Multi-segment component for an aerosol-generating article
There is provided a multi-segment component for an aerosol generating article, the multi-segment component including a combustible heat source; an aerosol-forming substrate downstream of the combustible heat source; a wrapper circumscribing the combustible heat source along at least part of a length of the combustible heat source; and an intumescent layer between the combustible heat source and the wrapper and circumscribing the combustible heat source, the intumescent layer being formed from an intumescent inorganic glue.
1. A multi-segment component for an aerosol generating article, the multi-segment component comprising:
a combustible heat source;
an aerosol-forming substrate downstream of the combustible heat source;
a wrapper circumscribing the combustible heat source along at least part of a length of the combustible heat source; and
an intumescent layer between the combustible heat source and the wrapper and extending around an entire circumference of the combustible heat source, the intumescent layer being formed from an intumescent inorganic glue,
wherein the combustible heat source has at least one shaped recess on an outer surface thereof,
wherein the intumescent inorganic glue of the intumescent layer at least partially fills the at least one shaped recess, and
wherein a depth of the at least one shaped recess is between about 0.05 mm and about 0.8 mm.
2. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue has an expansion ratio of at least about 1.5:1 when heated from 20 degrees Celsius to 700 degrees Celsius at ambient pressure.
3. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue has an expansion ratio of from about 2:1 to about 5:1 when heated from 20 degrees Celsius to 700 degrees Celsius at ambient pressure.
4. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue has an expansion ratio of about 3:1 when heated from 20 degrees Celsius to 700 degrees Celsius at ambient pressure.
5. The multi-segment component according to claim 1 , wherein the intumescent layer has a thickness of at least about 0.01 mm to about 0.1 mm.
6. The multi-segment component according to claim 1 , wherein the intumescent layer has a thickness of from about 0.01 mm to about 0.04 mm.
7. The multi-segment component according to claim 1 , wherein the intumescent layer has a thickness of about 0.02 mm.
8. The multi-segment component according to claim wherein the intumescent inorganic glue is a foaming intumescent inorganic glue.
9. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue comprises at least 1% by weight of water.
10. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue comprises between about 1% and about 7% by weight of water.
11. The multi-segment component according to claim 1 , wherein the intumescent inorganic glue comprises from about 1% to about 5% by weight of water.
12. The multi-segment component according to claim 1 , wherein the intumescent layer is formed from a sodium silicate glue.
13. The multi-segment component according to claim 12 , wherein the sodium silicate glue has a molar ratio of from about 2 to about 3.5 parts SiO 2 to 1 part Na 2 O.
14. The multi-segment component according to claim 1 , wherein the combustible heat source comprises a rear portion having a substantially constant cross-section, the at least one shaped recess terminating at an upstream end of the rear portion.
15. The multi-segment component according to claim 14 , wherein the rear portion has a length of less than about 3 mm.
16. The multi-segment component according to claim 14 , wherein the rear portion has a length of about 2 mm to about 3 mm.
17. The multi-segment component according to claim 1 , wherein radially outer edges of the at least one shaped recess are curved with a radius of curvature of at least about 0.05 mm.
18. The multi-segment component according to claim 1 , wherein an outer diameter of the combustible heat source is substantially constant along substantially an entire length of the combustible heat source.
19. The multi-segment component according to claim 1 , wherein the wrapper comprises one or more layers of heat-conductive material.
20. The multi-segment component according to claim 1 , wherein the wrapper comprises one or more layers of heat-insulative material.
21. The multi-segment component according to claim 1 , wherein the wrapper comprises a radially inner layer of heat-conductive material and a radially outer layer of heat-insulative material.
22. An aerosol generating article comprising the multi-segment component according to claim 1 .