Laser etched aerosol product wrappers, aerosol product articles containing such, and methods of making same - Patents.com

Abstract

The invention relates to an aerosol product wrapper (1) comprising at least one layer of cellulosic material having a thickness (t) of at least 35 micrometers and a tensile strength of at least 25 N / 15 mm, extending from a first surface (1a) to a second surface (1b) opposite the first surface. The wrapper material comprises at least a portion of an indicia (I) etched into said at least one layer from one of the first surface (1a) or the second surface (1b) to a determined depth (d) less than the thickness (t) of the wrapper material. The invention further relates to a method of producing such an aerosol product wrapper (1), comprising the step of etching at least a portion of the indicia (I) into the wrapper (1) by vaporizing the wrapper material according to an indicia vector line to a determined depth (d) less than the thickness (t) of the cellulosic material layer. The invention finally relates to an aerosol product comprising such a wrapper around at least a portion thereof, the etched indicia (I) of the wrapper being disposed on a surface facing the outside of the aerosol product (10).

Description

[Technical field]

[0001] The present invention relates to the field of aerosol product manufacturing, such as combustible or heat-not-burn (HNB) tobacco-containing articles. More specifically, the present invention relates to aerosol product wrappers that include at least a portion of indicia etched within a thickness of the wrapper material, methods of making such aerosol product wrappers, and aerosol product articles that include such wrappers. [Background technology]

[0002] Wrappers, particularly those for enclosing the aerosol-generating materials and / or mouthpiece and filter components of existing combustion-based or HNB aerosol product articles, often include indicia formed by embossing, debossing, or printing, primarily for decorative and branding purposes. While practical, common, and of high quality, these existing indicia-providing techniques are not without drawbacks.

[0003] Material modification techniques such as embossing require a forming tool, such as a special embossing roller, for each mark design to be formed in the wrapper material. Thus, each new mark design requires a corresponding new roller on each aerosol product manufacturing machine or wrapper manufacturing machine. This means that the design change process is very costly, since the embossing rollers cannot be retrofitted or converted to fit new designs.

[0004] Printing techniques are extremely popular and cost-effective. However, they imply the use of various inks or varnishes that may be transferred through the printed wrapper to the aerosol-generating material or, during use, to the aerosols generated during consumption of an aerosol-producing article containing such a wrapper, and thus to the user. Furthermore, changing regulatory constraints imposed on manufacturers by local authorities may also limit or prohibit the use of certain inks, varnishes, or wrapper fillers, which in turn may reduce the range of wrapper qualities or printing inks available to the wrapper designer. Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide a novel aerosol product wrapper and method for producing the same which does not suffer from the above-mentioned drawbacks and offers greater flexibility for providing indicia on the wrapper for decoration and branding of aerosol products. [Means for solving the problem]

[0006] According to a first aspect of the present invention, this object is met by the provision of an aerosol product wrapper comprising at least one layer of cellulosic material extending from a first surface to a second surface opposite the first surface and having a thickness (t) of at least 35 micrometers and a tensile strength of at least 25 N / 15 mm, said wrapper including at least a portion of an indicia etched into said at least one layer from one of the first surface or the second surface to a determined depth (d) less than the thickness (t).

[0007] In the context of the present invention, tensile strength is measured using the method defined in ISO1924-2:2008.

[0008] The inventors have found and confirmed that advantageously, indicia obtained by printing or material modification on a wrapper as known from the prior art can in many cases be replaced by etching a portion of the wrapper material to a defined depth of its total thickness. It has been found that the etched indicia provide a satisfactory visual presentation, cost-effective processing, and increased flexibility for design modifications compared to the prior art methods. Most importantly, it has also been confirmed that etching indicia into a wrapper material of selected qualities as defined herein does not result in significant changes in the physical performance of the wrapper required for the aerosol-generating product in which it is used. In particular, it has been found that the etched wrapper exhibits satisfactory mechanical resistance during machine manufacturing of the aerosol-generating product and during normal use by the consumer.

[0009] In the context of the present invention, the term "etching" is to be interpreted as a process or technique in which material is irreversibly removed in a controlled manner according to a specific design, which may be defined according to vector lines, by chemical or physical processes into a primary material layer over a controlled depth, length and width in said primary material layer.

