Smoke filter plug and process and cigarette made therefrom

Claim 2

A filter plug for a smoking article comprising a smoke impervious sleeve embracing a porous tow of longitudinally extending thermoplastic fibers exposed at opposite ends for the passage of smoke therethrough from end to end and a thin nonthermoplastic porous wrap for said tow, embracing in contacting non-spaced relationship the side wall of said tow between said ends, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial first portion of its length, said tow having a cavity molded in the wrap and said side wall and providing a smoke channel defined by the exterior surface of said wrap and a substantial second portion of the length of said sleeve, said channel extending from one of said ends to a location spaced from the other of said ends.

Claim 3

The filter recited in claim 1 wherein the porosity index of said porous wrap is less than about 2 seconds.

Claim 4

The filter recited in claim 1 in which there are a plurality of said cavities providing a plurality of said smoke channels.

Claim 5

The filter recited in claim 3 in which said channels are arranged in spaced, parallel, longitudinally extending relationship.

Claim 6

The filter recited in claim 3 wherein ratio of the surface area defined by said cavities to the surface area of said one end is between about 1 to 1 and 15 to 1.

Claim 7

A filter plug for a smoking article being in the form of a cylinder of essentially uniform cross-section throughout its length and comprising a smoke impervious sleeve embracing a porous tow of longitudinally extending thermoplastic fibers exposed at opposite ends for the passage of smoke therethrough from end to end and a porous paper wrap for said tow, closely embracing in contacting non-spaced relationship the cylindrical side walls of said tow between said ends, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial first portion of its length, said paper wrap having a porosity index less than about 2 seconds, said tow having a plurality of longitudinal, parallel, spaced cavities, molded in the paper wrap and the side wall of said tow, providing smoke channels in the cylindrical side wall of said tow defined by the exterior surface of said wrap and a substantial second portion of the length of said sleeve, said channels extending from one of said ends to a location spaced from the other of said ends, and the ratio of the exterior surface areas presented by said cavities to the exterior surface area of said one end is between about 1 to 1 and 15 to 1.

Claim 8

A filter plug for a smoking article being in the form of a cylinder of essentially uniform cross-section throughout its length and comprising a smoke impervious sleeve embracing a porous tow of longitudinally extending thermoplastic fibers exposed at opposite ends for the passage of smoke therethrough from end to end and a porous paper wrap for said tow, closely embracing in contacting non-spaced relationship the cylindrical side walls of said tow between said ends, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial first portion of its length, said paper wrap having a porosity index less than about 2 seconds, said tow having a plurality of longitudinal, parallel, spaced cavities, molded in the paper wrap and the side wall of said tow, providing smoke channels in the cylindrical side wall of said tow defined by the exterior surface of said wrap and a substantial second portion of the length of said sleeve, said channels extending from one of said ends to a location spaced from the other of said ends, and the ratio of the exterior surface areas presented by said cavities to the exterior surface area of said one end is between about 1 to 1 and 15 to 1.

Claim 9

The filter recited in claim 6 wherein the percentage of the exposed surface areas within said cavities is between about 25 and 90 percent of the total side wall surface area of said tow.

Claim 10

The filter recited in claim 6 wherein the fibers are cellulose acetate filaments, the denier of the filaments is between about 1.3 and 16 and the total denier of the tow is between about 38,000 and 100,000.

Claim 11

A cigarette comprising a tobacco section overwrapped with cigarette paper, a porous filter plug positioned at one end of said tobacco section, and a smoke impervious sleeve overlying portioNs of said plug and said tobacco section for holding them in fixed relationship, said plug comprising a tow of longitudinally extending thermoplastic fibers for the passage of smoke therethrough from end to end and a thin non-thermoplastic porous plug wrap, embracing and in contacting non-spaced relationship with the side wall of said tow between the ends thereof, said plug having a cavity, molded in the plug wrap and said side wall, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial portion of its length providing a smoke channel defined by the interior surface of said sleeve and the exterior surface of said wrap extending from one end of said plug to a location spaced short of the opposite end thereof whereby a portion of the smoke from the tobacco section passes through said tow from end to end of said plug and another portion of said smoke passes through said channel, said porous plug wrap and a portion of the two in said plug.

Claim 12

A cigarette comprising a tobacco section overwrapped with cigarette paper, a porous filter plug positioned at one end of said tobacco section, and a smoke impervious sleeve overlying portioNs of said plug and said tobacco section for holding them in fixed relationship, said plug comprising a tow of longitudinally extending thermoplastic fibers for the passage of smoke therethrough from end to end and a thin non-thermoplastic porous plug wrap, embracing and in contacting non-spaced relationship with the side wall of said tow between the ends thereof, said plug having a cavity, molded in the plug wrap and said side wall, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial portion of its length providing a smoke channel defined by the interior surface of said sleeve and the exterior surface of said wrap extending from one end of said plug to a location spaced short of the opposite end thereof whereby a portion of the smoke from the tobacco section passes through said tow from end to end of said plug and another portion of said smoke passes through said channel, said porous plug wrap and a portion of the two in said plug.

Claim 13

The cigarette recited in claim 9 wherein said one end of said plug faces upstream.

Claim 14

The cigarette recited in claim 9 wherein said one end of said plug faces downstream.

Claim 15

A cigarette comprising a tobacco section overwrapped with cigarette paper, a porous filter plug positioned at one end of said tobacco section, and a smoke impervious sleeve overlying portions of said plug and said tobacco section for holding them in fixed relationship, said plug having a uniform cross-section substantially the same as that of the tobacco section throughout its length and consisting essentially of a tow of longitudinally extending thermoplastic fibers for passage of smoke therethrough from end to end and a porous paper plug wrap, closely embracing and in non-spaced contacting relationship with the side walls of said tow between the ends thereof, said plug having a plurality of longitudinal, parallel, circumferentially spaced cavities, molded in the paper plug wrap and the side wAll of said tow, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial portion of its length provIding a plurality of smoke channels defined by the interior surface of said sleeve and the exterior surface of said wrap extending from one end of said plug to a location short of the opposite end thereof whereby a portion of the smoke from the tobacco section passes through said tow from end to end of said plug and another portion of said smoke passes through said channels, said porous plug wrap and a portion of the tow in said plug.

Claim 16

A cigarette comprising a tobacco section overwrapped with cigarette paper, a porous filter plug positioned at one end of said tobacco section, and a smoke impervious sleeve overlying portions of said plug and said tobacco section for holding them in fixed relationship, said plug having a uniform cross-section substantially the same as that of the tobacco section throughout its length and consisting essentially of a tow of longitudinally extending thermoplastic fibers for passage of smoke therethrough from end to end and a porous paper plug wrap, closely embracing and in non-spaced contacting relationship with the side walls of said tow between the ends thereof, said plug having a plurality of longitudinal, parallel, circumferentially spaced cavities, molded in the paper plug wrap and the side wAll of said tow, said wrap being in 360* angle contacting non-spaced relationship with said sleeve for a substantial portion of its length provIding a plurality of smoke channels defined by the interior surface of said sleeve and the exterior surface of said wrap extending from one end of said plug to a location short of the opposite end thereof whereby a portion of the smoke from the tobacco section passes through said tow from end to end of said plug and another portion of said smoke passes through said channels, said porous plug wrap and a portion of the tow in said plug.

Claim 17

The cigarette recited in claim 12 wherein the porosity index of said paper plug wrap is between about 0.1 and 2 seconds.

Claim 18

The cigarette recited in claim 13 wherein the ratio of the exterior surface areas presented by said cavities in the plug to the exterior surface area of said one end wall is between about 1 to 1 and 15 to 1.