RU2812695C1 - Method and installation for corrugating sheet - Google Patents

Abstract

FIELD: construction materials.

SUBSTANCE: group of inventions relates to a method and installation for corrugating sheets. A method for corrugating a sheet having thickness, moisture content, composition and width before corrugating, includes: obtaining one property before corrugating the sheet from the following: sheet thickness; sheet moisture; sheet composition; sheet width; corrugating a sheet to form several corrugations on a sheet. Corrugating includes: providing a pair of corrugating rollers, between which a gap is formed, which has the size of the gap; inserting the sheet into the gap; assessment of the properties after corrugating the sheet, performed after corrugation; and changing the gap size based on one of the obtained properties from the property before corrugating the sheet and based on the estimated property after corrugating the sheet.

EFFECT: sufficient corrugation of the sheet for its proper further processing and the correct level of corrugation, which is a balance between the properties of the sheet, ensuring its ability to fold, and the absence or minimization of damage.

15 cl, 7 dwg

Description

The present invention relates to a method and installation for corrugating sheets.

In the manufacture of aerosol-generating products, such as heated non-combustion products, rod-shaped components are often used. The components may comprise an aerosol-forming substrate and a filter element. One or both of the filter element and the aerosol-forming substrate may include multiple channels to provide air flow through the rod. Multiple channels can be formed by corrugating a sheet of material and then collecting the material inside the rod to form the channels. In such examples, the corrugated sheet is typically formed by corrugating a substantially continuous sheet.

This material to be corrugated, that is, a continuous sheet, in the field of aerosol generating products, can be, for example, homogenized tobacco, such as reconstituted tobacco or molded sheet, polylactic acid sheet, or cotton sheet.

Methods and installations for producing corrugated sheet for use in an aerosol generating product are known in the art. Known methods for making corrugated sheet typically involve feeding a substantially continuous sheet between a pair of alternating rollers and applying multiple foldable corrugations to the continuous sheet. The corrugated sheet is then assembled to form a continuous rod containing multiple axial channels. The rod is then wrapped and cut into smaller segments to form an aerosol generating substrate or filter for an aerosol generating article.

The corrugation process is important for the efficient manufacturing process of an aerosol generating product.

The present invention relates to a method for corrugating a sheet that has a certain thickness, moisture content, composition and width before corrugating, the method including: obtaining one property before corrugating the sheet, such as sheet thickness; leaf moisture; leaf composition; sheet width. The method may further include corrugating the sheet to form multiple corrugations on the sheet, the corrugation comprising: providing a pair of corrugating rollers with a gap formed between them, the gap having a certain gap size; and inserting the sheet into the gap. The method may further include assessing the post-corrugation property of the sheet obtained after corrugation. The method may further include changing the gap size based on one of the obtained properties from the properties before corrugating the sheet and based on the estimated property after corrugating the sheet.

The present invention also relates to a machine for corrugating a sheet that has a certain property before corrugation, such as thickness, moisture content, composition and width. The installation contains: a transport device adapted for transporting the sheet in the transport direction; a pair of corrugating rollers for corrugating a sheet to form several corrugations on the sheet, and a gap is formed between the pair of corrugating rollers, said gap having a certain gap size. The apparatus may also include a sensor adapted to evaluate the property after the sheet has been corrugated, the sensor being located downstream of the pair of corrugating rollers in the transport direction. The apparatus may also comprise one of the following: a sensor adapted to evaluate one of the properties before corrugating the sheet and send a signal function of one estimated property of the pre-corrugation properties, the sensor being located upstream of the pair of corrugating rollers in the transport direction; a storage device containing data relating to one of the properties before the sheet is corrugated. The apparatus may further comprise a control unit adapted to receive said signal function of one of the assessed properties of the pre-corrugation properties, or to receive data relating to one of the pre-corrugation properties. The method may also comprise a first actuator for changing the size of the gap; and a closed-loop feedback control system adapted to activate the first actuator based on one of the estimated properties of the property before corrugating the sheet or based on acquired data relating to one of the properties before corrugating and based on the estimated property after corrugating the sheet.

A sheet of material is corrugated between two corrugating rollers, between which a gap is formed. As a result of corrugation, several corrugations are formed on the sheet. The first assessment of the properties before corrugating the sheet is carried out earlier in the flow direction relative to the corrugating rollers. The second assessment of the property after corrugating the sheet is carried out further downstream relative to the corrugating rollers. The first assessment, carried out earlier in the flow, relates to one of the following properties: sheet thickness, sheet moisture content; leaf composition; sheet width. The second assessment, carried out further downstream, relates to the property of the sheet imparted by the corrugations, for example the property of multiple corrugations on the sheet. If necessary, the gap size can be changed based on the estimated property after corrugating the sheet and the obtained property before corrugating the sheet. In this way, a continuous feedback loop for optimal corrugation can be realized, since the size of the gap depends on the sheet properties present both before and after corrugation. The effect of corrugation on the sheet can be monitored and the gap size can be adjusted to the specific conditions of the corrugated sheet.

As used herein, the term “sheet” refers to a plate-like element having a width and a length substantially greater than its thickness. The width of the sheet is preferably greater than 10 millimeters, more preferably greater than about 20 millimeters or about 30 millimeters. Even more preferably, the sheet width is from about 60 millimeters to about 300 millimeters. The sheet thickness can be from about 50 micrometers to about 300 micrometers, it can be from about 100 micrometers to about 250 micrometers, it can be from about 175 micrometers to about 250 micrometers, it can be from about 130 micrometers to about 220 micrometers.

As used herein, the term “rod” refers to a cylindrical element of substantially cylindrical, oval or elliptical cross-section containing two or more components of an aerosol generating article.

The "aerosol generating articles" of the present invention may take the form of articles in which alkaloid-containing material, such as tobacco material, is heated to form an aerosol rather than burned. Aerosol-generating products are products in which an alkaloid-containing aerosol is generated from an alkaloid-containing material, such as tobacco extract or other nicotine source, without combustion or heating. The aerosol generating articles of the present invention may be entire assembled aerosol generating articles. The aerosol generating articles of the present invention may be components of an aerosol generating article combined with one or more other components to provide an assembled aerosol generating article. An example is the consumable part of a heated smoking device.

"Alkaloid-containing material" is a material that contains one or more alkaloids. Alkaloids may contain nicotine. Nicotine can be found, for example, in tobacco.

Alkaloids are a group of naturally occurring chemical compounds that primarily contain basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar structure are also called alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and, less commonly, other elements such as chlorine, bromine and phosphorus.

Alkaloids are produced by a wide range of organisms, including plants. They can be purified from primary extracts of these organisms by acid-base extraction. Caffeine, nicotine, theobromine, atropine, tubocurarine are examples of alkaloids.

As used herein, the term “homogenized tobacco material” means a material formed by agglomeration of bulk tobacco that contains the alkaloid nicotine. Thus, the alkaloid-containing material may be homogenized tobacco material.

The most widely used forms of homogenized tobacco material are reconstituted tobacco leaf and molded leaf. The process of forming sheets of homogenized tobacco material typically includes a step in which tobacco powder and a binder are mixed to form a slurry. The pulp is then used to create tobacco leaf. For example, by casting a viscous pulp onto a moving metal belt to produce what is called a cast sheet. Alternatively, low viscosity, high water content pulp can be used to produce reconstituted tobacco in a process similar to papermaking.

Other forms of sheet production are also possible.

A sheet of homogenized tobacco material may be formed using bulk tobacco (eg, reconstituted tobacco) or a bulk tobacco mixture, a humectant and an aqueous solvent to form a tobacco composition.

The homogenized tobacco leaf may contain, in addition to tobacco, a binder. The homogenized tobacco leaf may contain an aerosol-forming agent such as guar and glycerin.

As used herein, the term "corrugated sheet" means a sheet with multiple corrugations. The term "corrugation" refers to the process of forming several corrugations on a sheet of material. Preferably, the sheet of material is a substantially flat sheet of material or a pre-processed sheet of material in relation to creating a structured surface. However, it may also be possible to corrugate a sheet that already contains corrugations. Corrugations on the sheet can be formed by corrugating rollers. Corrugated rollers may contain corrugations on their surface.

As used herein, the term “corrugations” refers to a plurality of ridges formed from alternating peaks and valleys connected by the side surfaces of the corrugation. These include, but are not limited to, corrugations having a square wave profile, a sine wave profile, a triangular profile, a sawtooth profile, or any combination thereof. The corrugations can be defined on rollers, such as corrugated rollers, or on a sheet. Corrugations on a roller indicate several ridges formed on the outer surface of the roller. Corrugations in a sheet refer to multiple ridges when the sheet is laid on a flat surface without stretching the sheet itself.