[0010] In accordance with the present invention, a particularly suitable etching technique for producing indicia etched into an aerosol product wrapper is laser etching, whereby the cellulosic wrapper material is evaporated from the wrapper sheet by focusing a laser beam of determined wavelength and power that moves at a selected linear velocity over the wrapper sheet, thereby inscribing lines from the sheet material.

[0011] In one embodiment, the determined depth (d) of the etched indicia is selected to be at least one tenth, and preferably one fifth, of the thickness (t) of the cellulosic material layer. Such a depth has been determined to be most appropriate for obtaining a mark that is visually discernible to the naked eye on the wrapper even when the width of the etched line portion of the indicia is minimal.

[0012] In one embodiment, the determined depth of the etched indicia is selected to be at most two-thirds, and preferably at most one-half, of the thickness (t) of the cellulosic material layer. Such maximum depth is selected to ensure that the mechanical and physical properties of the etched wrapper meet the manufacturing constraints of both the wrapper and / or the aerosol product manufacture.

[0013] In one embodiment, at least one layer of cellulosic material has a thickness of at least 34 g / m 2 , preferably at least 40 g / m 2 The sheet has a basis weight of 1.0 g.

[0014] In one embodiment, at least one layer of cellulosic material has a porosity of at most 15 CU (Cholesta Units).

[0015] Such basis weights and porosities are particularly selected for the mouthpiece wrappers of aerosol product articles, such as the tip wrappers which will most likely have design features and indicia.

[0016] In one embodiment, at least one layer of the cellulosic material further comprises a perforation extending from a first surface to a second surface of the at least one layer, the perforation and the indicia being offset from one another by a non-zero distance within the at least one layer. Such perforations may be provided, for example, for ventilation of a filter portion of the aerosol product article, particularly a tip wrapper.

[0017] In one embodiment, the perforations and the markings are offset from one another by at least 1 mm, preferably at least 2 mm.

[0018] A second aspect of the present invention is a method for producing a wrapper material as hereinbefore described, comprising the steps of: - providing a laser marking device including a laser source having a nominal power output of about 20 W to 100 W; - providing an aerosol product wrapper material, the wrapper material comprising at least one layer of cellulosic material extending from a first surface to a second surface opposite the first surface, the layer having a thickness (t) of at least 35 micrometers and a tensile strength of at least 25 N / 15 mm; - etching at least a portion of the indicia into the wrapper material by evaporating the wrapper material using a laser beam following the indicia vector line to a determined depth (d) less than the thickness (t) of the cellulosic material layer; The present invention relates to a method comprising the steps of:

[0019] The inventors have found that laser etching is the most suitable etching technique for obtaining indicia etched at the individual wrapper level of aerosol product articles, with excellent design flexibility and etching speed, and limited quality defects.

[0020] Laser etching allows for easy changes of the engraved design since only the movement pattern of the laser beam on the wrapper material must be changed. Preferably, the stamper includes a control system which controls the movement of the laser beam on the wrapper material. Preferably, the control system converts a digital image file captured in the control system into control signals which control the movement of the laser beam. In this way, any digital image file can be converted into a laser etched indicia. To change the design to be etched, only the digital image file needs to be changed. Preferably, the control system includes data storage in which the digital image files can be saved. In this way, digital image files which are regularly used can be selected directly in the control system.

[0021] Laser etching also allows for the application of designs without the addition of additional substances to the wrapper material, which leads to an additive-free and easily adaptable imprint. Because there are no additives in the process, there is also no sensory impact on the aerosol generated by the aerosol product.

[0022] The power of the laser beam selected is low enough so that the amount of energy received by the wrapper material per unit area is low enough to prevent cutting, smoldering, or burning of the wrapper material, while the laser power is high enough to produce the desired etching or marking effect.

[0023] In one embodiment of the method, the laser beam is directed perpendicularly from the emission point to one of the first surface or the second surface of the wrapper material, and the distance between the laser beam emission point and the first surface or the second surface of the aerosol product wrapper material is at least 50 mm.

[0024] In one embodiment, the determined depth (d) of the etched indicia is at least one tenth, preferably one fifth, of the thickness (t) of the cellulosic material layer.

