EP3772467A1

EP3772467A1 - Method and apparatus for applying labels on tobacco products

Info

Publication number: EP3772467A1
Application number: EP20189706.3A
Authority: EP
Inventors: Fabrizio FAZZIOLI; Massimo Fortini; Stefano Villa; Alessandro RONCONI; Luca Federici
Original assignee: GD SpA
Current assignee: GD SpA
Priority date: 2019-08-09
Filing date: 2020-08-05
Publication date: 2021-02-10
Anticipated expiration: 2040-08-05
Also published as: EP3772467B1; IT201900014478A1; PL3772467T3

Abstract

A method and a related apparatus are proposed herein for applying labels (4) on products of the tobacco industry, and, that is to say, on blanks (2) for making wrappers (3) of smoking articles, on webs of material, on wrappers (3) of smoking articles, on partially ready packets or on packets of the tobacco industry. The method comprises the following steps:- conveying the products (2) to be labelled along a feed path (P) through a labelling unit (5) and providing a first labelling device (501) and a second labelling device (502) of the labelling unit (5), which are positioned along the path (P);- applying to each product (2) a relative label (4) by means of at least one of the two labelling devices (501; 502);- optically checking each labelled product (2) at least at the label (4) and identifying any labelled products (2) in which the label (4) is applied in a non-conforming way compared with a reference labelled product (2); wherein in a condition of adjusting the labelling unit (5) the method comprises the following steps:- selecting one of the two labelling devices (501; 502) as the main labelling device for applying labels (4) to respective products and selecting the other labelling device (502; 501) as the secondary labelling device;- applying at least one test label to a product by means of the secondary labelling device, obtaining a labelled test product;- adjusting the secondary labelling device if the test label optically checked in the labelled test product is applied in a non-conforming way;- performing said step of adjusting the secondary labelling device during application of labels by means of the main labelling device.

Description

TECHNICAL FIELD

This invention relates to a method for applying labels on products of the tobacco industry and a related labelling apparatus.
In detail, this invention relates to a method and a related apparatus for applying labels on products such as blanks for making wrappers of smoking articles, on webs of material, on wrappers of smoking articles, on partially ready packets or on packets of the tobacco industry.
This invention is advantageously applied for making a smoking article such as a cigarette packet containing a group of cigarettes, in which the group of cigarettes is wrapped in a folded blank which forms a smoking article wrapper, which is, in turn, further contained in a rigid outer container, in such a way as to make a packet of smoking articles having two rigid packages, one inside the other.
The blank, which may for example be made of rigid material and be equipped with an extraction opening, is intended to be folded to make the wrapper, which has a removal opening, defined by the extraction opening of the blank.
The method and the apparatus according to this invention may advantageously be used, for example, for applying a label on the extraction opening of the blank, before this is folded, and the following description will explicitly refer to this but without thereby limiting the scope of the invention. In fact, it should be noticed that the method and the apparatus according to this invention may also advantageously be used for applying labels to other components of the tobacco industry such as webs of material, partially ready packets or completed packets, without difficulty.

