US3739785A

US3739785A - Cigarette with coated wrapper ventilation flaps

Info

Publication number: US3739785A
Application number: US00250064A
Authority: US
Inventors: W Stephens
Original assignee: Philip Morris USA Inc
Current assignee: Philip Morris USA Inc
Priority date: 1972-05-08
Filing date: 1972-05-03
Publication date: 1973-06-19
Anticipated expiration: 1990-06-19
Also published as: SE383927B; US3831445A; IT984022B; GB1428987A; FR2183935B1; JPS4949660A; DE2322882A1; FR2183935A1

Abstract

A ventilated cigarette employing one or more flaps defined by slit patterns in the wrapper thereof and which flaps are adapted to move away from the wrapper encircling course when the cigarette is puffed to admit ventilating or diluting air streams to the tobacco cylinder which is made with the slit pattern fashioned to extend generally transverse of the article longitudinal axis to provide flap movement about a hinge line disposed generally parallel to said longitudinal axis. The slit pattern can be made the the form of an X, a V or other suitable configuration. The article further has a coating of an airimpervious normally rigid material on either the inner or outer surface of the wrapper in covering and encircling expanse about each slit pattern and associated flap to normally constrain or hold the flap in the encircling wrapper course. When the cigarette has been smoked to an extent that ventilation is advantageous or desirable, the material responsive to the presence of heat from warm smoke and the burning coal or to the ingredients of tobacco smoke becomes softened and constraint on the flap is released to permit the circular tension in the wrapper to cause the flap to move away from the wrapper encircling course and admit ventilation air.

Description

[ CIGARETTE WITH COATED WRAPPER VENTILATION FLAPS William K. Stephens, Jr., Mechanicsville, Va.

[75] Inventor:

[73] Assignee: Philip Morris Incorporated, New

York, NY.

[22] Filed: May 3, 1972 21 App]. No.: 250,064

[52] US. Cl. 131/9, 131/10 A, 131/15 B [51] Int. Cl A2411 01/00 [58] Field Of Search 131/9, 8 R, 15 R,

[56] 8 References Cited UNITED STATES PATENTS 2,754,828 7/1956 Swain 131/15 B X 2,841,153 7/1958 Pelletier 131/15 B X 3,020,915 2/1962 Miller 131/15 B X 3,054,409 9/1962 Miller..... 131/15 B UX 3,395,714 8/1968 Kahane... 131/9 3,473,535 10/1969 Stahly..... 131/15 B X 3,511,247 5/1970 Tamol 131/15 B 3,526,904 9/1970 Tamol 131/15 B FOREIGN PATENTS OR APPLICATIONS 696,911 11/1964 Canada 131/15 B 1,914,963 10/1970 Germany 131/8 R [111 3,739,785 June 19, 1973 Primary Examiner-Robert W. Michell Assistant ExaminerGeorge M. Yahwak Attorney-Elmer R. Helferich, Norman N. Schuttler. John T. Kelton et al.

[57] ABSTRACT A ventilated cigarette employing one or more flaps defined by slit patterns in the wrapper thereof and which flaps are adapted to move away from the wrapper encircling course when the cigarette is puffed to admit ventilating or diluting air streams to the tobacco cylinder which is made with the slit pattern fashioned to ex tend generally transverse of the article longitudinal axis to provide flap movement about a hinge line disposed generally parallel to said longitudinal axis. The slit pattern can be made the the form of an X, a V or other suitable configuration. The article further has a coating of an air-impervious normally rigid material on either the inner or outer surface of the wrapper in covering and encircling expanse about each slit pattern and associated flap to normally constrain or hold the flap in the encircling wrapper course. When the cigarette has been smoked to an extent that ventilation is advantageous or desirable, the material responsive to the presence of heat from warm smoke and the burning coal or to the ingredients of tobacco smoke becomes softened and constraint on the flap is released to permit the circular tension in the wrapper to cause the flap to move away from the wrapper encircling course and admit ventilation air.

13 Claims, 11 Drawing Figures Patontud June 19, 1913 3,139,735

3 Sheets-Sheet 1 TPM TPM

Patented June 19, 1973 3,739,785

3 Sheets-Sheet 8 0- CONTROL COATED FLAPS I I I I I I I l I I I I I I |2345e7a9|ou|z|3|4 PUFF. NO.

CIGARET "Y" 6 PUFF. NO.

CIGARET "z" I 2 3 4 5 6 7 8 9 IO II I2 PUFF. N0.