[0025] In one embodiment, the determined depth of the etched indicia is at most two-thirds, and preferably at most one-half, the thickness (t) of the cellulosic material layer.

[0026] In one embodiment, at least one layer of cellulosic material has a thickness of at least 34 g / m 2 , preferably at least 40 g / m 2 The sheet has a basis weight of 1.0 g.

[0027] In one embodiment, at least one layer of cellulosic material has a porosity of at most 15 CU (Cholesta Units).

[0028] In one embodiment, the laser source is a CO2 laser source having a beam wavelength of 10.6 micrometers.

[0029] In another embodiment, the laser source is a fiber laser source having a beam wavelength of 1062 nanometers.

[0030] Both the CO2 laser source and the fiber laser source described above have been found to be acceptable for providing the indicia etched onto the aerosol product wrapper according to the present invention. Each laser source can further be located in a variety of configurations, either at the wrapper manufacturing level or in the aerosol product manufacturing facility, with high packaging flexibility.

[0031] In a first alternative embodiment of the method of the invention, the aerosol-generating material wrapper is provided as a continuous web of wrapper material wound on a reel, and the method comprises the steps of: - unwinding the web from a reel and circulating the web at a determined linear speed along a process direction substantially perpendicular to the direction of the laser beam; - sequentially etching indicia or portions thereof into the web of wrapper material at regular intervals along the length of the web of wrapper material along the process direction; Further includes:

[0032] In the above defined embodiment of the method of the invention suitable for etching indicia at the wrapper production level, the laser beam is preferably moved over the surface of the wrapper material with a linear speed of at least 5 m / min, preferably at least 15 m / min.

[0033] Further, in this first alternative embodiment, the method further includes the step of cutting individual sheets of aerosol-generating wrapper material from the continuous web, such that each individual sheet includes at least one indicia etched into a surface thereof.

[0034] In a second alternative embodiment of the method of the present invention, at least one indicium or a portion of an indicium is etched into the aerosol-generating wrapper after it has been wrapped around a portion of the aerosol product article.

[0035] In this second alternative embodiment, the method allows for a mark or multiple markings to be etched across a group of aerosol product articles at once, and in some cases a single mark is etched across multiple articles, such as a collection of articles, whereby each individual article has only a portion of the mark and is therefore individually completely unique, providing a design opportunity to give the consumer the impression of a single mark upon opening.

[0036] In this second alternative of the method of the invention, the laser beam can advantageously be moved much faster than in the previous alternative, since the indicia to be etched can be much larger than would be the case if provided for an individual wrapper. The laser beam can therefore be moved over the surface of the wrapper material with a linear speed of at least 50 m / min, preferably at least 100 m / min.

[0037] In any one of the embodiments of the method of the present invention described above, it may be further provided that for control and quality purposes, a margin of at least 1 mm, preferably at least 2 mm, is placed between the edge of the indicia and the edge of the aerosol product wrapper material. This margin serves as an overlap area when the wrapper material is wrapped around the aerosol product portion. Adhesive may be applied to the overlap area to secure the wrapper material in place.

[0038] A further object of the present invention also relates to an aerosol product article, advantageously comprising the aforementioned wrapper material wrapped around at least a portion of the article, the etched indicia of the wrapper being disposed on an outer facing surface of the aerosol product article. In this way, an aerosol product article having design features etched at the wrapper level can be provided with visually identifiable indicia disposed on the material that constitutes the article, providing a highly distinctive design at minimal cost to both the manufacturer and the consumer.

[0039] Further advantages, objects and features of the present invention will be explained, by way of example only, in the following description with reference to the accompanying drawings in which similar elements of different embodiments may be provided with the same reference symbols, and in which: [Brief description of the drawings]

[0040] [Figure 1] FIG. 2 is a schematic diagram of an aerosol product wrapper etching process in accordance with the present invention. [Diagram 2] 2 is a schematic diagram of an aerosol product including a laser etched tip wrapper obtained by the method of FIG. 1. [Diagram 3] 3 is a continuous web of three different wrapper materials having laser etched indicia of three different designs. [Figure 4] 1 shows a photograph of individual laser-etched indicia representing the Camel® Beast on individual aerosol product tip wrapper sheets. [Diagram 5] 1 shows a photograph of indicia etched across the leading wrapper of a bundled collective aerosol product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] For the avoidance of doubt, references throughout this specification to aerosol product wrapper material 1 shall mean, and be interpreted interchangeably with, a continuous web of wrapper material wound in bobbin form produced by a wrapper manufacturer, or individual sheets of wrapper material cut from such a continuous web of wrapper material that are individually used to wrap a portion of an aerosol product during its manufacture, such as a filter plug wrapper or especially a tip wrapper.