As used herein, the term “substantially alternate”, when applied to a pair of beads formed by a first bellow and a second bell, means that the bellows of the first bell and the second bead are at least partially engaged. This includes arrangements where the corrugations of one or both rollers are symmetrical or asymmetrical. The corrugations of the bellows may be substantially aligned or at least partially offset. The top of one or more corrugations of the first corrugation roller or the second corrugation roller may alternate with the valley of a separate corrugation of another of the first corrugation roller and the second corrugation roller. Preferably, the corrugations of the first corrugation roller and the second bellows roller are alternated such that substantially all of the corrugation valleys of one of the first corrugation roller and the second bellows roller partially accommodate one crest of the corrugation of the other of the first corrugation roller and the second corrugation roller.

A "corrugating roller" is a roller used to corrugate a sheet. The corrugated roller defines the outer surface and the axis of rotation. The outer surface contains several corrugations. Preferably the corrugations extend in a radial direction around the outer surface. Preferably, the corrugations define circles on the surface of the corrugation roller. As used herein, "corrugated roll diameter" is considered to be the largest diameter of the diameters defined by cross sections along a plane perpendicular to the axis of rotation of the corrugated roll.

As used herein, "the distance between the first bellows having a first axis of rotation and the second bellows having a second axis of rotation" refers to the distance between their respective first axis of rotation and the second axis of rotation.

As used herein, the term "longitudinal direction" refers to a direction along or parallel to the length of the sheet.

In the context of the present description, the term "width" refers to a direction perpendicular to the direction of transport of the sheet during processing.

As used herein, the term "pitch" of corrugations refers to the lateral distance between the valleys on either side of the top of a particular corrugation, or the lateral distance between two adjacent tops of two adjacent corrugations. In the case where the corrugations are on the sheet, the step size is calculated in a configuration where the sheet lies on a plane without stretching the sheet itself.

As used herein, the term "amplitude" of a corrugation refers to the height of a corrugation from its apex to the deepest point of the deepest, immediately adjacent valley. For example, in the case where the corrugations are located in rollers, the amplitude of the corrugations can be measured in the radial direction. The radial direction is the direction along the radius connecting the axis of rotation of the roller and the peak or valley. The radius is perpendicular to the axis of rotation. The cavity height is measured as the distance along the radial direction between the axis of rotation and the deepest point of the cavity. Apex height is measured as the distance along the radial direction between the axis of rotation and the highest point of the apex. Thus, the "amplitude magnitude" is the difference between the height of the peak and the height of the valley. In the case where the corrugations are in the sheet, the amplitude value is calculated in a configuration where the sheet lies on a plane without stretching the sheet itself. The amplitude of the sheet corrugations is calculated as the distance between the first plane and the second plane, the first plane being parallel to the second plane. The first plane is in contact with the apex of the corrugation and the second plane is in contact with the deepest point of the valley adjacent to the apex.

When corrugations are formed on a sheet, the ridges may be parallel to each other. The ridges may be parallel to the direction of sheet transport during corrugation. The ridges can form an angle from 0 degrees to 45 degrees with the direction of sheet transport during corrugation.

As used herein, the term "side angle" refers to the angle between the side surfaces of a particular corrugation. The angle between the side surfaces can be the same for all corrugations. In addition, one or more corrugations may be asymmetrical with respect to the radial direction.

As used herein, the term "gap" refers to the spacing between the first bead and the second bead forming a pair of beads. The sheet intended for corrugation passes through the gap during operation. The first bellows roller and the second bellows roller define a first axis of rotation and a second axis of rotation, respectively. In addition, the first bellows defines a first outer surface, and the second bellows defines a second outer surface. The gap determines the size of the gap. The gap size is determined for each cross section of the first and second corrugated rollers along a plane perpendicular to the first axis of rotation or the second axis of rotation. In each cross section, the gap size is the smallest Euclidean distance between the first outer surface and the second outer surface for a given relative position between the first bead and the second bead. The size of the gap may change during the relative rotation of the first bellows roller and the second bellows roller. The size of the gap may be constant in the case where the surface of both the first and second corrugated rollers is rotationally constant for rotations about the first and second axes of rotation, or it may vary. In addition, the size of the gap may be constant along the width of the roller or it may also vary. Preferably, there are two gap sizes for each cross section. The size of the gap can also vary along the width of the roller. Two cross sections taken at two different locations along the axis of rotation of the corrugated roller may show different gap sizes.

Preferably, the size of the gap for each cross section is constant. Preferably, the size of the gap is constant in all cross sections. A constant gap size allows for uniform processing of the material across the entire width of the sheet.

However, the present invention also allows for the roller to flex slightly during use, so that the constant corrugation profile of the sheet of material requires that the gap size increase slightly towards the center of the roller.

The term "tack" is used to refer to the adhesive properties or cohesive properties of a sheet. Adhesion is the tendency of dissimilar particles or surfaces to stick to each other, while cohesion refers to the tendency of similar or identical particles or surfaces to stick to each other. The stickiness of the sheet can be measured using a LIDAR (Light Detection and Ranging) device adapted to measure the distance between the measuring apparatus and the sheet as it unwinds from the roller. The LIDAR is placed so that it faces the unwound part of the sheet. The “non-sticky” sheet has the shortest distance to LIDAR, since the unwound part of the sheet is immediately detached from the roller. The distance between the LIDAR and the unwound part of the sheet increases with increasing stickiness.

Hereinafter, the term “upstream” or “downstream” refers to the direction of movement or transport of the sheet.

As used herein, the terms "gathered" or "gathered" when referring to a sheet mean that the sheet is rolled or otherwise compressed or tapered substantially transversely relative to the direction of transport of the rod-shaped sheet.

In the context of this document, the terms “horizontal” and “vertical” have their standard meaning.

A sheet having the following properties: a given thickness, moisture content, composition and width is fed into the installation according to the present invention. The above properties are generally referred to as the “pre-corrugation properties” of the sheet. The properties before corrugation may be substantially constant within the sheet or may vary at different locations in the sheet. The thickness, moisture content, composition and width of the sheet can be within specified ranges, each property having its own range.

The sheet defines two opposite surfaces, and the opposite surfaces define opposite sides of the sheet.

Preferably, the sheet is supplied by unwinding from a reel.

At least one of the properties is obtained before corrugating the sheet. One property obtained from the properties before corrugation can be the thickness of the sheet. One property obtained from the pre-corrugation properties may be the moisture content of the sheet. One property obtained from the pre-corrugation properties can be the width of the sheet. One property obtained from the pre-corrugation properties may be the composition of the sheet.

Composition may refer to the chemical composition of the leaf, such as the constituents of the leaf. For example, the composition may include a mixture of the leaf. The leaf mixture is applicable if the leaf is a sheet of material containing alkaloids. In this case, the sheet is made by mixing a material containing alkaloids to obtain a predetermined mixture. The alkaloid containing material may be tobacco material. Preferably more than one type of tobacco is mixed with each other. For example, at least two different types of tobacco are mixed with each other. The term "tobacco type" refers to one of the different varieties of tobacco. For the purposes of the present invention, these different types of tobacco are divided into three main groups: light tobacco, dark tobacco and aromatic tobacco. The difference between these three groups is due to the drying process that the tobacco undergoes before it is further processed into a tobacco product.

Light-colored tobacco varieties are types of tobacco that typically have large, light-colored leaves. Throughout this description, the term “light tobacco” is used for types of tobacco that have been fire-cured. Examples of light tobacco varieties are Chinese flue-cured tobacco, Brazilian flue-cured tobacco, American flue-cured tobacco such as Virginia tobacco, Indian flue-cured tobacco, flue-cured tobacco from Tanzania, or other African flue-cured tobaccos. Light tobacco is characterized by a high ratio of sugar to nitrogen. From a sensory perspective, light tobacco is a type of tobacco that, once cured, is associated with a spicy and rich sensation. As used herein, light tobacco refers to a type of tobacco having a reducing sugar content of from about 2.5 percent to about 20 percent by leaf dry weight and a total ammonia content of less than about 0.12 percent by leaf dry weight. Reducing sugars contain, for example, glucose or fructose. The total ammonia content consists of, for example, ammonia and ammonia salts.

