US3572347A - Tobacco smoke filter - Google Patents

Abstract

A FILTER FOR A CIGARETTE IS PROVIDED WHICH INCLUDES AN ELONGATED CORE PIECE HAVING AN ELONGATED FLUTE FORMED IN THE EXTERIOR THEREOF AND A FIRST WEB OF SHEET MATERIAL PROVIDED WITH A PRFORATION. THE FIRST WEB ENCOMPASSED THE CORE PIECE SO THAT THE PERFORATION IS ALIGNED AND IN COMMUNICATION WIHT A FIRST PASSAGEWAY FORMED BY THE FLUTE. THE ENCOMPASSING FIRST WEB CARRIES A PLASTIC MASS WHICH IS DISPOSED ADJACENT THE PERFORATION AND FILLS A PORTION OF THE FLUTE SO AS TO FORM A SMOKE BARRIER IN THE FIRST PASSAGEWAY. A SECOND WEB OF SHEET MATERIAL IS PROVIDED WHICH ENCOMPASSES THE FIRST WEB; CORRESPONDING PORTIONS OF THE WEBS ARE DISPOSED IN SPACED RELATION AND FROM A SECOND PASSAGEWAY. THE SMOKE UPON CIRCULATING SUCCESIVELY THROUGH THE PASSAGEWAYS IS CAUSED TO PASS THROUGH THE PERFORATION AT A HIGH VELOCITY AND IMPINGE UPON A SURFACE FORMING THE SUCCEEDING PASSAGEWAY.

Description

March 1971 J. H. SHERRILL 3,572,347

TOBACCO SMOKE FILTER 2 Sheets-Sheet 1 Filed June 30, 1969 Invemor Jbseph H.- Sherri/l BW-Fbna'lfon, Alec/man, 5e Ibo Id f [l/i 18015 fl-fv nays March 23, 1971 J. H. SHERRILL TOBACCO SMOKE FILTER Filed June 30, 1969 2 SheetsSheet 2 V kt. lief/fit United States Patent US. Cl. Lil-10.5 Claims ABSTRACT OF THE DISCLOSURE A filter for a cigarette is provided which includes an elongated core piece having an elongated flu'te formed in the exterior thereof and a first web of sheet material provided with a perforation. The first web encompasses the core piece so that the perforation is aligned and in communication with a first passageway formed by the flute. The encompassing first web carries a plastic mass which is disposed adjacent the perforation and fills a portion of the flute so as to form a smoke barrier in the first passageway. A second web of sheet material is provided which encompasses the first web; corresponding portions of the webs are disposed in spaced relation and form a second passageway. The smoke upon circulating successively through the passageways is cau ed to pass through the perforation at a high velocity and impinge upon a surface forming the succeeding passageway.

BACKGROUND OF THE INVENTION Because of the extremely high production rate of filter cigarettes required to meet the present demand of the smoking public, it is essential that the filter be of simple and inexpensive construction and readily capable of being assembled with a tobacco rod by utilizing automatic high speed equipment, the function and operation of which are well understood in the cigarette-making art. Heretofore various cigarette filters have been proposed; however, because of their complexity, numerous component parts, and the difiiculty and cost of producing in large quantities certain of the parts thereof, they are unable to meet the aforesaid requirements.

Thus, it is an object of this invention to provide a cigarette filter which is highly eifective in removing the undesirable particles from the smoke as it passes therethrough.

It is a further object of this invention to provide a filter which has a minimum number of component parts that may be produced and assembled at a rate commensurate with the production rate of the tobacco rods to which the filters are attached.

Further and additional objects will appear from the description, accompanying drawings, and appended claims.

SUMMARY OF THE INVENTION In accordance with one embodiment of this invention a filter is provided which is adapted to be affixed to the downstream end of a tobacco rod. The filter comprises an elongated rodlike core piece having a plurality of elongated fiutes formed in the exterior surface thereof. The core piece is encompassed by a first web of sheet material having a plurality of perforations formed therein. The perforations encircle the core piece and are aligned in communication with first passageways formed by the flutes and first web. The first web is provided with a stripe of plastic which fills in a portion of each flute and forms a smoke barrier within each first passageway. Encompassing the first web is a second web of sheet material. Corresponding portions of the first and second webs are in closely spaced relation and form a second passageway 3,572,347 Patented Mar. 23, 1971 which circumvents the smoke barriers and is in communication with the perforations of said first web. As the smoke circulates, successively through the passageways, it is caused to flow at a high velocity through the perforations and then impinges upon a surface forming the succeeding passageway.

DESCRIPTION For a more complete understanding of the invention reference should be made to the drawings wherein:

FIG. 1 is an enlarged perspective view of one form of the improved filter with portions thereof cut away.

FIG. 2 is a perspective view of the filter of FIG. 1 and a tobacco rod and with the filter shown in partially disassembled relation.

