A METHOD FOR MANUFACTURING A HEAT SOURCE

Abstract

The invention relates to a method for the manufacturing of a combustible heat source (1) for an aerosol forming article, comprising: Providing a mould (100) defining a cavity (101) having a first opening (102); Providing a chamber (106) above said cavity (101), the chamber (106) having a second opening (108) fluidly connected to the first opening (102); Placing a particulate component (104) in the chamber (106); compressing the particulate component (104) in the chamber (106) up to a first pressure so that it forcedly flows into said cavity (101); and compressing the particulate component (104) in the cavity (101) up to a second pressure higher than said first pressure to form the combustible heat source (1).

Claims

1. A method for the manufacturing of a heat source for an aerosol forming article, comprising: providing a mould defining a cavity having a first opening; providing a chamber above said cavity, the chamber having a second opening fluidly connected to the first opening; placing a particulate component in the chamber; compressing the particulate component in the chamber up to a first pressure so that it forcedly flows into said cavity; compressing the particulate component in the cavity up to a second pressure higher than said first pressure to form the heat source; and between the step of compressing the particulate component at a first pressure and the step of compressing the particulate at a second pressure, applying no pressure, with the exception of the atmospheric pressure, to the particulate component in the chamber for a predetermined time.

2. A method for the manufacturing of a heat source for an aerosol forming article, comprising: providing a mould defining a cavity having a first opening; providing a chamber above said cavity, the chamber having a second opening fluidly connected to the first opening; placing a particulate component in the chamber; compressing the particulate component in the chamber up to a first pressure so that it forcedly flows into said cavity; compressing the particulate component in the cavity up to a second pressure higher than said first pressure to form the heat source; wherein said first pressure is comprised between about 0.005 MegaPascal and about 0.5 MegaPascal.

3. A method for the manufacturing of a heat source for an aerosol forming article, comprising: providing a mould defining a cavity having a first opening; providing a chamber above said cavity, the chamber having a second opening fluidly connected to the first opening; placing a particulate component in the chamber; compressing the particulate component in the chamber up to a first pressure so that it forcedly flows into said cavity; compressing the particulate component in the cavity up to a second pressure higher than said first pressure to form the heat source; wherein the heat source has a length between 2 mm and 20 mm.

4. The method according to claim 2, wherein, between the step of compressing the particulate component at a first pressure and the step of compressing the particulate at a second pressure, the method further comprises: Applying no pressure, with the exception of the atmospheric pressure, to the particulate component in the chamber for a predetermined time.

5. The method according to claim 1, further comprising: Providing a fluid flow in said chamber to push said particulate component towards said cavity.

6. The method according to claim 1, further comprising: Providing a first mechanical pressing device to compress the particulate component towards the cavity.

7. The method according to claim 1, further comprising: Sensing a weight of particulate component present inside the cavity.

8. The method according to claim 7, further comprising: Interrupting the compression inside the chamber when said weight of particulate component in said cavity is above a set threshold.

11. The method according to claim 7, further comprising: Slowly increasing a pressure during the compression step inside said chamber till the weight of the particulate component inside said cavity reaches a cavity set threshold.

12. The method according to claim 1, wherein said first pressure is comprised between about 0.005 MegaPascal and about 0.5 MegaPascal.

13. The method according to claim 1, wherein the pressure equal to the first pressure is applied for a time interval comprised between about 0.01 seconds and about 2 seconds.

14. The method according to claim 1, wherein said second pressure is comprised between about 1 MegaPascal and about 50 MegaPascal.

15. The method according to claim 1, wherein the pressure equal to the second pressure is applied for a time interval comprised between about 0.01 seconds and about 2 seconds.

16. The method according to claim 2, further comprising: Providing a fluid flow in said chamber to push said particulate component towards said cavity.

17. The method according to claim 2, further comprising: Providing a first mechanical pressing device to compress the particulate component towards the cavity.

18. The method according to claim 2, further comprising: Sensing a weight of particulate component present inside the cavity.

19. The method according to claim 18, further comprising: Interrupting the compression inside the chamber when said weight of particulate component in said cavity is above a set threshold.