Dark tobacco species are types of tobacco that typically have large, dark-colored leaves. Throughout this description, the term “dark tobacco” is used for types of tobacco that have been air-cured. Additionally, types of dark tobacco can be fermented. Types of tobacco that are used primarily for chewing, snorting, cigar and pipe blends are also included in this category. From a sensory perspective, dark tobacco is a type of tobacco that, when cured, is associated with the smoky flavor characteristic of dark cigars. Dark tobacco is characterized by a low sugar to nitrogen ratio. Examples of dark tobacco are Malawi burley or other types of African burley, dark cured Brazilian Galpao, sun-cured or air-cured Indonesian Kasturi. According to the present invention, dark tobacco species are those with a reducing sugar content of less than about 5 percent based on dry weight of the leaves and a total ammonia content of no more than about 0.5 percent based on the dry weight of the leaves.

Aromatic tobacco species are types of tobacco that often have small, light-colored leaves. Throughout the description, the term "aromatic tobacco" is used to refer to other types of tobacco that are characterized by a high content of aromatic substances, for example a high content of essential oils. From a sensory perspective, aromatic tobacco is a type of tobacco that, after drying, is associated with a spicy and aromatic sensation. Examples of types of aromatic tobacco are Greek oriental, Turkish oriental, semi-oriental tobacco, but also fire-cured tobacco, American Burley, for example Perique, Shag, American Burley or Maryland.

Additionally, the mixture may contain so-called tobacco fillers. Filler tobacco is not a specific type of tobacco, but includes various types of tobacco that are primarily used to complement the other types of tobacco used in the blend and that do not impart much of a distinctive flavor profile to the final product. Examples of tobacco fillers are the stems, midribs, or stems of other types of tobacco. A specific example would be fire-cured stems from the lower petioles of fire-cured Brazilian tobacco.

Within each type of tobacco, tobacco leaves are further sorted, for example, by place of origin, position on the plant, color, surface texture, size and shape. These and other properties of tobacco leaves are used to obtain a tobacco mixture. The tobacco mixture is a mixture of types of tobacco belonging to the same or different types, so that the tobacco mixture has an agglomerated characteristic. This property may be, for example, a unique taste or a specific aerosol composition resulting from heating or combustion. The mixture contains specific types and varieties of tobacco in a given quantitative ratio to each other.

In accordance with the present invention, different varieties within the same type of tobacco can be cross-blended to reduce the variability of each component of the mixture. According to the present invention, various tobacco fractions are selected to obtain a desired mixture having specific defined properties. For example, the mixture may have a target value for reducing sugars, total ammonia, and total alkaloids based on the dry weight of the homogenized tobacco material. The total alkaloid content includes, for example, the content of nicotine and minor alkaloids, including nornicotine, anatabine, anabasine and myosmin.

For example, light tobacco may include grade A tobacco, grade B tobacco, and grade C tobacco. Light grade A tobacco has slightly different chemical properties relative to light grade B and grade C tobacco. Aromatic tobacco may include grade D tobacco and grade E tobacco, where aromatic Grade D tobacco has slightly different chemical properties relative to Grade E aromatic tobacco. A possible target value for a tobacco blend, for example, would be to have a reducing sugar content of approximately 10 percent, on a dry weight basis, of the total tobacco blend. In order to achieve the selected target value, 70 percent light tobacco and 30 percent aromatic tobacco can be selected to form a tobacco blend. 70 percent of the light tobacco is selected from Grade A tobacco, Grade B tobacco and Grade C tobacco, while 30 percent of the aromatic tobacco is selected from Grade D tobacco and Grade E tobacco. Numbers of Grade A, B, C, D, E tobacco types included into the mixture, depend on the chemical composition of each of the tobacco varieties A, B, C, D, E to thus obtain the target value for a given tobacco mixture.

Different types of tobacco have different chemical properties. It is believed that there are more than 300 chemical constituents in tobacco leaves. Within the same type of tobacco, different varieties may also have differences in chemical composition. The chemical constituents of tobacco can be influenced by genetics, agricultural practices, soil and nutrient types, weather conditions, plant disease, petiole position, harvesting and drying procedures.

One of the resulting properties of the pre-corrugation properties can be measured, for example, using a suitable sensor. Preferably, the sensor measures the pre-corrugation property in real time, that is, the pre-corrugation property of the sheet is preferably measured while the sheet is being processed. Measuring the property before corrugating the sheet means measuring the property of the sheet at least at a predetermined location, that is, measuring at least the property before corrugating the first part of the sheet. Any sensor for measuring one of the properties prior to corrugation is preferably located upstream of the corrugating rollers.

One sensor or more sensors for measuring the same pre-corrugation property may be used to measure the pre-corrugation property of the sheet. The same property before sheet corrugation can be measured in one place or in several places. If it is measured at more than one location, each measurement creates data and that data is collected. Collected data from different dimensions can be statistically combined. The average value of all measurements of the same property before corrugation can be derived.

In case of thickness measurement, a thickness gauge can be used.

The thickness sensor may comprise a mechanical sensor. The thickness sensor may include an optical sensor. The thickness sensor may comprise a mechanical sensor and an optical sensor.

In the case of humidity measurement, a humidity sensor can be used. The humidity sensor may include a density sensor that measures in grams per square meter.

In the case of width measurements, a distance sensor can be used.

The pre-corrugation property can be obtained through the database. The method according to the present invention preferably includes accessing a database and retrieving data from the database relating to one of the properties before corrugating the sheet. The database may contain one or more pre-corrugation properties: thickness, moisture content, composition or pre-corrugation width of the sheet. Data related to one or more pre-corrugation properties may be stored in an accessible storage device where a database is present.

The pre-corrugation property can be obtained using user input. A panel or other input device may be provided and a user, such as an operator, may enter a property value prior to corrugating the sheet. In addition, data relating to one of the pre-corrugation properties can be obtained by scanning data provided on the reels on which the sheet is wound, such as a characteristic code.

The pre-corrugation property can be obtained via a signal from a remote source. In order to enter the property before corrugation, wireless or wired data transmission can be carried out.

Preferably, more than one property is obtained before corrugating the sheet. Preferably, the moisture content of the sheet is obtained. Preferably, the thickness of the sheet is obtained. Preferably, the moisture content and thickness of the sheet are obtained.

The sheet is transported along the transport direction. Transport can be accomplished by any suitable means, for example by pulling through rollers. Preferably, transport is carried out at a sheet speed of from about 50 meters per minute to about 400 meters per minute.

Then the sheet is corrugated. The corrugation is performed using a pair of corrugating rollers, designated the first corrugating roller and the second corrugating roller. The first corrugated roller and the second corrugated roller are located adjacent to each other, and a gap is formed between the first corrugated roller and the second corrugated roller. The first corrugated roller defines a first axis of rotation and a first outer surface. The second corrugated roller defines a second axis of rotation and a second outer surface. The first axis of rotation and the second axis of rotation are preferably parallel to each other. The first axis of rotation and the second axis of rotation are preferably horizontal. Preferably, the first corrugated roller and the second corrugated roller have a width that is greater than or equal to the width of the sheet, so that the entire sheet can be corrugated between the first corrugated roller and the second corrugated roller. Preferably, the cross sections of the first outer surface along a plane perpendicular to the first axis of rotation are circles. Preferably, the cross-sections of the second outer surface along a plane perpendicular to the second axis of rotation are circles. At least one of the first corrugated roller or the second corrugated roller contains corrugations. Preferably, the corrugations are formed on the first outer surface or on the second outer surface. Preferably, the corrugations are formed on both the first outer surface and the second outer surface. Corrugations on the first corrugated roller or the second corrugated roller, or both rollers, come into contact with the sheet when the sheet is inserted into the gap between the first corrugated roller and the second corrugated roller. Due to the effect of the corrugations on the sheet, corresponding corrugations are formed on the sheet as it passes through the gap. In the case where the first corrugation roller and the second corrugation roller include corrugations, the first corrugation roller and the second corrugation roller may be designed and arranged such that at least some of their corrugations are substantially alternated.

Alternatively, only one of the first bead and the second bead may be corrugated, and the other of the first bead and the second bead may have a substantially smooth outer surface. This smooth outer surface may be cylindrical.

Alternatively, both the first corrugated roller and the second corrugated roller may comprise corrugations located in non-corresponding sections. The first corrugated roller may comprise sections containing corrugations and sections without corrugations. Preferably, the corrugated section is located adjacent to the non-corrugated section on the first outer surface. The second corrugated roller may comprise sections containing corrugations and sections without corrugations. Preferably, the corrugated section is located adjacent to the non-corrugated section on the second outer surface. In such a configuration, when the first corrugated roller and the second corrugated roller face each other, the corrugated sections of the first corrugated roller face the non-corrugated sections of the second corrugated roller. For each portion of the sheet of material that comes into contact with the first bellow and the second bead, only one of the first bead and the second bead forms bendable corrugations on that portion of the sheet of material.

