over (t)},

where B is the liquid penetration coefficient [cm s.sup.−1/2]. The quantity

m=A√{square root over (t)}

is the mass of the absorbed liquid with A being the liquid absorption coefficient given in [g/(cm.sup.2 h.sup.1/2)]. B and A are related with each other:

[00002]$B=\frac{A}{\psi .Math.\rho }$

with ρ the density [g/cm.sup.3] of the liquid and ψ the liquid capacity [cm.sup.3/cm.sup.3] of the porous media. The liquid absorption coefficient A describes the velocity of the mass absorption per unit area. The liquid capacity ψ is closely related with the porosity as it describes the available space for the liquid in the porous media.

[0062] The packing density of the fibres 121 can be adjusted by different means. The packing density also influences the size of the cavity and passages 122 and is therefore a further option to tailor the liquid transporting properties.

[0063] Braiding the fibres 121, or groups of individual fibres 121, also increases the flexural stiffness of the wick 120 and is therefore one option to adjust the overall stiffness of the wick 120. FIG. 4 illustrates a REM photograph of a specific embodiment with groups of fibres 121 being braided to a cord. The numbers of the individual groups of fibres 121, and the number of individual fibres 121 in each group of fibres, can be selected according to specific needs. For example, each group of fibres can include a plurality of fibres forming a strand of the braided cord. The flexural stiffness depends, for example, from the number of individual strands formed by a single group of fibres 121 and the braiding pattern.

[0064] For further tightening the fibres 121 or strands together, ring elements can be used as shown in FIG. 4. Such ring elements can be beneficial at the leading end of the wick 120 to prevent the fibres 121 from fraying and blocking insertion of the wick 120.

[0065] The wick 120 is provided with sufficient flexural stiffness to allow automated wick insertion into the cavity 110 of the capsule 100. The upper limit is not specifically of importance in view of the insertion process but should not be too high so that the wick 120 remains sufficient flexible, for example to be coiled on a bobbin or reel.

[0066] A specific example of a wick 120 according to an embodiment is made of pure silicon dioxide fibres which are braided or stranded to form a string or cord with a diameter of about 1.5 mm. The fibres 121 are about 8 to 10 μm in diameter. The capillary properties of the material results from the stacking of the fibres 121 which create tiny passages between the fibres 121 to allow the liquid to creep through.

[0067] Silicon dioxide fibres have beneficial material properties as this material shows a temperature resistance of up to 1600° C., although such a high temperature resistance is not needed for the wick 120 arranged within the cavity 110 of the capsule 100. The content of silicon dioxide (SiO.sub.2) is typically at least 96%. The content of combustible material is preferably equal to or less than 5%.

[0068] Silicon dioxide further exhibits a low material loss, when subjected to high temperatures, of about 5% and less and comparably low linear shrinkage properties less than 5%. This material is also beneficial for a wick for use with an atomizer as described further below.

[0069] As silicon dioxide fibres are comparably expensive, amorphous silica, e.g. glass, can be used as material for the fibres 121. Glass is a cheaper and less brittle than pure silica. Glass can be made by adding calcium carbonate to the silicon dioxide, as well as other additives if desired. Addition of calcium carbonate results in a cheaper product with a lower melting point, which is, however, not critical for the intended application as wick material for the capsule.

[0070] An alternative material is polyester for the fibres 121. To provide the polyester fibres with sufficient flexural stiffness, the thickness of each fibre 121 should be selected accordingly. Polyester is less expensive in comparison to silicon dioxide and easy to handle as this material is less brittle.

[0071] Wicks which are too soft are not suitable for automated insertion processes as the wick will be pressed to some degree. Soft materials such as polyester sponges or cotton-like fibrous materials may be compressed which can affect the capillary properties of the material. Another disadvantage of sponge-like wicks is that the absorption of the liquid into the sponge is very time consuming and does not allow for a fast filling of the capsule at high speed which is intended for an automated process. When using sponges, the liquid needs a certain time to be soaked by the sponge before more liquid can be added. This requires a step-wise filling of the cavity with liquid which is time consuming.

[0072] Another beneficial material for the wick includes a porous material forming a cylindrical structure which has a hollow section to allow insertion of a filling needle for filling the cavity. FIG. 3 illustrates an embodiment of a capsule 100 having a wick 160, which forms in this embodiment the liquid transporting element, comprised of porous material. In addition to the different wick, the embodiment of FIG. 3 differs from the embodiment of FIG. 1 in that the shell 105′ is a single integrally formed body having a lateral wall 101′ integral with an end wall 103′.

