Aerosol-generating article with reduced visual defects

Abstract

The present invention relates to an aerosol-generating article (1) comprising a filter (2) and an aerosol-generating rod (6). The filter includes at least one filter segment. The filter segment includes a filter media comprising a liquid additive and at least one filter wrap. The filter wrap may be, for example, a filter segment package. A filter wrap extends from a first end of the filter to a second end of the filter to wrap the filter media.

Description

[0001] The present invention relates to an aerosol-generating article with reduced visual defects, the aerosol-generating article comprising a filter and an aerosol-generating rod.

[0002] Smoking articles such as cigarettes are mass-produced consumer goods. Smoking articles typically comprise a tobacco rod formed by wrapping tobacco cut filler in a paper-based wrapper in a longitudinally extending generally cylindrical rod. In addition to the main tobacco-wrapping function, the paper-based smoking article wrapper also often provides communication support for the manufacturer and may include various printed designs, colors, and / or markings (watermarks, embossing, etc.), which can form part of the brand identity and enable consumers to identify the product among others. Therefore, it is highly desirable to provide an attractive appearance for cigarette paper. Contamination of the visible paper surface should be avoided so as to provide a premium appearance for the cigarette and / or the cigarette paper.

[0003] Hereinafter, the terms "smoking article" and "cigarette" are used synonymously. In the past few years, so-called "heat-not-burn" devices have become increasingly popular. In such devices, instead of burning, a flavor source is heated to generate an aerosol that can be consumed by the user. The substrate (from which the aerosol is generated) typically comprises tobacco. The substrate is usually provided in the form of a replaceable cartridge to be inserted into an aerosol-generating device. Similar to conventional smoking articles such as cigarettes, in these cartridges, the tobacco is typically held in place by cigarette paper / wrapper. Some embodiments of the present invention are described only with respect to cigarettes or cigarette paper. However, these embodiments should be considered applicable to any other aerosol-generating article and / or aerosol-generating article wrapper and should be considered to be disclosed also with respect to them.

[0004] Many smoking articles include liquids. Some liquids such as menthol are added as flavorants. The taste or properties of the aerosol can be further altered by the liquids. Some of these liquids can give the aerosol a smoother taste. Examples of such liquids are fatty acids, fatty acid esters, polypropylene glycol (PPG), polypropylene glycol glycerol ethers, and polyethylene glycol (PEG). In addition, water can be present from different sources. In particular, natural products such as tobacco may contain water if not sufficiently dried.

[0005] A disadvantage of the liquid in the filter segment is that, even in the case of an optimal average application rate, due to the standard deviation of the raw materials and the production process, residual liquid moves from the filter to the adjacent tobacco compartment and extracts coloring substances from the tobacco. These coloring substances are then transported to the wrapper and cause unsightly stains on the tobacco wrapper.

[0006] In the past, attempts have been made to prevent the formation of such stains by coating the tobacco or wrapper, or attempts have been made to make the wrapper liquid-repellent. However, these additional coating agents often cause negative taste effects or create machine problems (such as paper dust).

[0007] US 2017 / 332694 A1 discloses a method for manufacturing an annular rod for wrapping a generally flat continuous material.

[0008] Accordingly, an object of the present invention is to provide an aerosol-generating article that includes a visible cigarette paper or wrapper that has an attractive appearance even in the presence of liquid in the aerosol-generating article.

[0009] It has been found that these problems can be overcome by an aerosol-generating article that includes a filter and an aerosol-generating rod; the filter includes at least one filter segment, the at least one filter segment includes a filter medium, the filter medium includes a liquid additive and at least one filter wrapper, and the at least one filter wrapper extends from a first end of the filter to a second end of the filter to wrap the filter medium;

[0010] the aerosol-generating rod includes an aerosol-generating substrate and a substrate wrapper for wrapping the aerosol-generating substrate,

[0011] wherein the filter and the aerosol-generating rod are combined together by an outer wrapper, the outer wrapper partially overlaps the filter wrapper and the substrate wrapper, and wherein the filter wrapper and the substrate wrapper are adjacent at the first end of the filter;

[0012] wherein the filter wrapper is formed as a tubular element and includes a wrapper seam that extends along the longitudinal direction of the article, and the seam is formed by a sealed overlapping region of the filter wrapper;

[0013] wherein there is no anchoring adhesive for the filter wrapper to extend to the filter medium up to the first end of the filter.