[0042] The present invention is primarily directed to providing an aerosol product wrapper material 1 that includes design features such as branding that are etched, preferably laser etched, as described below. Etched wrappers offer several advantages over prior art embossing and printing techniques that provide simple, single color indicia on the aerosol product wrapper.

[0043] Notably, laser etched markings are fast and can be applied at various stages in the manufacturing process, either in the wrapper material itself or at the final aerosol product level, providing great flexibility in implementation and shifting marking designs.

[0044] Furthermore, laser etching is an additive-free marking process that allows multiple marking designs and combinations thereof to be created at the wrapper level on the aerosol product without the need for multiple printing passes of the wrapper material or multiple deformation rollers.

[0045] FIG. 1 shows a schematic diagram of a first laser etching process for producing a continuous web of etched aerosol product wrapper material 1. A continuous web of virgin or unetched wrapper material 1 is fed in a feed direction F from a first reel at an unwinding station A through a laser etching station B. The wrapper material 1 can typically be an aerosol-generating aerosol article leading end wrapper material comprising at least one layer of cellulosic material having a thickness (t) of at least 35 micrometers, preferably at least 40 micrometers, extending from a first surface 1a to a second surface 1b opposite the first surface, as shown in the enlarged cross-sectional view of FIG. 1. Furthermore, the wrapper material 1 must have a tensile strength of at least 25 N / 15 mm, preferably at least 27 N / 15 mm. This thickness t and tensile strength have been tested and identified by the inventors as important wrapper qualities for high-quality and reproducible laser etching of the wrapper material 1 without perforations or changes in the mechanical resistance of the wrapper for subsequent aerosol product production.

[0046] More preferably, when the wrapper material is used as a tip wrapper, i.e., a mouthpiece outer element, of an aerosol product, at least one layer of cellulosic material has a thickness of at least 34 g / m 2 , preferably at least 40 g / m 2 and a porosity of at most 15 CU (Colesta Units). However, other wrapper material basis weights and porosities may be contemplated for use as other wrapper material components of typical aerosol product articles, such as filter plug wrappers or tobacco base wrappers.

[0047] A continuous web of wrapper material 1 is withdrawn from a feed station A and fed through and in a laser etching station B along a feed direction F by two pairs of rollers 2a, 2b and 3a, 3b respectively arranged in front and behind the etching zone E. Both rollers 2a, 2b, 3a, 3b of a pair are in contact with one of the two surfaces 1a, 1b of the wrapper material 1 respectively and rotate with the same angular velocity ω to ensure homogenous friction on the web of wrapper material 1 and its constant linear velocity across the laser etching station B.

[0048] The laser etching station B further comprises a laser source 5, which generates a laser beam 5a having a nominal power of at most about 20 W to 100 W. The laser beam 5a is directed from the laser head onto the first surface 1a of the wrapper material 1, for example via a mirror 6. The laser head and mirror 6 are positioned such that the distance D from either the laser head or the mirror 6 is at least 50 mm, depending on which of the laser head or mirror 6 directs the laser beam 5a onto the surface 1a of the wrapper material 1, to avoid excessive energy transfer from the laser beam 5a to the wrapper material 1 and possible cutting or perforating it.

[0049] The laser source 5 and the mirror 6 are controlled by digital control means such as a computer (not shown) running a dedicated control program. The computer is advantageously also connected to a digital design library, stored either in a local storage device such as a ROM (Read Only Memory) or RAM (Random Access Memory) or in a remote location, in particular a cloud-based library accessible via the Internet in a wired or wireless configuration. The digital design library advantageously stores a number of individual mark designs, digitally defined as vector lines, stored for example in CAD file format or an equivalent computer-readable format suitable for laser control, which are loaded by the control program of the computer to send corresponding drive commands to both the laser source and the mirror in order to etch a corresponding mark or marks on the surface 1a of the wrapper material directly under the laser beam 5a. Such laser control techniques are well known in the field of material laser processing and will not be described further here.

