EP4684654A1

EP4684654A1 - Aerosol-generating article wrapper paper processing apparatus with paper fiber opening unit

Info

Publication number: EP4684654A1
Application number: EP24191157.7A
Authority: EP
Inventors: Carlo GIANNETTA
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2024-07-26
Filing date: 2024-07-26
Publication date: 2026-01-28

Abstract

The present invention relates to an apparatus (10) for processing a wrapper paper for an aerosol-generating article. The apparatus (10) comprises a supply unit (12) for supplying a web of paper material (1) along a conveying path (100), a paper fiber opening unit (14) comprising at least one paper fiber opening element (16). The at least one paper fiber opening element (16) is configured to contact a first surface (11) of the web of paper material (1) to alter, in particular to irreversibly alter, the paper fiber structure of the web of paper material (1). The apparatus (10) further comprises an adhesive applicator (24) arranged downstream of the paper fiber opening unit (14) in the conveying path (100). The adhesive applicator (24) is configured to apply adhesive on at least one of the first surface (11) and a second surface (13) of the web of paper material (1) to the first surface (11). The present invention further relates to method for processing a paper wrapper for an aerosol-generating article.

Description

The present disclosure relates to an apparatus for processing a wrapper paper for an aerosol-generating article. The present disclosure further relates to a method for processing a paper wrapper for an aerosol-generating article.
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 substrate without requiring combustion thereof. Such articles are often designated as "heat-not-burn" aerosol-generating articles, since an aerosol-generating substrate 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 substrate.
Most of the aerosol-generating articles already existing in the market have rod shapes, reproducing the shape of standard cigarettes. Aerosol-generating articles may comprise one or more segments having different functional elements to enable the performance of the aerosol-generating article.
It is generally known to wrap the one or more segments of an aerosol-generating article, such as an aerosol-generating substrate, in a wrapper provided with one or more adhesive bands. A wrapper can help to keep the one or more segments of the aerosol-generating article, such as the aerosol-generating substrate, in place. The wrapper can also provide a barrier between the one or more segments of the aerosol-generating article, such as the aerosol-generating substrate, and the user. The wrapper may be made of paper. The paper wrapper is wrapped around the one or more segments of the aerosol-generating article. A layer of adhesive may be applied on a surface of the paper wrapper. Different grammage of wrapper paper may be selected. Grammage is defined as the mass per area of paper measured in grams per square meter. Increasing the grammage of the wrapper paper, e.g. using a thicker wrapper paper, may altered the adhesive strength of a glued section of the paper wrapper.
It would be desirable to be able to improve the adhesive strength of a glued section of the paper wrapper. In particular, it would be desirable to increase the grammage of the wrapper paper for an aerosol-generating article without reducing the adhesive strength of a glued section of the paper wrapper.
According to a first aspect of the present invention, there is provided an apparatus for processing a wrapper paper for an aerosol-generating article. The apparatus comprises a supply unit for supplying a web of paper material along a conveying path. The apparatus comprises a paper fiber opening unit comprising at least one paper fiber opening element. The at least one paper fiber opening element is configured to contact a first surface of the web of paper material to alter, in particular to irreversibly alter, the paper fiber structure of the web of paper material. The apparatus comprises an adhesive applicator. The adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path. The adhesive applicator is configured to apply adhesive on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material.
According to a second aspect of the present invention, there is provided an apparatus for processing a wrapper paper for an aerosol-generating article. The apparatus comprises a supply unit for supplying a web of paper material along a conveying path. The apparatus comprises a paper fiber opening unit comprising at least one paper fiber opening element. The apparatus comprises an adhesive applicator. The apparatus comprises a wrapping unit. The adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path. The at least one paper fiber opening element is configured to contact a first surface of the web of paper material in a first region of the web of paper material to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material. The adhesive applicator is configured to apply adhesive on the first surface of the web of paper material in a second region, the second region being distinct from the first region. The wrapping unit is configured to wrap the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive.
According to a third aspect of the present invention, there is provided an apparatus for processing a wrapper paper for an aerosol-generating article. The apparatus may comprise a supply unit for supplying a web of paper material along a conveying path. The apparatus may comprise a paper fiber opening unit comprising at least one paper fiber opening element. The at least one paper fiber opening element may be configured to contact a first surface of the web of paper material to alter, in particular to irreversibly alter, the paper fiber structure of the web of paper material. In particular, the at least one paper fiber opening element may be configured to contact the first surface of the web of paper material in a first region of the web of paper material to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material. The apparatus may comprise an adhesive applicator. The adhesive applicator may be arranged downstream of the paper fiber opening unit in the conveying path. The adhesive applicator may be configured to apply adhesive on a surface of the web of paper material. The adhesive applicator may be configured to apply adhesive only on one of the surfaces of the web of paper material. The apparatus may comprise a wrapping unit. The wrapping unit may be configured to wrap the web of paper material.
In any aspects of the invention, the altered paper fibers are formed on the surface opposite to the surface where the at least one paper fiber opening element is physically applied. Altering the paper fiber structure of the web of paper material may comprise modifying the cohesion, in particular the inter-cohesion, of the papers fibers of the web of paper material.
Altering the paper fiber structure of the web of paper material may comprise reducing the cohesion, in particular the inter-cohesion, of the papers fibers of the web of paper material at the second surface of the web of paper material. The cohesion in between the altered paper fibers at the second surface may be less than the cohesion in between the paper fibers at the first surface, in particular be reduced by at least 5%, in particular by at least 10%, more in particular by at least 20%. By reducing the cohesion between the paper fibers at the second surface of the web of paper material, a greater area of paper fibres may be configured to be in surface contact with the adhesive. Downstream the paper fiber opening unit, cohesion of the papers fibers at the first surface of the web of paper material may be greater than at the second surface of the web of paper material. Altering the paper fiber structure of the web of paper material may increase the surface area of paper fibers. The area of altered paper fibers on the second surface may be greater than the area of papers fibers on the first surface, in particular be increased by at least 5%, in particular by at least 10%, more in particular by at least 20%. In particular, the roughness, in particular the average mean roughness Ra, of the second surface may be increased by at least 5%, in particular by at least 10%, more in particular by at least 20%. An increased surface area may enable that an increased amount of adhesive may be absorbed in a predetermined time. In particular, the amount of adhesive absorbed by the second surface in the same time, in particular 1 second, as absorbed by the first surface may be increased, preferably by at least 5%, in particular by at least 10%, more in particular by at least 20%. Altering the paper fiber structure of the web of paper material may allow increasing the penetration of the adhesive in the paper material. The at least one paper fiber opening element may be configured to stretch the paper fibers at the second surface of the web of paper material. Downstream of the paper fiber opening element unit, a surface area of the paper fibers at the second surface of the web of paper material may be stretched more than a surface area of the paper fibers at the first surface of the web of paper material. The at least one paper fiber opening element may be configured to generate a stress on the web of paper material. The at least one paper fiber opening element may be configured to separate the paper fibers at the second surface of the web of paper material. The adhesive may be able to enter deeper into the paper fiber structure and create bonds with the paper's fiber. The depth of the adhesive absorbed by the paper fiber structure on the second surface may be increased by at least 5%, in particular by at least 10%, more in particular by at least 20% with respect to the first surface. The at least one paper fiber opening element may be configured to deform plastically the web of paper material. It has the advantage that the web of paper material paper may keep the paper fibers opened for the adhesive application. This may enable that the adhesive applicator is arranged in a greater distance with respect to the paper fiber opening unit.
The apparatus according to any aspects of the invention may further comprise a conveying unit. The conveying unit may be configured to advance the web of paper material from the supply unit. The conveying unit may be configured to advance the web of paper material relatively to the at least one paper fiber opening element at a speed of 200 meters per minutes to 500 meters per minutes, in particular of 240 meters per minutes to 400 meters per minutes. The at least one paper fiber opening element may be configured to apply a load to the web of paper material comprised between 200 grams to 2000 grams, in particular between 300 grams to 500 grams. The speed and the load, respectively, may be selectively adjusted to prevent a curling effect of the web of paper material.
The adhesive applicator according to any aspects of the invention may comprise a nozzle configured to apply an adhesive on a surface of the web of paper material.
In the first aspect of the invention, the adhesive applicator may be configured to apply adhesive directly on the altered paper fiber structure of the web of paper material.
In the second aspect of the invention, the apparatus may be configured such that the adhesive is applied indirectly on the altered paper fiber structure of the web of paper material, by means of the second region of the first surface of the web of paper material.
According to the first aspect of the invention, the adhesive applicator may comprise, alternatively to or in combination with the nozzle, a roller configured to apply an adhesive on the second surface of the web of paper material. The adhesive applicator according to the first aspect of the invention may be configured to apply adhesive only on the second surface of the web of paper material. The adhesive applicator according to the first aspect of the invention may be configured to apply adhesive in the one or more areas of the web of paper material wherein the paper fibers of the web of paper material have been altered, in particular only in this one or more areas.
According to the second aspect of the invention, the adhesive applicator may comprise, alternatively to or in combination with the nozzle, a roller configured to apply an adhesive on the first surface of the web of paper material. The adhesive applicator may be configured to apply adhesive only on the first surface of the web of paper material.
