Aerosol-generating article comprising a liquid delivery element

Abstract

An aerosol-generating article (10) includes a mouthpiece (14) comprising at least one segment of filter material (18,20) and a liquid delivery element (22). The liquid delivery element (22) comprises: an upstream end and a downstream end; a double-walled annular body portion (28) comprising: an inner wall (34) defining a longitudinal channel (38) extending through the liquid delivery element (22); and an outer wall (32) integrally formed with the inner wall (34), the outer wall (32) circumscribing the inner wall (34) such that a cavity (36) is defined between the outer wall (32) and the inner wall (34), the cavity (36) having an opening in at least one of the upstream end and the downstream end and containing a liquid; and annular sealing means (40) inserted between the inner wall (34) and the outer wall (32) of the annular body portion (28) to provide a liquid tight seal at the opening or openings of the cavity (36). The inner wall (34) and the outer wall (32) of the annular body portion (28) are configured such that the inner wall (34) is breakable upon application of a compressive force to the liquid delivery element (22) in a transverse direction and such that upon breakage of the inner wall (34) the liquid is released from the cavity (36) into the longitudinal channel (38).

Claims

1. An aerosol-generating article comprising an aerosol-generating substrate and a mouthpiece secured to a downstream end of the aerosol-generating substrate, the mouthpiece comprising at least one segment of filter material and a liquid delivery element, the liquid delivery element comprising: an upstream end and a downstream end; a double-walled annular body portion comprising: an inner wall defining a longitudinal channel extending through the liquid delivery element between the upstream end and the downstream end; and an outer wall integrally formed with the inner wall, the outer wall circumscribing the inner wall such that a cavity is defined between the outer wall and the inner wall, the cavity having an opening in at least one of the upstream end and the downstream end and containing a liquid; and annular sealing means inserted between the inner wall and the outer wall of the annular body portion to provide a liquid tight seal at the opening or openings of the cavity in the annular body portion; wherein the inner wall and the outer wall of the annular body portion are configured such that the inner wall is breakable upon application of a compressive force to the liquid delivery element in a transverse direction and such that upon breakage of the inner wall the liquid is released from the cavity into the longitudinal channel.

2. An aerosol-generating article according to claim 1 wherein the distance at breakage of the inner wall is smaller than the distance at breakage of the outer wall such that the inner wall breaks preferentially upon application of a transverse compressive force to the liquid delivery element, wherein the distance at breakage of the inner wall is defined as the transverse deformation of the liquid delivery element at the point of breakage of the inner wall, and the distance at breakage of the outer wall is defined as the transverse deformation of the liquid delivery element at the point of breakage of the outer wall.

3. An aerosol-generating article according to claim 1 wherein upon application of a transverse compressive force to the liquid delivery element that equals or exceeds a maximum compressive force that the annular body portion can withstand, the inner wall breaks and the outer wall remains intact.

4. An aerosol-generating article according to claim 1 wherein the radial thickness of the inner wall of the annular body portion is greater than the radial thickness of the outer wall of the annular body portion at all positions along the length of the cavity.

5. An aerosol-generating article according to claim 4 wherein the radial thickness of the inner wall of the annular body portion is at least twice the radial thickness of the outer wall at all positions along the length of the cavity.

6. An aerosol-generating article according to claim 1 wherein one or more grooves are provided on the inner surface of the inner wall of the annular body portion, the inner wall having a reduced thickness in the one or more grooves.

7. An aerosol-generating article according to claim 1 wherein the maximum radial spacing between the outer surface of the inner wall of the annular body portion and the inner surface of outer wall of the annular body portion is less than 1 mm.

8. An aerosol-generating article according to claim 1 wherein the inner wall and the outer wall of the annular body portion are integrally connected to each other at one end of the annular body portion and wherein the opening in the cavity is provided at the other end of the annular body portion.

9. An aerosol-generating article according to claim 1 wherein the cavity contains no more than 150 microlitres of liquid.

10. An aerosol-generating article according to claim 1 wherein the annular body portion is formed from a polymeric material having an elongation at break of between 5 percent and 20 percent when measured according to the test method of ASTM D 638.

11. An aerosol-generating article according to claim 1 wherein the annular body portion is formed from a polymeric material having a flexural strength of between 80 MPa and 110 MPa when measured according to the test method of ASTM D 790.

12. An aerosol-generating article according to claim 1 wherein the annular body portion is formed from a polymeric material having a flexural modulus of between 2500 MPa and 3500 MPa when measured according to the test method of ASTM D 790.

13. An aerosol-generating article according to claim 1 wherein the force at breakage of the inner wall of the annular body portion, which corresponds to a maximum compressive force that the annular body portion can withstand before breakage of the inner wall, is between 30 Newtons and 45 Newtons.

14. An aerosol-generating article according to claim 1 wherein the annular sealing means comprises an annular stopper having an outer wall received between the outer wall and the inner wall of the annular body portion for sealing the cavity and an inner wall received against the inner surface of the inner wall of the annular body portion.