[0050] The laser source 5 can be selected to be either a CO2 laser source with a laser beam wavelength of 10.6 micrometers or a fiber laser source with a beam wavelength of 1062 nanometers. Both laser sources are well suited to the needs of the etching process and are particularly suitable for vaporizing cellulosic materials as the wrapper material 1.

[0051] As the web of wrapper material 1 enters the etching area E in the laser etching station B, the laser beam 5a sequentially etches, i.e. partially and permanently removes cellulosic material from the wrapper, by vaporizing said wrapper material along an etching path followed by the laser beam 5a driven by a control computer, and forms dedicated indicia I according to indicia vector lines corresponding to at least one indicia design stored in a memory connected to said control computer. Thus, etched indicia I are provided at regular intervals along the length of the wrapper material web 1 along the feed direction F, as represented in Figure 3. Of course, etching can also be performed continuously over a continuous length of wrapper material, if desired.

[0052] The etching is performed in a controlled manner over a defined depth (d) less than the thickness (t) of the cellulosic layer by constant control of the power and distance of the laser beam 5a to the surface 1a of the wrapper material and constant feed speed of the web under the traction of the pairs of rollers 2a, 2b, 3a, 3b. According to various tests carried out by the inventors, the depth (d) of the etched mark can be at least one tenth, preferably one fifth, of the thickness (t) of the cellulosic layer, and at most two thirds, preferably at most half, of the thickness (t) of the cellulosic layer.

[0053] If a mirror 6 is used to direct the laser beam 5a onto the surface 1a of the wrapper material 1, the mirror 6 is movable along and around at least one, preferably two orthogonal directions X, Y. The moving directions X, Y preferably both extend perpendicular to the feed direction F, the direction X together with the feed direction F defining the horizontal plane of the web of wrapper material 1 and the direction Y extending perpendicular to its feed surface parallel to the vertical direction V. The movement of the laser beam 5a by the movable mirror 6 allows the etching of more complex mark designs more quickly. More specifically, in such a configuration of the movable laser beam 5a, the laser beam 5a may preferably be moved over the surface of the wrapper material 1 with a linear speed of at least 5 m / min, preferably at least 15 m / min.

[0054] After passing through the etching region E and the second pair of rollers 3a, 3b, the etched web of wrapping material 1 may be wound onto a final reel at a final conditioning station C, or may further be fed directly to an aerosol product maker assembly, where the wrapper material 1 is then cut from the continuous web 1 into individual sheets of aerosol-generating wrapper material such that each individual cut sheet includes at least one indicia I etched on its surface, to provide one aerosol product including such etched indicia I as shown in FIG. 2.

[0055] 2 shows a schematic diagram of one embodiment of an aerosol product article 10 including indicia I laser etched on the outer surface of a tip wrapper 13. The aerosol product article 10 includes a cylindrical shape as per most common industry standards. The aerosol product article 10 comprises a filter rod 11 and a rod of aerosol-forming material 12, both of which are longitudinally attached to one another along a longitudinal direction Ld by a tip wrapper 13. The rod of aerosol-forming material 12 is circumferentially wrapped with a typical cigarette wrapper 14. The filter rod 11 is generally circumferentially wrapped with a first plug wrapper 15, which is further wrapped on its outer surface with a tip wrapper 13 having indicia I on its outer surface such that the indicia I is visible to the consumer.

[0056] The laser etched indicia I indicate an etched area of ​​wrapper 13, which may be only a particular portion of the exterior surface of wrapper 13, as shown in the photographs of corresponding etched leading edge wrapper 13 in Figure 2 or Figure 4. However, it is contemplated that the exterior surface of leading edge wrapper 13 may include more than one laser etched indicia I in each of a plurality of engraved areas, or that a continuous indicia I may be etched across the entire exterior surface of the leading edge wrapper.