[0014] The aerosol-generating article according to the present invention includes a filter and an aerosol-generating rod. The filter includes at least one filter segment. The filter segment includes a filter medium that includes a liquid additive and at least one filter wrapper. The filter wrapper can be, for example, a filter segment wrapper. Both the terms "filter wrapper" and "filter segment wrapper" are used in the specification of the present invention. However, unless otherwise specified, all features disclosed for a particular embodiment of the filter segment wrapper should be understood to be also disclosed for any filter wrapper. The filter wrapper extends from a first end of the filter to a second end of the filter to wrap the filter medium.

[0015] The aerosol-generating rod includes an aerosol-generating substrate and a substrate wrapper. The substrate wrapper can be, for example, cigarette paper. Both the terms "substrate wrapper" and "cigarette paper" are used in the description of the present invention. However, unless otherwise specified, all features disclosed for a particular embodiment of cigarette paper should be understood to be disclosed for any substrate wrapper as well. The substrate wrapper wraps the aerosol-generating substrate.

[0016] The filter and the aerosol-generating rod are combined together by an outer wrapper. The outer wrapper can be, for example, tipping paper. Both the terms "outer wrapper" and "tipping paper" are used in the description of the present invention. However, unless otherwise specified, all features disclosed for a particular embodiment of tipping paper should be understood to be disclosed for any outer wrapper as well.

[0017] The outer wrapper overlaps partially with the filter wrapper and the substrate wrapper. The filter wrapper and the substrate wrapper are adjacent at a first end of the filter. The filter wrapper is formed as a tubular element and includes a wrapper seam that extends along the longitudinal direction of the article. The seam is formed by a sealed overlapping region of the filter wrapper. A further essential feature of the aerosol-generating article according to the present invention is that there is no anchoring adhesive for the extension of the filter wrapper to the filter medium up to the first end of the filter.

[0018] With such an aerosol-generating article, the diffusion of liquid from the filter to the adjacent tobacco compartment is reduced or even prevented. Therefore, no coloring substances are extracted from the tobacco, which may cause unsightly stains on the tobacco wrapper when being transferred to the wrapper. Unexpectedly, if the adhesive of the filter wrapper does not extend up to the first end of the filter, the diffusion of the liquid can be significantly reduced. It seems that the adhesive line extending up to the first end of the filter will act as a facilitator for any diffusion of the liquid, so that the liquid leaks into the substrate wrapper and causes stains. By shortening the facilitating line and preferably providing at least one gap near the first end of the filter, the generation of stains can be reduced or even prevented.

[0019] In a preferred embodiment of the aerosol-generating article, the distance of the anchoring adhesive to the filter medium from the first end of the filter is not less than 0.2 mm, preferably not less than 0.4 mm, preferably not less than 0.8 mm, more preferably not less than 0.8 mm, more preferably not less than 1 mm, and most preferably not less than 3 mm. It has been found that the distance between the first end and the anchoring adhesive is sufficient to inhibit the moisture transfer between the filter segment and the aerosol-generating rod. However, the contact surface of the adhesive is still large enough to fix the filter wrapper.

[0020] In a preferred embodiment of the aerosol-generating article, the filter wrapper is anchored to the filter medium by at least one discontinuous anchoring portion (preferably a discontinuous anchoring portion of an adhesive), the discontinuous anchoring portion of the adhesive starting at a distance from the first end of the filter in the longitudinal direction. Thus, the adhesive provides a secure bond of the wrapper ends but does not promote liquid diffusion to the first end of the filter, and liquid can pass through the first end of the filter to reach the aerosol-generating rod.