Patented June 19, 1973 3 Sheets-Sheet 5 FIG. 9

FIG. /0

CIGARETTE WITH COATED WRAPPER VENTILATION F LAPS BACKGROUND OF THE INVENTION The desirability of delayed ventilation to control TPM delivery during later puff stages during smoking of a cigarette is described, e.g., in U. S. Pat. Nos. 2,992,647; 3,511,247 and 3,526,904. The term profile is used to describe the plot of delivery (usually total particulate matter or TPM) with each puff versus the puff number. Because the profile of a conventional cigarette shows a steep increase with later puffs, it is desirable to have ventilation to reduce delivery at that stage, but to have little or no ventilation to diminish flavor at the early puffs.

Certain patents have disclosed means of ventilating cigarettes to reduce TPM delivery by using openings in the wrapper to provide a point of entry of ventilation air to the cigarette. Some patents disclose formation of slits in the wrapper to give flaps which open by being drawn inward with the puff on the cigarette, e.g., U. S. Pat. Nos. 3,057,360 and 3,020,915. U. S. Pat. No. 3,054,409 causes the slits to remain open by reinforcing them with a stiffening coating while in U. S. Pat. No. 3,310,055 it is taught to reinforce wrapper perforations by printing with a special ink or other material on the wrapper adjacent the openings.

The aforementioned types of cigarettes are all effective for the purposes enumerated but they are difficult products to make uniformly and unvaryingly in the way that modern commercial standards demand at high production line speeds, especially in respect of controlling opening size and insuring positive opening movement of the flaps when desired.

SUMMARY OF THE INVENTION The present invention is concerned with a cigarette which employs ventilation features as a means for controlling the TPM delivery profile of the smoke delivered to the smoker. It is more particularly concerned with ventilation type cigarettes wherein the paper wrapper of the cigarette which is drawn tightly against the tobacco for holding it under radial constraint thereby producing a circular tension in the wrapper, is provided with an arrangement therein of one or more slits of predetermined pattern and at predetermined positioning from the smoking or lighting end of the cigarette which slit patterns define corresponding flaps in the wrapper which are movable away from the encircling wrapper course when the cigarette is puffed to admit dilution air flow to the cylinder of tobacco. In accordance with the present invention each flap in the cigarette wrapper is maintained in a normally constrained position disposed in the encircling wrapper course by means of an air-impervious normally rigid material coating applied preferably at the inner side of the wrapper with the coating being disposed in a covering and encircling expanse around each slit and associated flap. The material is such as to be softenable responsive to the presence of heat from warm smoke and the burning coal of the cigarette or responsive to the action of smoke ingredients so that after the cigarette has been smoked to a predetermined distance, the material softens and permits the flap or flaps to move away from the wrapper encircling course either inwardly or outwardly thereof under the impetus of the circular tension in the wrapper and to thereby admit ventilation air. The arrangement of flaps in the wrapper is such that more are located near the mouth end than the smoking end so that increasing measures of ventilation air will be admitted in the later stage puffs when the TPM levels show a steep upwardly incline.

For the purposes of the present invention various materials can be employed as the coating, as for example, hot melt adhesives, as well as various types of resin materials.

In accordance with the present invention the number and size of the slit patterns and associated flaps provided in the wrapper will be provided on the basis of the desired degree of ventilation as well as the smoking characteristics of the ciagarette. Generally each slit pattern is formed to have a total slit length of between 2 to 6 mm. and the slits can be in various forms, as for example, in the fashion of an X, V or such other configuration as extends generally transverse of the longitudinal axis of the article to provide movement of the associated flaps about a hinge line disposed generally parallel to said axis.

In accordance with the present invention the slit patterns and accordingly the therewith defined flaps in the paper wrapper can be arranged in extending longitudinal array in the wrapper on a centerline spacing of about 5 mm. between adjacent ones of the slit patterns. Further, the slit patterns can be arranged in side-byside parallel arrangement extending in two or more rows longitudinally of the wrapper, each slit pattern being aligned with at least one other slit pattern. The coating applied on and around each slit pattern associated flap preferably should be applied in a range of about 3 to about 10 microns thick.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the constructions hereinafter set forth and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS A fuller understanding of the nature and objects of the invention will be had from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a cigarette embodying flaps in the wrapper thereof which are movable away from the wrapper encircling course during smoking to admit ventilation air streams to the tobacco cylinder, the flaps being held constrained by a heat and/or tobacco smoke softenable coating on the wrapper in accordance with the principles of the present invention until the cigarette has been smoke a predetermined distance.