A width, respectively a length, of the first region of the first surface may be the same than a width, respectively a length, of the second region of the first surface. Alternatively, a width, respectively a length, of the first region of the first surface may be greater than a width, respectively a length, of the second region of the first surface. A width may be defined along a direction transversal to the conveying direction. A length may be defined along a direction parallel to the conveying direction.
The first region of the first surface may be 1.1 to 5 times, preferably 1.5 to 3 times, larger than the second region of the first surface. The first region of the first surface may represent less than 90% of the first surface of the web of paper material, in particular less than 70%, more in particular less than 50%, even more in particular less than 30%, preferably less than 20%. The smaller the first region of the first surface is, the less stretch is applied to the paper fibers of the web of paper material on the second surface of the web of paper material. A stretched layer on the second surface of the web of paper material may be localized opposite to the first region of the first surface.
The stretched layer created on the second surface of the web of paper material may allow increasing the efficiency of the adhesion, in particular without having to exert too much pressure on the aerosol-generating article. Allowing exerting less pressure on the aerosol-generating article may advantageously prevent jeopardizing the cross-section shape of the resulting aerosol-generating article, in particular its ovality.
According to the second aspect of the invention, an altered paper fiber structure may be selectively created on a defined region of the second surface of the web of paper material, rather than on the entire second surface of the web of paper material. It may help preventing an unwanted curling effect. It may enable creating an altered paper fiber structure on the second surface of the web of paper material depending on the adhesive interface between the first surface and the second surface. The altered paper fiber structure in the second surface may only serve for adhesion purposes. The fibers of the paper material may be selectively altered in specific regions of the paper web corresponding to the adhesion interface in a wrapped configuration.
The first region of the first surface may be specifically adjusted with respect to the second region of the first surface. The first region may extend longitudinally with respect to the conveying direction. Alternatively, the first region may extend transversally with respect to the conveying direction. The second region may extend longitudinally with respect to the conveying direction. Alternatively, the second region may extend transversally with respect to the conveying direction.
The at least one paper fiber opening element may be configured to contact the first surface of the web of paper material in a plurality of first regions of the web of paper material to create a plurality of altered paper fiber structures on the second surface of the web of paper material. At least one first region of the plurality of first regions may extend transversally with respect to the conveying direction and at least one other first region of the plurality of first regions may extend longitudinally with respect to the conveying direction.
The adhesive applicator may be configured to apply adhesive on the first surface of the web of paper material in a plurality of second regions of the first surface. At least one second region of the plurality of second regions may extend transversally with respect to the conveying direction and at least one other second region of the plurality of second regions may extend longitudinally with respect to the conveying direction. A plurality of second regions may provide a redundancy of adhesion interfaces between the first surface and the second surface. It may allow improving the adherence in a wrapped configuration. In a wrapped configuration, the second region of the first surface may overlap the altered paper fiber structure created on the second surface of the web of paper material.
According to any aspects of the invention, the supply unit may be configured to supply a continuous web of paper material. The supply unit may be configured to supply a substantially flat web of paper material.
According to any aspects of the invention, the at least one paper fiber opening element may be configured to selectively alter the paper fibers of the web of paper material in one or more areas of the web of paper material.
According to any aspects of the invention, a position of the at least one paper fiber opening element with respect the web of paper material may be adjustable. Adjusting the position of the at least one paper fiber opening element with respect the web of paper material may allow adjusting the load applied by the at least one paper fiber opening element on the web of paper material. A position of the at least one paper fiber opening element with respect the web of paper material may be adjustable according to predetermined times so that the at least one paper fiber opening element may only contact the first surface of the web of paper material at predetermined intervals along the conveying path. Adjusting the position of the at least one paper fiber opening element with respect the web of paper material at predetermined intervals may allow creating a pattern of altered paper fibers on the second surface of the web of paper material. The at least one paper fiber opening element may be configured to generate a stretched gradient extending between the first surface and the second surface of the web of paper material.
According to any aspects of the invention, the adhesive applicator may be configured to apply adhesive on a surface of the web of paper material according to predetermined intervals along the conveying path. A position of the at least one paper fiber opening element with respect the web of paper material and a position of the adhesive application with respect the web of paper material may be synchronized with each other.
According to any aspects of the invention, the at least one paper fiber opening element may be a blade element. The blade element may have a blade edge. The blade edge may be preferably arranged substantially transverse to the conveying path of the web of paper material. The blade edge may have a radius of curvature comprised between 0.05 millimeters to 1 millimeter, in particular between 0.1 millimeters to 0.5 millimeters. The blade element may be formed by a triangular prism, a rectangular prism or a rhombic prism. The blade edge may be formed by one edge of the prism.
According to any aspects of the invention, the blade edge may comprise at least two longitudinal portions of different blade sharpness. At least one blade sharpness may be able to alter the paper fiber structure of the web of paper material. Only specific longitudinal portions of the blade edge may have a blade sharpness able to alter the paper fiber structure of the web of paper material. It allows avoiding stressing the whole web of paper material. The blade edge may comprises a central portion defined between two side portions. The two side portions of the blade edge may have respectively the same blade sharpness. The central portion of the blade edge may have a blade sharpness smaller than the blade sharpness of the respective two side portions.
According to any aspects of the invention, the adhesive applicator may be configured to selectively apply adhesive on the surface of the web of paper material according to a respective portion of the blade edge.
According to the first aspect of the invention, the adhesive applicator may be configured to selectively apply adhesive on the second surface of the web of paper material according to a respective portion of the blade edge.
According to the second aspect of the invention, the adhesive applicator may be configured to selectively apply adhesive on the first surface of the web of paper material according to a respective portion of the blade edge.
According to any aspects of the invention, an angle of inclination of the blade edge with respect to the first surface of the web of paper material may be comprised between 0 degree and 60 degrees, in particular between 15 degrees and 45 degrees. An angle of inclination of the blade edge with respect to the first surface of the web of paper material may be adjustable.
According to any aspects of the invention, the at least one paper fiber opening element may be arranged rotatable about a first rotary axis. The first rotary axis may be perpendicular to the conveying path of the web of paper material. The first rotary axis may be parallel to a blade edge of the blade element. The at least one paper fiber opening element may be provided with a plurality of blade edges. The plurality of blade edges may extend longitudinally parallel to each other. The plurality of blade edges may be respectively formed by a plurality of edges of a prism. The blades edges of the plurality of blade edges may have different blade sharpness with respect to one another. The at least one paper fiber opening element may be rotatable with respect to a web of paper material such that one of the plurality of blade edges may contact a surface of the web of paper material according to the rotational position of the at least one paper fiber opening element. A rotation of the least one paper fiber opening element about the first rotary axis may allow selectively applying one blade edge of the plurality of blade edges on a surface of the web of paper material. The at least one paper fiber opening element may be configured to be movable in a rotational position wherein none of the blade edges of the at least one paper fiber opening element are in surface contact with the web of paper material.
According to any aspects of the invention, the at least one paper fiber opening element may be configured to be rotated about the first rotary axis at predetermined times so that the at least one paper fiber opening element may only contact the first surface of the web of paper material at predetermined intervals along the conveying path. The paper fiber opening element may be configured to alter the paper's fiber structure only in areas on which adhesive is foreseen to be applied.
According to any aspects of the invention, the paper fiber opening unit may comprise a mounting plate. The paper fiber opening element may be mounted to the mounting plate. The mounting plate may be rotatable about a second rotary axis. The second rotary axis may be parallel to the first rotary axis and transversal to the conveying path. The rotation of the mounting plate may be synchronized with the speed of the web of paper material along the conveying path. The mounting plate may have a shape of a disk. The second rotary axis of the mounting plate may be aligned with a central axis of the disk. The second rotary axis of the mounting plate may be eccentric with respect to a central axis of the disk.
According to any aspects of the invention, the paper fiber opening unit may comprise an even number of paper fiber opening elements. A same number of paper fiber opening elements may be configured to contact each surface of the web of paper material. The paper fiber opening unit may be configured to apply a symmetrical stress to each surface of the web of paper material. The paper fiber opening unit may be configured to prevent curling of the web of paper material.
According to any aspects of the invention, the paper fiber opening unit may comprise two or more paper fiber opening elements. The two or more paper fiber opening elements may be movable independently from each other. The paper fiber opening unit may comprise a first paper fiber opening element configured to contact the first surface of the web of paper material. The paper fiber opening unit may comprise a second paper fiber opening element arranged downstream to the first paper fiber opening unit with respect to the conveying path. The second paper fiber opening element may be configured to contact the second surface of the web of paper material. The first paper fiber opening element and the second paper fiber opening element may be rotatable about a respective first rotary axis, independently from each other. The first paper fiber opening element and the second paper fiber opening element may be respectively mounted to the mounting plate. The first rotary axis of each blade element, the second rotary axis of the mounting plate and a central axis of the disk forming the mounting plate may be parallel with respect to each other and not aligned with one another. The paper fiber opening elements may be respectively removable from the mounting plate. The paper fiber opening elements may be interchangeable. The first paper fiber opening element may be mounted on a first secondary mounting plate so as to rotate integrally with the first secondary mounting plate about the first rotary axis. The second paper fiber opening element may be mounted on a second secondary mounting plate so as to rotate integrally with the second secondary mounting plate about the first rotary axis. Each of the secondary mounting plates may be rotatably mounted to the mounting plate. Each of secondary mounting plates may be slidably mounted to the mounting plate. Each of the secondary mounting plates may respectively be configured to slide within a respective sliding groove provided in the mounting plate. The mounting plate may comprise only one secondary mounting plate. Two or more paper fiber opening elements may be provided on one secondary mounting plate.