PRIOR ART

Patent US8123030B2 shows a cigarette packet comprising a group of cigarettes, wrapped in a rigid inner wrapper, having a removal opening through which the cigarettes can be taken out, and a rigid outer container, which contains the wrapper and is provided with a hinged lid; coupled to wrapper is a label, which is glued by means of glue and repositionable on the wrapper for closing the removal opening.
The wrapper is made by folding a blank having an extraction opening, intended to form the removal opening of the wrapper, and applying a label on the extraction opening. The blank has a longitudinal main axis of extension.
For making the inner wrapper described above, the Applicant shows in application EP3489156 a packer machine which comprises a labelling apparatus, suitable for applying to each blank a corresponding label or tab at the extraction opening.
The labelling apparatus comprises a labelling unit, for applying labels to respective blanks, and a conveying unit, which is configured to feed a series of blanks along a feed path through the labelling unit.
The blanks are fed by the conveying unit with the longitudinal axis perpendicular to the feed path.
The labelling apparatus also comprises an optical inspection device, positioned downstream of the labelling unit for optically checking each labelled blank, at least at the label, in such a way as to be able to reject blanks labelled in a non-conforming way. The terms "blanks labelled in a non-conforming way" means blanks in which the label is missing, or faulty (that is to say, with abnormal folds), or incorrectly positioned (that is to say, the label is not in the desired position or has an abnormal orientation), that is to say, labelled blanks which are different from a reference labelled blank, in which the label is applied in a reference position.
The conveying unit comprises a first labelling wheel and a second labelling wheel between which a transfer wheel is interposed. The first labelling wheel receives the blanks for transferring them to the transfer wheel. The transfer wheel receives them and in turn transfers them to the second labelling wheel.
The labelling unit comprises a first labelling device and a second labelling device, which are configured to apply labels on the blanks, wherein the first labelling device is positioned for applying the labels to the blanks at the first labelling wheel and the second labelling device is positioned for applying the labels to the blanks at the second labelling wheel.
The labels are typically glued to a backing web and supplied in the form of a reel to the labelling device, which feeds the backing web and the series of labels glued to it as far as a detaching zone where each label detaches from the backing web and is fed without backing in a direction of detachment so that it can be applied to a respective blank. The direction of detachment of the labels is parallel to the direction of feed of each blank and is superposed on it.
At least one of the two labellers applies labels to the blanks. In fact, the two labelling devices may be made to operate alternately, in such a way that one of the two labelling devices, considered to be the main one, applies labels, and the other, considered to be the secondary one, is paused, or they may be made to operate simultaneously, synchronising the application of labels to different blanks.
A technical intervention to substitute a reel is necessary when the reel of the labelling device which is applying labels is ending and must be substituted with a new reel.
In this case, the labelling device requiring the technical intervention is selected as the secondary labelling device in such a way that the other labelling device, selected as the main labelling device, applies labels to the blanks.
The presence to two labellers allows a technical intervention, manual or automatic, on the labelling device which is not applying labels, which may be cleaning, adjustment, or substitution of the reel which has ended with another, new reel. At the end of the technical intervention, the labelling device is ready to be able to change its role.
However, the Applicant has noticed that, after the change of role, the labelling device which is activated for applying labels requires a temporary adjusting period, since a large number of labels applied may not be in the reference position compared with a reference blank. For example, the labels applied on the extraction opening, may be moved longitudinally, or transversally relative to the longitudinal axis of the blank.
In fact, despite using reels which are "suitable" (that is to say, which meet the specifications required) and in theory the same as each other, there may be differences between one and another which cause non-conforming positioning of the labels; therefore, the non-conforming positioning of the labels is not caused by malfunctions of the labelling device or by non-conforming reels, but simply by the fact that there are differences, although minimal, between the reels.
However, even during normal operation of the main labelling device, it may be necessary to adjust that main labelling device, if within a short time there is an above tolerance threshold increase in the number of blanks labelled in a non-conforming way due to a tendency towards a drift in the position of the labels.
The same above-mentioned problems have been noticed by the Applicant in other labelling apparatuses for products of the tobacco industry.
The reason is due to the fact that the depositing direction, in which the labels are fed without backing from the detaching zone, may not be the same as a reference depositing direction, for example if the backing web on which the series of labels is glued is moved transversally in the detaching zone, or if the series of labels itself is moved transversally towards one of the two edges of the backing web, or even if between labels in the series there is a longitudinal distance different from a reference longitudinal distance.
If the labels are moved, transversally or longitudinally, in the detaching zone, their affixing to the respective products results in products which are labelled in a non-conforming way, that is to say, labelled products which are different from a reference labelled product, in which the label is applied in a reference position.
Therefore in the case of products labelled in a non-conforming way, a condition of adjusting the labelling device which applies labels to the products is necessary, to move the labelling device itself, or the backing web in the labelling device, transversally and/or longitudinally.
Usually, a manual intervention by an operator is required, or an automatic adjustment is activated, if motor-driven operation is provided, and the labelling device is stopped or operated at reduced speed.
An example of automatic adjustment of a labelling device for packages is, for example, show in document US4615757 , in which the packages are fed along a conveying path and the labelling device is movable horizontally above the conveying path relative to the size of the packages themselves. Consequently, production efficiency may be greatly reduced, for the whole duration of the condition of adjusting the labelling device.
The aim of this invention is to provide a labelling method and a related labelling apparatus which are free of the disadvantages described above and which, at the same time, are simple and inexpensive to make. Another aim of this invention is to provide a method for labelling products of the tobacco industry in which there is a labelling unit provided with a pair of labelling devices which allows production efficiency to be increased when a labelling device which applies labels to the products, and which was previously paused for a reel change, or for which a tendency towards a drift in the position of the labels applied is in progress, generates a large number of products labelled in a non-conforming way.
A further aim of this invention is to provide a method for labelling products, which allows a reduction in the number of products rejected in a simple and inexpensive way.
That aim is achieved by a method according to claim 1 and the claims dependent on it and by an apparatus according to claim 17 and the claims dependent on it.
Further features and advantages of the invention will be apparent from the following description with reference to the accompanying drawings, provided by way of example only and non-limiting, in which:

