Filter for a smoking article

1. A smoking article filter comprising a monolith circumscribed by a plugwrap, wherein the monolith comprises carbonized sintered resin and is configured such that a pressure drop of the filter does not significantly increase with monolith length.

2. The smoking article filter as claimed in claim 1 , wherein the monolith does not comprise resin particles bound together using a binder.

3. A smoking article filter comprising a monolith circumscribed by a plugwrap, wherein the monolith comprises a plurality of cells, each cell comprising a channel that extends through the monolith, the combined cross sectional surface area of the channels comprising 30-40% of the total cross sectional surface area of the monolith, and the monolith configured such that a pressure drop of the filter does not significantly increase with monolith length.

4. The smoking article filter as claimed in claim 3 , wherein the combined cross sectional surface area of the channels comprises 32-38% of the total cross sectional surface area of the monolith.

5. A smoking article filter, comprising: a monolith, the monolith configured such that a pressure drop of the filter does not significantly increase with monolith length, wherein the monolith comprises a plurality of cells, each cell comprising a channel that extends through the monolith, and wherein, in cross section, the monolith comprises 180-310 cells per square centimeter, and wherein the monolith has a pore volume of 0.4 to 1.5 cm 3 /g as estimated by nitrogen adsorption.

6. The smoking article filter according to claim 5 , wherein, in cross section, the monolith comprises 200-280 cells per square centimeter.

7. The smoking article filter as claimed in claim 5 , wherein the monolith comprises a carbon material having a pore structure that includes micropores and macropores.

8. The smoking article filter as claimed in claim 7 , wherein the pore structure also includes mesopores.

9. The smoking article filter as claimed in claim 5 , wherein the carbon material of the monolith encompassing the channels has a pore structure that includes macropores.

10. The smoking article filter as claimed in claim 5 , wherein the monolith comprises channels that are square in cross section.

11. The smoking article filter as claimed in claim 5 , wherein the carbon material of the monolith has a BET surface area of 700-1300 m 2 /g.

12. The smoking article filter as claimed in claim 11 , wherein the carbon material of the monolith has a BET surface area of 810-990 m 2 /g.

13. The smoking article filter as claimed in claim 5 , wherein the monolith is 8-12 mm in length.

14. The smoking article filter as claimed in claim 5 , the smoking article filter comprising a plurality of monoliths.

15. A smoking article comprising the smoking article filter as claimed in claim 5 .

16. The smoking article filter as claimed in claim 5 , wherein the monolith comprises carbonized sintered resin.

17. The smoking article filter as claimed in claim 16 , wherein the monolith does not comprise resin particles bound together using a binder.

18. The smoking article filter as claimed in claim 5 , wherein the combined cross sectional surface area of the channels comprises 30-40% of the total cross sectional surface area of the monolith.

19. The smoking article filter as claimed in claim 18 , wherein the combined cross sectional surface area of the channels comprises 32-38% of the total cross sectional surface area of the monolith.

20. A method of manufacturing a smoking article filter, comprising:

comminuting a partially cured resin to form particles of the partially cured resin;

forming particles of the partially cured resin into a dough and shaping the dough to produce a monolith;

sintering the particles of the monolith to form a sintered monolith;

carbonizing and activating the sintered monolith; and

incorporating the activated sintered monolith into a smoking article filter configured such that a pressure drop of the filter does not significantly increase with monolith length.

21. The method as claimed in claim 20 , wherein shaping the dough comprises extruding the dough.

22. The method as claimed in claim 20 , wherein the dough is free from a binder.

23. The method as claimed in claim 20 , wherein the resin is obtained by condensing a nucleophilic component with an electrophilic cross-linking agent in the presence of a pore former.