PT2160105E - Crenellated banded cigarette paper - Google Patents

Description

DESCRIPTION " SLIMMER WITH BELT BANDS "

FIELD OF THE TECHNIQUE There have been attempts to design smoking articles that will go off when inadvertently left unattended on a substrate and the tendency to do so is referred to herein as a smoking article having " low propensity for ignition ". Ideally, an article for smoking with a low ignition propensity will continue to burn when suspended freely, such as in the holder of an ashtray or when held in the hand without being inhaled (" free burning "). The tendency for a cigarette to go out during free burning is referred to herein as " self-extinguishing ". Many prior cigarette designs having low propensity characteristics for ignition exhibit high rates of self-extinguishment under free-burning conditions.

SUMMARY

According to the invention, there is provided a wrapping for a smoking article comprising a base fabric having a nominal permeability; and a striped region comprising sufficient additional material so that the shell has a permeability in the striped region smaller than the nominal permeability of the base fabric, wherein the striped region comprises an essentially continuous strip having a width of about 4 mm or less and a leading edge and a trailing edge of the striped region are amped and wherein the leading edge merlon is transversely aligned with rear edge harnesses and front edge harnesses are transversely aligned with rear edge harnesses.

BRIEF DESCRIPTION OF THE DRAWINGS

Many objects and advantages of this disclosure will be apparent to those skilled in the art when this disclosure is read in conjunction with the accompanying drawings, wherein like reference numerals are applied to like elements and wherein: FIG. 1 is a perspective view of a smoking article in accordance with this disclosure; FIG. 2 is a schematic view of a wrapping paper having a first embodiment of an amped striped region; FIG. 3 is a schematic view of a wrapping paper having a second embodiment of an amped striped region; and FIG. 4 is a schematic view of a wrapping paper having a third embodiment of an amped striped region. 2

DETAILED DESCRIPTION

According to this disclosure, a smoking article 1 includes a tobacco roll 2. The tobacco roll 2 may contain a filler 3 cut from tobacco and is surrounded by wrapping paper 10. One end of the smoking article may include a suitable filter 4 wrapped by suitable filter paper. The smoking article 1 may normally have an essentially circular cross-section along the length of the smoking article. However, other cross-sectional shapes including, for example, oval are within the scope of this disclosure. The tobacco roll 2 has a nominal length measured from the filter paper to the free end of the tobacco rod along a longitudinal axis of the smoking article. By way of example, this nominal length may be in the range of about 60 mm to about 100 mm. The wrapping paper 10 includes a base fabric which is typically air permeable. The permeability of the wrapping paper is usually identified in Coresta units. A Coresta unit measures the permeability of the paper in terms of volumetric flow rate (i.e., cm3 / sec) per unit area (i.e. cm2) per unit of pressure drop (i.e., cm2 of water). The conventional wraparound paper base fabric also has well-known weights, measured in grams per square meter, abbreviated as " gsm ". The permeability and grammage for the base fabric of typical smoking articles commonly used in the industry are shown in the table below:

Permeability / Units Coresta Weight / gsm 24 25 33 25 46 25 60 26

For purposes of this disclosure, the base fabric of a preferred wrapping paper has a permeability of at least about 20 Coresta units. Most preferably, the wrapping paper has a permeability of greater than about 30 Coresta, such as common base screens having nominal permeabilities of about 33 and about 46 Coresta with a grammage of about 25 gsm. For some applications, the base fabric may have a permeability of greater than about 60 Coresta or greater than about 80 Coresta or even higher permeability values.

It should be noted for the sake of convention that, in describing the dimensions of various embodiments herein, " width " of a striped region extends in a longitudinal direction of the tobacco roll, while a dimension in the circumferential direction of a striped region will be expressed as " transverse " or " in transverse direction " or " direction transverse to the screen ".

For purposes of this disclosure, regions with ranges of additional material as described herein are applied to the wrapping paper for improved ignition propensity characteristics and also for improved self-extinguishing characteristics. The Propensity for Ignition is a standard test conducted as set forth in ASTM E 2187-04, " Standard

Test Method for Measuring the Ignition Strength of Smoking articles " which is incorporated herein in its entirety by this reference thereto. The propensity for ignition measures the likelihood of an article smoking when placed on a substrate, generating sufficient heat to maintain the static burning of the tobacco roller. Low values for the propensity for ignition are desirable, since such values correlate with a reduced probability of a smoking article in slow combustion causing combustion in an underlying substrate.

