Patent ID: 7669604

Claim:
A cigarette comprising a tobacco rod and a filter element connected to the tobacco rod, said filter element having an end proximal to the tobacco rod and an end distal from the tobacco rod, wherein said filter element comprises: a first longitudinally extending section of fibrous tow filter material positioned at the end of the filter element proximal to the tobacco rod and abutting a charge of smokable filler material of the tobacco rod, wherein the first section of fibrous tow filter material consists of plasticized fibrous tow; a second longitudinally extending section of fibrous tow filter material positioned at the end of the filter element distal from the tobacco rod and spaced apart from said first section of filter material, wherein the two sections of filter material are circumscribed by a plug wrap and a compartment is defined and bounded by the two sections of filter material and the plug wrap, wherein the second section of fibrous tow filter material consists of plasticized fibrous tow and the plug wrap forms an inner wall of the compartment; and a semi-permeable barrier dividing said compartment into a hollow first region proximal to the tobacco rod and a second region distal to the tobacco rod and containing an adsorbent material, the semi-permeable barrier consisting of a porous paper or a plasticized fibrous tow filter material, wherein the hollow first region consists of an empty space for intermixing of mainstream smoke prior to entry of the smoke into the adsorbent-containing region of the compartment.