Cigarette filter comprising a carbonaceous fiber
The invention provides a cigarette filter including at least one filter segment having one or more composite fiber structures imbedded therein, the composite fiber structure including a carrier fiber and an adsorbent fiber, the adsorbent fiber including an adsorbent material. The filter can include one or more segments of fibrous tow material, with the one or more composite fiber structures imbedded within the fibrous tow, the composite fiber structure including a carrier fiber and a carbonaceous fiber.
1. A cigarette filter comprising at least one filter segment of fibrous tow material having one or more composite fiber structures imbedded within the fibrous tow, the composite fiber structure comprising two fiber types comprising a carrier fiber and a carbonaceous fiber, the carrier fiber and the carbonaceous fiber being connected together to enable co-insertion of the composite fiber structure into the filter segment.
2. The cigarette filter of claim 1 , wherein the carbonaceous fiber is prepared by carbonization of a precursor fiber.
3. The cigarette filter of claim 2 , wherein the precursor fiber is selected from the group consisting of phenolic fibers, cellulosic fibers, rayon fibers, acrylic fibers, and pitch fibers.
4. The cigarette filter of claim 1 , wherein the composite fiber structure comprises multiple carrier fibers or multiple carbonaceous fibers.
5. The cigarette filter of claim 1 , wherein at least one of the carrier fiber and the carbonaceous fiber is in the form of a yarn.
6. The cigarette filter of claim 1 , wherein the composite fiber structure is in the form of a yarn.
7. The cigarette filter of claim 1 , wherein the carbonaceous fiber is wrapped around the carrier fiber.
8. The cigarette filter of claim 1 , wherein the fibrous tow material is a cellulose acetate tow.
9. The cigarette filter of claim 1 , wherein the carrier fiber and the carbonaceous fiber are connected together by wrapping, intertwining or weaving the two fiber types together, bonding the fiber types together using an adhesive or binder, co-extruding the two fiber types, or tying the two fiber types together using a separate connecting element.
10. The cigarette filter of claim 7 , wherein the composite fiber structure comprises 1 to about 50 circumferential wrappings of the carbonaceous fiber per inch of carrier fiber.
11. The cigarette filter of claim 1 , wherein each composite fiber structure comprises 1 to about 20 carrier fibers and 1 to about 20 carbonaceous fibers.
12. The cigarette filter of claim 1 , wherein the composite fiber structures extend linearly in the longitudinal direction of the filter segment.