[0073] The wick 160 can have a size and shape adapted to nearly completely fill the cavity 110 of the capsule 100. As illustrated in FIG. 3, the wick 160 can include a centre portion 161 and an outer portion 162 surrounding the centre portion 161. The porous material of the centre portion 161 can have a mean pore size which is lower than the mean pore size of the outer portion 162 to provide the wick 160 with a non-uniform porosity distribution. For example, the porosity can be adjusted such that the absorptive capacity increases radially from the centre of the cylinder to the outer periphery.

[0074] The centre portion 161 is recessed relative to the outer portion 162 at the end of the wick 160 facing the membrane 104 to form the hollow section for the needle to be inserted to facilitate rapid automated needle filling of the cavity 110. Due to the different porosity, a larger total cavity volume is provided to increase the storage capacity within the wick 160. A higher porosity of the centre portion 161 also increases the uptake capacity of the liquid during filling which is beneficial for automated filling.

[0075] The porous material can be comparably stiff which makes the insertion process easier as a stiff material is also dimensionally stable. Furthermore, different to a fibrous wick, the wick 160 made of one or two porous materials do not fray at its ends so that the outer size and shape of the wick 160 can substantially correspond to the internal space of the cavity 110 as the ends are not expanded by fraying. In comparison to a fibrous wick, the volume of the porous wick 160 can thus be increased to improve the capillary efficiency.

[0076] Furthermore, using porous materials of different porosity for the centre portion 161 and the outer portion 162 allows tailoring of the capillary function to ensure that the capillary action remains substantially constant until the liquid in the cavity 110 is depleted. For example, the centre portion 161 can have smaller pores with increased capillary action in comparison to the outer portion 162 having larger pores. The outer portion 162 thus functions as reservoir while the centre portion 161 functions as transport zone absorbing or sucking the liquid contained in the outer portion 162. The liquid is therefore completely drawn into the centre portion 161 which increases the depletion rate of the capsule 100.

[0077] According to a further embodiment, the porous material can have a non-uniform pore size distribution that changes in the axial or longitudinal axis of the porous material. For example, small pores can be at the end facing the membrane (sealing foil end), while large pores are at the end facing the bottom of the capsule (cupsule bottom end). The axial inhomogeneous pore size distribution improves suction and thus transport in axial direction which allows to completely nearly empty the cavity as also liquid, which is at the capsule bottom end of the porous material is transported.

[0078] According to an embodiment, the porous material can have a non-uniform porosity distribution both in axial direction and in radial direction. This would encourage liquid to travel from the outside of the porous material to the centre of the porous material, and from the capsule bottom end of the porous material to the sealing foil end.

[0079] FIGS. 4 and 5 are REM photographs of a liquid transporting element in accordance with an embodiment of the present invention.

[0080] In the example shown, illustrated in the Figures the liquid transporting element comprises a wick which is made of pure silicon dioxide fibres which are splined to form a string with diameter 1.5 mm. The fibres are around 8-10 microns in diameter. The capillary properties of the material are given from the stacking of the fibres that create tiny passages for the liquid to creep through.

[0081] As can be seen in the FIGS. 4 and 5, the arrangement of the individual fibres is such that the passages between the fibres are substantially aligned with the longitudinal extent of the wick 160. When arranged within a capsule, the passages between the fibres are also similarly aligned with the longitudinal extent of the capsule 100 which facilitates liquid being drawn from the end of the cavity 110 within the capsule 100 remote from an open end of the capsule 100.

[0082] An electronic smoking device 200 according to an embodiment is described with reference to FIG. 6. The smoking device 200 includes an elongated housing 210 comprising a first hollow part 211 and a second hollow part 212 releasably connected to the first hollow part 211. The first hollow part 211 and the second hollow part 212 define together an internal space 220 of the housing 210. Each of the first and second hollow parts 211, 212 is basically cylindrically shaped and has a closed end and an open end.

[0083] As illustrated in FIG. 6, the first hollow part 211 and the second hollow part 212 engage with each other at their respective open ends for example by means of a snap fit. For example, the first hollow part 211 can be provided with deflectable arms 213 each having a nose 215 projecting radially inwardly to engage with a recess 215 formed at the outer side of the second hollow part 212. When the first and second hollow parts 211, 212 are pushed with their opens ends towards each other, the arms 213 come into contact with a conically shaped open end 216 of the second hollow part 212 and are radially deflected until the noses 215 snap back into the recesses 215 provided at the second hollow part 212. Other releasable connections between the first and second hollow part 211, 212 are also possible and include, for example, threw connections and bayonet connections.