[0057] The leading edge wrapper 13 further includes additional vent perforations 16 that, in this example, extend completely through the wrapper material layer (i.e., from the first surface 1 a to the second surface 1 b if the wrapper were considered to be flat as shown in FIG. 1 ). The vent perforations 16 and the etched indicia I are offset from one another by a non-zero distance g within at least one layer of wrapper material 1.

[0058] The perforations 16 are typically created by laser perforation during the manufacture of the aerosol product after the leading wrapper material 13 has been wrapped around the filter rod 11 and tobacco rod 14 and attached together. However, due to the different power and motion required for etching and perforation, one and the same laser device cannot simultaneously or consecutively provide both the indicia I and the perforations 16. Therefore, it is preferred that the etching of the indicia is performed separately from the perforations, either prior to the aerosol product manufacture at the continuous wrapper bobbin level as in the method of FIG. 1, or at a later stage, such as during the packaging process as further described below.

[0059] Figure 3 shows three different wrapper materials 1 resulting from the method of Figure 1 having laser etched indicia I featuring different designs disposed along the length of the wrapper material and along a central etched region 1c. The wrapper materials 1 also include unetched side regions 1d in contrast to the etched region 1c. The wrapper materials 1 extend along a longitudinal direction L, and only a portion of the wrapper material 1 is shown.

[0060] The leftmost wrapper material 1 shown in Figure 3 shows a margin 20. The margin 20 is located at an edge 24 of the wrapper material 1. The edge 24 is parallel to the longitudinal direction and does not include any etched markings. Said margin 20 shows a width 22 measured perpendicular to the longitudinal direction L, the margin 20 being at least 1 mm, preferably at least 2 mm, between the edge 24 of the wrapper material 1 and the part of the marking I that is furthest from the longitudinal axis of the wrapper material.

[0061] Margin 20 is preferably and advantageously provided to correspond to overlapping adhesive areas of individual cut sheets of wrapper material, such as leading wrapper 13 of Figure 2. These overlap areas are preferably free of markings to ensure better contact and adhesion of the wrapper around corresponding portions of the aerosol product article during manufacture and further use of the aerosol product article, thereby preventing unwanted peeling of the wrapper from the article.

[0062] The present invention is particularly suitable for providing wrapper material including indicia etched into individual wrappers, such as tip wrappers arranged around the filter rods of individual aerosol product articles, as shown in Figures 1 to 4 and described above, but can also extend to a broader level, in particular to the provision of laser etched indicia across a group of aerosol product articles arranged in a bundle BU as shown in Figure 5.

[0063] In such an embodiment, at least one indicium I or a portion of the indicium is etched into the aerosol product wrapper 1 before the article is cut and manufactured, i.e., not offline, but after the wrapper 1 is wrapped around a portion of the aerosol product 10 and further bound into an assembly before being wrapped in an outer cardboard or paper outer package as is well known in the tobacco industry.

[0064] The etching process in such a case is much the same as that described in connection with Figure 1, except that a bundle BU of aerosol product articles 10 replaces the continuous web 1 of wrapper material and is exposed to laser beam 5a to form indicium I or indicium I across the entire group of articles in the bundle. Of course, individual wrappers, for example the leading wrappers of each or some of the articles included in the bundle, may further include individual etched indicium provided in accordance with the method of Figure 1.

[0065] The advantage of the etching mark I over the group of articles BU is that it provides a much larger etching area compared to individual wrappers and also much faster laser speed operation, with the laser beam 5a moving over the surface of the wrapper material of the group of articles 10 in the bundle being processed at a linear speed of at least 50 m / min, preferably at least 100 m / min.

[0066] The present invention therefore provides novel aerosol product wrappers having etched decorative indicia obtained by the various methods described above, with high flexibility to implement at various points in the aerosol product production, and extremely high flexibility in design, at a cost competitive with existing wrapper decoration techniques.

Claims

1. In an aerosol-generating article wrapper (1) comprising at least one layer of a cellulosic material having a thickness (t) of at least 35 micrometers and a tensile strength of at least 25 N / 15 mm, extending from a first surface (1a) to a second surface (1b) opposite the first surface, the wrapper material of the aerosol-generating article wrapper (1) is characterized in that it comprises at least a part of a mark (I) etched into the at least one layer over a defined depth (d) less than the thickness (t) of the wrapper material, from one of the first surface (1a) or the second surface (1b). Aerosol-generating article wrapper (1).