The apparatus according to the first aspect of the invention may further comprise a wrapping unit arranged downstream of the paper fiber opening unit. The wrapping unit according to any aspects of the invention may be configured to wrap the web of paper material into a rod-shape.
The wrapping unit according to any aspects of the invention may be arranged downstream of the adhesive applicator.
The adhesive applicator according to any aspects of the invention may be configured to apply adhesive along a direction parallel to the conveying path of the web of paper material. The adhesive applicator may be configured to apply adhesive along a direction transversal to the conveying path of the web of paper material.
In any aspects of the invention, the paper wrapper may be wrapped around at least a portion of the aerosol-generating article. The paper wrapper may therefore be wrapped around one or more segments or components of the aerosol-generating article, such as one or more of a rod of aerosol-forming substrate, an upstream element, a mouthpiece element, a support element, an aerosol-cooling element, a filter segment, and a cavity. In some embodiments, the paper wrapper is wrapped around only some of the segments of the aerosol-generating article. Preferably, the paper wrapper is wrapped around at least two segments of the aerosol-generating article. Preferably, the paper wrapper is wrapped around the rod of aerosol-forming substrate and at least one other segment of the aerosol-generating article. Preferably, when the wrapper paper is wrapped around at least a portion of the aerosol-generating article, the layer of adhesive on the inner surface of the wrapper paper may circumscribe a plurality of portions or components of the aerosol-generating article. The layer of adhesive may advantageously help to also keep the one or more components of the aerosol-generating article in place. The addition of the layer of adhesive to the wrapper may help the wrapper to more effectively retain the one or more components of the aerosol-generating article and minimise or eliminate any relative motion between the components. The paper wrapper may comprise an outer surface. The outer surface of the paper wrapper may correspond to the first surface of the web of paper material. The paper wrapper may comprise an inner surface. A layer of adhesive may be provided by means of the adhesive applicator on the inner surface of the paper wrapper.
According to the first aspect of the invention, the inner surface of the paper wrapper may correspond to the second surface of the web of paper material.
According to the second aspect of the present invention, the inner surface of the paper wrapper may correspond to the first surface of the web of paper material.
The apparatus according to any aspects of the invention may further comprises a cutting unit. The cutting unit may be arranged between the paper fiber opening unit and the adhesive applicator. The cutting unit may be configured to cut portions of predetermined length of the web of paper material.
The apparatus according to any aspects of the invention may further comprise a heating unit arranged downstream the paper fiber opening unit. The heating unit may be configured to remove a defined amount of moisture from the web of paper material. The heating unit may be configured to expose the paper wrapper to a temperature of at least 35 degrees Celsius. The heating unit may be arranged upstream the adhesive applicator. The heating unit may be arranged downstream the adhesive applicator. A first heating unit may be arranged upstream the adhesive applicator and a second heating unit may be arranged downstream the adhesive applicator.
The apparatus according to any aspects of the invention may further comprise a moisture sensor. The moisture sensor may be arranged upstream of the heating unit.
The apparatus according to any aspects of the invention may comprise a controlling unit. The controlling unit may be configured to control independently the supply unit, the paper fiber opening unit and the adhesive applicator. In particular, the controlling unit may be configured to synchronize the paper fiber opening unit and the adhesive applicator with each other. The controlling unit may be configured to synchronize the contact of the at least one paper fiber opening element on a surface of the web of paper material with the application of adhesive on a surface of the web of paper material. The controlling unit may be configured to control an angle of inclination of the blade edge of the at least one paper fiber opening element with respect to a surface of the web of paper material. The controlling unit may be configured to control a load applied by the at least one paper fiber opening element on a surface of the web of paper material. The controlling unit may be configured to control a speed of the web of paper material with respect to the at least one paper fiber opening element. The controlling unit may be configured to control a rotational position of the at least one paper fiber opening element, in particular about the first rotary axis. The controlling unit may be configured to control a rotational position of the mounting plate, in particular about the second rotary axis. The controlling unit may be configured to synchronize a rotational position of the at least one paper fiber opening element with the speed of the web of paper material with respect to the at least one paper fiber opening element. The controlling unit may be configured to control a plurality of paper fiber opening elements independently from each other.
The supply unit according to any aspects of the present invention may comprise a web of paper material having a grammage equal to or greater than 45 grams per square metre (gsm). The supply unit may comprise a web of paper material having a grammage preferably greater than 47 gsm, more preferably greater than 50 gsm, more preferably greater than 53 gsm, more preferably greater than 55 gsm, more preferably greater than 57 gsm, more preferably greater than 60 gsm, more preferably greater than 63 gsm, more preferably greater than 65 gsm. Increasing the grammage of the wrapper paper may allow reducing the risk of breakage of the aerosol-generating article. An aerosol-generating article may comprise a susceptor and an aerosol-generating substrate. The susceptor may be inductively heatable. The susceptor may comprise metal. A wrapper paper for an aerosol-generating article comprising a susceptor may have a grammage greater than a wrapper paper for an aerosol-generating article free of susceptor. In particular, a wrapper paper for an aerosol-generating article comprising a susceptor may have a grammage greater than a wrapper paper for a conventional cigarette. A wrapper paper for an aerosol-generating article comprising a susceptor may have a grammage preferably comprised between 45 gms and 75 gms. The supply unit may comprise a web of paper material having a grammage less than 300 gms. The supply unit may comprise a web of paper material having a thickness comprised between 50 micrometers and 160 micrometers. According to a fourth aspect of the invention, there is provided a method for processing a paper wrapper for an aerosol-generating article comprising: exerting pressure against a first surface of a web of paper material by means of a paper fiber opening element contacting the first surface of the web of paper material when the web of paper material moves with respect to the paper fiber opening element, and applying adhesive downstream of the paper fiber opening element on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material. The method according to the fourth aspect of the invention may be carried out by means of the apparatus according to the first aspect of the invention.
According to a fifth aspect of the invention, there is provided a method for processing a paper wrapper for an aerosol-generating article comprising: exerting pressure against a first surface of a web of paper material in a first region of the web of paper material by means of a paper fiber opening element contacting the first surface of the web of paper material when the web of paper material moves relative to the paper fiber opening element to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material, and applying adhesive downstream of the paper fiber opening element on the first surface of the web of paper material in a second region, the second region being distinct from the first region, wrapping the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive. The method according to the fifth aspect of the invention may be carried out by means of the apparatus according to the second aspect of the invention.
Each of the methods according to the fourth aspect and the fifth aspect of the invention may comprise exerting pressure against the second surface of a web of paper material, in particular for preventing a curling effect. Each method may comprise contacting the first surface of the web of paper material with the paper fiber opening element at predetermined intervals. Each method may comprise wrapping the web of paper material around a rod element, in particular a continuous rod element, so as to form a wrapped rod element. Each method may comprise cutting the wrapped rod element into portions of predetermined length. The rod element may comprise an aerosol-generating substrate. The rod element may comprise a susceptor. Each method may further comprise supplying a susceptor and wrapping the paper wrapper around the susceptor. Each method may comprise using a wrapper paper having a grammage equal to or greater than 45 grams per square metre (gsm). Using wrapper paper with a grammage equal to or greater than 45 gms, in particular equal to or greater than 60 gsm, may be beneficial for forming an aerosol-generating article comprising a susceptor. It may advantageously improve the robustness of the aerosol-generating article. It may reduce the likelihood that the aerosol-generating article breaks, in particular due to the presence of a susceptor therein.
The present disclosure comprises various aspects, embodiments, and examples. Features, advantages, and explanations disclosed with reference to any one of these aspects, embodiments, and examples may be combined with, or transferred to, any other one of the aspects, embodiments, and examples described herein. Any one of the methods or uses described herein may be carried out using any one of the devices or systems described herein. Any one of the devices or systems described herein may be adapted, designed or configured to carry out any one of the methods or uses described herein.
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.
Example Ex1: An apparatus for processing a wrapper paper for an aerosol-generating article, the apparatus comprising: a supply unit for supplying a web of paper material along a conveying path; a paper fiber opening unit comprising at least one paper fiber opening element; and an adhesive applicator; wherein the at least one paper fiber opening element is configured to contact a first surface of the web of paper material to alter the paper fiber structure of the web of paper material, wherein the adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path, and wherein the adhesive applicator is configured to apply adhesive on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material.