[0021] In a preferred embodiment of the aerosol-generating article, the filter wrapper is anchored to the filter medium by an anchoring portion that extends in both the longitudinal direction and the circumferential direction of the article, and wherein the extension length in the longitudinal direction is greater than the extension length in the circumferential direction. Alternatively or additionally, the filter medium is anchored by a plurality of anchoring portions that extend in the longitudinal direction of the article and possibly also in the circumferential direction of the article, and wherein the extension length of the plurality of anchoring portions is greater than the extension length of the plurality of anchoring portions in the circumferential direction. This particular arrangement along the longitudinal direction of the article further reduces the risk of soiling by restricting the diffusion of liquid towards the circumference of the article.

[0022] In a preferred embodiment of the aerosol-generating article, the filter wrapper is anchored to the filter medium by adhesive anchoring points that start at a distance from the first end of the filter in the longitudinal direction. Preferably, the adhesive anchoring points are arranged along a line that extends from the first end of the filter to the opposite second end of the filter in the longitudinal direction of the filter. It has been found that the points of the adhesive can be easily applied by known means. Additionally, less adhesive is consumed when provided as points rather than a continuous line. Thus, the anchoring portion can be produced at low cost. Another advantage of the points is that the points can be applied to be separated from each other. Thus, not only is the diffusion of liquid in the region near the first end of the filter prevented, but even away from the first end of the filter, each gap between adjacent points can be considered a barrier that hinders or at least slows down the diffusion of liquid along the longitudinal direction of the filter towards the first end of the filter.

[0023] In a preferred embodiment of the aerosol-generating article, the filter wrapper is anchored to the filter medium by a non-straight but continuous anchoring adhesive layer that starts at a distance from the first end of the filter wrapper in the longitudinal direction. Compared with a straight line, the curved layout forms an extended path. Thus, the diffusion of liquid along the longitudinal direction of the filter towards the first end of the filter is slowed down. Additionally, it has been found that a tight curve locally decelerates the diffusion along the curved path. This can be explained by the locally increased moisture in the curved region. This effect also slows down the diffusion of liquid along the longitudinal direction of the filter towards the first end of the filter.

[0024] In a preferred embodiment of the aerosol-generating article, the filter wrapper is anchored to the filter medium by a helical or multi-annular anchoring adhesive layer. Since these two geometries also provide the above effects, they have been found to be advantageous. The helical geometry of the anchoring adhesive further increases the length of the lines of the anchoring adhesive. Accordingly, the relative velocity of diffusion towards the first end of the filter along the longitudinal direction of the filter is reduced. The multi-annular geometry of the anchoring adhesive provides a circle along which diffusion is facilitated. However, moisture is trapped within the rings or by the annular portions formed by the anchoring adhesive. This also results in a retarded diffusion of the liquid along the longitudinal direction of the filter towards the first end of the filter.

[0025] In a preferred embodiment of the aerosol-generating article, the liquid additive in the filter medium comprises an oily substance and / or a flavoring substance. These liquids can be used to modify the taste or properties of the aerosol. For example, some liquids can give the aerosol a smoother taste.

[0026] In a preferred embodiment of the aerosol-generating article, the amount of the liquid additive in the filter medium (per filter) is at least 1 mg, preferably between 1 and 50 mg, more preferably between 10 and 20 mg. These amounts have been found to be suitable for improving the taste or properties of the aerosol when passing through the filter.

[0027] In a preferred embodiment of the aerosol-generating article, the liquid additive is selected from the group consisting of: alcohols, fatty acids, fatty acid esters, polyether polymers, essential oils, and combinations thereof. More preferably, the liquid is selected from the group consisting of: polypropylene glycol (PPG), polypropylene glycol glycerol ether, polybutylene glycol, diglycerol, sorbitan fatty acid esters, glycerol fatty acid esters, polyglycerol fatty acid esters, propylene glycol fatty acid esters, polyethylene glycol, octylene glycol, and combinations thereof. At least some of these substances are suitable for reducing the amount of phenols from the aerosol, which gives the user a smoother taste.

