ES2409934T3 - Cigarette paper banded with incoming and outgoing. - Google Patents

Abstract

A wrap for a smoking article comprising; a base sheet (10) having a nominal permeability; and a banded region (12) comprising sufficient additional material so that the shell has a permeability in the banded region less than the nominal permeability of the base sheet, in which the banded region comprises a substantially continuous band of approximately 4mm of width or less and a leading edge (14) (40) and a trailing edge (16) (42) (64) of the flanged region are formed with recesses and projections and in which the projections (18) (44) of the edge front are transversely aligned with the recesses (24) (48) (62) of the rear edge and the recesses (20) (46) of the front edge are transversely aligned with the projections (22) (50) (60) of the front edge.

Description

Cigarette paper banded with incoming and outgoing

FIELD OF THE TECHNIQUE

There have been attempts to design smoking articles that go out when left unnoticed unattended on a substrate, and the tendency to do so is here called a smoking article that has a "low propensity to ignite." Ideally, a low ignition propensity smoking article will continue to burn when it is freely held as in the support of an ashtray or when it is held in the hand without puffing on it ("burn free"). The tendency for a cigarette to end during free burning is referred to here as "self extinguishing." Many previous cigarette designs that achieve low ignition propensity characteristics have high auto-shutdown speeds under free burn conditions.

SUMMARY

According to the invention, a wrapper for a smoking article is provided comprising a base sheet having a nominal permeability; and a region comprising sufficient additional material so that the shell has a permeability in the banded region less than the nominal permeability of the base sheet, wherein the banded region comprises a substantially continuous band that is approximately 4 mm wide or minor and a leading edge and a trailing edge of the banded region have recesses and projections and where the projections of the leading edge are transversely aligned with the recesses of the trailing edge and the recesses of the leading edge are transversely aligned with the projections of the rear edge.

BRIEF DESCRIPTION OF THE DRAWINGS

Many objectives and advantages of this invention will be apparent to those skilled in the art when this memory is read in combination with the accompanying drawings in which the reference numbers are applied to equal elements and in which:

Fig. 1 is a perspective view of a smoking article in accordance with this invention,

Fig. 2 is a schematic view of a wrapping paper having a first embodiment of a banded region with recesses and protrusions;

Fig. 3 is a schematic view of a wrapping paper having a second embodiment of the banded region with recesses and protrusions; Y

Fig. 4 is a schematic view of a wrapping paper having a third embodiment of a banded region with recesses and protrusions.

DETAILED DESCRIPTION

According to this description, a smoking article 1 includes a tobacco bar 2. The tobacco bar 2 may include a cut mastic 3 of tobacco and is surrounded by a paper wrap 10. One end of the smoking article may include a filter 4 surrounded by a suitable nozzle paper. The smoking article 1 can typically have a generally circular cross-section over the length of the smoking article. However, other cross-sectional shapes that include, for example, the oval shape, are within the scope of this description. The tobacco bar 2 has a nominal length measured from the nozzle paper to the free end of the tobacco bar along the longitudinal axis of the smoking article. By way of example, the nominal length can be between approximately 60 mm and approximately 100 mm.

The wrapping paper 10 includes a base sheet that is typically air permeable. The permeability of the wrapping paper is normally identified in Coresta units. A Coresta unit measures the permeability of the paper in terms of volumetric flow rate (i.e. (cm3 / s) per unit area (i.e., cm2) per unit of pressure drop (i.e., cm of water). For conventional wrapping paper it has well-known base weights, measured in grams per abbreviated square meter as “gsm.” The permeability and basis weight for the base sheet of the typical smoking article papers commonly used in the industry is set forth in la For the purposes of this description, the base sheet of a preferred wrapping paper has a permeability of at least about 20 Coresta units More preferably, the wrapping paper has a permeability greater than about 30 Coresta, such as the sheets of common bases that have nominal permeabilities of approximately 33 and approximately 46 Coresta with a basis weight of approximately 25 gsm.

following table:

Permeability / Coresta Units

Base Weight / gsm

24

25

33

25

46

25

60

26

2

5 For some applications, the base sheet may have a permeability greater than about 60 Coresta, or greater than about 80 Coresta, or even higher permeability values.