Here, self-extinguishing is a reference to slow combustion characteristics of a smoking article under free-burning conditions. To evaluate self-extinguishment, a laboratory test at a temperature of 23 ± 3 ° C and relative humidity of 55 ± 5%, both of which shall be monitored by a recording hygrothermograph. One or more exhaust fans remove combustion products formed during the test. Prior to the test, smoking articles to be tested are conditioned at 55% ± 5% relative humidity and 23 ° C ± 3 ° C for 24 hours.

Immediately prior to the test, smoking articles are placed in glass beakers to ensure free access to air. The self-extinguishment test takes place within an enclosure or test box. A single hole smoking machine or an electric lighter is used to light the smoking articles for the test. During the test, an apparatus or " angle bracket " keeps smoking articles to be tested by maintaining an end at 0 ° (horizontal), 45 ° and / or 90 ° (vertical) angles. Twenty (20) smoking articles are tested at each of the 0 °, 45 °, and 80 ° positions. If more than one apparatus is used, the apparatus is preferably positioned so that the smoking articles are turned in opposite directions relative to one another to avoid cross-interference. If a smoking article goes out before the front line of the burning coal in slow combustion reaches the filter paper, the result is considered as " self-extinguishing "; on the other hand, if the smoking article continues to burn in slow combustion until the front line of the coals in slow combustion reaches the filter paper, then the result is considered as " non-extinction ". Thus, for example, a 95% self-extinguishing value 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 smoking articles tested exhibited self-extinguishing under free-burning conditions. The self-extinguishing value can be referred to in terms of " self-extinguishing in the value 0o ", " self-extinguishing in the value 45o " or " self-extinguishing 90o ", each of which refers to the self-extinguishing value at the specified test angle. In addition, the value of self-extinguishing can be referred to in terms of the " average value of self-extinguishing ", which refers to a mean of the three angular positions: namely, a mean of (i) a " in the value 0o ", (ii) a " self-extinguishing in the value 45o " and (iii) the " self-extinguishing 90o value ". A reference to " Self-Extinguishment value " or " self-extinguishing value " does not distinguish between self-extinction at 0 °, self-extinction at 45 °, self-extinction at 90 ° or average values of self-extinction and may refer to any of them.

The phrases " self-extinguish in free-burning conditions " or " self-extinguishing under free-burning conditions ", as used herein, refers to the quenching of a slow-burning cigarette without being inhaled, when such a cigarette is subject to or exposed to free-burning conditions. 6

As used herein, " amid " refers to a pattern of multiple, regularly spaced, geometric shape spaces removed from a region with otherwise solid and continuous bands. A pattern or web may also be described as having notches or appearing to be similar to a pulse wave. As used herein, " battlements " refer to apertures, or valleys, on a bulged edge, while " merlons " refer to raised parts or plateaus of a bulged rim between nests.

As used herein, the phrase " leading edge " refers to the edge of a striped region that is closest to an approaching ember during the slow combustion of a smoking article whose shell contains the striped region, while the phrase " rear " refers to the edge of a striped region which is further away from an approaching ember during the slow combustion of a smoking article whose enclosure contains the striped region.

A wrapping for a smoking article comprises a base fabric 10 (see Figure 2) having a nominal permeability and a plurality of striped regions 12 with sufficient additional material, so that the wrapping has a permeability in the region with smaller bands than the nominal permeability of the base screen. A leading edge 14 and a trailing edge 16 of each striped region 12 are amped.

While various arrangements of the regions subject to those skilled in the art may occur, a number of such arrangements are shown in the accompanying drawings. For example (see Figure 2), the striped region 12 may have a leading edge 14 on which the crenels 20 are disposed between merlons 18.

In this embodiment, the merlons 18 have a transverse direction dimension of the base fabric 10 which is substantially equal to the cross-sectional dimension of the crenels 20. As shown, the merlons 18 and the associated crenels 20 may be generally rectangular. If desired, however, the merlons 18 and the meridians 20 may have other geometric shapes including, without limitation, quatlars, trapezoids, triangles, hexagons and other regular or irregular geometric configurations. The distance between the top of a merlin 18 and the base of an adjacent merge 20 may be in the range of about 2 mm to about 5 mm and preferably may be about 3 mm.