Example Ex2: An apparatus for processing a wrapper paper for an aerosol-generating article, the apparatus comprising: a supply unit for supplying a web of paper material along a conveying path; a paper fiber opening unit comprising at least one paper fiber opening element; an adhesive applicator; and a wrapping unit; wherein the adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path, wherein the at least one paper fiber opening element is configured to contact a first surface of the web of paper material in a first region of the web of paper material to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material, and the adhesive applicator is configured to apply adhesive on the first surface of the web of paper material in a second region, the second region being distinct from the first region, and the wrapping unit is configured to wrap the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive.
Example Ex3: The apparatus according to Ex1 or Ex2, wherein altering the paper fiber structure of the web of paper material comprises modifying the cohesion, in particular the inter-cohesion, of the papers fibers of the web of paper material.
Example Ex4: The apparatus according to any one of the preceding examples, wherein the at least one paper fiber opening element is configured to deform plastically the web of paper material.
Example Ex5: The apparatus according to any one of the preceding examples, further comprising a conveying unit configured to advance the web of paper material from the supply unit.
Example Ex6: The apparatus according to Ex5, wherein the conveying unit is configured to advance the web of paper material relatively to the at least one paper fiber opening element at a speed of 200 meters per minutes to 500 meters per minutes, in particular of 240 meters per minutes to 400 meters per minutes.
Example Ex7: The apparatus according to any one of the preceding examples, wherein the at least one paper fiber opening element is configured to apply a load to the web of paper material comprised between 200 grams to 2000 grams, in particular between 300 grams to 500 grams.
Example Ex8: The apparatus according to any one of the preceding examples, wherein the adhesive applicator comprises a nozzle configured to apply an adhesive towards at least one of the surfaces of the web of paper material.
Example Ex9: The apparatus according to any one of the preceding examples, wherein the adhesive applicator comprises a roller configured to apply an adhesive on at least one of the surface of the web of paper material.
Example Ex10: The apparatus according to any one of the preceding examples, wherein a position of the at least one paper fiber opening element with respect the web of paper material is adjustable.
Example Ex11: The apparatus according to Ex10, wherein the position of the at least one paper fiber opening element with respect the web of paper material is adjustable according to predetermined times so that the at least one paper fiber opening element only contacts the first surface of the web of paper material at predetermined intervals along the conveying path.
Example Ex12: The apparatus according to Ex11, wherein the adhesive applicator is configured to apply adhesive on at least one of the surface of the web of paper material according to the predetermined intervals along the conveying path.
Example Ex13: The apparatus according to any one of the preceding examples, wherein the at least one paper fiber opening element is a blade element, having a blade edge, which is preferably arranged substantially transverse to the conveying path of the web of paper material.
Example Ex14: The apparatus according to Ex13, wherein the blade edge has a radius of curvature comprised between 0.05 millimeter to 1 millimeter, in particular between 0.1 millimeter to 0.5 millimeter.
Example Ex15: The apparatus according to Ex14, wherein the blade element is formed by a triangular prism, a rectangular prism or a rhombic prism.
Example Ex16: The apparatus according to Ex15, wherein the blade edge is formed by one edge of the prism.
Example Ex17: The apparatus according to Ex13, wherein the blade edge comprises at least two longitudinal portions of different blade sharpness.
Example Ex18: The apparatus according to Ex17, wherein the blade edge comprises a central portion defined between two side portions, the two side portions having respectively the same blade sharpness, and the central portion having a blade sharpness smaller than the blade sharpness of the respective two side portions.
Example Ex19: The apparatus according to Ex17 or Ex18, wherein the adhesive applicator is configured to selectively apply adhesive on the surface of the web of paper material according to a respective portion of the blade edge.
Example Ex20: The apparatus according to any one of Ex13 to Ex19, wherein an angle of inclination of the blade edge with respect to the first surface of the web of paper material is comprised between 0 degree and 60 degrees, in particular between 15 degrees and 45 degrees.
Example Ex21: The apparatus according to any one of Ex13 to Ex20, wherein an angle of inclination of the blade edge with respect to the first surface of the web of paper material is adjustable.
Example Ex22: The apparatus according to any of the preceding examples, wherein the at least one paper fiber opening element is arranged rotatable about a first rotary axis, and the first rotary axis is perpendicular to the conveying path of the web of paper material.
Example Ex23: The apparatus according to Ex22, wherein the first rotary axis is parallel to a blade edge of the blade element.
Example Ex24: The apparatus according to Ex22 or Ex23, wherein the at least one paper fiber opening element is configured to be rotated about the first rotary axis at predetermined times so that the at least one paper fiber opening element only contacts the first surface of the web of paper material at predetermined intervals along the conveying path.
Example Ex25: The apparatus according to Ex24, wherein the paper fiber opening unit further comprises a mounting plate, the paper fiber opening element is mounted to the mounting plate and the mounting plate is rotatable about a second rotary axis, the second rotary axis being parallel to the first rotary axis and transversal to the conveying path.
Example Ex26: The apparatus according to Ex25, wherein the rotation of the mounting plate is synchronized with the speed of the web of paper material along the conveying path.
Example Ex27: The apparatus according to Ex25 or Ex26, wherein the mounting plate has a shape of a disk.
Example Ex28: The apparatus according to Ex27, wherein the second rotary axis of the mounting plate is aligned with a central axis of the disk.
Example Ex29: The apparatus according to Ex27, wherein the second rotary axis of the mounting plate is eccentric with respect to a central axis of the disk.
Example Ex30: The apparatus according to any of the preceding examples, wherein the paper fiber opening unit comprises an even number of paper fiber opening elements and a same number of paper fiber opening elements is configured to contact each surface of the web of paper material.
Example Ex31: The apparatus according to Ex30, wherein the paper fiber opening unit is configured to apply a symmetrical stress to each surface of the web of paper material.
Example Ex32: The apparatus according to any of the preceding examples, wherein the paper fiber opening unit comprises two paper fiber opening elements.
Example Ex33: The apparatus according to Ex32, wherein the paper fiber opening unit comprises a first paper fiber opening element configured to contact the first surface of the web of paper material, and a second paper fiber opening element is arranged downstream to the first paper fiber opening unit with respect to the conveying path and is configured to contact the second surface of the web of paper material.
Example Ex34: The apparatus according to any of the preceding examples, wherein the paper fiber opening unit comprises two paper fiber opening elements and the two paper fiber opening elements are movable independently from each other.
Example Ex35: The apparatus according to Ex34, wherein the first paper fiber opening element and the second paper fiber opening element are rotatable about a respective first rotary axis, independently from each other.
Example Ex36: The apparatus according to Ex34 or Ex35, wherein the first paper fiber opening element and the second paper fiber opening element are respectively mounted to the mounting plate.
Example Ex37: The apparatus according to Ex22, Ex25 and Ex27, wherein the first rotary axis of each blade element, the second rotary axis of the mounting plate and a central axis of the disk forming the mounting plate are parallel with respect to each other and not aligned with one another.
Example Ex38: The apparatus according to Ex1, further comprising a wrapping unit arranged downstream of the paper fiber opening unit.
Example Ex39: The apparatus according to Ex2 or Ex38, wherein the wrapping unit is configured to wrap the web of paper material into a rod-shape.
Example Ex40: The apparatus according to any of the preceding examples, wherein the adhesive applicator is configured to apply adhesive along a direction parallel to the conveying path of the web of paper material.
Example Ex41: The apparatus according to any of one of Ex1 to Ex39, wherein the adhesive applicator is configured to apply adhesive along a direction transversal to the conveying path of the web of paper material.
Example Ex42: The apparatus according to any of the preceding examples, further comprising a cutting unit arranged between the paper fiber opening unit and the adhesive applicator, the cutting unit being configured to cut portions of predetermined length of the web of paper material.
Example Ex43: The apparatus according to any of the preceding examples, further comprising a heating unit arranged downstream the paper fiber opening unit and configured to remove a defined amount of moisture from the web of paper material.
Example Ex44: The apparatus according to Ex43, wherein the heating unit is configured to expose the paper wrapper to a temperature of at least 35 degrees Celsius.
Example Ex45: The apparatus according to Ex43 or Ex44, wherein the heating unit is arranged upstream the adhesive applicator.
Example Ex46: The apparatus according to Ex43 or Ex44, wherein the heating unit is arranged downstream the adhesive applicator.
Example Ex47: The apparatus according to Ex43 or Ex44, wherein a first heating unit is arranged upstream the adhesive applicator and a second heating unit is arranged downstream the adhesive applicator.
Example Ex48: The apparatus according to any one of Ex43 to Ex47, further comprising a moisture sensor arranged upstream the heating unit.
Example Ex49: The apparatus according to any of the preceding examples, wherein the supply unit comprises a web of paper material having a grammage equal to or greater than 45 grams per square metre (gsm), preferably greater than 47 gsm, more preferably greater than 50 gsm, more preferably greater than 53 gsm, more preferably greater than 55 gsm, more preferably greater than 57 gsm, more preferably greater than 60 gsm, more preferably greater than 63 gsm, more preferably greater than 65 gsm.
Example Ex50: The apparatus according to any of the preceding examples, wherein the supply unit comprises a web of paper material having a grammage less than 300 grams per square metre (gsm).
Example Ex51: The apparatus according to any of the preceding examples, wherein the supply unit comprises a web of paper material having a thickness comprised between 50 micrometers and 160 micrometers.
Example Ex52: A method for processing a paper wrapper for an aerosol-generating article comprising: exerting pressure against a first surface of a web of paper material by means of a paper fiber opening element contacting the first surface of the web of paper material when the web of paper material moves with respect to the paper fiber opening element, and applying adhesive downstream of the paper fiber opening element on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material.
Example Ex53: A method for processing a paper wrapper for an aerosol-generating article comprising: exerting pressure against a first surface of a web of paper material in a first region of the web of paper material by means of a paper fiber opening element contacting the first surface of the web of paper material when the web of paper material moves relative to the paper fiber opening element to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material, and applying adhesive downstream of the paper fiber opening element on the first surface of the web of paper material in a second region, the second region being distinct from the first region, wrapping the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive.
Example Ex54: The method according to Ex52 or Ex53, comprising supplying a susceptor before wrapping the web of material so as to wrap the web of paper material around the susceptor.
Examples will now be further described with reference to the Figures.