20. The method according to claim 18, further comprising: Slowly increasing a pressure during the compression step inside said chamber till the weight of the particulate component inside said cavity reaches a cavity set threshold.

21. The method according to claim 3, wherein, between the step of compressing the particulate component at a first pressure and the step of compressing the particulate at a second pressure, it includes: Applying no pressure, with the exception of the atmospheric pressure, to the particulate component in the chamber for a predetermined time.

22. The method according to claim 3, wherein said first pressure is comprised between about 0.005 MegaPascal and about 0.5 MegaPascal.

23. The method according to claim 3, further comprising: Providing a fluid flow in said chamber to push said particulate component towards said cavity.

24. The method according to claim 3, further comprising: Providing a first mechanical pressing device to compress the particulate component towards the cavity.

25. The method according to claim 3, further comprising: Sensing a weight of particulate component present inside the cavity.

26. The method according to claim 25, including: Interrupting the compression inside the chamber when said weight of particulate component in said cavity is above a set threshold.

27. The method according to claim 25, including: Slowly increasing a pressure during the compression step inside said chamber till the weight of the particulate component inside said cavity reaches a cavity set threshold.

Description

[0066] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

[0067] FIGS. 1a-1d show schematic diagrams of steps of the method to produce a heat source according to the invention; and

[0068] FIGS. 2a and 2b show a top view and a lateral view of a heat source realized according to the method of the invention.

[0069] FIGS. 1a, 1b, 1c and 1 d show schematic representations of steps for the manufacture of a heat source according to the present invention and globally indicated with 1. The realized heat source 1 at the end of the method of the invention is depicted in an enlarged view in FIGS. 2a and 2b.

[0070] The machinery 10 utilised to manufacture the heat source 1 is arranged as follows. A mould 100 is provided that defines the side walls of a cavity 101 for forming the heat source 1. The top wall of the cavity is open defining a first opening 102. The mould side walls and the bottom wall may be movable relative to each other in order to change the size of the cavity. The cavity 101 is cylindrical.

[0071] A hopper 103 is provided that is configured to hold and release particulate matter 104 via an hopper outlet 105. Further, the machinery 10 includes a chamber 106 which is fluidly connected to the hopper 103 by means of a pipe 107. The chamber 106 is slidably mounted relative to the mould 100, such that it can reciprocate along a line perpendicular to the longitudinal axis of the cavity 102. Further, chamber 106 is positioned on top of the mould 100 and includes a second opening 108. Preferably, the dimension of the second opening is equal to or bigger than that of the first opening 102.

[0072] A piston 109 is provided vertically above the cavity 102 and is arranged such that the longitudinal axis of the piston and the longitudinal axis of the cavity 101 are aligned. Preferably, the piston 109 has a compressive area, that is the area that enters into contact to the particulate during the application of a pressure onto the particulate, of about 0.5 square centimetres. Optionally a second piston (not depicted in the drawings) including a bottom wall of the cavity is also slidable and arranged such that the longitudinal axis of the second piston and the longitudinal axis of the cavity 101 are aligned. Piston 109 and second piston may cooperate to compress material present in the cavity therebetween.

[0073] Further, a fluid reservoir 110 is fluidly connected to the chamber 106 by means of pipe 111. Preferably pipe 111 branches off pipe 107. Fluid reservoir 110 preferably includes a fan or blower 112 to blow the fluid towards the chamber 106.

[0074] The chamber 106 could be air-sealed to the forming mould 100, except for the pipes 107/111. For instance, the chamber could have all around its bottom a compressible seal (not visible in the drawings) and the chamber could be mechanically pressed on the mould 100, making it air-sealed, except for the pipes.

[0075] A weight sensor 113 can be provided inside cavity 101 to weight the particulate material introduced therein. The weight sensor 113 may send signals relating to the weight of the particulate material to a control unit 114 apt to command fan or blower 112 and to increase, decrease or interrupt the air flow in the chamber 106 as a function of the particulate material weight. The connection between control unit 114, fan or blower 112 and sensor 113 is depicted as dashed lines in the FIGS. 1a-1b.