At the trailing edge of the striped region 12, a similarly arranged arrangement may also be provided. To this end, a plurality of merlons 22 may be spaced transversely across the base screen 10 and separated from each other by a corresponding plurality of crenels 24. As shown, the leading edge merlons 18 are aligned transversely with crenels 24 of rear edge and front edge harnesses 20 are aligned transversely with rear edge harnesses 22. The battlements 24 have a cross-sectional dimension substantially equal to the cross-sectional dimension of the merlons 18 at the leading edge 14 of the strip. Similarly, the merlons 33 of the trailing edge 16 may have a cross-sectional dimension substantially equal to the cross-sectional dimension of the crenellations 20 of the leading edge 14. The distance from the top of a merlin 2 2 3 to the base of an adjacent magnet 24 at the trailing edge may also be in the range of about 2 mm to about 5 mm and preferably may be about 3 mm. As with the merlons 18 and the crenellations 20 of the leading edge 14, the merlons 22 and the posterior edge crenels 24 may be generally rectangular, generally quadrilateral, generally trapezoidal, generally triangular, generally hexagonal or other geometric configurations. The bottom of the leading edge battlements 20 is preferably spaced from the bottom of the rear edge battlements 24 by a distance x lying in the range of about 2 mm to about 5 mm and, preferably, in the range of about 3 mm to about 4 mm. With such an arrangement, a substantially continuous band of width x extends transversely along the base fabric 10. The bottom of the leading edge battlements 20 corresponds to a forward edge of the substantially continuous band, while the bottom of the rear edge battlements 24 corresponds to a trailing edge of the substantially continuous band.

The regions 12 with adjacent bands of the base web 10 are spaced longitudinally from one another by a nominal spacing. The nominal spacing may be in the range of about 10 to about 30 mm. Although the depth of the battlements 20 at the leading edge of the striped region 12 and the depth of the battlements 24 at the trailing edge of the striped region 12 are shown in FIG. 2 as being equal, it is within the scope of this disclosure to constitute these different depths, if desired.

The transverse direction dimensions of the merlons 18, 22 and the harnesses 20, 24 may be substantially the same as shown in FIG. Preferably, however, an integer number of pairs of merlons 18 and nests 20 have a cross-sectional dimension corresponding to the nominal circumference of a smoking article. For example, two sets of merlons 18 and battlements 20 may have transverse dimensions to the screen of about 6.2 mm, so that two pairs each have a total cross-sectional dimension of about 24.8 mm, corresponding to the nominal circumference of a smoking article. With such a sizing for the merlons and nests, when the base fabric 10 is longitudinally divided to form foil paper reels for a smoking article, for example on the lines 30, 32, the pattern of the region 12 with overlapping strips, in a longitudinal seam constituting the tobacco roll.

Turning to FIG. 3, the proportions of the merlons 44 and the merlons 46 of the leading edge 40 are different from the arrangement of FIG. 2. In FIG. 3, merlons 44 may have a cross-sectional dimension of the screen about one-half the cross-sectional dimension of the associated meridian screen 46. However, an integer number of pairs of merlons 44 and nests 48 corresponds to the nominal circumference of the smoking article, as discussed above. The height of the merlons 44 or the depth of the merlons 46 is preferably in the same range of values as discussed with respect to FIG. 2.

In other words, when establishing a printing pattern for a roll of paper jammed, the pattern should be repeated along the roll according to a transverse dimension equal to the nominal circumference of the cigarette that will withstand the pattern, although the roll may be cut to a size slightly larger than the nominal circumference of the cigarette (to provide edge portions for the seam along the tobacco rod). This practice will ensure the setting of the pattern as intended in the cigarette 10 irrespective of where the cut is initiated or the dimensions of the seam. For example, if the cigarette were to have a pattern of eight (8) merlons and the cigarette should have a nominal circumference of the cigarette of 24.8 mm, the roll of paper would be cut every 27 mm but the standard of eight 8) merlons would repeat every 24.8 mm.

At the rear edge of the embodiment of FIG. 3, the cross-sectional dimensions of the webs of the trailing edges 50 and the trailing edge apertures 48 are different from the dimensions transverse to the web of the webs 44 of the leading edge and the nubs 46. Here again, however, an integer number of merlons 48 and nests 50 have a cross-sectional dimension corresponding to the nominal circumference of a smoking article. As shown, the cross-sectional dimension of the crenellations 46 is substantially less than the cross-sectional dimension of the crenellations 44 on the opposite side of the leading edge 40. Further, the depth of the battlements 48 or the height of the merlons 50 lies in the range of dimensions discussed above with respect to FIG. 2. Furthermore, the spacing between the bottom of the battlements 46 in the leading edge and the bottom of the battlements 48 in the trailing edge is also in the range of dimensions discussed above with respect to FIG. 2. The spacing between adjacent regions 12 in FIG. 3 also lies in the same range discussed above with respect to FIG. 2.

