CA3210042A1

CA3210042A1 - High strength wrapping material containing extracted tobacco

Info

Publication number: CA3210042A1
Application number: CA3210042A
Authority: CA
Inventors: Hugues ALVAREZ
Original assignee: SWM Luxembourg SARL
Current assignee: SWM Luxembourg SARL
Priority date: 2021-03-02
Filing date: 2022-03-01
Publication date: 2022-09-09
Also published as: US20220279835A1; CN117295411A; AU2022228734A1; JP2024508145A; KR20230152061A; WO2022185217A1; EP4301166A1

Abstract

A wrapping material for an aerosol producing product is disclosed that contains extracted tobacco material combined with strength building fibers. The strength building fibers are refined and optionally bleached bast fibers. In one aspect, the bast fibers can be hemp fibers. The wrapping material can contain the extracted tobacco material in amounts greater than 40% by weight.

Description

HIGH STRENGTH WRAPPING MATERIAL CONTAINING
EXTRACTED TOBACCO
RELATED APPLICATIONS
[0001] The present application is based upon and claims priority to U.S.
Provisional Patent Application Serial No. 63/155,518, having a filing date of March 2, 2021, and which is incorporated herein by reference.
BACKGROUND

[0002] Various different aerosol generating products exist that generate an aerosol for enjoyment by a user. Such products include, for instance, smoking articles, heat but not burn sticks, and the like. Aerosol generating products typically include an aerosol generating filler in the shape of a rod that is covered by an outer wrapper.

[0003] Traditionally, outer wrappers for aerosol generating products have been made from papermaking fibers, such as pulp fibers. The use of papermaking fibers, for instance, provides a wrapper that has sufficient strength to be fed through high speed machinery used to produce the aerosol generating products.

[0004] Although papermaking fibers provide various advantages when producing wrapping materials for aerosol generating products, such as smoking articles, papermaking fibers can negatively affect the overall taste of the product.
Thus, in the past, those skilled in the art have attempted to incorporate tobacco materials into wrapping papers. Incorporating significant amounts of tobacco material into wrapping papers, however, negatively impacts the strength of the product. In particular, wrapping papers made in the past containing substantial amounts of tobacco material have not displayed sufficient strength to be used in high speed machines, such as cigarette making machines.

[0005] In view of the above, a need exists for a wrapping material containing substantial amounts of tobacco that has sufficient strength for use in constructing aerosol generating products.
SUMMARY

[0006] In general, the present disclosure is directed to a wrapping material for an aerosol generating product that is made from a tobacco material. More particularly, the present disclosure is directed to a high strength wrapping material

7 containing substantial amounts of a tobacco material. The wrapping material of the present disclosure can be used to produce all different types of products, including cigarettes and other smoking articles, heat but not burn sticks, and the like.
[0007] In one embodiment, for example, the present disclosure is directed to a wrapping material for covering an aerosol producing filler. The wrapping material includes a web comprising at least about 40% by weight of an extracted tobacco material. The extracted tobacco material is blended with strength building fibers.
The strength building fibers comprise refined bast fibers. The refined bast fibers have an average fiber length of less than about 4 mm. The wrapping material has a basis weight of from about 15 gsm to about 45 gsm.

[0008] In certain aspects, the web can contain at least about 50% by weight, such as at least about 60% by weight, such as at least about 70% by weight, such as at least about 80% by weight extracted tobacco material. The tobacco material is extracted such that the tobacco material and/or the web has a water soluble content of less than about 20% by weight, such as less than about 17% by weight, such as less than about 15% by weight, such as less than about 12% by weight, such as less than about 10% by weight, such as less than about 8% by weight.
The refined bast fibers can comprise hemp fibers and can be present in the web in an amount greater than about 10% by weight, such as in an amount greater than about 12% by weight, such as in an amount greater than about 14% by weight, such as in an amount greater than about 16% by weight. In one aspect, the refined bast fibers are also bleached.

[0009] In accordance with the present disclosure, the wrapping material can have a tensile strength when measured according to ASTM Test D828-97 of greater than about 2,100 cN/30 mm, such as greater than about 2,200 cN/30 mm, such as greater than about 2,300 cN/30 mm, such as greater than about 2,400 cN/30 mm, and generally less than about 3,400 cN/30 mm. The wrapping material can also have a stretch of greater than about 1%, such as greater than about 1.2%, such as greater than about 1.5% when measured according to ISO Test 1924 (2008).

[0010] Optionally, the wrapping material can also contain wood pulp fibers. The wood pulp fibers, for instance, can be softwood fibers, hardwood fibers, or mixtures thereof. Wood pulp fibers can be present in the web in an amount up to about 10% by weight, and generally in an amount less than about 8% by weight, such as in an amount less than about 6% by weight.

[0011] In one aspect, the tobacco material contained in the wrapping material has been fed through an extraction process for removing water soluble components and has also been refined. In one embodiment, however, the tobacco material has not been fed through a pulping process, which refers to combining the tobacco material with a base, such as sodium hydroxide, and cooked in a digester.
Of particular advantage, the use of the refined bast fibers allows for the use of extracted but non-pulped tobacco fibers while still providing sufficient strength and formation properties.