All corrugations on the first corrugation roller or on the second corrugation roller preferably have the same pitch. More preferably, the corrugations are present in both the first corrugation roller and the second corrugation roller, all of which have the same pitch. In addition, preferably all the corrugations in the first corrugation roller or in the second corrugation roller have the same amplitude.

Preferably, the size of the gap between the first bead and the second bead is from about 100 micrometers to about 300 micrometers. A gap size that is too small, that is, a gap size less than 100 micrometers, can damage the sheet. A gap size that is too large may not provide sufficient corrugation of the sheet for proper further processing of the sheet, such as collecting it into a rod shape.

Preferably, the pitch of the ridges in the first corrugated roller or in the second corrugated roller, or in both rollers, is from 200 micrometers to 1500 micrometers. More preferably, the pitch is from 800 micrometers to 1200 micrometers.

One embodiment of corrugated rollers that can be used in the present invention is described in document WO 2018/189325 by the same applicant. Preferably, all corrugations in the first corrugated roller or in the second corrugated roller have the same angle between the side surfaces. Preferably, all the corrugations in the first corrugation roller or in the second corrugation roller have the same amplitude. Preferably, all corrugations in the first corrugated roller or in the second corrugated roller have the same pitch.

The corrugations in the first corrugated roller or in the second corrugated roller may have an amplitude of from about 0.1 millimeter to about 1.5 millimeters.

The gap between the first corrugated roller and the second corrugated roller has a predetermined gap size. Preferably, the size of the gap changes during rotation of the first bellows roller and the second bellows roller for a given cross-section formed along a plane perpendicular to the first axis of rotation or the second axis of rotation. The gap size is preferably a step function between the first value and the second value. Before and after the "jump" between the first value and the second value, the size of the gap is preferably constant.

The size of the gap is determined, among other things, by the distance between the first bellows and the second bellows and the diameter of the first bellows and the second bellows.

During the corrugating process, the sheet passes through a gap formed between the first corrugating roller and the second corrugating roller. The first corrugated roller and the second corrugated roller form bendable corrugations on a sheet of material with a given pattern. The corrugations on the sheet have a pattern determined by the corrugation pattern on the first corrugated roller and the second corrugated roller. The corrugations on the sheet also have a certain pitch and amplitude. The amplitude and pitch of the corrugations on the sheet may differ from the amplitude and pitch of the corrugations on the first corrugated roller or on the second corrugated roller due to the flexibility and elasticity of the sheet.

The size of the gap can be changed, for example by means of the first actuator. The first actuator can change the size of the gap by changing the distance between the first bellows roller and the second bellows roller. For example, a linear actuator may be present. The linear actuator can change the position of the axis of rotation of the first corrugated roller, or the second corrugated roller, or both rollers. The eccentric mechanism can rotate and, when rotated, change the position of the axis of rotation of the first corrugated roller, or the second corrugated roller, or both rollers. The gap size variation can be within the gap size range of ±50 micrometers. The gap size may vary from 20 percent to 50 percent of the original gap size, even more preferably from 20 percent to 30 percent.

Further along the flow path relative to the first corrugated roller and the second corrugated roller in the transport direction, the property of the sheet is assessed, for example, the property of the corrugations formed on the sheet is assessed. For this purpose, the installation may include a sensor for detecting one of the properties of the corrugations formed in the sheet by the corrugating rollers. The sensor may be an optical sensor, such as an infrared or laser sensor. The optical sensor may include a light emitter on one side of the sheet and a light detector on the other side of the sheet. The optical sensor may include a laser profilometer.

By "corrugated property" of the sheet is meant at least one property of the sheet after corrugation. The post-corrugation property may be a property of the corrugations formed on the sheet. The property of not only corrugation can also be assessed. By corrugation property we mean any property of the pattern formed by corrugated rollers on a sheet. The property may be, for example, the number of corrugations formed on the sheet, the pitch of the corrugations formed on the sheet, the amplitude of the corrugations formed on the sheet, the angle between the side surfaces of the corrugations formed on the sheet, the stability of the corrugations formed on the sheet, and so on. The corrugations on the sheet have a given geometric pattern, which determines, among other things, pitch, amplitude, angle between the side surfaces and other geometric parameters. By "corrugation stability" is meant the stability of these geometric properties over time, that is, a property is stable if, after a given period of time, its value remains essentially the same or it varies within a given interval. The post-corrugation property may be the diameter of the rod formed by collecting the corrugated sheet. The diameter of the rod depends on the properties of the sheet, such as the depth of corrugation, that is, on the amplitude of the corrugations formed on the sheet. The property after corrugation may be the resistance to tightening of the formed rod obtained by collecting the corrugated sheet. Among other factors, the tightening resistance depends on the corrugations formed in the sheet, which create "air channels" in the rod.

Evaluation of the properties after corrugating the sheet is carried out after corrugating the sheet. Evaluation of the property after corrugating the sheet means evaluating the property after corrugating the sheet in at least one place.

Preferably, the property evaluation after sheet corrugation is performed in real time. The property after corrugation is preferably evaluated at different times. Preferably, the evaluation of the post-corrugation property is performed at a predetermined frequency while the sheet is moving. A statistical quantity can be calculated from all post-corrugation assessments of the same property made at different times.

Preferably, performing a property evaluation after corrugating the sheet includes measuring the property after corrugating the sheet. More preferably, performing a property evaluation after corrugating the sheet includes performing an evaluation of the property of the corrugations formed on the sheet. Preferably, performing an assessment of the property of the corrugations formed on the sheet includes measuring the property of the corrugations. More preferably, measuring the corrugation property includes measuring the corrugation property via a sensor.

One sensor can be used to measure the post-corrugation property of corrugated sheet. Several sensors can be used to measure the post-corrugation property of corrugated sheet.

The property after corrugating the sheet can be assessed at one location of the corrugated sheet. The property after corrugating the sheet can be assessed at several places in the corrugated sheet. If an assessment is performed at more than one location, each determination generates data and the data is collected. Collected data from different determinations can be statistically combined, for example a statistical quantity can be calculated based on all determinations of the same property after corrugation at different locations on the sheet. The average value of all determinations for the same property after sheet corrugation can be derived.

Evaluation of the property after corrugating the sheet is used to adjust the gap size. Depending on the magnitude of the property after corrugating the sheet, it may be determined that the gap size is not optimal. Determining whether the gap size is optimal depends on one property obtained from the property before corrugating the sheet. For each value of one property obtained from the properties before corrugation, one can expect a given value of the property after corrugation of the sheet. Therefore, this expected value of the property after corrugating the sheet depends on the property before corrugating the sheet. If the estimated value of the property after corrugating the sheet differs from the expected value, the gap size is preferably changed. “Expected value” also refers to the range of expected values.

For example, for a given resulting sheet thickness, a specific gap size is preliminarily set before corrugating. However, upon evaluation of the post-corrugation property of the sheet performed after corrugation, it can be seen that the preset gap size is not optimal because the value of the post-corrugation property, such as the corrugation property of the sheet, is outside the desired range. According to the present invention, for this reason, the gap size is adjusted based on the evaluated property after corrugating the sheet after presetting based on the thickness before corrugating.

The step of changing the gap size based on one of the obtained properties from the properties before corrugating and based on the estimated property after corrugating the sheet may include one of the following. A single change step can be implemented based on both the pre-corrugation property and the post-corrugation property. The modification step may also be implemented as two sub-steps: a first sub-step in which the change is performed based on the pre-corrugation property, and a second sub-step in which the change is performed based on the post-corrugation property. The first auxiliary step and the second auxiliary step may be reversed: a first auxiliary step in which the change is performed based on the post-corrugation property and a second auxiliary step in which the change is performed based on the pre-corrugation property may also be carried out.

Preferably, the corrugated sheet is used in an aerosol generating article. Preferably, corrugated sheet is used to form the aerosol generating component of the article.

The corrugating process creates different effects on the material forming the sheet that is compressed between the corrugating rollers.

The first range of effects occurs during subsequent manufacturing processes, such as the fact that a corrugated sheet of material can be more easily compressed into a rod than a sheet that has not been corrugated. In addition, a more predictable result is obtained.

Once the corrugated sheet of material is compressed into a rod and added to an aerosol generating article, a second range of effects associated with the corrugation occur, such as affecting the user's smoking experience. In particular, the corrugating process affects the contact between the air entering the aerosol generating product and the corrugated sheet of material, as well as the resistance to draw (RTD).

However, a suboptimal or suboptimal corrugating process can excessively weaken the corrugated web of material. A suboptimal or suboptimal process may prevent the release of substances from the corrugated sheet of material into the air entering the core and also negatively affect the RTD value.