Figure 1 shows a schematic representation of an apparatus for processing a wrapper paper for an aerosol-generating article according to a first embodiment of the present invention.
Figure 2 shows an enlarged schematic representation of the wrapper paper at the paper fiber opening unit of the apparatus illustrated in Figure 1.
Figure 3 shows a schematic representation of a paper fiber opening element according to a second embodiment of the present invention.
Figure 4 shows a schematic representation of the second surface of a web of paper material downstream the paper fiber opening element of Figure 3.
Figure 5 shows a schematic representation of a paper fiber opening unit according to a third embodiment of the present invention.
Figure 6 shows a schematic representation of the paper fiber opening unit according to the third embodiment of the present invention in a first position.
Figure 7 shows a schematic representation of the paper fiber opening unit according to the third embodiment of the present invention in a second position.
Figure 8 shows a schematic representation of the paper fiber opening unit according to the third embodiment of the present invention in a third position.
Figure 9 shows a schematic representation of the first surface of the web of paper material downstream of the paper fiber opening unit of Figure 8.
Figure 10 shows a schematic representation of an example of a rectangular wrapper paper with at least one transversal glue line.
Figure 11 shows a schematic representation of a web of paper material for wrapping a continuous rod.
Figure 12 shows a schematic representation of a paper fiber opening element according to one embodiment.
Figure 13 shows a schematic representation of a paper fiber opening element according to another embodiment.
Figure 14 shows a schematic representation of the wrapper paper at the paper according to another embodiment.