[0012] In one aspect, the wrapping material has a basis weight of from about 25 gsm to about 38 gsm. The wrapping material can have a permeability of from about 5 Coresta to about 80 Coresta, such as from about 8 Coresta to about 38 Coresta. The wrapping material can optionally contain a filler. For example, in one embodiment, the wrapping material contains no filler particles.
Alternatively, filler particles can be present in the wrapping material in an amount from about 0.5% by weight to about 30% by weight, such as from about 1% by weight to about 12% by weight.

[0013] In one aspect, the wrapping material can be treated with a burn control agent for better control of the burn properties. For instance, the burn control agent can comprise a salt of a carboxylic acid, such as a citrate or a succinate.
The burn control agent can be present on the wrapping material in an amount from about 0.3% by weight to about 3% by weight, such as in an amount from about 1% by weight to about 2% by weight.

[0014] The wrapping material can also be treated with a humectant and/or a gum. The humectant, for instance, can comprise glycerol, propylene glycol, or mixtures thereof. The gum, on the other hand, can comprise guar gum, an alginate, carboxymethyl cellulose, or mixtures thereof. The gum can be present on the wrapping material in an amount from about 0.1% by weight to about 2% by weight.

[0015] VVhen used in smoking articles, the wrapping material can also optionally include a plurality of discrete reduced ignition areas spaced along a first direction of the wrapping material. The reduced ignition areas can have a diffusivity of less than about 0.5 cm/s at 23 C. The plurality of reduced ignition areas can be formed by applying a reduced ignition composition to the web. The reduced ignition composition, for instance, can comprise cellulose fibers, a film forming material, or mixtures thereof.

[0016] Other features and aspects of the present disclosure are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A full and enabling disclosure of the present disclosure is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Figure 1 is a perspective view of one embodiment of an aerosol generating product incorporating the wrapping material of the present disclosure;
and Figure 2 is an exploded view of the aerosol generating product illustrated in Figure 1.

[0018] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
DEFINITIONS

[0019] As used herein, an "aerosol generating material" is meant to include both a combustible material that undergoes combustion in a smoking article and to an aerosol-forming material that is heated but not combusted to form an inhalable aerosol. Combustible smoking articles can include cigarettes, cigarillos and cigars, pre-rolled cones etc. In a cigarette, the aerosol generating material is generally surrounded by a wrapping material to form a smokable rod. Aerosol generating devices for generating an aerosol include, for instance, devices in which an aerosol is generated by electrical heating or by the transfer of heat from a combustible fuel element or heat source to heat but not burn the aerosol generating material, which releases volatile compounds. As the released compounds cool, they condense to form an aerosol that is inhaled by the consumer.

[0020] As used herein, "extracted tobacco fibers" refers to tobacco fibers that have been subjected to an extraction process in which the tobacco has been contacted with an aqueous solution to remove greater than 40%, such as greater than 50%, such as greater than 60%, such as greater than 70%, such as greater than 75% of the water soluble components contained in the tobacco. The extraction process is from a delignification process and from a bleaching treatment.

[0021] As used herein, "delignified" cellulosic fibers refers to fibers that have been subjected to a pulping or delignification process by which the cellulose fibers are separated from the plant material through chemical means, mechanical means, or through a combination of chemical and mechanical means.

[0022] As used herein, the term "refine" is used to mean that the plant material is subjected to a mechanical treatment that modifies the fibers of the material so that they are better suited to forming a fibrous sheet or substrate. Refining can be accomplished using a conical refiner or a disks refiner or a Valley beater.
The mechanical process exerts an abrasive and bruising action on the plant material such that the plant material is defibrillated. Refining is a different process than delignification and pulping.

[0023] As used herein, the "amount of water soluble extracts"
present in a substrate or reconstituted plant material or in an aerosol-generating material is determined by taking 5 grams of a sample in boiling distilled water for 10 minutes to obtain an extract containing water soluble components. The weight of dry matter of the extract that is soluble in the solvent is calculated by the difference between the dry weight of the sample and the dry weight of the sample after extraction. The difference in dry weight is then used to determine the percentage of water soluble extracts in the sample.
DETAILED DESCRIPTION

[0024] It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present disclosure.

[0025] The present disclosure is generally directed to a wrapping material for an aerosol generating product that is formed from a web that includes extracted tobacco fibers combined with strength building fibers. The strength building fibers comprise refined bast fibers, such as hemp fibers. In accordance with the present disclosure, the wrapping material can contain a tobacco material in amounts greater than 40% by weight and still have sufficient strength and other properties needed for mass producing aerosol generating products, such as smoking articles, heat but not burn sticks, and the like.

[0026] The high amount of tobacco fibers contained in the wrapping material creates a natural and pleasant tobacco taste when consumed in an aerosol producing product. In addition, the tobacco material is extracted by removing water soluble components. Removing the water soluble components can remove undesirable components. In one aspect, the water soluble components can be optionally concentrated and/or filtered and reapplied. In another aspect, flavorants can be applied to the wrapping material. Due to the mechanical properties, the wrapping material of the present disclosure also has great runnability characteristics on conventional cigarette making machines. The wrapping material of the present disclosure can be used to produce all different types of aerosol generating products, such as cigarettes, cigarillos, and the like. The wrapping material can also be combined with substantial amounts of a humectant for use in heat but not burn applications.