The correct gap size is important for proper corrugation of the sheet. The size of the gap may determine, among other parameters, whether the corrugated sheet has the correct “corrugation level.” The correct "corrugation level" is important for subsequent sheet processing steps. For example, the right amount of corrugation can give a sheet enough "foldability" to assemble into a rod shape without breaking. The correct level of corrugation can prevent structural damage to the "foldable" sheet. For example, when wrapping a sheet into a wrapper, if it has a level of corrugation that is less than the correct level, then the material forming the sheet, after being assembled into a core and wrapped into the wrapper, may exhibit a drag force that opposes the wrapper. This prevents the sheet from forming cores properly. In addition, low levels of corrugation can also affect the sheet's ability to bend. On the other hand, if the sheet's corrugation level is greater than the correct level, the sheet may exhibit structural damage. Small portions of the material forming the sheet may become detached from the formed core. Small parts may move within the aerosol generating product. Small parts can also move around inside the machines that process the rods. This may increase machine downtime associated with cleaning. Thus, the correct level of corrugation is a balance between the sheet's folding properties and avoiding or minimizing damage.

The correct level of corrugation refers to the property after corrugation of the sheet. Preferably, the correct level of corrugation refers to the property of the sheet caused by the corrugations formed during the corrugation process. The correct level of corrugation may refer to the properties of the corrugations in the sheet. For example, the level of corrugation is determined by assessing the amplitude of the corrugations formed on the sheet by corrugating rollers. Preferably, the corrugation property assessed after corrugation is the amplitude of at least one corrugation formed on the sheet.

Thus, a closed loop control system for the corrugating process is preferably implemented according to the present invention and obtains data related to the properties of the sheet before the corrugating process and after the corrugating process. For example, the closed loop control system may include sensors located upstream and downstream of the first bell and the second bell. The closed loop feedback system is preferably coupled to the first actuator for sending commands to the first actuator. The closed-loop feedback control system is able to adjust the gap size to continuously optimize it throughout the process.

For example, due to empirical data, for each obtained property before corrugation, a given property after corrugation is expected. A range of property values can be expected after corrugation. A lookup table or database may be constructed such that, for a given property before corrugation, the expected value of the property after corrugation can be retrieved. A range of expected values for this property after corrugation can be extracted. Preferably, based on empirical data, this expected value or range of values of the property after corrugation corresponds to a certain value of the gap size. The first corrugated roller and the second corrugated roller are then positioned so that there is an appropriate gap size between them. The sheet is then corrugated using the appropriate gap size. An evaluation of the expected corrugation property is then performed. If the assessed property after corrugation differs from the expected one, then the gap size is changed. This also applies in the case where several pre-corrugation properties are used as input: a multi-dimensional table may be present whereby for several selected pre-corrugation properties the value of a given post-corrugation property is first retrieved and then the value of a given post-corrugation property is estimated.

The property after corrugation can be the amplitude of the corrugations formed on the sheet. Therefore, for a given sheet thickness or moisture content before corrugation, the corresponding expected corrugation amplitude value is retrieved from the database. It is known from empirical data that the expected amplitude value can be obtained together with the corresponding gap size. Set the appropriate gap size and corrugate the sheet. Then the amplitude of the corrugations formed on the sheet is measured. If the measured amplitude value is "too much" different from the expected value, that is, if the absolute value of the difference between the expected amplitude value and the measured amplitude value is above a certain threshold, the gap size is changed.

Preferably the method includes changing the size of the gap during corrugation. Evaluations performed upstream and downstream of the corrugated rollers can preferably be performed at a certain frequency during the manufacturing process. For example, the assessment can be performed several times per minute. It can be performed anywhere from once every 1 minute to once every 30 minutes. Preferably, the assessment is performed at intervals of 1 minute to 15 minutes. Preferably, pre-corrugation and post-corrugation data are continuously collected and evaluated. The size of the gap can be changed during sheet corrugation and there is no need to stop the manufacturing process for this. The process can adapt to changing environmental conditions. The process can accommodate changing properties before the sheet is corrugated.

Preferably the sheet is a sheet of alkaloid containing material. Preferably the sheet is a sheet of plastic. The corrugating method or apparatus may be used for sheets of material containing alkaloids, for example sheets of homogenized tobacco, which are “sticky” and relatively brittle. The corrugating method or apparatus can be used for sheets of plastic, such as sheet made from polylactic acid (PLA), which is elastic.

Preferably the sheet has mechanical property, tackiness, temperature. The method preferably includes determining one additional property before corrugating the sheet. An additional property prior to corrugating the sheet may be a mechanical property of the sheet. A "mechanical property" may include one or more of the following: tensile strength, modulus of elasticity, elastic limit, maximum elongation, hardness, melting point, glass transition temperature, and others. An additional property before corrugating the sheet may be the temperature of the sheet. An additional property before corrugating the sheet may be the stickiness of the sheet. The method may include changing the gap size based on one particular property of the additional properties before corrugating the sheet. The method may include changing the size of the gap based on a mechanical property of the sheet. The method may include changing the size of the gap based on the temperature of the sheet. The method may include changing the size of the gap based on the stickiness of the sheet. The method may include changing the gap size based on a combination of two parameters from additional properties prior to corrugation. The method may include changing the gap size based on a combination of three parameters from additional properties prior to corrugation. “Mechanical property, stickiness, sheet temperature” are collectively referred to as additional properties before sheet corrugation. In addition, other sheet parameters can be defined as a supplement or replacement for the listed parameters. These other parameters can be used in the method according to the present invention as a basis for changing the size of the gap.

It should be understood that the sheet has an additional property before being corrugated in a given location. This means that the sheet may have different additional properties before corrugation depending on the location of the sheet selected for determination. For example, different parts of the sheet may have different stickiness, temperature values, and mechanical properties. Preferably, at least one of the additional properties is determined at a predetermined location of the sheet before corrugation. The determination is carried out, for example, using suitable sensors. The determination can be made through measurement. Alternatively, the user can enter one of the properties before corrugation. Alternatively, one of the additional properties may be retrieved from the storage device prior to corrugating the sheet. For example, a mechanical property of a sheet may already be known from a previous process step and data related to this mechanical property has already been extracted. In this case, no measurement is required. An additional property before corrugation can be read by scanning a bar code located on the reel formed by the sheet.

One additional property may be specified prior to corrugation. Several additional properties may be determined prior to corrugation. A combination of measured additional pre-crimp properties and otherwise determined (eg, user-entered or retrieved from memory) pre-corrugation properties can be used as a basis for changing the gap size. The type and number of additional properties specified prior to corrugation may depend on the type and number of sensors available. In addition, one determination can be made for the same additional property before corrugation. Several determinations can be made for the same additional property before corrugation. The final determination may be a statistical combination of all determinations made. The statistical combination may include an average of the measurements of the same additional property before corrugation. The gap size may be changed based on one or more of these additional property determinations prior to corrugation. The effect that gap size has on the sheet may be due to the above-mentioned additional properties prior to corrugation. For example, the size of the gap may have a different "corrugation effect" depending on the properties of the material being corrugated, such as its mechanical properties, tack, composition, temperature, or other parameters. Thus, these additional pre-corrugation properties may also be important in determining the optimal gap size. In addition, additional pre-corrugation properties may vary depending on process conditions, for example, additional pre-corrugation properties may vary depending on the temperature or humidity of the environment where the sheet is located. The additional pre-corrugation properties may vary during the corrugation process and thus it is preferable to adjust the gap size depending on one or more additional pre-corrugation properties. As an example, ambient temperature or humidity can change the fragility of the sheet and, in turn, its behavior during corrugation. Therefore, changes in humidity or temperature during this process can trigger changes in gap size to maintain optimal corrugation results.

The method preferably includes: measuring the temperature of the environment where the sheet is located during corrugation. The method preferably includes: measuring the humidity of the environment where the sheet is located during corrugation. The method preferably includes: measuring the temperature of a portion of a sheet corrugating plant. The method preferably includes: changing the size of the gap based on ambient temperature, or ambient humidity, or installation temperature. In the following, “ambient temperature, ambient humidity, installation temperature” are collectively referred to as ambient parameters. "Environmental Settings" may include other settings. Preferably at least one of the surrounding parameters is measured by suitable sensors. Ambient parameters, that is, the environmental parameters where the sheet is located, can influence the parameters of the sheet and thus the corrugation effect that the gap size has on the sheet. One of the surrounding parameters can be measured, depending on the available sensors. More than one environmental parameter can be measured. The size of the gap can be changed depending on these surrounding parameters.

Preferably, the evaluation of the post-corrugation property of the sheet performed after corrugation includes evaluation of the post-corrugation property of multiple corrugations formed on the sheet.