Figure 1 is a schematic front view, with some parts cut away for clarity, of a labelling apparatus in accordance with this invention;
Figure 2 is a perspective front view of an inner wrapper, provided with a removal opening and without a removal opening label, the inner wrapper being usable for wrapping a group of cigarettes;
Figure 3 is a plan view of a blank for making the inner wrapper of Figure 2 labelled with a respective closing label, wherein the blank is a reference blank and the label is applied in a reference position;
Figure 4 is an enlarged partial view of the blank of Figure 3;
Figure 5 is a partial view of a labelled blank, when the label is positioned in a position which is non-conforming because it is moved transversally relative to the reference position;
Figure 6 is a partial view of a labelled blank, when the label is positioned in a position which is non-conforming because it is moved longitudinally relative to the reference position.

In Figure 1, the numeral 1 denotes a labelling apparatus for applying labels 4 on products of the tobacco industry.
The products may be blanks for making wrappers of smoking articles, webs of wrapping material, wrappers of smoking articles, partially ready packets or packets of the tobacco industry.
In detail, the labelling apparatus of Figure 1 is in particular configured to apply labels 4 on blanks 2, in such a way as to make wrappers 3 of smoking articles as shown in Figure 2. It should be noticed that the label 4 is omitted in Figure 2.
Each wrapper 3 is obtained by folding a respective blank 2, shown in Figure 3, which is, for example, rigid (being constituted of cardboard or stiff paperboard) and has an extraction opening 201.
In the various figures the same elements are labelled using the same numbers.
The wrapper 3 comprises a front wall 301, two side walls 302 which are folded at 90° relative to the front wall 301, a rear wall 303 which is folded at 90° relative to the side walls 302 and is parallel to the front wall 301, a top wall 304 which is perpendicular to the walls 301, 302, 303, and a bottom wall 305 which is parallel to and opposite the top wall 304, and is perpendicular to the walls 301, 302, 303.
Without limiting the scope of the invention, the wrapper 3 may advantageously be used in making a rigid cigarette packet (not illustrated) in which a group of cigarettes (not illustrated) is wrapped in the wrapper 3, which is in turn received in an outer container (not illustrated) which has an open top end and is supplied with a cup-shaped lid hinged to the outer container so that it rotates between an open position, in which a user can access the wrapper 3, and a closed position.
The wrapper 3 has a removal opening 306, which is positioned centrally and affects a portion of the front wall 301 and a portion of the top wall 304. The removal opening 306 is made by making in the relative blank 2 a through cut having a closed shaped which delimits inside it a disposable portion which is eliminated so as to leave a hole which constitutes the extraction opening 201.
As illustrated in Figure 3, the removal opening 306 of the wrapper 3 is normally closed by a reusable label 4 which is fixed to the wrapper 3 by means of the repositionable glue which is positioned around the removal opening 306 to allow the label 4 to be partly separated from the wrapper 3 multiple times, each time the wrapper 3 is opened, for accessing the contents of the wrapper 3, and then fixed to the wrapper 3 again, each time the wrapper is closed.
The repositionable glue is a glue which does not dry after it has been applied and therefore allows the label 4 to be repeatedly separated from and stuck to the underlying wrapper 3 again.
As already indicated, the wrapper 3 is obtained by folding the blank 2.
It should be noticed that the blank 2 has a main longitudinal axis A of extension and comprises two longitudinal fold lines 202 and a plurality of transversal fold lines 203 which define, between the two longitudinal fold lines 202, a panel 301' which constitutes the upper part of the front wall 301, a panel 304' which constitutes the top wall 304, a panel 303' which constitutes the rear wall 303, a panel 305' which constitutes the bottom wall 305 of the wrapper 3, and a panel 301" which constitutes the lower part of the front wall 301 of the wrapper 3.