[0027] In addition to the above advantages, the wrapping material of the present disclosure also has excellent aesthetic properties. For instance, the wrapping material can have a visual association with a tobacco identity due to the great amounts of tobacco material that are contained in the product. In addition, the wrapping material can be treated with a coloring agent, such as a dye, in order to further enhance a natural tobacco look.

[0028] As described above, the wrapping material of the present disclosure includes a blend of an extracted tobacco material and strength building fibers.
Optionally, the wrapping material may also contain pulp fibers and/or filler particles.

[0029] The tobacco materials that can be used to produce the wrapping material can include any suitable type of tobacco furnish. The tobacco furnish, for instance, can contain tobacco stems, such as flue-cured stems, leaves, fines, and/or other tobacco by-products. In accordance with the present disclosure, the tobacco material can be subjected to an extraction process for removing water soluble components. Specifically, the compounds naturally present in the tobacco material that are soluble in a solvent, such as water, may give rise to problems, such as during making of the wrapping material or later during the making of aerosol generating products. Consequently, the tobacco materials incorporated into the wrapping material are preferably subjected to an extraction process.
The extraction process may include placing the tobacco materials in water and allowing the water soluble portions to be extracted into the water. In an alternative embodiment, various solvents that are water-miscible, such as alcohols (e.g., ethanol), and/or suitable oils and fats, can be combined with water to form an aqueous solvent. The water content of the aqueous solvent can, in some instances, be greater than about 50% by weight, such as greater than about 90%

by weight of the solvent. Deionized water, distilled water, or tap water may be employed. The amount of the solvent in the tobacco material suspension can vary widely, but is generally added in an amount from about 50% by weight to about 99% by weight, such as from about 60% by weight to about 95% by weight, and, in one aspect, from about 75% by weight to about 90% by weight of the suspension.

In one embodiment, the solvent may be heated prior to or during contact with the tobacco materials. For example, in one aspect, the extraction solution may be a hot aqueous solution.

[0030] The tobacco material and solvent can optionally be agitated by stirring, shaking, or otherwise mixing the suspension in order to increase the rate of solubilization. Typically, the process can be carried out for about ten minutes to about six hours. Process temperatures may range from about 10 C to about 100 C, such as from about 23 C to about 80 C. In one aspect, the temperature of the suspension can be from about 40 C to about 80 C.

[0031] After the tobacco materials are soaked and optionally agitated, the insoluble portion of the tobacco material can be mechanically separated from the soluble portion of the tobacco material using a press or a centrifuge or any other suitable device or method. Once the soluble fraction is separated from the insoluble fraction, the soluble fraction can be discarded or further processed, such as by being concentrated. The soluble fraction can be concentrated using any known type of concentrator, such as a vacuum evaporator. In some applications, the water soluble fraction can be discarded or used in other processes.
However, if desired, a portion or all of the soluble fraction can be concentrated and reapplied to the web formed from the extracted tobacco materials.

[0032] The extraction process carried out on the tobacco material removes soluble compounds which facilitates the processing of the tobacco material into a web. The extraction process can also be used to remove undesired compounds.
For instance, through the extraction process, various different components, such as nitrosamines, may be removed from the tobacco material. The extraction process can also remove, if desired, nicotine.

[0033] The resulting water insoluble, extracted tobacco material is generally in an unrefined state. The tobacco material can comprise particles and fibers. In one embodiment, the insoluble and extracted tobacco material can optionally be subjected to a refining process. For instance, the extracted tobacco material can be fed through any suitable refining device, such as a conical refiner or a disk refiner. Other refining devices that may be used include a beater, such as a Valley beater. Refining can occur while the tobacco materials are moist or after being combined with water. For instance, in one embodiment, refining can occur while the tobacco material is at a consistency of less than about 10%, such as less than about 5%, such as less than about 3%.

[0034] The extracted and refined tobacco materials, in one aspect, can contain a relatively low amount of water soluble components. For instance, the extracted tobacco material can contain water soluble components in an amount less than about 30% by weight, such as in an amount less than about 20% by weight, such as in an amount less than about 17% by weight, such as in an amount less than about 15% by weight, such as in an amount less than about 12% by weight, such as in an amount less than about 10% by weight, such as in an amount less than about 8% by weight, such as in an amount less than about 6% by weight and generally greater than about 2% by weight. As described above, optionally the water soluble components can be concentrated, otherwise treated, and reapplied to the web formed from the tobacco material. In one preferred embodiment, however, the water soluble components are not reapplied to the extracted tobacco materials.

[0035] In accordance with the present disclosure, the extracted tobacco material or tobacco fibers are combined with strength building fibers, particularly refined bast fibers. The extracted tobacco fibers can be non-pulped meaning that the fibers have not been fed through a pulping process in which the fibers are combined with an alkaline material (Kraft process) or an acid material (Sulfite process) and cooked in a digester. The strength building fibers, on the other hand, can be pulped or delignified. In one aspect, the extracted tobacco material can be combined with water or an aqueous solution to form a slurry. The strength building fibers, such as delignified cellulosic bast fibers, can be combined with the tobacco material in forming the slurry. The fiber slurry is then used to form a continuous web that has the characteristics of paper. For example, in one embodiment, the fiber slurry can be fed to a papermaking process that can include a forming wire, gravity drain, suction drain, a felt press, and a dryer, such as a Yankee dryer, a drum dryer or the like. In one aspect, the fiber slurry is formed into a continuous sheet on a Fourdrinier table.