The corrugation process creates corrugations on the sheet, in particular several corrugations, and the corrugations have a given amplitude and pitch. Preferably, the step of assessing the properties of several corrugations formed on the sheet includes assessing the pitch or amplitude of at least one of the several corrugations. The multi-corrugation property that is preferred for determining whether the correct level of corrugation has been achieved is the pitch or amplitude of at least one of the multiple corrugations. More preferably, the pitch or amplitude of more than one of several corrugations is determined. An average value derived from pitch values or amplitude values determined for more than one corrugation can be calculated. Both the pitch and the amplitude of at least one of several corrugations can be assessed. “Estimating the pitch or amplitude of a corrugation” means estimating a value that depends on the pitch or amplitude of the corrugations.

Preferably, the estimated pitch or estimated corrugation amplitude is compared with the expected pitch range or expected amplitude range, respectively. If the estimated amplitude or estimated pitch is outside the expected amplitude range or expected pitch range, respectively, the gap size is changed. Preferably, the average pitch value across multiple corrugations or the average amplitude value across multiple corrugations is compared to the expected pitch range or expected amplitude range, respectively.

Preferably, estimating the pitch or amplitude of at least one of several corrugations includes determining the profile of at least one corrugation. More preferably, estimating the pitch or amplitude of at least one corrugation includes determining the profile of more than one of several corrugations. Preferably, the profile of the corrugations is determined perpendicular to the direction of transport of the sheet. A corrugated profile is essentially a profile formed by a cross-section of a sheet made at a given location with a plane perpendicular to the direction of transportation. Preferably, the profiles define alternating peaks and valleys. Preferably, the amplitude of the profile peaks is estimated. Preferably, the average amplitude is calculated by calculating the average of different amplitudes among different corrugations. The average amplitude may be a property of the corrugations.

Preferably, assessing the properties of several corrugations includes: collecting at different places along the sheet or at certain time intervals the pitch or amplitude of at least one of several corrugations; and comparing the pitch or amplitude of at least one corrugation collected at different locations along the sheet or at specified intervals. More preferably, the method also includes changing the size of the gap based on the comparison. A parameter that can change the effect that corrugation has on the sheet is the "stability" of the created corrugations on the sheet. "Stability" means that the property of the corrugations, such as the pitch or amplitude of the corrugations formed on the sheet, remains substantially unchanged from the moment of formation by the corrugated rollers. The first corrugated roller and the second corrugated roller form corrugations on the sheet, having a certain amplitude and pitch. It is preferable to check whether the corrugation property remains the same on the sheet, for example whether the amplitude or pitch changes or whether both the amplitude and pitch change. The amplitude or pitch of the corrugations can change over time, that is, at a given point in time they can have a certain value and after a certain period of time this certain value can change. The amplitude or pitch of the corrugations may vary depending on the location on the sheet where the measurement is made, that is, at a given location the pitch or amplitude may have a certain value, and in another place the pitch or amplitude may have a different value. If this difference is above a certain threshold value, that is, if the change in amplitude or pitch value exceeds a certain percentage of this value, then the size of the gap can be changed, for example, the size of the gap can be reduced in order to form more stable corrugations.

Preferably, the method includes: removing at least a portion of the sheet based on the assessed property after corrugating the sheet. The method preferably includes the step of removing a portion of the sheet based on the estimated property after corrugating the sheet and one obtained property from the property before corrugating the sheet. The entire sheet may be removed or only a portion of the sheet may be removed and the remaining sheet without the removed portion may be further processed. The remainder of the sheet, which is subjected to further processing, has a post-corrugation property of the sheet, such as a post-corrugation property, within the desired tolerance values. For example, if the property value after corrugating the sheet is outside a predetermined range in a predetermined portion of the sheet with respect to the property before corrugating the sheet, the corrugated sheet is rejected and not subjected to further processing. Alternatively, only that portion of the sheet is cut or otherwise removed that has a property outside the predetermined range after corrugating the sheet. Thus, the part of the corrugated sheet that does not meet the acceptable values is removed from the processing line as quickly as possible.

The method preferably includes creating a database containing one derived property from the property before corrugating the sheet, associated with any of the following: the date of manufacture of the sheet, the temperature of the environment where the sheet is located during corrugation, the length of fibers present in the sheet, the humidity of the environment, where the sheet is located during corrugation, the workability of the sheet. This database may be used to provide operational control of a corrugated sheet or an aerosol generating product component manufactured using a corrugated sheet. The database can be used to create relationships between different parameters. Thus, in the case where some sensors for determining the pre-corrugation properties or surrounding parameters are not present in the installation, using such a database it is possible to predict the value of the desired sheet parameter (ie the pre-corrugation property of the sheet) or the value of the surrounding parameter.

Preferably, the method includes setting the first gap size based on one of the obtained properties from the properties before corrugating the sheet. The method may further include adjusting the first gap size to set the second gap size based on the estimated property after corrugating the sheet. Preferably, the adjustment of the gap size is carried out in two stages. First, the gap size is set as a first value based on the properties before corrugating the sheet. Then the property after corrugation is evaluated. If the property after corrugation is not expected from the property obtained before corrugation, then the first gap size is adjusted. The first gap size becomes the second gap size. The second gap size is determined based on the post-corrugation property. Typically, considering the properties before corrugation, the gap size is set correctly, that is, the first gap size is usually the gap size that provides the correct level of corrugation of the sheet. However, in cases where the first gap size does not provide the correct level of corrugation, the gap size can be changed after evaluating the post-corrugation properties.

Preferably, the sensor adapted to evaluate one of the properties prior to corrugating the sheet comprises a sensor adapted to measure the thickness of the sheet. More preferably, the sensor for measuring sheet thickness comprises a mechanical sensor comprising a wheel or roller in contact with the sheet. Preferably, the sensor for measuring sheet thickness includes an optical sensor for directing an electromagnetic beam onto the sheet. Preferably, the sensor for measuring sheet thickness comprises an interferometer. More than one sensor may be used to measure sheet thickness, such as two or more sensors of the same type, such as two optical sensors, or two or more sensors of different types, such as an optical sensor and a mechanical sensor.

The mechanical sensor may include a wheel that rolls along the top surface of the sheet. The mechanical sensor may include a roller that is in contact with the top surface of the sheet. The wheel height or roller height and its variations are preferably checked and compared with the expected sheet thickness. The comparison is made within a predetermined error.

The interferometer may include an optical light emitter for directing a beam of light, such as a beam of infrared light, onto the sheet of material and onto an additional surface, such as a highly reflective metal surface, placed underneath the sheet. When a beam of light falls on a sheet, some of the light is reflected back by the top surface of the sheet, and some of the light passes through the sheet and is reflected by the metal sheet. The reflected light can form an interference pattern that can be detected. With interferometry, sheet thickness can be calculated from the optical path differences between light reflected by the top surface of the sheet and light reflected by the metal surface underneath the sheet, which creates interference or phase shifts.

The optical sensor may comprise an LED emitter and a receiver located on two opposite sides of the sheet. The LED may emit a beam of diffuse LED light in a parallel, uniform manner on one side of the sheet, and this light is detected by a receiver located on the other side of the sheet, such as at a control roller on which the sheet is moved. Since the location of the reference roller is known, the material thickness is calculated as the difference between the roller location and the optical sensor measurements.

Preferably, the sensor for assessing the property after corrugating the sheet comprises a sensor adapted to measure the property of multiple corrugations. Preferably, the sensor for assessing the corrugation properties of the sheet comprises a laser profilometer. The laser profilometer emits a beam of laser light that is essentially in the shape of a line. A laser profilometer is designed to determine the profile of an object onto which a laser line falls. Preferably, the laser profilometer emits a laser line substantially perpendicular to the direction of transport of the sheet. Preferably the laser line is long enough (wide) to fall onto several corrugations. The laser profilometer is adapted to determine the cross-sectional profile of a sheet on a plane perpendicular to the direction of transportation. Preferably, the laser profilometer acquires profiles at a given frequency. The laser profilometer is adapted to form images during sheet corrugation. Images are formed from sequences of obtained data from a laser profilometer, with each acquired data corresponding to one laser line incident on the sheet. The laser profilometer used in the present invention is, for example, a Keyence LJV7020 using an XG-X2800 controller. The laser profilometer is adapted to obtain an average amplitude value for the profile obtained by each laser line. The profile obtained by each laser line contains the profile of several corrugations.

Preferably, the control unit is connected to a laser profilometer, the control unit being adapted to determine the amplitude or pitch of the profiles obtained by the laser profilometer. From the sheet profile, it is possible to determine the pitch and amplitude of the corrugations formed on the sheet by the first corrugating roller and the second corrugating roller.