Turning to FIG. 4, the trailing edge 14 of the striped region 12 may have substantially the same characteristics discussed above with respect to FIG. 2. However, the rear edge 64 may have merlons 60 having dimensions transverse to the screen substantially greater than the dimensions transverse to the screen of the forward rims 20 of the leading edge 11 while the dimensions transverse to the aperture 62 of the front edge are substantially less than the dimensions transverse to the web of the corresponding opposite merlons 18 of the leading edge 14. The spacing between the rearward and the anterior edges are shown in FIG. 4 and the longitudinal spacing between adjacent strip regions 12 of FIG. 4 are substantially the same as described above with respect to FIG. 2.

The leading edge merlons may have a transverse dimension in the range of about 3 mm to about 7 mm. For example, leading edge merlons may have a transverse dimension of about 3.1 mm, about 4.2 mm or about 6.2 mm. The leading edge battens may have a transverse dimension in the range of about 3 mm to about 7 mm. For example, leading edge crenels may have a transverse dimension of about 3.1 mm, about 4.2 mm, about 5.2 mm or about 6.2 mm. The posterior edge merlons may have a transverse dimension in the range of about 6 mm to about 10 mm. For example, trailing edge merlons may have a transverse dimension of about 5.775 mm, about 6.2 mm or about 6.775 mm. The rear edge battens may have a transverse dimension in the range of about 1 mm to about 7 mm. For example, rear edge nicks 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 roller and a wrapper as described herein. The casing preferably has a cross-sectional dimension which takes into account a circumference of the tobacco roller and an overlapping seam. As a result, irrespective of where the casing is cut, when the smoking article is formed, there is always an accurate overlap of the smoothed pattern. In other words, the cross-sectional dimensions of merlons and battlements of the striped region are determined so that in the smoking article the leading edge of the striped region preferably comprises at least two battlements and minus two merlons. For example, the leading edge of the striped region may comprise two merlons and two merlons, three merlons and three merlons or four merlons and four merlons. Thus, regardless of how the smoking article is placed on a substrate during the ASTM test, there is always symmetry of the striped region. Without wishing to be bound to any theory, it is believed that while the smoking article remains in the substrate during slow combustion, combustion is modulated by the buoyant leading edge; specifically, leading edge merlons reduce the progression of slow combustion, while front edge niches allow a limited amount of slow combustion to continue under free-burning conditions. Accordingly, desirable characteristics of self-extinguishing and propensity for ignition should be achievable.

As currently understood, regions with ranges of additional material according to this disclosure enable a smoking article to be designed as an advantageous combination of low propensity values for ignition and low self-extinguishing values. Regions with low permeability bands of additional material provide areas of film-forming compound along the length of the tobacco rod which may cooperate with a substrate to quench the smoking article when it is placed on a substrate, yet such areas of film-forming compound does not cause a smoking article to self-extinguish when the smoking article is held by a smoker in a free-burning condition. Thus, the smoking article 13 may exhibit a reduced propensity for ignition while retaining a desirable free burning or low self-extinguishing value when applying striped regions of film forming compound to the base fabric therein description. The additional material may be applied to one or both sides of the base fabric.

In order to obtain desirable ignition propensity and self-extinguishing characteristics of the smoking article, striped regions are applied to the base fabric of the wrapping paper. An object of this disclosure is to provide wrap papers which, when formed in a tobacco rod, exhibit propensity values for ignition of not more than 25% and self-extinguishing values not greater than 50%. Even more preferably, it is an ignition propensity value for the resultant smoking article of not more than about 15%; and the most preferred ignition propensity value for the resulting smoking article is not more than about 10%. Lower self-extinguishing values are also desired. In this connection, a more preferred self-extinguishing value is less than about 25%; while the most preferred value of self-extinguishing is less than about 10%.

The transverse dimensions of the wrapping paper are selected based on the diameter of the finished smoking article (about 7 mm to about 10 mm) and allowing overlapping material in a longitudinal seam of about 1 mm to about 2 mm. For example, by allowing 1mm of overlapping seams, the size of wrapping paper in crosswise direction may be about 27mm for a smoking article having a circumference of about 23.6mm. 14