[0036] The fiber slurry containing the extracted tobacco material and the strength building fibers, for instance, can be laid onto a porous forming surface and formed into a sheet. Excess water can be removed by a gravity drain and/or a suction drain. In addition, various presses can be used to facilitate water removal.
The formed sheet can be dried and further treated.

[0037] As described above, the strength building fibers are refined bast fibers.
The bast fibers can also be pulped or delignified and/or bleached. Examples of bast fibers that may be used in the present disclosure include hemp fibers, flax fibers, abaca fibers, ramie fibers, cotton fibers, bamboo fibers, esparto fibers, and mixtures thereof. The bast fibers can be highly refined using, for instance, a Dutch Valley Beater. In one particular embodiment, the bast fibers are hemp fibers alone or in combination with other bast fibers.

[0038] As described above, the bast fibers can be highly refined. The bast fibers can have an average fiber length of generally greater than about 0.5 mm, such as greater than about 0.8 mm, such as greater than about 1 mm, such as greater than about 1.2 mm, such as greater than about 1.5 mm. The average fiber length of the refined bast fibers is generally less than about 4 mm, such as less than about 3.6 mm, such as less than about 3.3 mm, such as less than about 3 mm, such as less than about 2.8 mm, such as less than about 2.5 mm, such as less than about 2.3 mm, such as less than about 2.1 mm. In one particular aspect, the bast fibers can be delignified hemp fibers having an average fiber length of from about 1.5 mm to about 2 mm.

[0039] Optionally, the web formed according to the present disclosure can also contain wood pulp fibers and/or botanical fibers. The wood pulp fibers, for instance, can comprise delignified fibers, such as softwood fibers, hardwood fibers, or mixtures thereof.

[0040] The extracted tobacco material, strength building fibers, and optionally wood pulp fibers can be combined together in order to form a web. In one aspect, the fibers are all combined together in an aqueous suspension and used to form a web through a wetlaid process. In this manner, a substantially homogeneous fiber distribution is achieved. The amount of each fiber contained in the resulting web can vary. In general, the web formed according to the present disclosure contains extracted tobacco material in an amount greater than about 40% by weight and in an amount up to about 90% by weight, including all increments of 1% by weight therebetween. For example, the extracted tobacco material can be contained in the web in an amount greater than about 45% by weight, such as in an amount greater than about 50% by weight, such as in an amount greater than about 55%
by weight, such as in an amount greater than about 60% by weight, such as in an amount greater than about 65% by weight, such as in an amount greater than about 70% by weight, such as in an amount greater than about 75% by weight, such as in an amount greater than about 80% by weight, such as in an amount greater than about 85% by weight. The extracted tobacco material can be contained in the web in an amount less than about 80% by weight, such as in an amount less than about 75% by weight, such as in an amount less than about 70%

by weight.

[0041] The strength building fibers can be present in the web generally in an amount up to about 50% by weight. The strength building fibers are generally present in the web in an amount greater than about 5% by weight, such as in an amount greater than about 10% by weight, such as in an amount greater than about 15% by weight, such as in an amount greater than about 17% by weight, such as in an amount greater than about 20% by weight, such as in an amount greater than about 23% by weight, such as in an amount greater than about 25%
by weight, such as in an amount greater than about 28% by weight, such as in an amount greater than about 30% by weight. The strength building fibers are generally present in an amount less than about 35% by weight, such as in an amount less than about 30% by weight, such as in an amount less than about 25%

by weight, such as in an amount less than about 20% by weight. As described above, in one embodiment, the strength building fibers are refined hemp fibers.

[0042] Wood pulp fibers can optionally be present in the web.
In one aspect, for instance, the web can be produced without any wood pulp fibers. In other embodiments, however, the wood pulp fibers can be present in an amount up to about 12% by weight, such as in an amount up to about 10% by weight, such as in an amount up to about 8% by weight. The wood pulp fibers can generally be present in an amount greater than about 2% by weight, such as in an amount greater than about 5% by weight, such as in an amount greater than about 7% by weight. In one particular aspect, the wood pulp fibers and the extracted tobacco fibers can be preblended and then later combined with the strength building fibers.
For instance, the extracted tobacco material and wood pulp fibers can be preblended at a weight ratio of from about 85:15 to about 95:5 and then combined with the strength building fibers.

[0043] In one aspect, the extracted tobacco material, strength building fibers, and optionally wood pulp fibers can be combined together and refined together prior to forming the web. Alternatively, each fiber can be refined separately.
In still another embodiment, each fiber can be refined separately, combined together, and then refined a further amount.

[0044] Optionally, the web can also contain filler particles.
Filler particles that can be used include carbonate particles, oxide particles, and mixtures thereof.
Particular filler particles include, for instance, calcium carbonate particles, magnesium oxide particles and mixtures thereof. Filler particles can be present in the web generally in an amount from about 0.5% by weight to about 30% by weight, including all increments of 0.5% therebetween. For instance, filler particles can be present in an amount greater than about 1% by weight, such as in an amount greater than about 2% by weight, such as in an amount greater than about 5% by weight, and generally in an amount less than about 25% by weight, such as in an amount less than about 20% by weight, such as in an amount less than about 15% by weight, such as in an amount less than about 12% by weight, such as in an amount less than about 8% by weight. In one aspect, filler particles can be present in an amount from about 0.5% by weight to about 5% by weight, such as from about 0.5% by weight to about 2% by weight when the web contains extracted tobacco material in an amount of about 50% by weight or greater. In another aspect, the web can be completely free of any filler particles, particularly alumina particles or other aluminum-containing filler particles.