[0028] In a preferred embodiment of the aerosol-generating article, the filter medium comprises paper and / or other natural cellulose fibers. It has been found that filter media comprising paper and / or other natural cellulose fibers are particularly suitable since the diffusion of moisture through these media is slow. Accordingly, if the diffusion along the adhesive to the first end of the filter section is not possible or very slow due to the anchoring portion of the adhesive starting at a certain distance from the first end, the overall diffusion of the liquid from the filter section to the aerosol-generating substrate will be not possible or very slow.

[0029] In a preferred embodiment of the aerosol-generating article, the filter wrapper has no hydrophobic or oleophobic coating. Since the diffusion of liquid through the filter material can generally be controlled, the wrapper has been considered important for controlling the diffusion of moisture. Thus, attempts have been made to reduce the diffusion of liquid from the filter section to the aerosol-generating substrate by applying a hydrophobic or oleophobic coating to the wrapper. However, these coatings provide disadvantages because they can have a negative impact on the taste of the aerosol. The present invention provides a different way of preventing or slowing down the diffusion of liquid. It is thus possible and preferred to provide a filter wrapper that does not have a hydrophobic or oleophobic coating. Thus, the taste of the aerosol is not negatively affected by the coating of the wrapper.

[0030] In a preferred embodiment of the aerosol-generating article, it is a combustible article or a heat-not-burn article for heating in an e-aerosol-generating device. Thus, the aerosol-generating article can preferably be provided as a traditional tobacco product (such as cigarettes, cigars, cigarillos, and roll-your-own tobacco) or as an aerosol substrate for a so-called "heat-not-burn" device. This type of device generates aerosol and / or vapor by heating a solid aerosol substrate (usually comprising tobacco) to a temperature typically in the range of 200°C to 350°C.

[0031] Experiments have been conducted to evaluate the advantages of the aerosol-generating article according to the present invention (line 2) relative to the aerosol-generating article according to the prior art (line 1). The aerosol-generating article according to the prior art includes a filter having an anchoring glue that extends up to the first end of the filter closest to the aerosol-generating substrate. In contrast, in the aerosol-generating article according to the present invention (line 2), the anchoring glue does not extend up to the first end of the filter closest to the aerosol-generating substrate.

[0032] As shown in Table 1, when 200 aerosol-generating articles according to the prior art were stored under "normal conditions" (22°C and 60% relative humidity (RH)), stains on the tipping paper (TP) were observed at 14 rods (which is equal to 7% of all rods). In contrast, when the aerosol-generating article according to the present invention was stored under the same conditions, stains were observed at only one aerosol-generating article according to the present invention (equal to 0.5%). When stored under these conditions, no stains on the cigarette paper (CP) were observed for any of the aerosol-generating articles.

[0033] When stored under so-called “climatic conditions” (35 °C and 40% relative humidity (RH)), stains on the tipping paper (TP) were observed at 18 rods of the aerosol-generating article according to the prior art. This corresponds to 9% of all rods. In contrast, when stored under the same conditions, stains were observed only at 6 rods (equal to 3%) of the aerosol-generating article according to the invention. When stored under these conditions, no stains on the cigarette paper (CP) were observed for any aerosol-generating article.

[0034] Table 1

[0035]

[0036] Other advantages, objects and features of the present invention will be described by way of example only in the following description with reference to the accompanying drawings. In the drawings, like parts in different embodiments may bear the same reference numerals.

[0037] In the drawings:

[0038] Figures 1a to 1d Schematic diagrams showing different embodiments of the wrapper seam arrangement in the overlapping region of the filter wrapper of an aerosol-generating article; and

[0039] Figure 2 Photographs showing different stains on the tipping paper.