[0084] The first hollow part 211 forms a mouth piece at its closed end opposite to its open end at which the user sucks on the electronic smoking device 200 to generate an underpressure or air stream within the internal space 220 of the housing 210. A capsule 240 is insertable into the first hollow part 211 with the closed end 242 of the capsule 240 pointing towards the mouth piece of the housing 210.

[0085] An atomizer 250 is accommodated and fixed in the second hollow part 212. The atomizer 250 includes a rupture element which includes an atomizer bridge 251 and a nickel foam or nickel mesh 253 surrounding and supported by the bridge 251. The bridge 251 can be formed by a sufficiently rigid metal wire bracket to allow rupture of the membrane 244 of the capsule 240 as described further below.

[0086] The atomizer 250 further includes a cylindrical nickel foam part 255 (or cylindrical nickel mesh part) which is in contact with the nickel foam 253 supported by the bridge 215. The cylindrical nickel foam part 255 and the nickel foam 253 form together a liquid transporting path of the atomizer 250 to transport the liquid from the cavity 241 of the capsule 240 to a glass fibre wick 252 of the atomizer 250 around which a heating coil 254 is wound. The heating coil 254 is connected to a battery and control circuitry which are not shown in FIG. 6. The battery and the control circuitry are accommodated in the second hollow part 212 of the housing 210.

[0087] When the capsule 240 is inserted into the first hollow part 211 with the open end sealed by the membrane 244 facing the atomizer, the bridge 251 pierces and ruptures the membrane 244 with a not-illustrated piercing spike formed at the leading end of the bridge 251. Upon further pushing the first and the second hollow parts 211, 212 toward each other, the nickel foam 253 supported by the bridge 251 enters the interior of the cavity 241 of the capsule 240 and comes into contact with the wick 245 arranged within the cavity 241 of the capsule 240 to form a liquid transporting path from within the cavity to the glass fibre wick 252.

[0088] The bridge 251 advances into the cavity 241 by given extent which depends on the length of the bridge 251 and the final arrangement of the capsule 240 and bridge 251 relative to each other when the first and the second hollow parts 211, 212 fully engages with each other.

[0089] Typically, the wick 245 accommodated within the cavity 241 is cut to a length which ensures sufficient contact with the bridge 251 without generating a large tension for the wick 245 and the bridge 251. For example, if the bridge 251 enters the capsule 240 by a length of 3 mm, the wick 240 is cut to the length of the cavity 241 minus 3 mm. The wick 245 is thus shorter than the length of cavity 241 of the capsule 240.

[0090] A wick length shorter than the length of the cavity 241 furthermore ensures a proper sealing of the cavity 241 by the membrane 244, since the injection of the liquid during the filling process can cause the wick 245 to rise out of the capsule if the material of the wick 245 does not absorb the liquid fast enough. This will be explained in more detail with reference to the manufacturing processes further below.

[0091] Since the cavity 241 of the capsule 240 has typically a comparably small volume, the surface tension of the liquid contained in the small and narrow cavity 241 acts against withdrawal of the liquid from the cavity. This may effectively limit the transfer of liquid to the glass fibre wick 252 if no additional means are provided. For example, when a capsule without wick is pierced onto the bridge of the atomiser 250, the nickel foam 253 absorbs the liquid via capillary action. The level of the liquid within the capsule will therefore decrease during consumption of the liquid. When the level of liquid decreases so that the liquid is no longer in contact with the nickel foam 253 supported by the bridge 251, the capillary ‘connection’ is lost, and the liquid remains inside the capsule, and there is an under supply of liquid to the atomizer.

[0092] Complete depletion of the liquid is ensured when using a wick 245 accommodated in the capsule 240, as the wick 245, when the capsule 240 is inserted into the housing 210, transports the liquid from the bottom of the cavity 241 toward the nickel foam 253 and thus provides a substantially constant capillary flow until the liquid is completely depleted. Hence, the consumption efficiency is increased, and significant less liquid is disposed.

[0093] A process for manufacturing a capsule according to an embodiment is described with reference to FIGS. 7A, 7B and 8.

[0094] The wick can be manufactured, for example, by braiding multiple strands each including a plurality of individual fibres, for example glass fibres or silica fibres, into a long cord. The cord is wound onto a large bobbin and then placed onto a cutting machine which draws the cord and cuts it size using a rotary cutting saw to obtain individual wicks. The stiff and robust nature of the wick allows an automated wick insertion process as described further below.