Figure 1 shows schematic representation of an apparatus 10 for processing a web of paper material 1 for an aerosol-generating article according to a first embodiment of the present invention. The apparatus 10 comprises a supply unit 12 for supplying the web of paper material 1 along a conveying path 100. The supply unit 12 may be a supply roll. The apparatus 10 comprises a paper fiber opening unit 14. The paper fiber opening unit 14 comprises a paper fiber opening element 16. In the first embodiment represented in Figure 1, the paper fiber opening element 16 has a square shape in a cross-section defined transversally to the conveying path 100 of the web of paper material 1. The paper fiber opening element 16 provides a blade element in that two adjacent edges 18, 20 of the paper fiber opening element 16 forms a blade edge 22. The blade edge 22 is arranged substantially transversally to the conveying path 100. The blade edge 22 of the paper fiber opening element 16 is configured to contact a first surface 11 of the web of paper material 1 to alter the paper fiber structure of the web of paper material 1. The first surface 11 of the web of paper material 1 is opposite to a second surface 13 of the web of paper material 1. Upstream of the blade edge 22 with respect to the conveying path 100, an angle 200 is formed between the web of paper material 1 and the edge 18 of the paper fiber opening element 16. Downstream of the blade edge 22, an angle 202 is formed between the web of paper material 1 and the edge 20 of the paper fiber opening element 16. The angle 200 may be comprised 0 degree and 60 degrees, in particular between 15 degrees and 45 degrees. The angle 202 may be substantially equal to the angle 200.
The apparatus 10 further comprises an adhesive applicator 24. The adhesive applicator 24 is arranged downstream of the paper fiber opening unit 14 in the conveying path 100. In the first embodiment represented in Figure 1, the adhesive applicator 24 is provided with a nozzle 26 for applying adhesive.
According to the first aspect of the invention, the adhesive applicator 24 is configured to apply adhesive, in particular by means of the nozzle 26, on the second surface 13 of the web of paper material 1.
According to the second aspect of the invention, not represented by Figure 1, the adhesive applicator 24 is configured to apply adhesive, in particular by means of the nozzle 26, on the first surface 13 of the web of paper material 1.
The apparatus 10 further comprises a roller 28 arranged between the supply unit 12 and the paper fiber opening unit 14 for conveying the web of paper material 1 along the conveying path 100. The apparatus 10 also comprises a roller 30 arranged between the paper fiber opening unit 14 and the adhesive applicator 24 for conveying the web of paper material 1 along the conveying path 100. The apparatus 10 may comprise further rollers (not represented) for conveying the web of paper material 1 along the conveying path 100.
The apparatus 10 may comprise a cutting unit (not represented) arranged between the paper fiber opening unit 14 and the adhesive applicator 24.
Figure 2 shows an enlarged schematic representation of the web of paper material 1 at the paper fiber opening unit 14 of the apparatus 10 illustrated in Figure 1. Features with the same numerical references already used for the description of the Figure 1 will not be described again in detail, and reference is made to their descriptions above.
The web of paper material 1 has a thickness 300 defined between the first surface 11 and the second surface 13. The web of paper material 1 contains paper fibers 32. The blade edge 22 is configured to apply a pressure on the web of paper material 1, which is advancing along the conveying path 100 with respect to the paper fiber opening unit 14. The blade edge 22 is configured to create a stress in the web of paper material 1, in particular mainly due to the stretching of the paper fibers 32 at the second surface 13, as schematized in Figure 2 by the stretched layer 34 of thickness 302. The thickness 302 of the stretched layer 34 may be preferably smaller than the thickness 300 of the web of paper material 1. In the stretched layer 34, the paper fiber 32 structure of the web of paper material 1 may be irreversibly altered. In the stretched layer 34, the paper fibers 32 may be more opened (i.e. having less inter-cohesion) than in the rest of the thickness 300 of the web of paper material 1. Applying the adhesive by means of the adhesive applicator 24 on the second surface 13 in the stretched layer 34 helps the adhesive to better penetrate in the paper material 1, thereby improving the adherence of the adhesive to the paper fibers.
Four main parameters may impact the stress created in the web of paper material 1: the sharpness of the blade edge 22, the load that the paper fiber opening unit 16 applies on the web of paper material 1, the relative speed of the web of paper material 1 with respect to the blade edge 22, and the angles 200 and 202.
Thereafter, features in Figures 3 to 14 having the same numerical references already used for the description of the Figures 1 and 2 will not be described again in detail, and reference is made to their descriptions above.
Figure 3 shows a schematic representation of a blade edge 38 according to a second embodiment of the present invention. The blade edge 38 comprises a plurality of longitudinal portions 40, 42, 44 of different blade sharpness. The blade edge 38 comprises a central portion 40 of length 304 defined between two side portions 42, 44.
In the example of Figure 3, the two side portions 42, 44 of the blade edge 38 have respectively the same blade sharpness. The two side portions 42, 44 of the blade edge 38 have respectively a same length 306. In the example of Figure 3, the lengths 306 are respectively smaller than the length 304. The central portion 40 of the blade edge 38 have a blade sharpness smaller than the blade sharpness of the respective two side portions 42, 44. In the embodiment shown by Figure 3, only the two side portions 42, 44 of the blade edge 38 have a blade sharpness configured for altering the paper fiber structure of the web of paper material.
At the central portion 40, the blade edge 38 has a substantially rounded edge, in contrast to the sharper edges of the side portions 42, 44, for avoiding applying stress to the web of paper material.
Figure 4 shows a schematic representation of the second surface 13 of a web of paper material 1 downstream of a paper fiber opening unit provided with the blade edge 38 according to Figure 3. As a result of the structure of the blade edge 38 (see Figure 3), the second surface 13 of the web of paper material 1 comprises a central band 46 of width 304 and two side bands 48, 50 having a respective width 306. The widths in Figure 4 are respectively defined transversal to the conveying path 100.
The paper fibers in the side bands 48, 50 are more stretched than the paper fibers in the central band 46. Adhesive may thus adhere better in the side bands 48, 50 than in the central band 46. The adhesive applicator may be configured to apply adhesive only on the side bands 48, 50 of the second surface 13 of the web of paper material 1.
Figure 5 shows a schematic representation of a paper fiber opening unit 52 according to a third embodiment of the present invention. The paper fiber opening unit 52 comprises a mounting plate 54. In the third embodiment, the mounting plate 54 have a shape of a disk. The mounting plate 54 is rotatable around a rotary axis 102. In the third embodiment, the rotary axis 102 is eccentric with respect to a central transversal axis 104 of the disk-shape mounting plate 54.
In another embodiment according to the present invention and not represented, the rotary axis 102 may be aligned with the central transversal axis 104 of the disk-shape mounting plate 54.
The mounting plate 54 is provided with two secondary rotating plates 56, 58. In the third embodiment, the two secondary rotating plates 56, 58 have respectively a shape of a disk. Each secondary rotating plate 56, 58 can rotate independently around their respective central transversal axis 106, 108. The secondary rotating plate 56 is rotatable about the central transversal and rotary axis 106. The secondary rotating plate 58 is rotatable about the central transversal and rotary axis 108.
A first paper fiber opening element 60 is attached to the secondary rotating plate 56 so as to rotate integrally with the secondary rotating plate 56. A second paper fiber opening element 62 is attached to the rotating secondary plate 58 so as to rotate integrally with the secondary rotating plate 58. The first and second paper fiber opening element 60, 62 may be attached to the respective secondary plate 56, 58 by means of a clamping element (not represented). The first paper fiber opening element 60 and the second paper fiber opening element 62 are rotatable about the respective rotary axis 106, 108 independently from each other. The above-mentioned axis 102, 104, 106 and 108 are parallel with each other. The above-mentioned axis 102, 104, 106 and 108 are respectively transversal to a conveying path of the web of paper material (not represented) with respect to the paper fiber opening unit 52.
In the third embodiment, each of the paper fiber opening element 60, 62 have a respective blade element 64, 66 formed by a rhombic prism. Each blade element 64, 66 provides four blade edges that may contact a web of paper material. The blade element 64 of the first paper fiber opening element 60 comprises four blade edges 68, 70, 72, 74. The blade element 66 of the first paper fiber opening element 62 comprises four blade edges 76, 78, 80, 82. The blade edges 68, 70, 72, 74, 76, 78, 80, 82 respectively extends longitudinally parallel to the axis 102, 104, 106 and 108. The inclination of each blade edge 68, 70, 72, 74, 76, 78, 80, 82 with respect to a web of paper material may be adjusted by rotating one or more of the mounting plate 54, the secondary rotating plate 56 and the secondary rotating plate 58, as further explained thereafter in reference to the Figures 6 to 8. Thereby, some parameters of the stress applied to the web of paper material, like the load or the inclination angle of the blade edge with respect to the paper, may be adjusted while keeping constant other parameters, like the sharpness of the blade edge and the speed of the web of material paper.
Figure 6 shows a schematic representation of the paper fiber opening unit 52 according to the third embodiment of the present invention in a first position.
The web of paper material 1 is arranged to be advanced along the conveying path 11 by means of the rollers 28, 30. The rotation of the mounting plate 54 may be synchronized with the speed of the web of paper material 1 along the conveying path 100. The first paper fiber opening element 60 is positioned upstream of the second paper fiber opening element 62 with respect to the conveying path 11. In the first position shown in Figure 6, the secondary rotating plate 56 is positioned such that the blade edge 72 of the first paper fiber opening element 60 is in surface contact with the first surface 11 of the web of paper material 1.
In the first position shown in Figure 6, the secondary rotating plate 58 is positioned such that the blade edge 76 of the second paper fiber opening element 62 is in surface contact with the second surface 13 of the web of paper material 1. The two paper fiber opening elements 60, 62 may be positioned with respect to one another so as to balance the stress applied on both surfaces 11, 13 of the web of paper material 1.
The paper fiber opening unit 52 according to the third embodiment of the present invention may be be configured to apply a symmetrical stress to each surface 11, 13 of the web of paper material 1. In particular, the paper fiber opening unit 52 may be configured to prevent curling of the web of paper material 1.
In the first position illustrated by Figure 6, a stretched layer, like the stretched layer 34 shown in Figure 2, may be created on each surfaces 11, 13 of the web of paper material 1. Hence, in an embodiment wherein the paper fiber opening unit 52 is in this first position, adhesive may be applied on either one of the surfaces 11, 13 of the web of paper material 1 because both surfaces 11, 13 exhibit a stretched layer.
Figure 7 shows a schematic representation of the paper fiber opening unit 52 according to the third embodiment of the present invention in a second position.