Banded regions may be formed by applying one or more layers of an aqueous film former composition to the base web of the wrap paper to reduce the permeability of the paper in such banded regions. Alternatively, a cellulosic material may also be used for the banded regions. When a film forming composition is used, such film forming composition may preferably include water and a high concentration of an etching agent, e.g. g. , 20% to about 50% by weight. The film-forming compound may include one or more blocking agents such as starch, alginate, cellulose or gum and may also include calcium carbonate as a filter. When the starch is the film-forming compound, a concentration of about 24% may be advantageous. The film forming composition may be applied to the base web of the wrapping paper 24 using gravure printing, digital printing, coating or spraying using a mold or any other suitable technique. For example, film forming compounds and methods for applying film forming compounds disclosed in US-A1-2007 / 0102017 may be chosen to apply striped regions to the wrap paper base web. If desired, regions with strips of additional material may be formed by printing multiple successive layers, e.g. two or more successive layers coinciding or aligning with one another. Further, when layers are used to form regions with bands of additional material, the layered material may be the same or different. For example, one layer may be starch while the next layer may be starch and calcium carbonate. 15

Additionally, the ability to extinguish the smoking article may depend more on providing a minimum longitudinal extent of film-forming compound, rather than a weight per particular area of film-forming compound. The amount of film-forming compound used can be increased without losing a free burning quality if a burning accelerator is applied to the paper. Preferably, regions with bands of additional material reduce the permeability of the wrapper paper in the range of about 0 to about 10 Coresta.

A multi-stage printing apparatus as described herein typically includes a reel, first engraving station, second engraving station, third engraving station, collection reel, rollers, printing cylinder, roller support, clamping elements, reservoir, pump, heat exchanger, applicator, bath, manifold, drain, scraper blade, adjustment cylinders and intermediate roller.

As an alternative to a gravure printing operation, regions with strips, or lists, can be applied to a base fabric using the same cellulosic material forming the base fabric. The striped regions may comprise a suspension of highly refined fibrous cellulose (eg, fibers, fibrils, micro-fibrils or combinations thereof) or other additional material applied using various spraying or coating techniques, including application techniques using an applicator of bore in the forming section of a papermaking machine as described in US-A-5 997 691 and US-A-6 596 125. While in the past such technology has been used to shape regions with circumferential bands 16, adjusting the relative movement between the paper web and the moving orifice track of the apparatus described in US-A-5 997 691 and US-A-6 696 125 of the same applicant, the striped regions of this disclosure can be easily molded . It is understood that such an arrangement operates the orifice device in motion at a slower belt speed which is conducive to the application of wider belts and higher application speeds.

The terms and phrases used here should not be interpreted with mathematical or geometric precision, rather the geometric terminology should be interpreted as meaning roughly or similar to geometric terms and concepts. Terms such as " generally " are intended to encompass both precise meanings of the terms and associated concepts as well as provide reasonable scope that is consistent with form, function and / or meaning. The term " about " when in relation to numerical quantities it is intended to include values within a tolerance of 10% of the specified quantities.

Although various embodiments have been described, it will be understood that various modifications, variations and equivalents may be invoked as will be apparent to those skilled in the art. Such modifications, variations and equivalents shall be considered within the scope and scope of the claims appended hereto.

Lisbon, May 20, 2013 17

Claims (8)

A wrapping for a smoking article comprising: a base screen (10) having a nominal permeability; and a striped region (12) comprising sufficient additional material such that the shell has a permeability in the striped region less than the nominal permeability of the base fabric, wherein the striped region comprises a substantially continuous strip having a width of about 4 mm or less and a front edge 14 and a rear edge 16 of the striped region are amped and wherein the leading edge blanks 18 are aligned transversely with rear edge harnesses 244 and front edge harnesses 20 are aligned transversely with rear edge harnesses 22,50. A wrapper according to claim 1, wherein the margins (18) of the leading edge (14) have transverse dimensions equal to the margins (24) of the trailing edge (16) and the toes (20) of the leading edge have transverse dimensions equal to (22) of the trailing edge. The wrapper according to claim 1 or 2, wherein the striped region comprises a substantially continuous strip and a distance between tops of merlons (18) (44) of the leading edge (40) and the substantially is about 4 mm or less. A wrapper according to any preceding claim wherein the banded portion (12) comprises a substantially continuous band and further wherein a distance between tops of merlons (18) (44) of the leading edge (40) and substantially continuous strip is about 4 mm or less and the bottom of the leading edge battlements (20) corresponds to a leading edge of the substantially continuous strip. A wrapper according to any preceding claim wherein nipples (20) of the leading edge (14) (40) and leading edge merlons have transverse dimensions that are substantially the same. A smoking article comprising a tobacco roll (2) and a wrapper according to any preceding claim. A smoking article according to claim 6, wherein the casing has a length in the transverse direction which takes into account a circumference of the tobacco roll (2). A smoking article according to claim 6 or 7, wherein the leading edge (14) (40) comprises at least two crenels (20) (46) and at least two merlons (18) (44) ). Lisbon, May 20, 2013 2