[0045] Although the web may contain filler particles, in one aspect, the web is primarily made from fibers, such as tobacco fibers, strength building fibers, and optionally pulp fibers. For instance, the fiber content of the web can be greater than about 90% by weight, such as greater than about 92% by weight, such as greater than about 95% by weight, and generally less than about 99% by weight, such as less than about 98% by weight, such as less than about 97% by weight.

[0046] As described above, the extracted tobacco material is combined with the strength building fibers and formed into a web, in one aspect, using a wet lay process. Webs made according to the present disclosure have good strength, are smooth, and can be formed to have optimum basis weight and permeability. Thus, a wrapping material made according to the present disclosure is capable of withstanding a papermaking process as well as the mechanical stress of mass production of smoking articles, while also having improved sensory characteristics and burn properties.

[0047] For instance, wrapping materials made in accordance with the present disclosure have excellent mechanical characteristics and have a very desirable and aesthetic appearance. In general, the wrapping material has a basis weight of greater than about 15 gsm, such as greater than about 18 gsm, such as greater than about 20 gsm, such as greater than about 23 gsm, such as greater than about 25 gsm. The basis weight of the wrapping material is generally less than about 100 gsm, such as less than about 50 gsm, such as less than about 45 gsm, such as less than about 43 gsm, such as less than about 40 gsm, such as less than about 38 gsm, or any ranges therebetween. Within the above basis weights, the wrapping material is very strong and can exhibit a tensile strength of greater than about 2,100 cN/30 mm, such as greater than about 2,200 cN/30 mm, such as greater than about 2,300 cN/30 mm, such as greater than about 2,400 cN/30 mm, and generally less than about 4,000 cN/30 mm. Tensile strength can be measured using ASTM Test D828-97.

[0048] In addition to relatively high tensile strength, the wrapping material can also have excellent stretch properties. For instance, the wrapping material can display a stretch of greater than about 1cY0, such as greater than about 1.2%, such as greater than about 1.4%. The stretch of the wrapper is generally less than about 4%, such as less than about 2%.

[0049] The wrapping material according to the present disclosure may also have a permeability that facilitates suitable smoking properties, such as good mainstream smoke control or good smoking comfort. For instance, the wrapping material according to the present disclosure may have a permeability measured in Coresta units of from below detectable limits (i.e. 0 Coresta) to about 100 Coresta, such as from about 5 Coresta to about 80 Coresta, such as from about 8 Coresta to about 38 Coresta, or any ranges therebetween. The permeability can be greater than about 8 Coresta, such as greater than about 10 Coresta, such as greater than about 15 Coresta, such as greater than about 20 Coresta, such as greater than about 25 Coresta, and generally less than about 65 Coresta, such as less than about 55 Coresta, such as less than about 45 Coresta. The above permeability characteristics refer to the inherent permeability of the paper meaning the permeability of the paper without subjecting the paper to any treatments, such as perforating, that changes the permeability characteristics.

[0050] While the wrapping material according to the present disclosure may naturally or inherently have a desired permeability, in one embodiment, it may be desirable to also perforate the wrapping material after formation. Perforation may be performed as known in the art, and the number and size of the perforations may be selected as needed for the desired application.

[0051] In addition to the above physical properties, the wrapping material made in accordance with the present disclosure can exhibit a distinct natural appearance with natural speckling and/or coloration from the one or more tobacco fibers or particles. Optionally, the wrapping material may be formulated with pigments (natural or synthetic) to adjust its final coloration. For instance, a coloring agent, such as a dye, may be applied to the fibers in a head box in an aqueous solution or applied to the web using a size press during formation of the web and prior to drying_ In one aspect, for instance, one or more coloring agents may be used that provide the web with a natural tobacco color, such as a brown color.

[0052] Furthermore, in addition to having a natural appearance, the wrapping material according to the present disclosure may also have a pleasant texture.
The wrapping material can have a relatively rough surface, which emphasizes its natural appearance or can be further calendared to provide a smoother feeling.

[0053] The wrapping material of the present disclosure may also be used to produce smoking articles having better taste and sensory properties. For instance, the wrapping material of the present disclosure produces a less papery taste than conventional smoking papers. Instead, a pleasant neutral or distinct, natural tobacco taste has been observed, even when the wrapping material contains cellulosic strength building fibers. In one aspect, one or more flavorants can also be applied to the fibers and/or to the web during or after formation of the web.
Flavorants can include sweetening agents, terpenes or the like.

[0054] Wrapping materials made according to the present disclosure can be incorporated into all different types of smoking articles and aerosol-generating products. For illustrative purposes only, one such smoking article is shown in Figs.
1 and 2. As shown, the smoking article 10 includes a smokable column 12. The smokable column 12, for instance, can be in the shape of a cylindrical rod comprising an aerosol producing filler. The smoking article 10 may also include a wrapping material 100 that defines an outer circumferential surface 16 when wrapped around the smokable column 12. The wrapping material 100 can include overlapping edges 114 and 116 that are sealed together. The article 10 may also include a filter 26 that may be enclosed by a tipping paper, however, depending upon the smokable column material, a filter may be optional or omitted.