The panel 301' is partly superposed on the panel 301" to constitute the front wall 301 of the wrapper 3 and there is a superposing band in which a lower portion of the panel 301' is resting over an upper portion of the panel 301". The blank 2 comprises a pair of flaps 302', which are positioned on opposite sides of the panel 301', are connected to the panel 301' along the two longitudinal fold lines 202, and constitute part of the side walls 302. The blank 2 comprises a pair of flaps 302"', which are positioned on opposite sides of the panel 303', are connected to the panel 303' along the two longitudinal fold lines 202, constitute part of the side walls 302, and are superposed on the corresponding flaps 302' to constitute part of the side walls 302 themselves. The blank 2 comprises a pair of flaps 302", which are positioned on opposite sides of the panel 301", are connected to the panel 301" along the two longitudinal fold lines 202, constitute part of the side walls 302, and are superposed on the corresponding flaps 302'" to constitute part of the side walls 302 of the wrapper 3.
The blank 2 comprises a pair of first flaps 204, which are positioned on opposite sides of the panel 304', are connected to the panel 304' along the two longitudinal fold lines 202, and are folded at 90° relative to the panel 304' so that they are resting on the flaps 302"'. The blank 2 additionally comprises a pair of second flaps 205, which are positioned on opposite sides of the panel 305', are connected to the corresponding flaps 302"' along a transversal fold line 203, and are folded at 90° relative to the corresponding flaps 301'" so that they are resting on the panel 305'. According to a preferred variant, the wrapper 3 may be free of glue inside and it may be glued only to the outer container of the cigarette packet by means of adhesive material 210, positioned at the panel 303' of the blank 2, that is to say, the rear wall 303 of the wrapper 3, at the panel 305', that is to say, at the bottom wall 305, and at the panel 301", that is to say, at the lower part of the front wall 301 of the wrapper 3. Alternatively, the various panels of which the wrapper 3 is made up may be not just superposed but also glued to each other for insertion in different types of cigarette packets. The blank 2 is delimited by a pair of longitudinal edges 206 and 207, parallel to the longitudinal fold lines 202, and by a pair of transversal edges 208 and 209, wherein the transversal edge 208 is parallel to the transversal fold lines 203 and delimits the panel 301' whilst the edge 209 is shaped because it delimits the superposing band of the panel 301".
Considering Figure 3 and without limiting the scope of the invention, the longitudinal edge 206 may be called the upper edge whilst the longitudinal edge 207 may be called the lower edge.
The relative label 4 is applied to each blank 2.
As shown in more detail in Figure 4, in a labelled blank 2, that is to say, a blank having the respective label 4, the label 4 is considered applied in a conforming way if considering a lower corner 401 of the label 4, for example the right-hand lower corner applied in the panel 301', the corner is placed at a first predetermined distance D1 from the lower edge 207 and is placed at a second predetermined distance D2 from the transversal edge 208, subject to a respective predetermined permitted first tolerance given for the distance D1 and a respective predetermined second tolerance given for the distance D2. For simplicity, we will refer to the first distance D1 and to the second distance D2, although there is a more precisely identifiable first range of validity associated with D1 and a second range of validity associated with D2.
If, in the labelled blank 2, it is detected that the lower corner 401 is placed at a first distance D' from the lower edge 207 which is different from the predetermined first distance D1; or is placed at a second distance D" from the transversal edge 208 which is different from the predetermined second distance D2, then the label 4 is considered applied in a non-conforming way as illustrated in Figure 5 and in Figure 6.
Figure 5 shows the lower corner 401 of the label 4 placed at the first distance D', which is different from the predetermined first distance D1. In contrast,
Figure 6 shows the lower corner 401 placed at the second distance D", which is different from the predetermined second distance D2.
Even if in other types of products on which the label 4 is applied, for example the wrapper 3 or a packet partially completed, the label 4 is considered applied in a conforming way using assessment criteria different from the first distance D1 and the second distance D2, it should be noticed that they are subject to the same considerations which are valid for the apparatus 1 and the method described below.
As illustrated in Figure 1, the labelling apparatus 1 comprises a labelling unit 5, configured to apply labels 4 to the relative products.
In detail, if the product is a blank 2, the apparatus 1 is configured to apply to each blank 2 a relative label 4, for closing the extraction opening 201. The labelling apparatus 1 comprises a conveying unit 6, which is configured to feed a series of products, for example the blanks 2, along a feed path P, shown in Figure 3, through the labelling unit 5.