[0076] FIG. 1a shows the chamber 106 positioned above the mould 100 such that the first and second openings 102, 108 are located one on top of the other. In this position, the hopper 103 is filled with particulate material 104 and therein stored. The hopper 103 provides the chamber 106 with particulate material 104 via pipe 107 along the direction of arrows 20. Sufficient particulate material is provided into the chamber 106 to form a single heat source 1. The flow of the particulate material takes place by gravity.

[0077] Then chamber 106 is air-tighten to mould 100.

[0078] After the particulate material 104 has reached the chamber 106 from the hopper 103, FIG. 1b shows the activation of the fan or blower 112 so that a flow of air is introduced in the chamber 106 by means of pipe 117 along the direction of the arrow 30. Fan or blower can be activated by means of a command sent by control unit 114. In this way, due to the air-tight connection between chamber and mould, a pressure is built up in chamber 106 and the particulate material 104 present in the chamber 106 moves into the cavity 101 being pushed by the air blow. The pressure built up in the chamber is controlled, for example by means of suitable sensors (not depicted) so that it does not exceed the first pressure. Preferably, the air pressure applied is comprised between about 0.02 MegaPascal and about 0.1 MegaPascal for about 0.15 seconds so that the particulate component enters the chamber. Weight sensor 113 may send signals to the control unit 114 which, depending on the weight of the particulate material 104 introduced in the cavity, may vary the pressure exerted by the air flow. When the desired weight is achieved, control unit 114 stops the air flow and thus no more pressure in addition to the atmospheric pressure is present in the chamber 106. The control unit in order to interrupt the application of the chamber pressure may for example send a switch off signal to the fan 112.

[0079] FIG. 1c shows the chamber 106 retreating from the cavity filling position shown in FIGS. 1a and 1b. As the chamber 106 slides away from the mould cavity opening 102, the piston 109 advances towards the cavity 101, in the direction as shown by arrow 40. Therefore, the particulate material 104 present in the cavity 101 is compressed by the piston 109 which presses the particulate towards the walls of the cavity 101. The piston 109 compresses particulate material 104 till a second pressure is reached which is pre-determined. The second pressure is high enough to pack together the particulate material which then is substantially glued together to form a single unit.

[0080] Preferably, the second pressure is reached in three different subsequent sub-steps. The piston 109 moves down towards the bottom of the cavity and starts compressing the particulate in a first sub-step, applying a force of between about 0.05 kiloNewton to about 0.15 kiloNewton for a time interval comprised between about 0.2 seconds to 0.3 s seconds. The piston 109 then proceeds further compressing the particulate in a second sub-step with a strength of between about 0.2 kiloNewton to about 0.4 kiloNewton for a time interval comprised between about 0.2 seconds to about 0.3 seconds. In the third sub-step, the piston compresses the particulate in the cavity even more, with strength of between about 0.5 kiloNewton to about 0.6 kiloNewton, which defines the second pressure value, for a time interval comprised between about 0.2 seconds to about 0.3 seconds. FIG. 1d shows the piston 109 retreated from the cavity 101. As the piston 109 retreats, the mould portion defining the walls of the cavity is preferably lowered relative to the portion of the mould forming the bottom of the cavity. In this way, the heat source 1 is ejected from the mould cavity. As the mould portion defining the side walls of the cavity is lowered, the chamber 106 is slidably advanced along the top face of the mould to begin the process of manufacturing a further heat source. As the chamber advances, the leading edge of the chamber 106 is utilised to clear the formed heat source from the work area. In this way, a continuous process is provided.

[0081] FIGS. 2a and 2b show the formed heat source 1. The compressed particulate material forms the heat source. The heat source is approximately about 7.8 mm in diameter and approximately about 9 mm in length. As shown in FIG. 2b the combustible heat source 1 is substantially circular in cross-section.

[0082] The heat source is used in an aerosol forming device. The article comprises a heat source formed as described above, an aerosol forming substrate provided adjacent the barrier of the heat source, a diffuser, a transfer section, a filter adapted to condense vapour, and a mouthpiece filter. As the user draws on the aerosol forming article, air is drawn through ventilation holes upstream of the aerosol-forming substrate which entrains the aerosol.

[0083] The embodiments and examples described above illustrate but do not limit the invention. Other embodiments of the invention may be made without departing from the spirit and scope thereof, and it is to be understood that the specific embodiments described herein are not limiting.