[0055] The smoking article shown in Figs. 1 and 2 can be a cigarette, a cigarillo, a little cigar, or the like. Alternatively, the article can a heat but not burn stick.

[0056] In still another aspect, the wrapping material can be formulated as a booklet of individual wrapping materials. The individual wrapping materials, for instance, can be adhered to each other using a smokable or edible adhesive.
The book of wrapping materials can be used in roll-your-own applications where a user would use the wrapping material to make his or her own smoking article or heat but not burn stick.

[0057] In one aspect, the wrapping material of the present disclosure can be treated with a gum. In one aspect, the gum can serve as an adhesive. In one embodiment, the gum may include alginates, arabic gum, guar gum, pectin, polyvinyl alcohol, polyvinyl acetate, cellulose derivatives such as ethyl cellulose, methyl cellulose, and carboxymethyl cellulose, starch, starch derivatives, and the like.

[0058] In one particular embodiment, the gum may include an Arabic gum, cellulose, and/or cellulose derivatives. In one embodiment, cellulose derivatives include carboxy methyl cellulose (CMC), methylcellulose (CM), hydroxypropyl methyl cellulose (HPMC).

[0059] Regardless of the gum used, the gum may be present on the wrapping material or web in an amount of from about 0.1% to about 15% by weight, such as from about 2% to about 5% by weight. In one embodiment, the gum may be applied using direct or indirect coating methods. The gum can be applied via a spray, such as a microspray, or may be otherwise applied so as to form a thin coating over the desired area using, for instance, gravure printing.

[0060] In one embodiment, smoking articles made according to the present disclosure can also have reduced ignition propensity characteristics. For instance, the wrapping material of the present disclosure may be used as an outer wrapper of the smoking article and can have inherent reduced ignition properties or can optionally include a plurality of discrete reduced ignition areas spaced in the axial direction of the smoking article. For instance, in one embodiment, the discrete reduced ignition areas may be in the form of circular bands. The bands can have a width so that oxygen is limited to the burning coal for a sufficient length or period of time to extinguish the coal if the smoking article were left in a static burn condition. The bands, for instance, can have a width of generally greater than about 3 mm, such as greater than about 4 mm, such as greater than about 5 mm, and generally less than about 10 mm, such as less than about 8 mm, such as less than about 7 mm.

[0061] The spacing between the reduced ignition areas can also vary depending upon a number of variables. The spacing should not be so great that the cigarette burns for a sufficient length of time to ignite a substrate before the coal burns into a reduced ignition area. The spacing also affects the thermal inertia of the burning coal, or the ability of the coal to burn through the reduced ignition areas without self-extinguishing. In general, the band spacing should be greater than about 5 mm, such as greater than about 10 mm, such as greater than about 15 mm, and generally less than about 50 mm, such as less than about 40 mm, such as less than about 30 mm. Each smoking article can contain from about 1 to about 3 bands.

[0062] In general, any suitable ignition reducing composition can be applied to the outer wrapper/wrapping material of the smoking article. In one embodiment, for instance, the ignition reducing composition contains a film-forming material.
For example, film-forming materials that can be used in accordance with the present invention include alginates, guar gum, pectin, polyvinyl alcohol, polyvinyl acetate, cellulose derivatives such as ethyl cellulose, methyl cellulose, and carboxymethyl cellulose, starch, starch derivatives, and the like.

[0063] In one particular embodiment, the film-forming material may comprise an alginate, alone or in combination with starch. In general, an alginate is a derivative of an acidic polysaccaride or gum which occurs as the insoluble mixed calcium, sodium, potassium and magnesium salt in the Phaeophyceae brown seaweeds.
Generally speaking, these derivatives are calcium, sodium, potassium, and/or magnesium salts of high molecular weight polysaccarides composed of varying proportions of D-mannuronic acid and L-guluronic acid. Exemplary salts or derivatives of alginic acid include ammonium alginate, potassium alginate, sodium alginate, propylene glycol alginate, and/or mixtures thereof.

[0064] In one embodiment, a relatively low molecular weight alginate may be used. For example, the alginates may have a viscosity of less than about 500 cP
when contained in a 3% by weight aqueous solution at 25 C. More particularly, the alginates may have a viscosity of less than 250 cP at the above conditions, particularly less than 100 cP, and in one embodiment at a viscosity of about cP. As used herein, viscosity is determined by a Brookfield LVF Viscometer with a suitable spindle according to the viscosity. At the above lower viscosity levels, alginate compositions can be formed at a higher solids content, but yet at a low enough solution viscosity to permit the application of the composition to a paper wrapper using conventional techniques. For example, the solids content of an alginate solution made in accordance with the present invention can be greater than about 6%, particularly greater than about 10%, and more particularly from about 10% to about 20% by weight.

[0065] At the above solids levels, alginate compositions used in accordance with the present invention can have a solution viscosity of greater than about cP, particularly greater than about 500 cP, more particularly greater than about 800 cP, and in one embodiment at a viscosity of greater than about 1,000 cP at 25 C. In general, the solution viscosity of the alginate film-forming composition can be adjusted depending upon the manner in which the composition is being applied to the wrapper. For instance, the solution viscosity of the composition can be adjusted depending upon whether or not the composition is being sprayed onto the paper or printed onto the paper.

