INNER LINER SHEET MATERIAL FREE OF A METALLIC LAYER

[0001] The present disclosure relates to an inner liner sheet material for lining a package unit for at least one aerosol-generating article, a method for producing such an inner liner sheet material, a package unit, a method for producing a package unit and a use of a biodegradable barrier layer in an inner liner sheet material.

[0002] Aerosol-generating articles not only refer to filter cigarettes and other smoking articles in which material is combusted to form smoke, but also those articles that generate an aerosol from an aerosol-generating material without requiring combustion thereof. Such articles are often designated as “heat-not-burn” aerosol-generating articles, since an aerosol-generating material is heated to a relatively low temperature to induce the formation of an aerosol but prevent the combustion of material contained within the aerosol-generating material.

[0003] Aerosol-generating articles are available in flavored varieties. Flavoring an aerosol-generating article may be achieved by incorporating flavoring components directly into the aerosol-generating material or by including flavoring components in the form of threads or capsules into the aerosol-generating material or a corresponding filter section associated therewith. However, such flavoring methods may pollute the production machinery with residual flavoring contaminants, requiring extensive cleaning prior to the production of non-flavored aerosol-generating articles. Furthermore, such flavoring methods may require complex machinery, increasing production costs and manufacturing efficiency.

[0004] In order to mitigate such disadvantages, aerosol-generating articles may be flavored by indirect flavoring methods such as by a flavor migration process, wherein an object not defining an aerosol-generating article is provided with an infusion substance. Said object is then arranged in the near-vicinity of at least one aerosol-generating article for a predetermined amount of time, during which a flavor component of the infusion substance migrates from said object to the aero-sol-generating article.

[0005] Conventionally, an object provided with an infusion substance is an inner liner sheet, which encompasses multiple aerosol-generating articles and is itself typically enclosed in a paper-based box. Such an inner liner sheet is generally comprised of a multi-layered construct, which includes a paper base, a metallic layer and an adhesion layer there between, amongst others. Said multi-layered construct is commonly manufactured via a lamination process.

[0006] An inner liner sheet is known from U.S. Pat. No. 6,692,835B1 , wherein a paper layer is adhesively bonded to an aluminum foil layer and the aluminum foil layer is provided with a polyvinyl alcohol slip coating. Said slip coating is meant to prevent adhesion of the aluminum foil layer to the corresponding machinery during manufacturing and processing of the inner liner sheet.

[0007] Due to the multi-layered nature of the inner liner sheet, which not only exhibits layers of various material types but also a permanent assembly thereof as a consequence of lamination, the recyclability of the inner liner sheet is difficult to achieve.

[0008] Consequently, the present invention aims to provide an inner liner sheet material with an improved environmental impact.

[0009] According to a first aspect of the present invention, there is provided an inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article. The inner liner sheet material comprises a base layer and a barrier layer, wherein the base layer is provided with an infusion substance. The inner layer sheet material is free of a metallic layer.

[0010] The inner liner sheet material may be a laminar object that exhibits length and width dimensions substantially larger than a dimension defining a corresponding thickness. The inner liner sheet material may be defined as manifesting two outer surfaces separated by the thickness of the inner liner sheet material.

[0011] The inner liner sheet material may be provided as a continuous product, for example from a bobbin.

[0012] The base layer may be a substrate layer onto which any one or combination of the following layers are provided upon.

[0013] A layer denotes a laminar objection exhibiting length and width dimensions substantially larger than a corresponding thickness dimension. The layers of the inner liner sheet material may exhibit distinct boundaries or interfaces between each adjacent layer, so that the separate layers are geometrically discernable. The absorption of further components into one of more of the layers of the inner liner sheet material does not form a layer but rather a further additive or constituent of the relevant layer or layers.

[0014] A barrier layer is provided on the base layer. Specifically, the barrier layer may be provided on the outer surface of the base layer opposite the surface to which the infusion substance is provided.

[0015] The barrier layer may be provided directly on the base layer. In such a case, no further layers may be between the barrier layer and the base layer.

[0016] The inner liner sheet material may consist of the base layer and the barrier layer. In particular, the inner liner sheet material only comprises the base layer and the barrier layer. This does not exclude the absorption of the infusion substance into the base layer or the barrier layer.