[0095] An insertion system adapted to allow automated insertion of the wick can be based on a pallet transfer unit where the capsules are first sorted followed by insertion of the wicks. A pallet transfer unit can include a dead plate with aluminium pallets being pushed around this plate. The pallets are moved around several working areas and will finally be transferred into a carrier for shipment.

[0096] Several processes are described subsequently.

Process 1 (410)

[0097] For inserting the wicks into capsules, the capsules are first sorted and oriented properly. For example, the capsules 100 can be fed by a vibratory bowl feeder 310 as illustrated in FIG. 7A. The vibratory bowl feeder 310 includes a vibrating bowl 320 with a spiral-shaped ramp along which the capsules 100 move due to the vibration of the bowl 320. As the capsules 100 have an asymmetrical shape with a barycentre located closer to the end wall 103, the initially randomly orientated capsules 100 orientate with their open end 111 facing upwards when subjected to vibration and movement along the spiral-shaped ramp. The open ends 111 are illustrated in FIG. 7A.

[0098] The vibratory bowl feeder 310 further includes two feeder lanes 311, 312 which branches-off from each other to transport the capsules 100 to two pockets 341, 342 of a pallet 340 at a loading station. Each pallet 340 can include multiple pockets 341, 342 depending on circumstances. The pallet 340 will be manipulated underneath the feeder lanes 311, 312, and pairs of pockets 341, 342 of the pallet 340 are filled within a given operating time.

Process 2 (420)

[0099] In a further process, the pallet 340 is moved to an inspection station (not shown) for checking whether the capsules 100 have been correctly placed into the pockets 341, 342 of the pallet 340. Pockets 341, 342 with misaligned capsules 100 or damaged capsules 100 will be rejected.

Process 3 (430)

[0100] If a row of capsules 100, for example 6 capsules if each pocket 341, 342 is sized to accommodate rows of 6 capsules, is deemed to be correctly oriented and not damaged, the pocket 341, 342 is transferred to six-lane wick feeding station 360 as indicated in FIG. 7B. The feeding station 360 includes a number of wick feedings lanes 361 to 366. The number of the wick feeding lanes 361 to 366 corresponds to the numbers of capsules 100 in a row of a pocket 341, 342.

[0101] As illustrated in FIG. 7B, the open ends of the feedings lines 361 to 362 are close to the open ends 111 of the capsules 100 so that the wicks 120 fed by the feeding lines 361 to 366 pushes the wicks 120 into the cavity 110 of the capsules 100.

Process 4 (440)

[0102] After insertion of the wicks 120, the pallets 340 are moved to an inspection station for inspection whether the wicks 120 have been completely and correctly inserted into the capsules 100 and that none of the wicks 120 is either hanging over the open end 111 the capsule 100 or has fallen out and is lying on the pallet 340. Inspection can be done automatically using a camera and image-processing software. If any there is any misplacement of a wick 120 detected, the complete row the capsules is rejected into a reject chute which transports the capsules 100 to a waste bin.

[0103] As the complete row is rejected when misplaced wick 120 is detected, the number of capsules 100 within one row should not be too high.

[0104] The pallets 340 which pass inspection can either be emptied with the capsules 120 collected in a separate carrier or transferred to a liquid filling section.

Process 5 (450)

[0105] In a further process, the liquid containing the tobacco compound is filled into the cavities 110 of the capsules 100, for example by inserting a needle into the cavity 110. As the wick 120 is shorter than the internal length of the cavity 110, the needle can be inserted to a given extent without pressing and damaging the inserted wick 120.

[0106] The needle may also remain in the cavity 110 until the wick 120 is completely soaked with the liquid. This ensures that the wick 120 is not pushed out of the cavity 110 during the filling process due to air entrapped in the passages which needs a given time to be replaced by the liquid.

Process 6 (460)

[0107] After filling the capsules 100 with liquid, the open end 111 is sealed by the membrane 104 as illustrated in FIG. 1, for example. The sealed capsules 100 are then removed from the pallets, packed and shipped.

Process 7 (470)

[0108] After removing the capsules 100 from the pallets 340, the pallets 340 are cleaned with, for example, vacuum to remove any particle from the pallets 340 and the pockets 341, 342, and then allowed to recycle to the loading stations.

[0109] The above processes can be carried out at a single wick inserting and filling system. Alternatively, the wick insertion process can be handled by a wick insertion apparatus separate to a liquid filling apparatus. In this case, sealing of the capsules 100 with the membrane 104 will be conducted by the liquid filling apparatus.