[0066] In other embodiments, it should also be understood that depending upon the application a relatively high molecular weight alginate may be used. For example, the alginate may have a viscosity of greater than about 500cP when contained in a 3% by weight aqueous solution at 25 C.

[0067] In addition to the film-forming material, the reduced ignition composition applied to the wrapper can contain various other ingredients.

[0068] For instance, in one embodiment, a filler can be contained within the composition. The filler can be, for instance, calcium carbonate, calcium chloride, calcium lactate, calcium gluconate, and the like. In addition to calcium compounds, other various particles may be used including magnesium compounds such as magnesium oxide, clay particles, and the like.

[0069] The ignition reducing composition, in one embodiment, can be water based. In particular, the ignition reducing composition may comprise an aqueous dispersion or aqueous solution. Alternatively, the ignition reducing composition prior to being applied to the paper wrapper may comprise a non-aqueous solution or dispersion. In this embodiment, for instance, an alcohol may be present for applying the composition to the wrapper.

[0070] As opposed to a film-forming composition, the ignition reducing composition may also comprise a cellulose slurry (a type of dispersion). As used herein, a slurry containing papermaking materials is not a film-forming composition. The cellulose slurry applied to the paper substrate may comprise fibrous cellulose, one or more fillers, and/or cellulose particles. As used herein, cellulose fibers and cellulose particles are to be differentiated from derivatized cellulose such as carboxymethyl cellulose. Cellulose fibers and cellulose particles, for instance, are not water soluble. In one embodiment, the cellulose slurry applied to the paper substrate may comprise microcrystalline cellulose.

[0071] Once the ignition reducing composition is formulated, the composition can be applied to a paper wrapper in discrete areas. The manner in which the composition is applied to the paper wrapper can vary. For example, the composition can be sprayed, brushed, applied with a moving orifice, or printed onto the wrapper. To form a treated area, the composition can be applied in a single pass or in a multiple pass operation. For instance, the composition can be applied to the wrapping paper in successive steps in order to form areas on the paper having reduced ignition proclivity. In general, during a multiple pass process, the treated areas can be formed by applying the composition during from about 2 to about 8 passes.

[0072] The amount of reduced ignition composition applied to the wrapper can also vary. For instance, the composition can be applied to the wrapper in an amount less than about 15% by weight, such as less than about 10% by weight, such as less than about 8% by weight. In general, the composition is applied in an amount greater than 1% by weight based upon the weight of the composition within the reduced ignition areas.

[0073] As used herein, the above weight percentages are based on the area treated with the chemical components. In other words, the weight percentages above for the reduced ignition composition is the amount applied within the treated areas as opposed to the total amount applied over the entire surface of the wrapper.

[0074] Through the process of the present disclosure, reduced ignition areas can be produced having a relatively high permeability while also having a relatively low diffusivity. For instance, the reduced ignition areas can have a permeability greater than 10 CORESTA while still being capable of producing smoking articles that pass ASTM Test E2187-09 at least 75% of the time.

[0075] In general, the reduced ignition areas or the natural wrapper itself can have a diffusivity that is relatively low. The diffusivity can be measured at room temperature (23 C). In general, the diffusivity at 23 C of the reduced ignition areas or the diffusivity of the inherent wrapper (without being coated or treated) can be less than about 0.5 cm/s, such as less than 0.4 cm/s, such as less than 0.3 cm/s, such as less than 0.1 cm/s, such as less than 0.08 cm/s. In one embodiment, the reduced ignition areas may have a diffusivity of greater than about 0.01 cm/s, such as greater than about 0.03 cm/s, such as greater than 0.05 cm/s, such as greater than 0.1 cm/s, while still having the desired reduced ignition proclivity characteristics. Diffusivity is measured using a Sodim CO2 diffusivity tester.

[0076] VVhile additives may not be necessary in the wrapping material, as the wrapping material according to the present disclosure naturally has good manufacturing properties (e.g tensile strength) and sensory properties, generally, a wrapping material according to the present disclosure may include one or more additives. Additives may be used for manufacturing wrapping papers so as to develop or give the wrapping material new properties, for instance chemical, optical, sensory or mechanical properties such as tear strength or folding resistance. In one embodiment, an additive may be a humectant, burn control additives, wet strength agent, an oil-barrier and fat-barrier agent, a antiblocking agent, a dry strength agent, a softener, a flavoring agent, a wetting agent or lattices.

[0077] In one embodiment, the web material can further contain a humectant.
The humectant can be incorporated into the wrapping material for various different reasons in order to provide different benefits and advantages. For instance, in one embodiment, a humectant may be incorporated into the wrapping material in order to improve the processability and handling of the resulting fiber substrate.

