Improved Cigarette Filters Comprising Compound Fibers

Abstract

An improved cigarette filter material/method is provided, especially a compound fiber filter. Cylindrical, with paper tube, filled with tow of interconnected compound fibers in parallel with the cylindrical axis. Said compound fiber comprises a fiber core with a surface layer made from adsorptive materials on. The adsorptive material and the improved filter can effectively adsorb harmful substances from tobacco smoke, and not affect the cigarette taste or flavor.

Description

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application claims the priority benefit of the Chinese patent application No. 200520011670.X filed on Apr. 7, 2005.

FIELD OF THE INVENTION

The invention relates to cigarette filters, especially compound fiber cigarette filter rods.

BACKGROUND OF THE INVENTION

In recent years, due to the influence of World Health Organization and various anti-smoking movements, some developed countries have started limiting the component of tar, nicotine, and carbon monoxide, etc in the cigarettes. The raised health awareness of consumers also pushes manufacturers to produce cigarette products with lower levels of harmful substances, to reduce the damage to consumers.

As shown in FIG. 1, cigarette filter rods are usually cylindrical rods of size 7.7×120 mm (D×L) or the scale thereabout. The filter rods are cut into segments of certain lengths and attached to the cigarette as a filter mechanism while smoking cigarettes. On the outside of the rod is paper. The paper tube is filled with tow of interconnected compound fibers in parallel with the cylindrical axis. The fibers are usually Cellulose acetate fiber, Polypropylene fiber, etc. Polypropylene fiber has an alkyl surface, and is chemically inactive. Cellulose acetate fiber has a mostly acetate surface, and is average in the level of chemical activity. These chemical characteristics limit the effectiveness of filter rods for removing harmful substances.

SUMMARY OF THE INVENTION

The present invention relates to overcoming the inadequacies of current filter technologies, providing a compound fiber filter rod that effectively adsorbs harmful substances in cigarette smoking, while preserves or improves the taste of the cigarette. The present invention's technical solution: a compound fiber filter rod. It is cylindrical, with paper tube as the outer shell, filled with tow of interconnected compound fibers in parallel with the cylindrical axis. Said compound fiber is comprised of filter fiber core and adsorptive materials, which attach on the surface. The present invention has the following characteristics:

1. The filter rod's physical attributes, such as circumference, roundness hardness, and draw resistance comply with filter rod requirements of a cigarette.

2. The filter rod has strong adsorptive filter materials with larger surface area, and it is effective in filtering tar, carbon monoxide, free radicals, and other harmful substances in cigarette smoke.

3. The filter rod does not negatively affect the taste of the cigarette.

4. The filter rod is non-toxic, tasteless, and high safety. The filter rod is safely produced in a clean environment with no unpleasant smells.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the cigarette filter rod.

FIG. 2 is a cross section view of the cigarette filter rod.

FIG. 3 is an enlarged view of part A in FIG. 2.

FIG. 4 is a schematic representation showing the structure of the compound fiber.

FIG. 5 is a schematic representation showing the adsorptive material.

DETAILED DESCRIPTION OF THE INVENTION

As shown in the FIG. 2 the present invention has an outer shell paper tube (1). The paper tube (1) is filled with tow of compound fibers (2) in parallel with the cylindrical axis. The fibers are interconnected (3) to form a filter rod with high permeability.

The compound fibers within the paper tube have the total count of 9000 or greater. Optimally, 12000 or greater.

As shown in FIG. 4, said compound fiber (2) comprises a core (21) and a surface layer (22). The core (21) is generally cigarette filter fibers, such as polypropylene fiber, cellulose acetate fiber, etc. The surface layer (22) comprises adsorptive material(s). The surface is rich in ion exchange groups and bases.

The core (21) generally has a diameter of 20 μm or thinner (≦20 μm) and the surface layer 0.5 μm or greater (≧0.5 μm).

As shown in FIG. 5, the adsorptive material has an affinity to the core. As shown, one side is hydrophilic (24), and the other side lipophilic (25). The lipophilic material attaches the adsorptive material to the core, while also completes the inter-fiber “welding”. In other words, this adsorptive material builds the construction of the compound filter rod. To increase the compound fiber filter rod's effectiveness in reducing tar and other harmful substances, other materials can also be added to the fibers, such as porous absorbers, Chinese medicinal herb extracts, biochemical substances, and other strong adsorptive material against harmful substances in tobacco smoke.

Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.

Claims

1. A cigarette filter comprising a paper tube; compound fibers which is filled in said tube in parallel with the axis of said tube; said compound fibers being interconnected to form the filter having high permeability.

2. The cigarette filter of claim 1, wherein said compound fiber Comprises a fiber core and a surface layer made from adsorptive materials.

3. The cigarette filter of claim 2, wherein the diameter of said fiber Core is 20 μm or thinner (≦20 μm), and the thickness of said surface layer is 0.5 μm or greater (≧0.5 μm).

4. The cigarette filter of claim 1, wherein the total count of said fibers is greater than 9000.

5. The cigarette filter of claim 2, wherein the total count of fibers is greater than 9000.

6. The cigarette filter of claim 1, wherein the total count of fibers is greater than 12000.

7. The cigarette filter rod of claim 2, wherein the total count of fibers within the paper tube is greater than 12000.

8. The cigarette filter of claim 2, wherein said core is polypropylene fiber or cellulose acetate fiber.

9. The cigarette filter of claim 2, wherein said adsorptive material has an affinity to said core, its one side is hydrophilic, and the other side is lipophilic which attaches said adsorptive material to said core.

10. The cigarette filter of claim 9, wherein said adsorptive materials are rich in ion exchange groups and bases.

11. The cigarette filter of claim 1, wherein said compound fiber is covered with porous adsorptive material, or herbal extracts, or biochemical substances, or other strong adsorptive material against harmful substances in tobacco smoke.

12. The cigarette filter of claim 2, wherein the fiber is covered with porous adsorptive material, or herbal extracts, or biochemical substances, or other strong adsorptive material against harmful substances in tobacco smoke.