[0017] The barrier layer is the least permeable layer of the inner liner sheet material with respect to the infusion substance. The barrier layer may be adapted to hinder or impede the movement of chemical compounds to and from the inner layer sheet material. Specifically, the barrier layer is adapted to restrict the permeation of the infusion substance from the base layer to the outermost surface of the barrier layer. In particular, the barrier layer is adapted to be less permeable to the infusion substance than the base layer. The barrier layer may be adapted to prevent permeation of the infusion substance. This helps prevent loss of the infusion substance to the outside environment and re-directs the permeation and diffusion of the infusion substance in the direction of the at least one aerosol-generating article.

[0018] The barrier layer may be biodegrable.

[0019] The barrier layer may be lipophobic.

[0020] The barrier layer may be hydrophobic.

[0021] The barrier layer may be an outer layer of the inner liner sheet material. The barrier layer may define one of the outer surfaces of the inner liner sheet material. The barrier layer may be one of the outermost surfaces of the inner liner sheet material.

[0022] The barrier layer is less permeable to the infusion substance than the base layer.

[0023] The barrier layer may exhibit an alcohol permeation level below 0.8 gram per square meter per day, preferably, below 0.1 gram per square meter per day, more preferably below 0.01 gram per square meter per day and most preferably below 0.001 gram per square meter per day.

[0024] The alcohol permeation level may be a menthol permeation level. More specifically, the barrier layer may exhibit a menthol permeation level below 0.8 gram per square meter per day, preferably, below 0.1 gram per square meter per day, more preferably below 0.01 gram per square meter per day and most preferably below 0.001 gram per square meter per day.

[0025] In particular, the barrier layer may comprise polyvinyl alcohol. The barrier layer may further comprise glyoxal, preferably 0.1 to 1 weight percent glyoxal. Such components may provide an increased barrier effect against the permeation of alcohol or menthol. Polyvinyl alcohol and glyoxal may also preventing swelling of the inner liner sheet material, which may occur as a result of the infusion substance. Reduced swelling of the inner liner sheet material may also enhance the mechanical resistance of the of the inner liner sheet material against friction during processing thereof.

[0026] The base layer may comprise paper.

[0027] The base layer may predominantly consist of paper.

[0028] The base layer may only consist of paper.

[0029] The base layer may comprise a paper fiber layer and a paper coating. The base layer may comprise paper or predominantly consists of paper and may include a paper fiber layer and a paper coating. The paper coating may alter certain qualities to the underlying paper fiber layer to influence the physical or chemical properties of the resulting base layer. For example, the paper coating may improve chemical absorption properties or the friction coefficient and overall surface qualities, such as smoothness, of the base layer. The paper fiber layer may manifest a paper coating on one or both of its outer surfaces. The paper coating may comprise a polymer.

[0030] The paper fiber layer may be calendared craft paper.

[0031] The paper coating may be clay-based.

[0032] The base layer is provided with an infusion substance. If the base layer manifests a paper coating, the infusion substance may be provided on the surface of the base layer free of the paper coating. The infusion substance may be provided on the surface of the base layer opposite the surface exhibiting the paper coating.

[0033] The infusion substance may be a liquid. In such a case, the infusion substance may also comprise a carrier component. Such a carrier component may be a solvent to enable the dissolution of at least one flavoring component to produce a liquid solution of the infusion substance. A carrier component may be realized by the chemical compound ethanol.

[0034] The infusion substance may be at least partially absorbed into the base layer.

[0035] The infusion substance may provided in the form of an infusion layer. The infusion substance may be a solid or gel-like substance to be provided on the base layer in the form of such an infusion layer.

[0036] The infusion substance may be a flavor carrier adapted to transfer flavor to adjacent aerosol-generating articles. The infusion substance is adapted to at least partially migrate or diffuse to the aerosol-generating articles. The infusion substance may be a chemical compound or a mixture of at least two chemical compounds. The two chemical compounds may further comprise at least one flavoring component.