[0040] Figure 1a Schematic diagram showing the wrapper seam arrangement in the overlapping region of the filter wrapper of an aerosol-generating article known from the prior art. The aerosol-generating article 1 includes a filter 2 and an aerosol-generating rod 6. The filter 2 and the aerosol-generating rod 6 are arranged adjacent to each other along the longitudinal direction of the aerosol-generating article 1. The filter and the aerosol-generating rod are held together by an outer wrapper (not shown) which partially overlaps with the filter wrapper and the matrix wrapper (not shown). The filter wrapper surrounds the filter material. The two ends of the filter wrapper are attached to each other by a seam 4 extending along the longitudinal direction of the article. The seam 4 is formed by a sealed overlapping region of the filter wrapper. The seam of the filter wrapper extends up to the first end of the filter 2 adjacent to the aerosol-generating rod 6.

[0041] By diffusion, the liquid 3 can migrate along the seam 4 from any position in the filter up to the first end of the filter 2 adjacent to the aerosol-generating rod 6.

[0042] Figure 1bA schematic view of a single droplet of liquid 3 on the surface of the filter material 2 is shown. Since the migration and diffusion through the filter material 2 are restricted, the size of the droplet 3 is restricted. If there is no seam, the liquid 3 will not migrate through the filter until the first end of the filter 2 adjacent to the aerosol generating rod 6.

[0043] Figure 1c A schematic view of the wrapper seam arrangement in the overlapping region of the filter wrapper of an embodiment of an aerosol generating article according to the present invention is shown. Similar to the aerosol generating article 1 as Figure 1a shown, the aerosol generating article 1 includes a filter 2 and an aerosol generating rod 6. The filter 2 and the aerosol generating rod 6 are arranged adjacent to each other along the longitudinal direction of the aerosol generating article 1. The filter and the aerosol generating rod are held together by an outer wrapper (not shown) which partially overlaps the filter wrapper and the substrate wrapper (not shown). The filter wrapper surrounds the filter material 2. The two ends of the filter wrapper are attached to each other by a seam 4. The seam is formed by an anchoring adhesive arranged in an overlapping circle (or oval). However, the seam does not extend to the first end of the filter 2 adjacent to the aerosol generating rod 6.

[0044] Due to the geometry of the seam and the different concentrations of the anchoring adhesive in different regions of the filter wrapper, the migration and diffusion of the liquid are restricted. The liquid tends to concentrate in the regions where the concentration of the anchoring adhesive is high, while in the regions where the concentration of the anchoring adhesive is low or there is no anchoring adhesive, the concentration of the liquid 3 is low.

[0045] Since the seam and / or the anchoring adhesive do not extend to the first end of the filter 2 adjacent to the aerosol generating rod 6, the liquid concentration in this region is very low and no liquid can migrate from the filter to the aerosol generating rod 6. Accordingly, the liquid cannot extract coloring substances from the aerosol generating substrate, which may stain the tipping paper when migrating to the surface or around the aerosol generating rod 6.

[0046] Figure 1d A schematic view of the wrapper seam arrangement in the overlapping region of the filter wrapper of a further embodiment of an aerosol generating article according to the present invention is shown. Similar to the aerosol generating article 1 as Figure 1c shown, the two ends of the filter wrapper are attached to each other by a seam 4. However, the seam is formed by an anchoring adhesive arranged at a number of points that are spaced apart from each other. None of these points extend to the first end of the filter 2 adjacent to the aerosol generating rod 6.

[0047] The liquid 3 present in the filter material 2 will remain at a high concentration in the area around the points of the anchoring adhesive. Depending on the spacing between two adjacent points, the migration of the liquid from one point to the next is highly restricted.