[0078] VVhile various humectants may be incorporated into the wrapping material of the present disclosure, humectants may include a polyol, a non-polyol or a mixture thereof. Typically, a polyol generating agent may be sorbitol, glycerol, propylene glycol, triethylene glycol or a mixture thereof. Typically, a non-polyol generating agent may be lactic acid, glyceryl diacetate, glyceryl triacetate, triethyl citrate or isopropyl myristate or a mixture thereof. In one embodiment, the humectant is glycerol, propylene glycol, or a mixture of glycerol and propylene glycol, glycerol being preferred glycerol, propylene glycol, or mixtures thereof.
Regardless of the humectant selected, the humectant may be present in the wrapping material in an amount of from 0.1% to about 30% by weight of the wrapping material, such as from about 1% to about 10%, such as from about 2%
to about 8% by weight of the wrapping material, or any ranges therebetween.

[0079] The burn control agent, for instance, may comprise a salt of a carboxylic acid. For example, the burn control agent may comprise an alkali metal salt of a carboxylic acid, an alkaline earth metal salt of a carboxylic acid, or mixtures thereof. Examples of burn control agents that may be used include a salt of acetic acid, citric acid, malic acid, lactic acid, tartaric acid, carbonic acid, formic acid, propionic acid, glycolic acid, fumaric acid, oxalic acid, malonic acid, succinic acid, nitric acid, phosphoric acid, or mixtures thereof. Particular burn controlling agents that may be used include potassium citrate, sodium citrate, potassium succinate, sodium succinate, or mixtures thereof. When present, the burn control agent can be applied to the wrapping material generally in an amount greater than about 0.1% by weight, such as in an amount greater than about 0.5% by weight, such as in an amount greater than about 1% by weight and generally less than about 5%
by weight, such as less than about 4% by weight, such as less than about 3% by weight, such as less than about 2% by weight.

[0080] The finished web or wrapper is dried and wound into rolls. For instance, in one embodiment, the dried sheet is wound into bobbins having a width of from about 15 mm to about 80 mm, such as from about 19 mm to about 28 mm. Prior to winding the web into a bobbin, the web may be calendered to increase the smoothness and runnability of the material. In one embodiment, for instance, a multi-nip calender device may be used.

[0081] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.

Claims

WHAT IS CLAIMED:

1. A wrapping material for an aerosol producing filler comprising:
a web comprising at least about 40% by weight of an extracted tobacco material, the extracted tobacco material being blended with strength building fibers, the strength building fibers comprising refined bast fibers, the refined bast fibers having an average fiber length of less than about 4 mm, the wrapping material having a basis weight of from about 15 gsm to about 45 gsm.

2. A wrapping material as defined in claim 1, wherein the web contains the extracted tobacco material in an amount greater than about 50% by weight, such as in an amount greater than about 60% by weight, such as in an amount greater than about 70% by weight, such as in an amount greater than about 80%
5 by weight.

3. A wrapping material as defined in any of the preceding claims, wherein the web has a tensile strength of greater than about 2,100 cN/30 mm, such as greater than about 2,200 cN/30 mm, such as greater than about 2,300 cN/30 mm, such as greater than about 2,400 cN/30 mm when tested according to 5 ASTM Test D828-97.

4. A wrapping material as defined in claim 1, wherein the refined bast fibers are present in the web in an amount greater than about 10% by weight, such as in an amount greater than about 12% by weight, such as in an amount greater than about 14% by weight, such as in an amount greater than about 16% by 5 weight.

5. A wrapping material as defined in any of the preceding claims, wherein the refined bast fibers comprise refined hemp fibers.

6. A wrapping material as defined in any of the preceding claims, wherein the wrapping material further contains wood pulp fiber in an amount up to about 10% by weight.

7. A wrapping material as defined in any of the preceding claims, wherein the refined bast fibers have been bleached.

8. A wrapping material as defined in any of the preceding claims, wherein the extracted tobacco material has been refined but has not been pulped.

9. A wrapping material as defined in any of the preceding claims, wherein the extracted tobacco material contains water soluble components in an amount less than about 20% by weight, such as in an amount less than about 15%

by weight, such as in an amount less than about 10% by weight, such as in an amount less than about 8% by weight.

10. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has a basis weight of from about 25 gsm to about 38 gsm.

11. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has a stretch of greater than about 1%.

12. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has a permeability of from about 5 Coresta to about 80 Coresta, such as from about 8 Coresta to about 38 Coresta.

13. A wrapping material as defined in any of the preceding claims, wherein the web further contains filler particles in an amount from about 0.5%
to about 30% by weight, such as in an amount from about 1% to about 12% by weight.

14. A wrapping material as defined in any of claims 1-12, wherein the web contains no filler particles.

15. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has been treated with a burn control agent.

16. A wrapping material as defined in claim 15, wherein the burn control agent comprises a salt of a carboxylic acid, such as a citrate or a succinate, the burn control agent being present in the web in an amount from about 0.3% by weight to about 3% by weight, such as in an amount from about 1% by weight to 5 about 2% by weight.

17. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has been treated with a gum.

18. A wrapping material as defined in claim 17, wherein the gum comprises guar gum, an alginate, carboxymethyl cellulose, or mixtures thereof.

19. A wrapping material as defined in any of the preceding claims, wherein the wrapping material has a diffusivity of less than about 0.5 cm/s at 23'C.

20. A wrapping material as defined in claim 19, wherein the wrapping material includes a plurality of reduced ignition areas that have been formed by applying a reduced ignition composition to the web.

21. An aerosol generating product comprising:
a cylindrical rod comprising an aerosol producing filler surrounded by the wrapping material of any of the preceding claims.