FIG. 2A is an enlarged fragmentary sectional view through the tobacco cylinder of the cigarette shown in FIG. 1, the wrapper ventilation flaps being depicted in constrained closed position wherein they are held by the coating of normally rigid but heat and/or tobacco smoke softenable material.

FIG. 2B is the same as FIG. 2A except it shows the moved position of the ventilation flaps following softening of the materialf FIG. 3 is a perspective view of a somewhat different FIG. 4 is a plan view of the wrapper embodied in the cigarette shown in FIG. 3, the inner surface of the wrapper facing the viewer. I

FIG. 5 is a graph illustrating the delivery profile of a cigarette of the type depicted in FIG. 1 as compared with a cigarette not provided with ventilation flaps.

FIGS. 6 and 7 are graphs illustrating the respective delivery profiles of FIG. 3 cigarettes in which the heat and/or tobacco smoke softenable material with which the wrappers were coated is a hot melt adhesive, and

1 greater the number of slit patterns and associated flaps,

greater dimension transversely of the smoking article s longitudinal axis than in the direction of such axis.

Throughout the following description like reference numerals are used to denote like parts in the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the cigarette 10 depicted in FIG. 1, it includes a cylinder of tobacco l2 enclosed in a paper wrapper l4 and having a filter element 16 connected at the mouth end thereof in conventional manner. The wrapper 14 encircles the tobacco cylinder 12 and is drawn tightly thereagainst and held in securement along overlapped

longitudinal edges

115, 117 for holding the tobacco under radial constraint, which condition produces a circular tension in the wrapper. The wrapper 14 is provided with an arrangement of slit patterns 18 which as can best be seen in FIGS. 2A and 28 form and define a corresponding pattern of flaps 22 in the paper wrapper which as will be explained later lie in the encircling course of the wrapper being held in such disposition by a coating of material to be described later, but which flaps when the ciagarette is puffed, can move inwardly or outwardly of the wrapper encircling course to provide openings through which dilution streams of ventilating air are admitted to the tobacco cylinder. The slit patterns can be formed in various arrangements in the wrapper depending upon the level of dilution desired as well as the point at which such dilution is to first occur. Further, the slit patterns should be arranged or fashioned in the wrapper to extend generally transversely of the longitudinal article to provide for movement of the associated flaps about a hinge line disposed generally parallel to said axis. In this manner, the circular tension in wrapper can be employed to bias the flap away from the wrapper encircling course when constraint on the same is released upon removal of the above-mentioned coating of material from the wrapper. Advantageously, the slit pattern is fashioned in the form of an X and preferably where the X is of relatively greater dimension transversely of the greater the degree of ventilation provided. In the depicted embodiment, the first slit pattern 18, and accordingly associated ventilation flaps 22, is located about 22 mm. from the lighting end of the cigarette with the remaining slit patterns being spaced longitudinally downstream therefrom on a centerline spacing of about 5 mm. The distance between the last slit pattern 18 and the filter end of the tobacco cylinder is about 15 mm.

In accordance with the present invention the wrapper is further provided with a coating 20 of a normally rigid material preferably disposed at the inner surface of the wrapper in covering and encircling expanse about each slit pattern 18 and flap 22 defined thereby. The material, however, is a type which becomes softened responsive to heat from the burning coal or smoke of the cigarette when smoked, or which is softened responsive to exposure to certain ingredients of tobacco smoke, e.g., moisture. The material as seen in FIG. 2A normally maintains the flaps 22 in the encircling course of the wrapper and thereby prevents dilution of the cigarette until a predetermined point during the smoking of the same. When the cigarette has been smoked from the lighting end a certain distance down to a location near the first slit and flap group, the action of the tobacco smoke and/or heat of the advancing coal will have softened the material coating 20 sufficiently to release the axis so that the circular tension in the wrapper will move the flap away from the wrapper encircling course to admit dilution air. The manner in which the flaps 22 move following softening of the material 20 is depicted in FIG. 2B. The present invention also provides as described earlier that the coating of air impervious normally rigid material can be on the outer surface of the wrapper. Thus, as shown in FIG. 9, the wrapper 134 is provided with a coating of material 144 on the outer wrapper surface 162, the slit pattern thus being disposed under the coating in the finished smoking article.

Materials suitable for use in the cigarette of the present invention include microcrystalline wax; Polyox" polyoxyethylene resins (Union Carbibe Corp.); blends of Penna. Industrial Chemical Co.s Piccotex petroleum hydrocarbon resins as follows: I00 with equal part refined paraffin wax (Gulf Oil Co.), LC with equal part P2X wax blend (Alexander Saunders & Co.); or any hot-melt adhesive resin of melting point from 130 to F., preferably light in color.