2. The aerosol-generating article wrapper (1) according to claim 1, wherein the defined depth (d) of the etched mark (I) is at least one tenth of the thickness (t) of the layer of the cellulosic material.

3. The aerosol-generating article wrapper (1) according to claim 1, wherein the defined depth of the etched mark (I) is at most two thirds of the thickness (t) of the layer of the cellulosic material.

4. At least one layer of the cellulose-based material has a basis weight of at least 34 g / m ２ of the aerosol-generating article wrapper according to claim 1.

5. The aerosol-generating article wrapper according to claim 1, wherein the at least one layer of the cellulosic material has a porosity of at most 15 CU (cholesteric unit).

6. The aerosol-generating article wrapper according to claim 1, wherein the at least one layer of the cellulosic material further comprises a perforation (16) extending from the first surface (1a) to the second surface (1b) of the at least one layer, and the perforation (16) and the mark (I) are offset from each other by a non-zero distance (g) within at least one layer of the wrapper material (1).

7. A method of manufacturing a wrapper material for an aerosol-generating article wrapper (1) according to any one of claims 1 to 6, comprising: a. providing a laser marking device comprising a laser source (5) having a nominal output of about 20 W to 100 W; b. providing an aerosol-generating article wrapper (1) material, the wrapper material comprising at least one layer of a cellulosic material having a thickness (t) of at least 35 micrometers and a tensile strength of at least 25 N / 15 mm, extending from a first surface (1a) to a second surface (1b) opposite the first surface. c. etching at least a part of the mark (I) in the wrapper material by evaporating the wrapper material over a determined depth (d) less than the thickness (t) of the layer of the cellulose-based material along the indicia vector line using a laser beam (5a); A method comprising. **Claim 8** The method according to claim 7, wherein the laser beam (5a) is directed perpendicular to one of the first surface (1a) or the second surface (1b) of the wrapper material from a laser beam emission point (S), and the distance between the laser beam emission point (S) and the first surface or the second surface of the wrapper material is at least 50 mm. **Claim 9** The method according to claim 7, wherein the determined depth (d) of the mark (I) to be etched is at least one tenth of the thickness (t) of the layer of the cellulose-based material. **Claim 10** The method according to claim 7, wherein the determined depth of the mark (I) to be etched is at most two thirds of the thickness (t) of the cellulose-based material layer. **Claim 11** At least one layer of the cellulose-based material has a basis weight of at least 34 g / m ２ The method according to claim 7, having a basis weight of. **Claim 12** The method according to claim 7, wherein at least one layer of the cellulose-based material has a porosity of at most 15 CU (cholesteric unit). **Claim 13** The wrapper material of the aerosol-generating article wrapper (1) is provided as a continuous web of material wound on a reel, and the method comprises: a. unwinding the continuous web from the reel and circulating the continuous web at a determined linear velocity along a processing direction (F) substantially perpendicular to the direction of the laser beam (5a); b. sequentially etching the mark (I) or a part of the mark (I) in the continuous web of the wrapper material at regular intervals along the length of the continuous web of the wrapper material along the processing direction (F); The method according to claim 7, further comprising. **Claim 14** The method according to claim 13, wherein the laser beam (5a) is moved over the surface of the wrapper material (1) at a linear velocity of at least 5 m / min. **Claim 15** The method according to any one of claims 7 to 14, wherein the at least one mark (I) or a part of the mark (I) is etched in the wrapper material (1) after being wound around a part of the aerosol-generating article (10). **Claim 16** The method according to claim 15, wherein the laser beam (5a) moves on the surface of the wrapper material (1) at a linear speed of at least 50 m / min.

17. An aerosol-generating article (10) comprising the wrapper material (1) according to any one of claims 1 to 6 around at least a part of the aerosol-generating article (10), wherein the etched mark (I) of the wrapper material is arranged on a surface facing the outside of the aerosol-generating article (10). Aerosol-generating article (10).

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