[0037] The infusion substance may comprise at least one flavoring component. At least one flavoring component may be an essential oil. The essential oil may contain volatile chemical compounds extracted from plants. At least one flavoring component may be plant-based. For example, from thyme, eucalyptus, cinnamon or rose. At least one flavoring component may be fruit-based. For example, from strawberry, mango, banana or watermelon. At least one flavoring component may be mint-based. For example, from peppermint or spearmint.

[0038] At least one flavoring component may comprise menthol, more specifically synthetic menthol.

[0039] The flavoring component may be natural or artificially based.

[0040] If the base layer includes a paper coating on one of its outer surfaces, the barrier layer may be adjacent to the paper coating. The barrier layer may be directly adjacent to the paper coating with no further layers there between.

[0041] Due to these properties of the barrier layer, the inner liner sheet material can be free of a metallic layer, as the barrier function of a metallic layer with respect to the infusion substance is no longer required

[0042] The inner liner sheet material is free of a metallic layer. Due to the absence of such a layer, the recyclability of the inner liner sheet material is improved.

[0043] According to a second aspect of the present invention, there is provided a package unit with at least one aerosol-generating article, a container and an inner liner sheet material according to the first aspect of the present invention. The inner liner sheet material at least partially encloses the at least one aerosol-generating article, the inner liner sheet material is at least partially enclosed by the container and the barrier layer is more distant from the at least one aerosol-generating article than the base layer.

[0044] The infusion substance may be adapted to at least partially migrate from the base layer to the aerosol-generating articles in the package unit.

[0045] In particular, the barrier layer is adjacent to at least one inner surface of the container.

[0046] The base layer may be in direct contact with an aerosol-generating article.

[0047] The container may comprise paper.

[0048] The barrier layer may be adjacent to at least one inner surface of the container.

[0049] According to a third aspect of the present invention, there is provided a method for producing an inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article. Said method comprises the following steps: providing a base layer with a barrier layer and providing the base layer with an infusion substance, wherein the barrier layer is provided directly on the base layer.

[0050] The infusion substance may at least partially absorbed into the base layer, while the barrier layer may be the least-permeable layer of the inner liner sheet material with respect to the infusion substance.

[0051] The infusion substance may be sprayed onto the base layer.

[0052] The method may further comprise unwinding the base layer with the barrier layer from a coil. Subsequent to providing the base layer with the barrier layer, both layers may be wound into a coil for transportation and further processing purposes. Thereafter, the base layer and barrier layer may be unwound from said coil, in order for the infusion substance to be provided to the base layer, for example.

[0053] The method may further comprise winding the base layer with the barrier layer and provided with the infusion substance onto a coil. The ensuring inner liner sheet material may then be wound onto a coil for transportation and further processing purposes.

[0054] In particular, the base layer of the method may be paper while the infusion substance may be menthol.

[0055] The barrier layer may be coated onto the base layer.

[0056] The barrier layer may be printed onto the base layer.

[0057] The barrier layer may be sprayed onto the base layer.

[0058] The barrier layer may be provided onto the base layer via a technically known coating, printing or spraying process.

[0059] The base layer may be adjacent to the at least one aerosol-generating article.

[0060] According to a fourth aspect of the present invention, there is provided a method for a producing package unit for at least one aerosol-generating article, the method comprising a step of folding an inner liner sheet material produced according to the third aspect of the present invention.

[0061] According to a fifth aspect of the present invention, there is provided a use of a biodegradable barrier layer in an inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article, wherein the inner liner sheet material comprises two layers, a base layer provided with an infusion substance and the barrier layer, wherein the barrier layer is the least-permeable layer of the inner liner sheet material with respect to the infusion substance.

[0062] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0063] Example Ex1: Inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article, comprising a base layer, and a barrier layer, wherein the base layer is provided with an infusion substance, and wherein the inner liner sheet material is free of a metallic layer.

[0064] Example Ex2: Inner liner sheet material according to Ex1, wherein the barrier layer is provided directly on the base layer.

[0065] Example Ex3: Inner liner sheet material according to Ex1 or Ex2, wherein the inner liner sheet material consists of the base layer and the barrier layer.

[0066] Example Ex4: Inner liner sheet material according to any Ex1 to Ex3, wherein the barrier layer is the least-permeable layer of the inner liner sheet material with respect to the infusion substance.