FIG. 3 is an enlarged sectional view taken along line 3--3 of FIG. 1.

FIG. 4 is an enlarged perspective view of a segment of a tape from which the first web is formed and with stripes of plastic shown applied thereto.

FIG. 5 is a fragmentary perspective view of a portion of the automatic equipment used to form the improved filter.

Referring now to the drawings and more particularly to FIGS. 1 and 2, one form of an improved filter 10 is shown which is adapted to be aflixed to the downstream end 11 of a tobacco rod 12. The filter comprises an elongated rodlike core piece 13 formed of a stilt smoke impervious material. The core piece is preferably formed by extrusion. The exterior of the core piece is provided with a plurality of elongated continuous flutes 14 which are coextensive with the piece. The piece is adapted to be placed in abutting, aligned relation with respect to end 11 of the tobacco rod 12.

Encompassing the core piece is a first Web 15 of sheet material, such as thin paper, which, prior to encompassing the piece, has formed therein spaced rows of perforations 16a and 16b and a stripe 17 of soft plastic material, adhesively disposed between alternate rows of perforations, see FIGS. 2 and 4. In the illustrated embodiment the perforations comprising each row are arranged in a slightly staggered relation; however, the arrangement may be varied, if desired, provided the perforations 16a and b are in communication with the flutes 14.

As the first web 15 encompasses the core piece, the stripe 17 of plastic will be deposited within corresponding portions of the flutes and form smoke barriers within the passageways 18, see FIG. 3, defined by the web and core piece. Once the plastic material has been deposited within the flutes, it will normally harden.

Encompassing the first web 15 is a second web 20 which in the illustrated embodiment is a composite member comprising a slotted inner lamina 21 and an imperforate outer lamina 22, both of which are preferably formed of thin paper material. The slots 21a formed in lamina 21 are arranged in parallel spaced relation, see FIG. 2. The length of each slot is such that each slot communicates at its ends with the perforations 16a and b and thereby circumvents the smoke barriers formed by the stripe 17.

The second or outer lamina 22, which is imperforate cooperates with lamina 21 and the first web 15 so as to form a plurality of narrow shallow passageways 23, see FIG. 3. The outer lamina 22 may be of tipping paper and aflixed by adhesive to the exterior of the downstream end 11 of the tobacco rod 12.

If desired, the second web 20 may be a single lamina, not shown, on which spacer strips, either of paper or beads of adhesive, are afiixed. In a further modification, not shown, the second web 20 may be a single lamina and the first web 15 provided with longitudinally spaced, transversely extending embossments between which are located the perforations 16a and b and the stripe of plastic material 17. In the latter described modification the embossments would encircle the core piece and be in sealing engagement with the interior surface of the second web. The height of the embossments will determine the shallowness of the passageway which cricumvents the smoke barriers formed by the stripe 17.

In FIG. 3, it will be noted that perforations 16a and b are located upstream and downstream, respectively, of the smoke barrier 17. Thus, when a smoker draws on the free end or tip of the filter, the smoke from the lighted end of the tobacco rod 12 passes through the plurality of passageways 18 disposed upstream of the barriers 17, whereupon the smoke is diverted out through the perforations 16a and into the shallow passageways 23 which are defined by the slotted lamina 21. By reason of the smallness (e.g., .0102" diameter) of each perforation 16a, the velocity of the smoke while passing therethrough is very high. The shallowness of each of the passageways 23 is approximately .005"-.020 with the result that the high velocity smoke entering into the passageways 23 will impinge against the interior surface of lamina 22 causing the solid and/or liquid particles entrained in the high velocity smoke to be deposited thereon. The smoke, upon reaching the downstream ends of the passageways 23, is again diverted so as to pass through the perforations 16b. Perforations 16b may be the same or slightly greater in size than perforations 16a. As the smoke is diverted through perforations 16b, it will pass into the passageways 18 disposed downstream of barrier 17 and cause further deposition of the smoke particles within the downstream passageways 18 prior to reaching the smokers mouth. If desired, a plug of fibrous material (e.g., cellulose acetate), not shown, may be placed in abutting relation with the upstream or downstream end of the filter 10. A charcoal or other absorbent filter material, not shown, which affects primarily the gas phase of the circulating smoke, may be used in conjunction with the filter 10.

In forming the filter 10, an elongated rodlike member 13A is first extruded through a suitable die, not shown. The shape of the die is such that the desired number of flutes is formed. The member 13A is moved in an axial direction at a predetermined rate. At a selected station of travel, see FIG. 5, the webs 15 and 21 are brought into encompassing relation with the member 13A. Web 15 is formed from a tape 15A which is withdrawn from a roll 24. Upon leaving roll 24, the tape 15A passes between a pair of perforating rolls 26a and b at which point the perforations 16a and b are formed. The perforated tape 15A then passes through an adhesive applicator, at which point a thin coating of adhesive is applied to portions of the bottom surface of the tape, as seen in FIG. 5. Where a thermoplastic adhesive coating has previously been applied to the tape 15A, the latter upon leaving the perforating rolls 26a and 12 passes between a pair of heating elements 27 so as to activate the coating.