Preferably, the apparatus includes an ambient temperature sensor adapted to measure the temperature of the environment where the sheet is located and to send a signal indicating the measured ambient temperature. Preferably, the apparatus includes an ambient humidity sensor adapted to measure the relative humidity of the environment where the sheet is located and to send a signal indicative of the measured relative humidity. Preferably, the apparatus includes a stickiness sensor adapted to measure the stickiness of the sheet at a predetermined location and to send a signal indicating the measured stickiness. The feedback control loop may be adapted to activate the first actuator based on a signal sent by the ambient temperature sensor. The feedback control loop may be adapted to activate the first actuator based on a signal sent by the ambient humidity sensor. The feedback control loop may be adapted to activate the first actuator based on a signal sent by the stickiness sensor. The advantages of having additional sensors have been described with reference to the method.

Preferably, the apparatus comprises a second actuator for rejecting at least a portion of the sheet, the closed loop control system being adapted to activate the second actuator based on a measured pre-corrugation property of the sheet, or based on acquired data relating to one of the pre-corrugation properties, or based on the assessed property after corrugation. The second actuator may include a shutter for removing defects. The second actuator is preferably activated when a sheet or part of a sheet needs to be rejected because the property after corrugating the sheet is not within the recommended range considering the property before corrugation.

Preferably, the control unit communicates with a sensor adapted to measure one of the properties before the sheet is corrugated, as well as with a laser profilometer and the first actuator. In addition, the control unit may be adapted to receive data entered by the user. The control unit can access the memory where the properties are stored before the sheet is corrugated. The control unit may be a microprocessor, microcontroller or computer. The control unit preferably communicates with all pre-corrugation property sensors and post-corrugation property sensors present in the plant, so that the signals from the sensors can be processed centrally. Preferably, the control unit contains a memory device in which the measured values can be stored. The control unit may also receive user input, such as through a keyboard, touch screen, pointing device, or buttons.

Preferably, the closed-loop feedback system is adapted to activate the second actuator based on a signal related to the ambient temperature. Preferably, the closed-loop feedback system is adapted to activate the second actuator based on a signal related to the ambient relative humidity. Preferably, the closed-loop feedback system is adapted to activate the second actuator based on a signal related to the ambient stickiness of the sheet. Preferably, the closed-loop feedback system is adapted to activate the second actuator based on multiple signals from different sensors.

Other advantages of the present invention will become apparent from the detailed description thereof with non-limiting reference to the accompanying drawings:

in fig. 1 is a schematic side view of a machine for producing corrugated sheet material;

in fig. 2 is a schematic perspective view of a pair of corrugating rollers that are part of the installation shown in FIG. 1;

in fig. 3 is a schematic side view of the installation shown in FIG. 1, in which a sheet of material has been removed and additional details are shown;

in fig. 4 is a schematic enlarged cross-sectional front view of a sheet of material corrugated using the apparatus shown in FIG. 1-3;

in fig. 5 is a schematic side view of part of the installation shown in FIG. 1 showing more details;

in fig. 6 is a schematic top view of a corrugated sheet according to the present invention; And

in fig. 7 is a graph representing a phase of the method according to the present invention.

In fig. 1 is a schematic side view of the basic layout of a plant 1 for producing a corrugated sheet of material 10 for an aerosol generating product (not shown in the drawings).

The sheet of material is fed by means of a feed reel 3. On the feed reel 3 there is an "endless" sheet of flat and thin layer of material 2 intended to be corrugated by means of a machine 1. The material 2 may be a sheet of homogenized tobacco. It should be understood that the sheet of material 2 wound on the feed reel 3 is not strictly speaking infinite, but the total length of the sheet of material may be several hundred meters and thus significantly greater than its width. In addition, a transmission mechanism can be provided between two successive feed reels 3 (not shown) to ensure a continuous corrugating process.

The installation 1 contains a first corrugating roller 4 and a second corrugating roller 5. A gap 6 is formed between the first corrugating roller and the second corrugating roller. The gap determines the size 14 of the gap. The first corrugated roller 4 defines the first axis 24 of rotation. The second corrugated roller 5 defines the second axis 25 of rotation. The first rotation axis 24 and the second rotation axis 25 are indicated by crosses in FIG. 1 and 3, and their extent is visible in Fig. 2. The first rotation axis 24 and the second rotation axis 25 are preferably parallel and horizontal. Preferably, one of the first bellows roller 4 or the second bellows roller 5 rotates clockwise while the other of the first bellows roller or the second bellows roller rotates counterclockwise during operation.

The first corrugated roller 4 and the second corrugated roller 5 exhibit a structured outer surface containing a plurality of ridges or corrugations. Corrugations are not visible on graphic materials. Another configuration may also be chosen, in particular, only one of the first corrugated roller 4 or the second corrugated roller 5 may exhibit a structured surface.

To perform corrugation, sheet 2 is inserted into the gap 6 between the first corrugated roller 4 and the second corrugated roller 5. Further along the flow direction relative to the first corrugated roller 4 and the second corrugated roller 5, a corrugated sheet 10 is formed, in which the corrugations are formed by the pressure applied by the corrugated rollers 4 , 5.

The sheet 2 is transported to the first corrugated roller 4 and the second corrugated roller 5 by means of a transport device 7. The transport device 7 determines the transport direction of the sheet 2, indicated by arrow 8 in FIG. 1, 2, 5 and 6.

Previously, in the flow direction relative to the first corrugated roller 4 and the second corrugated roller 5, the property is measured before the sheet 2 is corrugated. For example, the thickness 11 of the sheet 2 is measured. The installation 1 contains a thickness sensor 9 adapted to measure the thickness 11 of the sheet 2 in one or more parts of this sheet. before corrugation. Alternatively or in addition, the installation 1 includes a moisture sensor 90 adapted to measure the moisture content of the sheet 2 in one or more parts of the sheet before corrugation.

In addition, installation 1 contains a control unit 100 that communicates with the thickness sensor 9 and the humidity sensor 90. The thickness sensor 9 and the moisture sensor 90 are adapted to send one or more signals indicative of the thickness 11 and moisture content, respectively, of the sheet 2 in one or more parts of the sheet to the control unit 100.

Further downstream of the first corrugated roller 4 and the second corrugated roller 5 is a sensor for detecting the corrugation property, such as a laser profilometer 12. The sensor 12 is adapted to detect the corrugation property; in this example, it is adapted to detect the profile of the corrugations formed on the corrugated sheet 10 in one or more parts thereof. The laser profilometer 12 communicates with the control unit 100 and is adapted to send one or more signals indicative of the profile of the corrugated sheet 10 in one or more parts to the control unit 100.

As best seen in Fig. 3, in which the sheet of material is not shown for the sake of clarity, the gap 6 between the first bellow 4 and the second bell 5 is adjustable. Installation 1 includes a first actuator, indicated by arrow 13 in FIG. 3, which is used to change the gap size 14. The first actuator 13 can change the distance between the first and second axes 24, 25 of rotation. The first actuator 13 is activated using signals sent by the control unit 100.

The installation 1 also contains a second actuator 15, indicated by an arrow only in FIG. 3, which is adapted to reject the corrugated sheet 10 based on signals generated by the control unit 100 after receiving signals from the laser profilometer 12. The second actuator 15 is connected to the control unit 100, which sends a signal to the second actuator 15 in case the laser profilometer 12 detects a corrugation profile on the corrugated sheet 10 having properties outside the specified range.

The installation 1 may also include a temperature sensor 16 for measuring the temperature of the environment where the sheet 2, the corrugated sheet 10 and the installation 1 are located; a humidity sensor 17 adapted to measure the relative humidity of the environment where the sheet 2, the corrugated sheet 10 and the installation 1 are located; a temperature sensor 19 adapted to measure the temperature of the sheet 2 or corrugated sheet 10 in a predetermined area. All sensors 16, 17, 19 (visible in Fig. 3) are connected to the control unit 100. Other sensors may also be present. In addition, the control unit 100 contains a storage device 18 where the database is located. The database contains data such as leaf composition.

In addition, the memory 18 stores other data, such as expected values for the properties of the corrugations formed by the corrugating rollers 4, 5 on the sheet, the expected values being based on the properties before the sheet is corrugated. For example, in FIG. 7 depicts three expected corrugation amplitudes, each expected corrugation amplitude corresponding to a moisture value before corrugation of the sheet 2. Depending on the moisture value measured by the sensor 90, a different expected corrugation amplitude value is expected.

In fig. 4 is an enlarged front cross-sectional view of the corrugated sheet 10. The corrugated sheet 10 contains several corrugations, all of which are designated by the number 20, which form a “wavy” pattern. Corrugations 20 determine a given amplitude 23 and a given pitch 26.