With respect to the first position shown in Figure 6, in the second position the mounting plate 54 has been rotated counter-clockwise around the rotary axis 102.
The secondary rotating plate 56 has been rotated clockwise around the rotary axis 104. Hence, the first paper fiber opening element 60 has also been rotated clockwise around the rotary axis 104. As a result of the rotation of the first paper fiber opening element 60, the blade edge 72 is not in contact anymore with the first surface 11 of the web of paper material 1, like in Figure 6. In the second position shown by Figure 7, it is the blade edge 70 of the first paper fiber opening element 60 that is in surface contact with the first surface 11 of the web of paper material 1.
The secondary rotating plate 58 has been rotated counter-clockwise around the rotary axis 106. Hence, the second paper fiber opening element 62 has also been rotated counter-clockwise around the rotary axis 106. As a result of the rotation of the second paper fiber opening element 62, the blade edge 76 is not in contact anymore with the second surface 13 of the web of paper material 1, like in Figure 6. In the second position shown by Figure 7, it is the blade edge 78 of the second paper fiber opening element 62 that is in surface contact with the second surface 13 of the web of paper material 1.
The stress applied on the web of paper material 1 is greater in the second position illustrated by Figure 7 than in the first position shown by Figure 6.
Figure 8 shows a schematic representation of the paper fiber opening unit 52 according to the third embodiment of the present invention in a third position.
In the third position, the secondary rotating plate 58 has been rotated so that none of the blade edges 76, 78, 80, 82 are in surface contact with the web of paper material 1.
In the third position, the secondary rotating plate 56 and the web of paper material 1 have been respectively positioned such that the blade edge 74 of the first paper fiber opening element 60 is in surface contact with the second surface 13 of the web of paper material 1. In the third position, downstream of the blade edge 74, it is thus the paper's fiber on the first surface 11 of the web of paper material 1 that are been stretched. Indeed, as previously explained, the overstretching of the paper fibers induced by the pressure of the blade edge on one side of the paper material opens the paper fibers on the opposite side of the paper material. In the case of the third position, the adhesive applicator may thus be configured to apply adhesive on the first surface 11 of the web of paper material 1.
In a variant of the third embodiment, the paper fiber opening unit 52 may be configured to move periodically the paper fiber opening element 60 in the third position, i.e. in surface contact with the web of paper material 1. The paper fiber opening unit 52 may be configured to rotate the paper fiber opening element 60, in particular by means of the secondary rotating plate 56, at predetermined times so that the paper fiber opening element 60 may only contact the second surface 13 of the web of paper material 1 at predetermined intervals along the conveying path 100.
As shown in Figure 9 , which represents schematically the first surface 11 of the web of paper material 1 downstream of the paper fiber opening unit 52 of Figure 8, it allows creating an intermittent stress on the web of paper material 1. As a result, the paper fibers are only stretched in the transversal areas 84. Two successive transversal stretched areas 84 are separated by an unstretched, or less stretched, area 86. The transversal areas 84 are the areas where the adhesive shall be applied. The transversal areas 84, 86 are defined along the transversal direction 101 shown in Figure 9. The transversal direction 101 is transversal to the conveying path 100.
Figure 10 shows a schematic representation of a rectangular wrapper paper 88. The rectangular wrapper paper 88 has been formed by cutting the web of paper material 1 by means of a cutting unit (not represented). The cutting unit may be configured to cut portions of predetermined length of the web of paper material, thereby forming successive rectangular wrapper papers 88. The cutting unit may be arranged between the paper fiber opening unit and the adhesive applicator.
As can be seen in Figure 10, a transversal glue line 90 has been applied on a surface 92 of the wrapper paper 88. The surface opposite to the surface 92 is not visible in the top view of Figure 10. The surface opposite to the surface 92 has been contacted at predetermined times by a paper fiber opening element, like described in relation to Figure 8 and Figure 9, thereby creating transversal stretched areas in the surface 92. The transversal glue line 90 has been applied on the surface 92, in particular on a transversal stretched area. Further glue lines may be provided on the surface 92 of the wrapper paper 88.
In the example of Figure 10, the two longitudinal glue lines 94, 96 extends perpendicularly to the transversal glue line 90. The transversal direction is shown by the arrow 101 in Figure 9. The two longitudinal glue lines 94, 96 are parallel with one another. The longitudinal glue lines 94, 96 are positioned with respect to the surface 92 of the wrapper paper 88 so that the glue line 94 may help securing the wrapper paper 88 to a first rod element 98. The glue line 96 may help securing the wrapper paper 88 to a second rod element 108. The transversal glue line 90 allows closing the wrapper paper 88 in a rod shape after the first rod element 98 and the second rod element 108 have been rolled in the wrapper paper 88, as schematized by the arrow of Figure 10. The first rod element 98 may comprise an aerosol-generating substrate 110 and a susceptor (not represented).
Figure 11 shows a schematic representation of the application of adhesive on a web of paper material 1 for wrapping a continuous rod 3. The adhesive is applied by means of a nozzle 112 of an adhesive applicator 114. Upstream of the adhesive applicator 114, the web of paper material 1 is partially curved around the continuous rod 3. The adhesive is applied as a glue band 116 on a stretched band 118 on the second surface 13 of the continuous web of paper material 1.
The second surface 13 of the web of paper material 1 thus corresponds to an inner side and faces directly the continuous rod 3. The first surface 11, opposite to the second surface 13, corresponds to an outer side. The stretched band 118 on the first surface 11 has been created by contacting a paper fiber opening element (not represented) on the second surface 13, as previously explained with respect to Figure 1 and Figure 2 for instance.
Downstream of the adhesive applicator 114 along the conveying path 100, the continuous web of paper material 1 is progressively enclosed around the continuous rod 3 by means of a wrapping unit 120. The glue band 116 is pressed against the second surface 13. The resulting continuous wrapped rod 122 may then be cut in a plurality of rods of predetermined lengths by means of a cutting unit (not represented). The continuous wrapped rod 122 may comprise an aerosol-generating substrate 124 and a susceptor (not represented).
Figure 12 shows a schematic representation of a paper fiber opening element according to one embodiment. The paper fiber opening element of Figure 12 comprises two rollers 400, 402. Each roller 400, 402 comprises a portion 404, 406 provided with an abrasive surface 408, 410. The rollers 400, 402 are arranged with respect to one another such that the respective abrasive surfaces 408, 410 do not face one another. The respective abrasive surfaces 408, 410 only respectively contact a portion 412, 414 of the web of paper material 1. It allows creating two longitudinal portions 412, 414 wherein the paper fiber structure of the web of paper material 1 is altered. Downstream of the paper fiber opening element of Figure 12, adhesive may be advantageously provided on the longitudinal portions 412, 414, in particular only on the longitudinal portions 412, 414. Preferably, the adhesive is applied on the surface of the longitudinal portion 412 that has been in surface contact with the abrasive surface 408. Respectively, the adhesive is preferably applied on the surface of the longitudinal portion 414 that has been in surface contact with the abrasive surface 410.
Figure 13 shows a schematic representation of a paper fiber opening element according to another embodiment. The paper fiber opening element of Figure 13 comprises two rollers 500, 502. The roller 500 is provided with a series of radially extending pins 504. The roller 502 is provided with a substantially flat surface 506. By advancing the web of paper material 1 through the rollers 500, 502, the roller 500 creates a sequence of holes 508 in the web of paper material 1. Downstream of the paper fiber opening element of Figure 13, adhesive may be advantageously provided at the sequence of holes 508.
Figure 14 shows a schematic representation of a web of paper material 1 partially wrapped around an aerosol-generating substrate or rod element 110, according to the second aspect of the invention.
As described in relation to Figure 2, the web of paper material 1 has a thickness 300 defined between the first surface 11 and the second surface 13. The web of paper material 1 contains paper fibers 32. The web of paper material 1 comprises a stretched layer 34 of thickness 302. The stretched layer 34 defines an altered paper fiber structure (shown by the reference sign 34) on the second surface 13 of the web of paper material 1. The stretched layer 34 is formed by the application of pressure against the first surface 11 of the web of paper material 1 in a first region 340 of the web of paper material 1. The pressure may be applied by means of a paper fiber opening element contacting the first surface 11 of the web of paper material 1 when the web of paper material 1 moves relative to the paper fiber opening element, as explained in reference to the previous embodiments and to which reference is made. The first region 340 of the first surface 11 is opposite to the stretched layer 34 of the second surface 13 with respect to the thickness 300 of the web of paper material 1. The size of the stretched layer 34 is defined by the size and shape of the first region 340 of the first surface 11.
According to the second aspect of the invention, adhesive 341 is applied on the first surface 11 of the web of paper material 1 in a second region 342. The second region 342 of the first surface 11 is distinct from the first region 340 of the first surface 11. Adhesive 341 may further be applied on the first surface 11 of the web of paper material 1 in a third region 343, the third region 343 being distinct from the second region 342. The third region 343 enables attaching, in particular directly, the first surface 11 of the web of paper material 1 to the aerosol-generating substrate or rod element 110. In this embodiment, the first surface 11 of the web of paper material 1 defines the inner surface of the web of paper material 1. The second surface 13 of the web of paper material 1 defines the outer surface of the web of paper material 1. The second region 342 allows attaching the first surface 11 of the web of paper material 1 to the second surface 13 of the web of paper material 1 at the stretched layer 34, i.e. wherein the paper fiber structure is altered. The stretched layer 34 is localized towards a first edge 344 of the web of paper material 1. The first edge 344 is geometrically opposite to a second edge 345 of the web of paper material 1. The second region 342 is localized towards the second edge 345 of the web of paper material 1.
When the web of paper material 1 is wrapped, the stretched layer 34 of the second surface 13 is attached to the second region 342 of the first surface 11 by means of the adhesive 341. Preferably, the first region 340 is greater than the second region 342 so that the adhesive 341 is able to be spread in the stretched layer 34 upon overlapping and pressing the first surface 11 on the second surface 13. The stretched layer 34 created on the second surface 13 may allow increasing the efficiency of the adhesion without having to exert too much pressure on the aerosol-generating substrate or rod element 110, which could otherwise jeopardize the cross-section shape of the resulting aerosol-generating article, in particular its ovality.
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.