It is observed for convention purposes that in the dimensions described of the various elements herein, that the "width" of a banded region extends in a longitudinal direction of the tobacco bar, while a dimension in the circumferential direction of a banded region it will be expressed as "transversal" or direction

10 transverse ”or“ transverse sheet direction ”.

For the purposes of this description, the banded regions of additional material as described herein are applied to the wrapping paper to obtain improved ignition propensity characteristics and also to obtain improved auto-off characteristics. The ignition propensity is a standardized test performed as described in ASTM E 2187-04, “Standard Test Method for Measuring the Ignition

15 Strength of Smoking articles ”, which is incorporated herein in its entirety as a reference. The propensity of ignition measures the probability that a smoking article, when placed on a substrate, generates enough heat to maintain static burning of the tobacco bar. Low ignition propensity values are desirable such as values that correlate with a reduced probability that a burning smoking article will cause combustion in an underlying substrate.

20 The auto off here is a reference to the burning characteristics of a smoking article under free burning conditions. To evaluate the auto off, a laboratory test is carried out at a temperature of 23 ° C ± 3 ° C and a relative humidity of 55% ± 5 ° C and a relative humidity of 55% ± 5%, both should be controlled by a recording hygrometer . An extraction hood (s) eliminates combustion products formed during the test. Before the test, the smoking articles to be tested are placed in

25 conditions of 55% ± 5% relative humidity and 23 ° C ± 3 ° C for 24 hours. Just before the test, smoking items are placed in glass cups to ensure access to the outdoors.

The auto-off test takes place inside an enclosure or test box. A single-entry smoking machine or an electric lighter is used to light smoking items for rehearsal. During the test, an apparatus or "angle fastener" holds the smoking articles to be tested by holding an angled end of 0 (horizontal), 45 °, and / or 90 ° (vertical). Twenty (20) smoking articles are tested in each of the 0º, 45º and 80º positions. If more than one device is used, the devices are preferably placed so that the smoking articles are facing away from each other to avoid cross interference. If a smoking article comes out before the front line of burning coal reaches the nozzle paper, the result is counted as "auto-off"; on the other hand, if the smoking article continues to burn until

35 the front line of burning coal reaches the nozzle paper, then the result is counted as "no quenching". Thus, for example, a self-extinguishing value of 95% indicates that 95% of the smoking articles tested exhibited self-extinguishing under free burning conditions; while a 20% self-extinguishing value indicates that only 20% of the items tested had self-extinguishing under the condition of free burning.

40 The auto-off value may be referred to in terms of “auto-shutdown at 0º value”, “auto-shutdown at 45º value”, or “auto-shutdown at 90º value”, each of which refers to the value auto-off at the specific angle tested. In addition, the auto-off value may be referred to in terms of "average auto-off value", which refers to an average of the three angular positions: namely, a means of (i) the "auto-off at value of 0º ”(ii)“ auto-off at a value of 45º ”, and (iii) auto-off at a value of 90º”. A reference to

45 "auto-extinction value" or "auto-off value" does not distinguish between auto-off at 0 °, auto-off at 45 °, auto-off at 90 ° or average auto-off values and may refer to any one of them.

The terms "auto-off under free burn conditions" or "auto-off under free burn conditions" or auto-off under free burn conditions "as used herein, refer to self-extinguishing of a cigarette that burns without giving puffs, when such a cigarette is subjected or exposed to conditions of

50 burned

As used herein, the expression "with incoming and outgoing" refers to an arrangement of geometrically shaped, multiple, regularly separated spaces, removed from a solid banded region or otherwise continued. An arrangement or band with incoming and outgoing can also be described as grooved

or similar in appearance to a pulse wave. As used here, "incoming" refers to openings or valleys,

55 on an edge with incoming and outgoing, while "outgoing" refers to elevated parts, or plateaus of an edge with incoming and outgoing, between incoming.