The uncoated surface of the tape 15A then passes beneath a plastic feed roll 28 which deposits thereon a meas ured amount of plastic material. The feed roll 28 is provided with a plurality of elongated pockets 28a which pick up a predetermined amount of the plastic material which is accumulated within a suitable reservoir 30. The arrangement of the pockets 28a on the roll 28 is coordinated with the rate of movement of the tape so that a stripe 17 of the plastic material will be properly deposited on the tape between predetermined rows of perforations formed therein, see FIG. 4.

After the tape 15A has moved past the feed roll 28, it is laminated to a slotted tape 21A which eventually becomes the lamina 21 of the composite second web 20. Tape 21A is initially taken from a supply roll 31 and is fed between a pair of rolls 32a and b which render the tape more pliable and thereby facilitate subsequent forming of the tape about the member 13A. The pliable tape 21A is then directed about a backup roller 33 before it is engaged by the slotter roll 34. The slotter roll 34 forms longitudinally spaced sets of slots 21a. Each set of slots 21a comprises the slots 21a formed in the inner lamina 21 of the composite outer web 20, see FIG. 2.

At the top of the backup roller 33, the slotted tape 21A is brought into contact with the coated surface of tape 15A whereupon the two tapes become laminated to one another prior to being formed about the member 13A by a conventional folder bottom 35.

Upon the web-wrapped rodlike member leaving the folder bottom 35, it then passes beneath a cutter, not shown, wherein segments of predetermined length are severed therefrom. The length of each segment may be varied as desired depending upon the eventual length of filter. Once the segment of desired length has been formed, it is then placed in aligned relation with respect to the downstream end 11 of the tobacco rod 12 and then afiixed thereto by the web lamina 22, normally referred to as tipping paper.

While the improved filter is shown with the inner web 15 having two rows of perforations, one upstream and the other downstream of the barrier 17, it is to be understood, of course, that only one row of perforations may be utilized so that the circulating smoke will either pass from the passageways 18 upstream of the barrier into passageway 23; or from the latter passageway into the passageways 18 downstream of the barrier. In both these latter variations the slots 21a formed in the lamina 21 would terminate either at the tobacco rod or at the free end of the filter.

Thus, it will be seen that an effective and simple filter has been provided which is inexpensive to produce and is capable of being expeditiously assembled by high speed automatic equipment.

I claim:

1. A filter adapted to be affixed to the downstream end of a tobacco rod, said filter comprising an elongated core piece of smoke impervious material having a flute formed in the exterior thereof; a plastic mass disposed within said flute and forming therein a smoke barrier; a first sleeve unit encompassing the exterior of said piece and cooperating with said flute and plasticmass to form an elongated first passageway through which smoke is caused to pass, said first sleeve unit being provided with a small opening, aligned and in communication with said first passageway whereby smoke is caused to pass therethrough at a high velocity, and a second sleeve unit encompassing the exterior of said first sleeve unit, corresponding portions of said first and second sleeve units being in spaced relation and forming a second passageway circumventing said smoke barrier and through which smoke is caused to flow, said first and second passageways being in communication with one another through said opening whereby smoke upon flowing successively through one passageway, the opening and then the other passageway will impinge at a high velocity against a surface forming the latter passageway.

2. The filter of claim 1 wherein said core piece is extruded and has the flute thereof coextensive therewith.

3. The filter of claim 1 wherein the exterior of said core piece is provided with a plurality of elongated flutes extending longitudinally thereof, and said first sleeve unit is provided with a plurality of openings aligned and in communication with said flutes.

4. The filter of claim 1 wherein said plastic mass is disposed at substantially mid-length of said flute, and said first sleeve unit is provided with a pair of axially spaced openings, one of said openings being disposed upstream of said mass and in communication with one portion of said flute, and the other opening being disposed downstream of said mass and in communication with a second portion of said flute.

5 5. The filter of claim 1 wherein said plastic mass is in FOREIGN PATENTS adhesively aifixed sealing engagement with the interior 1,118,860 3/1956 France Surface of sald first Sleeve 1,510,851 12/1967 France 131-261(B) References Cited 5 SAMUEL KOREN, Primary Examiner UNITED STATES PATENTS J. F. PITRELLI, Assistant Examiner 1,505,413 8/1924 Nichols 131-201 1,582,971 5/1926 Conley 131-201 US. Cl. X.R. 2,954,774 10/1960 Lebert 131 -10.5

2,954,787 10/1960 Lebert 131-213X 10 131201 216

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