Claims

An apparatus for processing a wrapper paper for an aerosol-generating article, the apparatus comprising:
a supply unit for supplying a web of paper material along a conveying path;

a paper fiber opening unit comprising at least one paper fiber opening element; and

an adhesive applicator;

wherein the at least one paper fiber opening element is configured to contact a first surface of the web of paper material to alter the paper fiber structure of the web of paper material,

wherein the adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path, and

wherein the adhesive applicator is configured to apply adhesive on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material.
An apparatus for processing a wrapper paper for an aerosol-generating article, the apparatus comprising:
a supply unit for supplying a web of paper material along a conveying path;

a paper fiber opening unit comprising at least one paper fiber opening element;

an adhesive applicator; and

a wrapping unit;

wherein the adhesive applicator is arranged downstream of the paper fiber opening unit in the conveying path,

wherein the at least one paper fiber opening element is configured to contact a first surface of the web of paper material in a first region of the web of paper material to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material, and

the adhesive applicator is configured to apply adhesive on the first surface of the web of paper material in a second region, the second region being distinct from the first region, and

the wrapping unit is configured to wrap the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive.
The apparatus according to claim 1 or 2, wherein a position of the at least one paper fiber opening element with respect the web of paper material is adjustable.
The apparatus according to any of claims 1 to 3, wherein the at least one paper fiber opening element is a blade element, having a blade edge, which is preferably arranged substantially transverse to the conveying path of the web of paper material.
The apparatus according to claim 4, wherein the blade edge comprises at least two longitudinal portions of different blade sharpness.
The apparatus according to claim 5, wherein the adhesive applicator is configured to selectively apply adhesive on the surface of the web of paper material according to a respective portion of the blade edge.
The apparatus according to any of claims 4 to 6, wherein an angle of inclination of the blade edge with respect to the first surface of the web of paper material is comprised between 0 degree and 60 degrees, in particular between 15 degrees and 45 degrees.
The apparatus according to any of claims 4 to 7, wherein an angle of inclination of the blade edge with respect to the first surface of the web of paper material is adjustable.
The apparatus according to any of the preceding claims, wherein the at least one paper fiber opening element is arranged rotatable about a first rotary axis, and the first rotary axis is perpendicular to the conveying path of the web of paper material.
The apparatus according to claim 9, wherein the at least one paper fiber opening element is configured to be rotated about the first rotary axis at predetermined times so that the at least one paper fiber opening element only contacts the first surface of the web of paper material at predetermined intervals along the conveying path.
The apparatus according to any of the preceding claims, wherein the paper fiber opening unit comprises an even number of paper fiber opening elements and a same number of paper fiber opening elements is configured to contact each surface of the web of paper material.
The apparatus according to claim 11, wherein the paper fiber opening unit comprises two paper fiber opening elements and the two paper fiber opening elements are movable independently from each other.
The apparatus according to claim 1, further comprising a wrapping unit arranged downstream of the paper fiber opening unit, the wrapping unit being configured to wrap the web of paper material into a rod-shape.
The apparatus according to any of the preceding claims, wherein the supply unit comprises a web of paper material having a grammage equal to or greater than 45 grams per square metre (gsm).
A method for processing a paper wrapper for an aerosol-generating article comprising:
exerting pressure against a first surface of a web of paper material in a first region of the web of paper material by means of a paper fiber opening element contacting the first surface of the web of paper material when the web of paper material moves relative to the paper fiber opening element to create an altered paper fiber structure on a second surface of the web of paper material, the second surface being opposite to the first surface of the web of paper material, and

applying adhesive downstream of the paper fiber opening element on the first surface of the web of paper material in a second region, the second region being distinct from the first region,

wrapping the web of paper material for attaching the altered paper fiber structure to the second region of the first surface by means of the adhesive.