[0048] Since no points of the anchoring adhesive are arranged in the area near the first end of the aerosol generating rod 6 adjacent to the filter 2, the liquid concentration in this area is very low and no liquid can migrate from the filter to the aerosol generating rod 6. As described for the arrangement shown above with respect to Figure 1c the liquid cannot come into contact with the aerosol generating substrate to extract coloring substances that may stain the tipping paper.

[0049] Figure 2 Photographs showing different stains on the tipping paper are presented. In the left photograph, the stain is very evident and extends to the cigarette paper (CP). In the photograph shown on the right, the stain appears only on the tipping paper (TP). It has been found that the stains mainly appear in the rings.

[0050] List of reference numerals

[0051] 1 Aerosol generating article,

[0052] 2 Filter, filter material,

[0053] 3 Liquid, droplet, propylene glycol,

[0054] 4 Seam, anchoring adhesive, ring, circle, point,

[0055] 6 Aerosol generating material, aerosol generating rod.

Claims

1. An aerosol - generating article, comprising a filter and an aerosol - generating rod; the filter comprises at least one filter segment, the at least one filter segment comprises a filter medium, the filter medium comprises a liquid additive and at least one filter wrapper, and the at least one filter wrapper extends from a first end of the filter to a second end of the filter to wrap the filter medium; The aerosol - generating rod comprises an aerosol - generating substrate and a substrate wrapper for wrapping the aerosol - generating substrate, Among them, The filter and the aerosol - generating rod are combined together by an outer wrapper, the outer wrapper partially overlaps with the filter wrapper and the substrate wrapper, and wherein the filter wrapper and the substrate wrapper are adjacent at the first end of the filter; Wherein, the filter wrapper is formed as a tubular element and comprises a wrapper seam, the wrapper seam extends along the longitudinal direction of the article, and the seam is formed by a sealed overlapping area of the filter wrapper; Wherein, there is no anchoring adhesive for the extension of the filter wrapper to the filter medium until the first end of the filter; Wherein, the filter wrapper is anchored to the filter medium by discontinuous anchoring portions of an adhesive, the discontinuous anchoring portions of the adhesive start at a distance from the first end of the filter in the longitudinal direction, and Wherein, the filter wrapper is anchored to the filter medium by adhesive anchoring points starting at a distance from the first end of the filter in the longitudinal direction.

2. The aerosol-generating article according to claim 1, wherein, The filter wrapper is anchored to the filter medium by a non - straight but continuous anchoring adhesive layer, the non - straight but continuous anchoring adhesive layer starts at a distance from the first end of the filter wrapper in the longitudinal direction.

3. The aerosol-generating article according to claim 3, wherein, The filter wrapper is anchored to the filter medium by a spiral or multi - looped anchoring adhesive layer.

4. The aerosol-generating article according to any one of claims 1 to 3, wherein, The liquid additive in the filter medium comprises an oily substance and / or a flavor substance.

5. The aerosol-generating article according to any one of claims 1 to 4, wherein, The amount of the liquid additive in the filter medium is at least 1 mg, preferably between 1 and 50 mg, more preferably between 10 and 20 mg.

6. The aerosol-generating article according to any one of claims 1-5, wherein, The liquid additive is selected from the group consisting of alcohols, fatty acids, fatty acid esters, polyether polymers, essential oils, polypropylene glycol, polypropylene glycol glycerol ether, polybutylene glycol, diglycerol, sorbitan fatty acid esters, glycerol fatty acid esters, polyglycerol fatty acid esters, propylene glycol fatty acid esters, polyethylene glycol, octanediol, and combinations thereof.

7. The aerosol-generating article according to any one of claims 1-6, wherein, The filter medium comprises paper and / or other natural cellulose fibers.

8. The aerosol-generating article according to any one of claims 1 to 7, wherein, The filter wrapper has no hydrophobic or oleophobic coating.

9. The aerosol-generating article according to any one of claims 1-8, wherein, The aerosol - generating article is a combustible article or a heat - not - burn article for heating in an e - aerosol - generating device.

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