As used herein, the term "leading edge" refers to the edge of a banded region that is closer to a coal that approaches during the glow of a smoking article whose envelope contains the

banded region, while the expression "back edge" refers to the edge of a banded region that is farther from an approaching coal during the incandescence of a smoking article whose shell contains a banded region.

A shell for a smoking article comprises a base sheet 10 (see Fig. 2), which has a nominal permeability and a plurality of banded regions 12 with sufficient additional material such that the envelope has a permeability in the smaller banded region than the nominal permeability of the sheet. A leading edge 14 and a trailing edge 16 of each banded region 12 have recesses and protrusions.

Although various arrangements of regions with recesses and protrusions may occur to those skilled in the art, several such arrangements are illustrated in the accompanying figures. For example (see Fig. 2), the banded region 12 may have a leading edge 14 in which the recesses 20 are deposited between the projections 18. In this embodiment, the projections 18 have a dimension in the transverse direction of the sheet 10 which is substantially the same as the dimension in the transverse direction of the recesses 20. As shown, the projections 18 and the associated recesses 20 can generally be rectangular. If desired, however, projections 18 and recesses 20 may have other geometric shapes including, without limitation, quadrilaterals, trapezoids, triangles, hexagons and other regular irregular irregular geometric configurations. The distance between the upper part of a projection 18 and the lower part of an adjacent recess 20 may be between approximately 2 mm and approximately 5 mm, and preferably may be approximately 3 mm.

At the rear edge of the banded region 12, an arrangement with recesses and projections can also be arranged. For this purpose, a plurality of projections 22 may be separated transversely across the sheet 10 and separated from each other by a corresponding plurality of recesses 24. As shown, the projections 18 of the leading edge are transversely aligned with the recesses 24 of the rear edge and the recesses 20 of the front edge are transversely aligned with the protrusions 22 of the rear edge. The recesses 24 have a transverse dimension to the sheet substantially the same as the transverse dimension to the sheet of the projections 18 at the leading edge 14 of the web. Similarly, the projections 33 of the leading edge 16 may have a transverse dimension to the sheet substantially equal to the transverse dimension to the recess 20 of the leading edge 14. The distance between the top of a projection 22 and the part The bottom of an adjacent projection 24 at the rear edge may also be comprised between approximately 2 mm and approximately 5 mm, and preferably approximately 3 mm. As with the projections 18 and the channels 20 of the leading edge 14, the projections 22 and the recesses 24 of the trailing edge can be generally rectangular, generally quadrilateral, generally trapezoidal, generally triangular, generally hexagonal, or other geometric configurations.

The lower part of the recesses 20 of the leading edge is preferably separated from the lower part of the recesses 24 of the trailing edge by a distance x which is between approximately 2 mm and approximately 5 mm, and preferably between approximately 3 mm and approximately 4 mm With such an arrangement, a substantially continuous band of width x extends transversely across the base sheet 10. The lower part of the recesses 20 of the leading edge corresponds to a leading edge of the substantially continuous strip, while the lower portion of the recesses 24 of the rear edge corresponds to a rear edge of the substantially continuous band.

The adjacent banded regions 12 of the paper sheet 10 are longitudinally separated from each other by a nominal separation. That nominal separation may be between approximately 10 and approximately 30 mm. Although the depth of the recesses 20 at the leading edge of the banded region 12 and the depth of the recesses 24 at the rear edge of the banded region 12 are shown in Fig. 2 being the same, it is within the scope of this invention. Do these different depths if desired.

The transverse direction dimensions of the projections 18, 22 and the recesses 20, 24 may be substantially the same as shown in Fig. 2. Preferably, however, an integer number of pairs of projections 18 and recesses 20 have a dimension transverse to the sheet corresponding to the nominal circumference of a smoking article. For example, two sets of projections 18 and recesses 20 may have transverse dimensions to the sheet of approximately 6.2 mm so that two pairs of each have a transverse dimension to the sheet of approximately 24.8 mm, which corresponds to the circumference Nominal of a smoking article. With such sizing for the projections and the recesses, when the base sheet 10 is divided longitudinally to form wrapping paper reels for smoking articles, for example on lines 30, 32, the design with recesses and projections of the banded region 12 will overlap substantially perfectly in a longitudinal suture making the tobacco bar.

