The present invention relates to a cigarette comprising a tobacco rod and an adjoining filter, and more particularly to a filter that includes a capsule packed with flavored adsorbent.

Cigarettes with filters are old in the art, and filters that include adsorbents also are well known (see e.g. DE 19527471 A1 or US-A-3251 365). However, when adsorbents are used in cigarette filter constructions it is important that they be presented in a fully packed condition so as to avoid or substantially reduce channeling of mainstream tobacco smoke in and around the adsorbent. Moreover, although flavors have been added to mainstream tobacco smoke it is important to maintain such flavors as fresh as possible for extended shelf life of the cigarette.

Accordingly, one of the objects of the present invention is a cigarette filter containing adsorbent particles in a fully packed condition so as to avoid channeling of mainstream tobacco smoke in and around the adsorbent particles.

Another object of the present invention is a cigarette filter containing flavored adsorbent particles wherein the amount of flavor is precise.

Still another object of the present invention is a cigarette filter containing fully packed flavored adsorbent particles within a capsule to preserve freshness of the flavored particles.

In accordance with the present invention, a cigarette comprises a filter and an adjoining tobacco rod. The filter includes a capsule having a first end wall with a surrounding side wall secured thereto. Adsorbent spherical carbon particles are packed into the enclosure of the capsule, and flavorant is placed on the particles. A second end wall caps-off the side wall, and a plurality of perforations are located in the end walls of the capsule. During smoking of the cigarette, mainstream tobacco passes into and through the capsule to thereby modify the characteristics of the smoke.

In one embodiment of the present invention, the adsorbent spherical carbon particles comprise a combination of two different sizes. Also, in the preferred embodiment of the present invention, the filter has a plug-space-plug configuration with the capsule in the central space. The plugs on opposite ends of the capsule may each comprise cellulose acetate tow.

Novel features and advantages of the present invention in addition to those mentioned above will become apparent to persons of ordinary skill in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein similar referenced characters refer to similar parts and in which:

• Figure 1 is a side elevational view of a cigarette comprising a tobacco rod and a filter that includes a capsuled adsorbent and flavorant, according to the present invention, with portions of the filter broken away to show interior details;
• Figure 2 is a perspective view of the capsuled adsorbent and flavorant of the cigarette filter shown in Figure 1;
• Figure 3 is an end elevational view of the capsuled adsorbent and flavorant shown in Figures 1 and 2; and
• Figure 4 is an elevational view of the capsuled adsorbent with flavorant being applied to the adsorbent within the capsule prior to capping the capsule, according to the present invention.

Referring in more particularity to the drawings, Figure 1 illustrates a cigarette 10 comprising a tobacco rod 12 and a filter 14 adjoining the tobacco rod. Filter 14 has a plug-space-plug configuration and the central space provides a compartment for a capsule 16 containing a flavored adsorbent material, as explained more fully below.

Plugs 18 and 20 each of cellulose acetate tow are located on opposite ends of the capsule 16. Tipping paper 22 is wrapped around the filter 14 and joins the filter to the tobacco rod. Perforations 40 may be provided in the tipping paper for the introduction of air which dilutes the mainstream tobacco smoke following through the filter.

Capsule 16 comprises an impervious surrounding side wall 24 and a first and second end wall 26, 28. Adsorbent spherical carbon particles 30, 32 are fully packed into the enclosure of the capsule, and a flavorant 34 is applied to the carbon particles. Both end walls 26 and 28 include a plurality of perforations 36 which enable mainstream smoke to pass through the capsule.

The capsule 16 is produced by initially forming the surrounding side wall 24 with one end wall 26 attached thereto. Carbon particles 28, 30 each having a different size are fully packed into the capsule and a precise amount of flavorant 34 is delivered onto the particles by an applicator device 38. The opposite end of the surrounding side wall 24 is then capped-off by end wall 28.

By encapsulating the adsorbent spherical carbon particles 30, 32 in this particular manner, a capsule fully packed with particles is presented and such fully packed condition avoids channeling of mainstream tobacco smoke in and around the particles. Vibration may be applied to obtain a fully packed capsule. Hence, the smoke is subjected to the fully effect of the adsorbent particles and the flavorant applied thereto. Moreover, the effectiveness of the encapsulated adsorbent particles 28, 30 is maintained over long periods thereby significantly increasing the shelf life of cigarette filters made in this manner. Overall the capsule 16 enables more exact filing of adsorbent particles 28, 30 and more control of flavor 34 per cigarette.