Installation 1 operates in accordance with the method according to the present invention.

Sheet 2 is unwound from the feed reel 3 and fed into the gap 6 between the first corrugating roller 4 and the second corrugating roller 5 of installation 1 in the form of a single flat layer of material 2. The sheet of material 2 is processed in the gap 6 formed between the corrugating rollers 4, 5 by suitable placing two corrugated rollers 4, 5 at a certain distance by means of the first actuator 13. The size 14 of the gap 6 is usually less than the thickness 11 of the supplied sheet 2, so the sheet 2 is slightly compressed in the gap 6.

The gap size 14 is selected according to the signals sent by the thickness sensor 9 and the humidity sensor 90 to the control unit 100, which in turn controls the first actuator 13. Using the storage device 18 and the data stored therein, as well as the measured thickness or moisture data , the control unit 100 extracts from a graph similar to that shown in FIG. 7, the expected value of the corrugation property to be formed on the corrugated sheet 10, for a measured thickness or moisture content. The graph shown in Fig. 7 is a representation of a lookup table, which is presented in graph form for clarity. For example, the control unit 100 extracts the expected value of the corrugation amplitude 23 for the measured sheet moisture value. Thus, the gap size 14 is set by correspondingly moving the actuator 13 so that the expected corrugation property can be obtained.

Due to the design of the first corrugated roller 4 and the second corrugated roller 5, in particular due to the design of the outer surfaces of the corrugated rollers 4, 5, corrugations 20 are formed on the sheet of material 2 passing through the gap 6. A top view of the corrugations 20 on part of the sheet 10 is shown in FIG. . 6.

Laser profilometer 12 detects the profile of corrugated sheet 10 at a given point. In order to detect the profile, the laser line 21 is incident on the corrugated sheet 10 and illuminates it, as shown in FIG. 6. Preferably, the laser line 21 is substantially perpendicular to the transport direction 8. Illumination of the sheet 10 by the laser profilometer 12 preferably occurs while the corrugated sheet 10 is rotating on the idle roller 70 (see FIG. 5). The length of the laser line 21 is preferably several millimeters in order to illuminate more than one corrugation 20. The profile obtained by the laser profilometer 12 is similar to the curve shown in FIG. 4. The laser profilometer 12 illuminates the sheet 10 at a predetermined frequency so as to obtain multiple profiles as the corrugated sheet 10 moves along the transport direction 8.

For each profile, as shown in FIG. 4, laser profilometer 12 or control unit 100 calculates the amplitude 23 of the corrugations. The average amplitude is then calculated for each profile. The average amplitude value is an important property of several corrugations 20. If the average amplitude value is outside a predetermined first range for a given measured humidity, the sensor 12 sends a signal to the control unit 100, which in turn sends a signal to the first actuator 13 in order to change 14 gaps. Alternatively, the average amplitude value can be calculated directly in the control unit 100.

In the case where the average amplitude value 23 is outside the second range, the sensor 12 sends a signal to the control unit 100, which in turn sends a signal to the second actuator 15 in order to reject the corrugated sheet 10. In case the average value amplitudes are calculated directly in control unit 100; sensor 12 does not send a signal.

The first actuator 13 may also be actuated to change the gap size 14 based on signals received from any of the sensors 16, 17, 19. The second actuator 15 may also be actuated to reject the corrugated sheet 10 based on signals received from any of sensors 16, 17, 19.

Signals from sensors 9, 12, 16, 17, 19, 90 are preferably sent to control unit 100 at a predetermined frequency and throughout the entire corrugating process. In this way, continuous adjustment of the gap size 14 can be performed. The control unit 100 together with sensors 9, 12, 16, 17, 19, 90 forms a feedback control loop.

If the sheet 10 is not rejected, the corrugated sheet 10 is fed to a product reel 27 on which the corrugated sheet 10 of material is wound.

Claims (57)

1. A method for corrugating a sheet having thickness, moisture content, composition and width before corrugation, the method including: obtaining one property before corrugating the sheet from the following: sheet thickness; leaf moisture; leaf composition; sheet width; corrugating a sheet to form several corrugations on the sheet, the corrugation including: providing a pair of corrugated rollers between which a gap is formed, the gap having the size of a gap; inserting the sheet into the gap; assessment of the properties after corrugating the sheet, performed after corrugation; And changing the gap size based on one obtained property from the property before corrugating the sheet and based on the estimated property after corrugating the sheet. 2. The method according to claim 1, characterized in that the sheet is a sheet of material containing alkaloids or a sheet of plastic. 3. The method according to claim 1 or 2, characterized in that the sheet before corrugation has mechanical properties, stickiness, temperature, and the method includes: determination of one additional property before corrugating the sheet from: mechanical properties of the sheet; leaf temperature; leaf stickiness; And changing the gap size based on one specific property from additional properties before corrugating the sheet. 4. The method according to one or more of the previous claims, characterized in that the evaluation of the post-corrugation property of the sheet, performed after corrugation, includes evaluation of the property of several corrugations formed on the sheet after corrugation. 5. The method according to claim 4, characterized in that several corrugations have a pitch and amplitude, and the assessment of the properties of several corrugations includes: assessment of the pitch or amplitude of at least one of several corrugations. 6. The method according to claim 5, characterized in that the assessment of the pitch or amplitude of at least one of several corrugations includes determining the profile of at least one corrugation. 7. A method according to one or more of the previous paragraphs, characterized in that it includes: removing at least a portion of the sheet based on the assessed property after corrugating the sheet. 8. A method according to one or more of the previous paragraphs, characterized in that it includes: setting a first gap size based on one of the obtained properties from the properties before corrugating the sheet; adjusting the first gap size to set the second gap size based on the evaluated property after corrugating the sheet. 9. Installation for corrugating a sheet that, before corrugation, has the property before corrugation, such as: thickness, humidity, composition and width, and the installation contains: a transport device configured to transport the sheet along the transport direction; a pair of corrugating rollers for corrugating the sheet to form several corrugations on the sheet, wherein a gap is formed between the pair of corrugating rollers and said gap has the size of the gap; a sensor configured to evaluate a property after corrugating the sheet, the sensor being located downstream of the pair of corrugating rollers in the transport direction; one of the following: a sensor configured to evaluate one of the properties before corrugating the sheet and send a signal function of one estimated property of the pre-corrugation property, the sensor being located upstream of the pair of corrugating rollers in the transport direction; a storage device containing data relating to one of the properties before corrugating the sheet; a control unit configured to receive said signal function of one estimated property of the pre-corrugation properties, or to obtain data relating to one of the pre-corrugation properties; a first actuator for changing the size of the gap; And a closed-loop control system with feedback configured to activate the first actuator based on one of the estimated properties from the property before corrugating the sheet or based on acquired data relating to one of the properties before corrugating and based on the estimated property after corrugating the sheet. 10. The installation of claim 9, wherein the sensor configured to evaluate one of the properties before corrugating the sheet comprises a sensor configured to measure sheet thickness, wherein the sensor configured to measure sheet thickness comprises one of the following: a mechanical sensor comprising a wheel or roller in contact with the sheet; an optical sensor for directing the electromagnetic beam onto the sheet; interferometer. 11. Installation according to one of paragraphs. 9 or 10, characterized in that the sensor configured to evaluate one of the properties after corrugating the sheet contains a sensor configured to evaluate the properties of several corrugations. 12. Installation according to claim 11, characterized in that the sensor, configured to evaluate the properties of several corrugations, contains: laser profilometer. 13. Installation according to claim 12, characterized in that the control unit is connected to a laser profilometer, and the control unit is configured to determine the amplitude or pitch of the profiles obtained by the laser profilometer. 14. Installation according to one or more of paragraphs. 9-13, characterized in that it contains one of the following: an ambient temperature sensor configured to measure the temperature of an environment in which the sheet is located and capable of sending a signal indicative of the measured ambient temperature; an ambient humidity sensor configured to measure the relative humidity of an environment in which the sheet is located and capable of sending a signal indicative of the measured relative ambient humidity; a stickiness sensor configured to measure the stickiness of the sheet at a predetermined location and send a signal indicating the measured stickiness; a transparency sensor configured to measure the transparency of the sheet and to send a signal indicating the measured transparency, the transparency sensor being located downstream of the pair of corrugated rollers. 15. Installation according to one or more of paragraphs. 9-14, characterized in that it contains a second actuator for rejecting at least a portion of the sheet, wherein the closed-loop control system with feedback is configured to activate the second actuator based on an assessed property before corrugating the sheet, or based on received data related to one of the properties before corrugation, or based on the assessed property after corrugation.

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