The coating as indicated is preferably applied to the inner side of the wrapper although it may advantageously be applied to the outer side of the same, with such coating being applied in any suitable manner. For

. example, the coating can be printed on with a conventional roller set or the printing can be combined with the slitting of the wrapper in a single operation in which the die that forms the slit patterns 18 has adjacent the die projection, a land formation which will print the coating of material simultaneously on the wrapper surface. In this manner the registration between the slits and the material coating will always be accurate and uniform. Further, the coating 20 holds the flaps 22 in the wrapper in proper positioning to insure that the flaps will not be affected by the circular tension produced in the wrapper when the latter is tightly wrapped around the cylinder of tobacco until the desired time at which the coating is softened to release the flaps constraint and allow such tension to bias the flaps outwardly of the wrapper encircling course.

The coating 20 of material applied to the wrapper can be applied to a thickness of about 3 to about mi- 5 and flaps defined by the slit patterns. On the other 10 hand, as shown in FIGS. 3 and 4, the coating can be applied as a relatively large contiguous layer which covers and encircles all of the slit patterns in the wrapper.

The cigarette 30 shown in FIG. 3 includes a tobacco cylinder 32 having a paper wrapper 34 enclosing a mass of tobacco as well as a filter element 36 at the mouth end. The wrapper 34 as best seen in FIG. 4 is provided with an arrangement of slit patterns 40 which each define a corresponding arrangement of flaps 42, all of which are covered and encircled by a coating 44 of normally rigid but heat and/or tobacco smoke softenable material as described above. In the FIG. 3 and 4 cigarette embodiments, the slit patterns are arranged, for example, to start at 15 mm. from the lighting end of the cigarette with the slit patterns being longitudinally spaced on 5 mm. centers with the slit patterns nearest the mouth end of the wrapper being approximately 10 mm. from that wrapper end. A total of four longitudinally disposed rows are provided with the slit patterns in each row being in longitudinal side-by-side array with at least some of the slit patterns in other of said rows as shown in FIG. 4.

The invention can be further understood from the following examples:

Example 1 A slow burning cigarette paper (as supplied by Sutliff Tobacco Company, Richmond, Virginia, for use with their RYO cigarette maker) was slit according to the pattern of FIG. 1. The inner side of the paper was then coated as shown with a very thin film of microcrystalline wax (150F. melt). These papers were used to make hand-made cigarettes from a commercial filler with the maker. Similar cigarettes were made as controls without slits or coating. Filters of cellulose acetate 45 tow, 20 mm., were attached to both sets of rods. The cigarettes were smoked by machine and puff-by-puff measurement of particulate delivery (TPM) was made. The comparative results shown in Table I below and in FIG. 5 show the leveling effect of the coated flaps.

Paper as used in the preceding example was slit in the pattern shown in FIG. 3 with slits 2 1% X 2 1% mm. approx. 5 mm. apart. The entire area of the slits was coated with about 3 microns of either high-melt adhesive type 34-3003 supplied by National Starch Co.

(Cigarette Y) or Polyox 3000 supplied by Union Carbide Corp. (Cigarette Z). Cigarettes were handmade with these wrappers, using a commercial filler, 1.0 g., and attaching a cellulose acetate filter, 3.4 denier/46000 total, 25 mm. long. When these cigarettes were smoked by machine for puff-by-puff analysis, they showed very level delivery profiles in both instances. Table II below and FIGS. 6 and 7 show the generally leveled profiles of Cigarettes Y and Z, respectively.

TABLE II TPM mg/puff Puff No. Cigarette Y Cigarette Z 1 1.40 1.30 2 0.75 1.47 3 0.93 1.39 4 1.04 1.62 5 1.23 1.62 6 1.14 1.51 7 1.07 1.82 8 1.28 1.89 9 1.13 1.85 10 1.36 1.90

The cigarette shown in FIG. 8 is substantially the same as that earlier described except the slit pattern 158 used in the wrapper 156 is in the shape of a V, extending transversely of the cigarette longitudinal axis. When the cigarette 150 has been smoked to a predetermined extent, heat from the burning coal 152 and smoke will soften the coating 154 at the inner surface of the wrapper 156 and the circular tension in the wrapper will cause the flap 160 to move away from the wrapper encircling course and admit dilution air stream flow to the tobacco cylinder. As smoking continues, the succeeding ones of the flaps 160 will open in progression to continue dilution, etc.