[0067] Example Ex5: Inner liner sheet material according to any Ex1 to Ex4, wherein the barrier layer is biodegradable.

[0068] Example Ex6: Inner liner sheet material according to any Ex1 to Ex5, wherein the barrier layer is lipophobic.

[0069] Example Ex7: Inner liner sheet material according to any Ex1 to Ex6, wherein the barrier layer is hydrophobic.

[0070] Example Ex8: Inner liner sheet material according to any Ex1 to Ex7, wherein the barrier layer is an outer layer of the inner liner sheet material.

[0071] Example Ex9: Inner liner sheet material according to any Ex1 to Ex8, wherein the barrier layer is less permeable to the infusion substance than the base layer.

[0072] Example Ex10: Inner liner sheet material according to any Ex1 to Ex9, wherein the barrier layer has an alcohol permeation level below 0.8 gram per square meter per day, preferably, below 0.1 gram per square meter per day, more preferably below 0.01 gram per square meter per day and most preferably below 0.001 gram per square meter per day.

[0073] Example Ex11: Inner liner sheet material according to Ex10, wherein the alcohol permeation level is a menthol permeation level.

[0074] Example Ex12: Inner liner sheet material according to any Ex1 to Ex11, wherein the barrier layer comprises polyvinyl alcohol.

[0075] Example Ex13: Inner liner sheet material according to Ex12, wherein the barrier layer further comprises glyoxal.

[0076] Example Ex14: Inner liner sheet material according to Ex13, herein the barrier layer comprises 0.1 to 1 weight percent glyoxal.

[0077] Example Ex15: Inner liner sheet material according to any Ex1 to Ex14, wherein the base layer comprises paper.

[0078] Example Ex16: Inner liner sheet material according to any Ex1 to Ex14, wherein the base layer predominantly consists of paper.

[0079] Example Ex17: Inner liner sheet material according to any Ex1 to Ex14, wherein the base layer consists only of paper.

[0080] Example Ex18: Inner liner sheet material according to any Ex1 to Ex17, wherein the base layer comprises a paper fiber layer and a paper coating.

[0081] Example Ex19: Inner liner sheet material according to Ex18, wherein the paper fiber layer is calendared craft paper.

[0082] Example Ex 20: Inner liner sheet material according to Ex 18 or Ex 19, wherein the paper coating is clay-based.

[0083] Example Ex21: Inner liner sheet material according to any Ex1 to Ex20, wherein the infusion substance is at least partially absorbed into the base layer.

[0084] Example Ex 22: Inner liner sheet material according to any Ex1, Ex 2, Ex 4 to Ex 21, wherein the infusion substance is provided in the form of an infusion layer.

[0085] Example Ex23: Inner liner sheet material according to any Ex1 to Ex22, wherein the infusion substance comprises at least one flavoring component.

[0086] Example Ex24: Inner liner sheet material according to Ex23, wherein at least one flavoring component is an essential oil.

[0087] Example Ex25: Inner liner sheet material according to Ex23, wherein at least one flavoring component is plant-based.

[0088] Example Ex26: Inner liner sheet material according to Ex23, wherein at least one flavoring component is fruit-based.

[0089] Example Ex27: Inner liner sheet material according to Ex23, wherein at least one flavoring component is mint-based.

[0090] Example Ex28: Inner liner sheet material according to Ex23, wherein at least one flavoring component comprises menthol.

[0091] Example Ex29: Inner liner sheet material according to Ex28, wherein the menthol is synthetic.

[0092] Example Ex30: Package unit with at least one aerosol-generating article, a container and an inner liner sheet material according to any one of Ex 1 to Ex 29, wherein the inner liner sheet material at least partially encloses the at least one aerosol-generating article, wherein the inner liner sheet material is at least partially enclosed by the container and wherein the barrier layer is more distant from the at least one aerosol-generating article than the base layer.

[0093] Example Ex31: Package unit according to Ex30, wherein the infusion substance is adapted to at least partially migrate from the base layer to the aerosol-generating articles in the package unit.

[0094] Example Ex32: Package unit according to Ex30 or Ex31, wherein the barrier layer is adjacent to at least one inner surface of the container.