15. A liquid delivery element for use in an aerosol-generating article, the liquid delivery element comprising: a first end and a second end; a double-walled annular body portion comprising: an inner wall defining a longitudinal channel extending through the liquid delivery element between the first end and the second end; and an outer wall integrally formed with the inner wall, the outer wall circumscribing the inner wall such that a cavity is defined between the outer wall and the inner wall, the cavity having an opening in at least one of the first end and the second end and containing a liquid; and annular sealing means inserted between the inner wall and the outer wall of the annular body portion to provide a liquid tight seal at the opening or openings of the cavity in the annular body portion; wherein the inner wall and the outer wall of the annular body portion are configured such that the inner wall is breakable upon application of a compressive force to the liquid delivery element in a transverse direction and such that upon breakage of the inner wall the liquid is released from the cavity into the longitudinal channel.

Description

(1) The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 shows a perspective view of an aerosol-generating article in accordance with the present invention;

(3) FIG. 2 shows an exploded view of the aerosol-generating article of FIG. 1, with the filter wrappers unwrapped;

(4) FIG. 3 shows a cross-sectional view of the liquid delivery element of the aerosol-generating article of FIG. 1, prior to activation; and

(5) FIG. 4 shows an exploded view of the liquid delivery element of FIG. 3;

(6) FIG. 1 shows an aerosol-generating article 10 according to an embodiment of the present invention. The aerosol-generating article 10 is a filter cigarette comprising an aerosol-generating substrate 12 in the form of a wrapped tobacco rod, and a mouthpiece 14. The mouthpiece 14 is secured to the wrapped tobacco rod by a tipping wrapper 16.

(7) As shown in FIG. 2, the mouthpiece 14 comprises an upstream filter segment 18 at an upstream end of the mouthpiece 14 and a downstream filter segment 20 at a downstream end of the mouthpiece 14. The mouthpiece 14 further comprises a liquid delivery element 22 positioned between the upstream and downstream filter segments 18, 20. A substantially transparent combining plug wrap 24 is wrapped around the upstream 18 and downstream 20 filter segments and the liquid delivery element 22 to combine them and form the mouthpiece 14. The tipping wrapper 16 comprises an aperture 26 overlying the liquid delivery element 22 and the substantially transparent plug wrap 24 so that the consumer can observe the liquid delivery element 22.

(8) As shown in FIGS. 3 and 4, the liquid delivery element 22 comprises an annular body portion 28 and an annular stopper 30. The annular body portion 28 has a double walled structure comprising an outer wall 32 and an inner wall 34 circumscribed by the outer wall 32. The inner wall 34 defines an open longitudinal channel 38 extending between the ends of the liquid delivery element 22. The longitudinal channel 38 has a circular transverse cross section and has a diameter that corresponds to approximately 60 percent of the external diameter of the liquid delivery element 22.

(9) The outer wall 32 and the inner wall 34 are spaced apart from each other radially to define an annular cavity 36 extending around the outside of the inner wall 34, which contains a coloured liquid comprising water. At one end of the annular body portion 28, the outer wall 32 and the inner wall 34 are integrally connected to each other to close the annular cavity 36. At the other end of the annular body portion 28, the annular cavity 36 has an opening which is sealed by means of the annular stopper 30.

(10) The inner wall 34 has a radial thickness that is approximately 2.5 times the radial thickness of the outer wall 32. The distance at breakage of the inner wall 34 is smaller than the distance at breakage of the outer wall 32 so that the inner wall 34 breaks first upon application of a compressive force to the liquid delivery element 22.

(11) The annular stopper 30 comprises an outer stopper wall 40 and an inner stopper wall 42 which are integrally connected to each other at one end of the annular stopper 30. The outer stopper wall 40 is inserted between the outer wall 32 and the inner wall 34 of the annular body portion 28 to seal the annular cavity 36 and the inner stopper wall 42 is provided against the inner surface of the inner wall 34 of the annular body portion 28. As shown in FIG. 3, the annular stopper 30 is inserted into the annular body portion 28 and is retained by means of a friction fit. An annular shoulder 44 is provided on the outer surface of the annular stopper 30, which abuts the edge of the outer wall 32 of the annular body portion 28 in order to prevent further movement of the annular stopper 30 into the annular body portion 28.

(12) Before or during smoking, the consumer may squeeze the liquid delivery element 22 to activate the liquid delivery element 22 and bring about release of the liquid. The compressive force applied to the liquid delivery element 22 causes deformation of the outer wall 32 of the annular body portion 28 and an increased pressure within the annular cavity 36. At a certain level of compressive force, the increased pressure within the annular cavity 36 causes the inner wall 34 of the annular body portion 28 to crack, thereby activating the liquid delivery element 22. The breakage of the inner wall 34 of the annular body portion allows the liquid to pass from the annular cavity 36 into the longitudinal channel 38. The liquid can then flow along the longitudinal channel 38 into the upstream filter segment 18 and the downstream filter segment 20. During this activation of the liquid delivery element 22, the consumer can observe, through the aperture 26 in the tipping wrapper 16, the coloured liquid moving from the annular cavity 36 into the filter segments 18, 20.