What is claimed is:

1. In a smoking article an elongated cylinder of tobacco,

a wrapper encircling said cylinder of tobacco and drawn tightly thereagainst and held in securement along overlapped longitudinal edges of said wrapper for holding said tobacco under radial constraint which produces a circular tension in said wrapper, said wrapper having inner and outer surfaces, said wrapper further having therein an arrangement of one or more slits of predetermined pattern, each slit pattern defining a corresponding flap in said wrapper, said flap being radially movable inwardly and outwardly from the encircling wrapper responsive to puffing of said smoking article to admit dilution air flow to said cylinder of tobacco, each slit pattern being fashioned in said wrapper such as to extend generally transverse of the longitudinal axis of said article to provide for movement of the associated flap about a hinge line disposed generally parallel to said longitudinal axis; and

a coating of an air-impervious normally rigid material on said wrapper at one side thereof and extending in covering and encircling expanse about each said slit pattern and the flap defined by said slit pattern to normally constrain said flap in the encircling wrapper,

said material being further characterized by being selected from materials softenably responsive to the presence of heat from the warm smoke and burning coal of said smoking article or moisture of tobacco smoke whereby the constraint on said flap is released and the circular tension in said wrapper causes said flap to move away from said encircling wrapper during the smoking of said smoking article.

2. The smoking article of claim 1 wherein each of the slit patterns is in the form of an X.

3. The smoking article of claim 2 wherein each of said slit patterns is of relatively greater dimension transversely of the article s longitudinal axis than in the direction of said axis.

4. The smoking article of claim 1 wherein the slit pattern is in the form of a V extending transversely of the articles longitudinal axis.

5. The smoking article of claim 1 wherein said material is a hot melt adhesive.

6. The smoking article of claim 5 wherein said material is a microcrystalline wax.

7. The smoking article of claim 1 wherein said material is a polyethylene resin.

8. The smoking article of claim 1 wherein said material is one having a melting point in the range of about 8 F. to about F.

9. The smoking article of claim 8 wherein at least some of said slit patterns are in side by side parallel arrangement with others of said slit patterns on said wrapper.

10. The smoking articles of claim 8 wherein the total slit length of each of said slit patterns is in a range of about 2 mm. to about 6 mm.

1 1. The smoking article of claim 1 wherein said material coating thickness is in the range of about 3 to about 10 microns.

12. The smoking article of claim 1 1 wherein said material coating thickness is about 3 microns.

13. The smoking article of claim 1 wherein said wrapper contains plural slit patterns extending in spaced array longitudinally of said wrapper on a centerline spacing of about 5 mm. between adjacent slit patterns.

Claims

1. In a smoking article an elongated cylinder of tobacco, a wrapper encircling said cylinder of tobacco and drawn tightly thereagainst and held in securement along overlapped longitudinal edges of said wrapper for holding said tobacco under radial constraint which produces a circular tension in said wrapper, said wrapper having inner and outer surfaces, said wrapper further having therein an arrangement of one or more slits of predetermined pattern, each slit pattern defining a corresponding flap in said wrapper, said flap being radially movable inwardly and outwardly from the encircling wrapper responsive to puffing of said smoking article to admit dilution air flow to said cylinder of tobacco, each slit pattern being fashioned in said wrapper such as to extend generally transverse of the longitudinal axis of said article to provide for movement of the associated flap about a hinge line disposed generally parallel to said longitudinal axis; and a coating of an air-impervious normally rigid material on said wrapper at one side thereof and extending in covering and encircling expanse about each said slit pattern and the flap defined by said slit pattern to normally constrain said flap in the encircling wrapper, said material being further characterized by being selected from materials softenably responsive to the presence of heat from the warm smoke and burning coal of said smoking article or moisture of tobacco smoke whereby the constraint on said flap is released and the circular tension in said wrapper causes said flap to move away from said encircling wrapper during the smoking of said smoking article.

3. The smoking article of claim 2 wherein each of said slit patterns is of relatively greater dimension transversely of the article''s longitudinal axis than in the direction of said axis.

4. The smoking article of claim 1 wherein the slit pattern is in the form of a V extending transversely of the article''s longitudinal axis.

5. The smoking article of claim 1 wherein said material is a hot melt adhesive.

8. The smoking article of claim 1 wherein said material is one having a melting point in the range of about 130*F. to about 180*F.

11. The smoking article of claim 1 wherein said material coating thickness is in the range of about 3 to about 10 microns.

12. The smoking article of claim 11 wherein said material coating thickness is about 3 microns.