[0095] Example Ex33: Method for producing an inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article, the method comprises the following steps: providing a base layer with a barrier layer, and providing the base layer with an infusion substance, wherein the barrier layer is provided directly on the base layer.

[0096] Example Ex34: Method according to Ex33, wherein the infusion substance is at least partially absorbed into the base layer, while the barrier layer is the least-permeable layer of the inner liner sheet material with respect to the infusion substance.

[0097] Example Ex35: Method according to Ex33 or Ex34, wherein the infusion substance is sprayed onto the base layer.

[0098] Example Ex36: Method according to any Ex33 to Ex35, wherein the method further comprises unwinding the base layer with the barrier layer from a coil.

[0099] Example Ex37: Method according to any Ex33 to Ex36, wherein the method further comprises winding the base layer with the barrier layer and provided with the infusion substance onto a coil.

[0100] Example Ex38: Method according to any Ex33 to Ex37, wherein the base layer is paper and the infusion substance is menthol.

[0101] Example Ex39: Method according to any Ex33 to Ex38, wherein the barrier layer is coated onto the base layer.

[0102] Example Ex40: Method according to any Ex33 to Ex38, wherein the barrier layer is printed onto the base layer.

[0103] Example Ex41: Method according to any Ex33 to Ex38, wherein the barrier layer is sprayed onto the base layer.

[0104] Example Ex42: Method for producing a package unit for at least one aerosol-generating article, the method comprising a step of folding an inner liner sheet material produced according to any Ex33 to Ex41.

[0105] Example Ex43: Use of a biodegradable barrier layer in an inner liner sheet material for lining an inner surface of a package unit for at least one aerosol-generating article, wherein the inner liner sheet material comprises two layers, a base layer provided with an infusion substance and the barrier layer, wherein the barrier layer is the least-permeable layer of the inner liner sheet material with respect to the infusion substance.

[0111] The inner liner sheet material 1 according to the state of the art, as shown in FIG. 1, manifests multiple layers. The base layer 2 comprises a paper fiber layer 3 covered in a paper coating layer 4. Said two-component base layer 2 is typical in the manufacturing of such a paper product. The infusion substance 5 is provided to the paper fiber layer 3 of the base layer 2 and is absorbed there within. In order to prevent the permeation and escape of the infusion substance 5 through the paper fiber layer 3 and the paper coating layer 4, a metallic layer 6 is provided to the outer surface of the paper coating layer 4. However, the metallic layer 6 requires a primer and adhesion layer 7 to be interposed between it and the base layer 2. This enables an appropriate bond between the two layers and acts as an initial barrier to hem the permeation of the infusion substance 5. Furthermore, in order to facilitate the further processing of such an inner liner sheet material 1, the metallic layer 6 must be covered in an outer layer to preventing galling of the metallic layer 6, due to friction between said metallic layer 6 and corresponding machinery.

[0112] In contrast to the inner liner sheet material 1 according to the state of the art, the inner liner sheet material 1 according an embodiment of the invention shown in FIG. 2, manifests a singular layer, a barrier layer 9. The base layer 2 comprises a paper fiber layer 3 covered in a paper coating layer 4. The application of said barrier layer 9, which preferably comprises polyvinyl alcohol, to a two-component base layer 2, hinders the permeation of the infusion substance 5 through said base layer 2 without the necessity of the application of a metallic layer 6.

[0113] In an embodiment of the method according to the present invention, the base layer 2 is formed by coating the paper fiber layer 3 with a paper coating layer 4. Subsequently, a barrier layer 9 is applied on the base layer 2. The according sheet material is wound on a coil 10 and stored. As illustrated in FIG. 3, a coil 10 of wound base layer 2, which has been provided with a barrier layer 9, is unwound and directed to a nozzle 11 so that the infusion substance 5 can be sprayed on said base layer 2. Subsequent to said spraying step, the resulting inner liner sheet material 1 is wound onto a different coil 12.

[0114] FIG. 4 depicts a package unit 13 with an inner liner sheet material 1 enclosed by a container 14. The inner liner sheet material 1 completely envelopes aerosol-generating articles, not shown in the figure, and is directly adjacent to the inner surface 15 of the container 14.

[0115] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term “about”. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ±10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.