Returning to Fig. 3, the proportions of the projections 44 and the recesses 46 of the leading edge 40 are different from the arrangement of Fig. 2. In Fig. 3, the projections 44 may have a transverse dimension to the sheet of approximately half of the cross-sectional dimension of the associated recess 46. However, an integral number of pairs of projections 44 and recesses 48 corresponds to the nominal circumference of the smoking article, as set forth above. The height of the projections 44, or the depth of the recesses 46 are preferably in the same range of values shown in relation to Fig. 2.

In other words, when a print design is established for a roll of paper with recesses and protrusions, the design should be repeated across the roll according to a transverse dimension equal to the nominal circumference of the cigarette that is to support the design, even though the roll can be divided into a dimension slightly larger than the nominal circumference of the cigarette (to provide edge parts for suturing at

5 length of the tobacco bar). This practice will ensure the establishment of the design as it is intended in the cigarette regardless of where the division is initiated or the dimensions of the suture. For example, if the cigarette is going to have a design of eight (8) and the cigarette is going to have a nominal cigarette circumference of 24.8 mm, the roll paper with incoming and outgoing will be divided every 27 mm but the design of eight (8) protrusions would be repeated every 24.8 mm.

10 At the rear edge of the embodiment of Fig. 3, the transverse dimensions to the sheet of the rear edge projections 50 and the rear edge recesses 48 are different from the dimensions transverse to the sheet of the front edge projections 44 and the leading edge recesses 46. Here again, however, an integer number of projection assemblies 48 and recesses 50 has a cross-sectional dimension to the section corresponding to the nominal circumference of a smoking article. As shown, the cross-sectional dimension of the

15 recesses 46 is substantially smaller than the cross-sectional dimension of the projections 44 at the opposite part of the leading edge 40. In addition, the depth of the recesses 48, or the height of the projections 50 are in the range of exposed dimensions above in relation to Fig. 2. In addition, the separation between the bottom of the recesses 46 at the leading edge and the bottom of the recesses at the trailing edge is also in the range of dimensions set forth above in relation to Fig. 2. The separation between regions

20 adjacent bands 12 in Figs. 3 is also within the same range set forth above in relation to Fig. 2.

Returning to Fig. 4, the leading edge 14 of the banded region 12 may have substantially the same characteristics set forth above in relation to Fig. 2. However, the trailing edge 64 may have protrusions 60 having dimensions transverse to the sheet substantially larger than the dimensions 25 transverse to the sheet of the recesses opposite 20 of the leading edge, while the dimensions transverse to the sheet of the recesses of the rear edge 62 are substantially smaller than the dimensions transverse to the sheet of the corresponding opposite protrusions 18 of the leading edge 14. The separation between the leading and trailing edges with recesses and protrusions in Fig. 4 and the separation between adjacent banded regions 12 of Fig. 4 are substantially the same as described above in relation to Fig. .

30 2.

The projections of the leading edge may have a transverse dimension between approximately 3 mm and approximately 7 mm. For example, the projections of the leading edge may have a transverse dimension of approximately 3.1 mm, approximately 4.2 mm, or approximately 6.2 mm. The recesses and projections of the leading edge may have a transverse dimension between approximately 3 mm and approximately 7 mm. For example, the front edge recesses can have a transverse dimension of approximately 3.1 mm, approximately 4.2 mm, approximately 5.2 mm or approximately 6.2 mm. The projections of the rear edge may have a transverse dimension between approximately 6 mm and approximately 10 mm. For example, the protrusions of the rear edge may have a transverse dimension of approximately 5,775 mm, approximately 6.2 mm, or approximately 6.775 mm. The edge entrees

40 rear can have a transverse dimension between approximately 1 mm and approximately 7 mm. For example, the recesses of the rear edge may have a transverse dimension of about 1 mm, about 2.1 mm, or about 6.2 mm.

