| abstract |
The invention is related to a new and improved filter for smoking articles, especially cigarettes, of the cavity type. In order to achieve better filtration, the cavity which is delimited by two substantially cylindrical filter portions made of fibrous material, spaced apart in the longitudinal direction of said filter, contains a particulate filtering matter being composed of two physical fractions of particles, the mean diameter of the particles of the first fraction being 20 to 50 times the mean diameter of the particles of the second fraction. Preferably, the particles of the first fraction have a mean diameter comprised between 0.2 and 1.2 mm, more preferably between 0.6 and 1.0 mm, and the particles of the second fraction have a mean diameter comprised between 0.006 and 0.040, more preferably between 0.010 and 0.030 mm. It is preferred that the volume ratio of the first to the second fraction is at least 2:1 and may amount until 50:1. |