A smoking article may comprise a tobacco bar and a wrap as described herein. The envelope preferably has a transverse direction dimension that takes into account a circumference of the tobacco bar and an overlapping suture. As a result, regardless of where the envelope is divided, when the smoking article is formed there is always an exact overlap of the design with incoming and outgoing. In other words, the transverse direction dimensions of the projections and recesses of the banded region with recesses and projections are determined such that in the smoking article, the leading edge of the banded region preferably comprises at least two recesses and the minus two outgoing. For example, the leading edge 50 of the banded region may comprise two recesses and two projections, three recesses and three projections, or four recesses and four projections. Thus regardless of how the smoking article is placed on a substrate during the ASTM test, there is always symmetry of the banded region. Without wishing to be bound by any theory, it is believed that when the smoking article is left on the substrate during burning, combustion is modulated by the leading edge with recesses and protrusions; specifically, the leading edge projections reduce

55 the spread of the burn while the front edge recesses allow a limited amount of combustion to continue during the free burn conditions. Therefore, desirable auto-off and ignition propensity characteristics should be achieved.

As currently understood, the banded regions of additional material according to this description allow a smoking article to be designed with an advantageous combination of low ignition propensity values and low auto-off values. Banded regions of low permeability and additional material provide areas of film-forming compounds along the length of the tobacco bar that

they can cooperate with a substrate to turn off the smoking article on when it is located on a substrate, yet these areas of film-forming compound do not cause the smoking article to self-extinguish when the smoking article is held by a smoker in a free burn condition. In this way, the smoking article may have a reduced propensity to ignite, while maintaining a desired free burn quality or low self-shutdown value by applying banded regions or film-forming compounds to the base sheet of I agree with this description. The additional material can be applied to one or both sides of the base sheet.

To achieve the desirable ignition propensity and the auto-off characteristics of the smoking article, the banded regions are applied to the base sheet of the wrapping paper. An object of this invention is to provide wrapping papers that, when formed in a tobacco bar, have ignition propensity values not greater than 25% and auto-off values not greater than 50%. Even more preferred is an ignition propensity value for the resulting smoking article not greater than about 15%; and the most preferred ignition propensity value for the resulting smoking article is not greater than about 10%. In this sense, a preferred auto-off value is less than about 25%; while the most preferred auto-off value is less than 10%.

The transverse dimensions of the wrapping paper are selected based on the diameter of the finished smoking article (approximately 7 mm to approximately 10 mm) and allowing the superposition of the material in a longitudinal suture of approximately 1 mm to approximately 2 mm. For example, by allowing overlapping sutures of 1 mm, the wrapping paper dimension in cross section may be approximately 27 mm for a smoking article having a circumference of approximately 25.6 mm.

The banded regions may be formed by applying one or more layers of aqueous film forming composition to the base sheet of the wrapping paper to reduce the permeability of the paper in those banded regions. Alternatively, a cellulosic material can also be used to form the banded regions. When a film-forming composition is used, that film-forming composition may preferably include water and a high concentration of an occlusion agent, for example 20% to about 50% by weight. The film-forming compound may include one or more occlusion agents such as starch, alginate, cellulose or gum and may also include calcium carbonate as a filter. When the film-forming compound is starch, a concentration of approximately 24% may be advantageous.

The film-forming composition may be applied to the base sheet of the wrapping paper 24 using engraving printing, digital printing, coating or spraying using a template, or any other suitable technique. For example, the film-forming compounds and the methods for applying film-forming compound, described in US-A-1007/0102017 can be chosen to apply banded regions to the base sheet of the wrapping paper. If desired, the banded regions of the additional material can be formed by printing multiple successive layers, for example, two or more layers coinciding or aligned with each other. In addition, when the layers are used to form the banded regions of additional material, the layered material may be the same or different. For example, one layer may be starch while the other layer may be starch and calcium carbonate.

Additionally, the ability to quench the smoking article may depend more on providing minimal extension along the length of the film-forming compound, rather than a particular weight per area of film-forming compound. The amount of film forming compound used can be increased without losing the free burn quality if a burn accelerator is applied to the paper. Preferably, the banded regions of the additional material reduce the permeability of the wrapping paper to a range between about 0 and about 10 Coresta.

A multi-stage printing apparatus as described herein includes a reel, first engraving printing station, second engraving printing station, third engraving printing station, collection spool, rollers, printing cylinder, backing rollers , pressure zones, tanks, pump, heat exchanger, applied, bath, manifold, drain, doctor sheet, adjustment cylinders, and idler roller.

As an alternative to the engraving printing operation, the banded or striped regions can be applied to a base sheet using the same cellulosic material that forms the base sheet. The banded regions may comprise an aqueous compound of highly refined fibrous cellulose (e.g., fibers, fibrils, microfibrils or combinations thereof) or other material applied using various spraying or coating techniques, which include application techniques using an applicator of hole in motion in the forming section of a papermaking machine as described in US-A-5 997 691 and US-A6 596 125. Although such technology has been used in the past to create circumferentially banded regions, By adjusting the relative movement between the sheet of paper and the mobile orifice band of the equipment described in common property patents US-A-5 997 691 and US-A-6 696 125, the banded regions of this invention can be easily created . It is noted that such an arrangement operates the mobile orifice device at a slower belt speed that is conducive to applying wider bands and higher application speeds.

The terms and expressions used here are not going to be interpreted with mathematical or geometric precision, instead, geometric terminology is meant to mean something approximate or similar to geometric terms and concepts. Terms such as "generally" are intended to encompass both precise meanings of the associated terms and concepts as well as to provide reasonable flexibility that is consistent with form,

5 function, and / or meaning. The term "approximately" when used in combination with numerical quantities is intended to include values within a tolerance of 10% of the established quantities.

Although different embodiments have been described, it will come to light that those skilled in the art can make various modifications, variations and equivalences. Such modifications, variations and equivalences are considered within the scope and field of the appended claims.

10.

Claims (7)

1. A wrap for a smoking article comprising; a base sheet (10) having a nominal permeability; Y 5 a banded region (12) comprising sufficient additional material so that the shell has a permeability in the banded region less than the nominal permeability of the base sheet, wherein the banded region comprises a substantially continuous band that is approximately 4 mm wide or smaller and a leading edge (14) (40) and a trailing edge (16) (42) (64) of the region 10 bands are formed with recesses and projections and in which the projections (18) (44) of the leading edge are transversely aligned with the recesses (24) (48) (62) of the trailing edge and the recesses (20) (46) of the leading edge are transversely aligned with the projections (22) (50) (60) of the leading edge. 2. A wrap according to claim 1, wherein the projections (18) of the leading edge (14) have 15 transverse dimensions equal to the recesses (24) of the rear edge (16) and the recesses (20) of the front edge have transverse dimensions equal to the projections (22) of the rear edge. 3. A wrap according to claim 1 or 2, wherein the banded region comprises a band substantially continuous and a distance between the upper portions of the projections (18) (44) of the leading edge 20 (14) (40) and the substantially continuous band is approximately 4 mm or less. 4. A wrap according to any preceding claim, wherein the banded region (12) comprises a substantially continuous band, and in which also a distance between the upper portions of the projections (18) (44) of the leading edge ( 14) (40) and the substantially continuous band is 25 of approximately 4 mm or less and the bottom of the recesses (20) (46) of the leading edge correspond to a leading edge of the substantially continuous web. 5. A wrap according to any preceding claim, wherein the recesses (20) of the edge front (14) (40) and the projections of the leading edge have transverse dimensions that are substantially the same. 6. A smoking article comprising a tobacco bar (2) and a wrap according to any preceding claim. A smoking article according to claim 6, wherein the envelope has a cross-sectional length that takes into account a circumference of the tobacco bar (2). 8. A smoking article according to claim 6 or 7, wherein the leading edge (14) (40) comprises at least two recesses (20) (46) and at least two projections (18) (44).