The labelling unit 5 comprises a first labelling device 501 and a second labelling device 502, which are positioned along the feed path P, which are configured to apply the labels 4.
The products, that is to say, the blanks 2, are fed in the feed path P in such a way that they have the respective longitudinal axes A transversal to the feed path P itself.
In detail, the conveying unit 6 is a single feed wheel 601 which is rotatably mounted with a horizontal axis of rotation and is provided with a plurality of suction seats (not illustrated) suitable for retaining by suction each blank 2 through the labelling unit 5.
The feed path P is defined in the feed wheel 601, between a receiving station 602 for the blanks 2 without closing labels 4, and a delivery station 603 for the labelled blanks.
However, the conveying unit 6 may be a plurality of labelling wheels (not illustrated) or a linear conveyor (not illustrated), comprising a conveying branch and a return branch, with regard to the product to be conveyed through the labelling unit 5. In the case of wrappers 3 or packets, preferably, the conveying unit is a linear conveyor.
The labelling apparatus 1 comprises a check unit (not illustrated), which comprises an optical inspection device 7, positioned downstream of the labelling unit 5 along the path P, for optically checking each labelled product at least at the label 4, and for identifying any labelled products in which the label 4 is applied in a non-conforming way compared with a reference labelled product.
The term "optically check" means that the optical inspection device 7 is configured to acquire an image of the labelled product and to process it, comparing it with the reference labelled product so as to identify products which are labelled in a non-conforming way as illustrated below.
The check unit comprises an actuating device (not illustrated) for operating at least one of the two labelling devices 501, 502, that is to say, the first labelling device 501 or the second labelling device 502, for applying the labels 4.
The first labelling device 501 and the second labelling device 502 can be controlled individually by the check unit actuating device.
During a labelling unit 5 production condition, the two labelling devices 501, 502, may operate alternately, that is to say, one of the two, considered the main labelling device, may be controlled so that it applies labels 4, whilst the other, considered the secondary labelling device, may be paused. Alternatively, the two labelling devices 501, 502, may operate simultaneously but at reduced speed, synchronising the application of labels 4 to different products.
The first labelling device 501 and the second labelling device 502 are similar in structure and operation and are configured to feed to the blanks 2, or more generally to the products, the labels 4, which are supplied glued equally spaced from each other on respective backing webs 504' and 504", which are wound in respective reels 503' and 503".
The first labelling device 501 and the second labelling device 502 each comprise a respective detaching zone, beyond which each label 4 detaches from the respective backing web 504' and 504" and is fed without backing in a respective direction of detachment (not illustrated).
In fact, each labelling device 501, or 502 comprises a depositing fin 505', 505", having a wedge-shaped cross-section, around which the label 4 backing web is wrapped.
Each depositing fin 505', 505" is shaped in such a way that at its end it imposes a sudden change of direction on the backing web 504' and 504", in order to cause the labels 4 to detach, one at a time, from the respective backing web 504' and 504". Each depositing fin 505', 505" defines the respective detaching zone of the first labelling device 501 and of the second labelling device 502. The backing web 504' and 504", without labels 4, is then wound in a respective recovery reel 506' and 506".
Therefore, each label 4 is fed in the respective direction of detachment from the detaching zone 505', 505", after detaching from the respective backing web 504' and 504".
Each label 4 is fed to the respective blank 2 parallel to the feed path P, that is to say, transversally to the longitudinal axis A of each blank 2. In other words, the direction of detachment of the labels 4 from each labelling device 501, or 502, is parallel to the feed path P.
In a condition of adjusting the labelling unit 1, the actuating device is configured to select one of the two labelling devices 501 or 502, of the labelling unit 5 as the main labelling device, for applying the labels to respective products, in particular to the blanks 2, and the other labelling device 502, or 501, as the secondary labelling device.
The actuating device is additionally configured to control the secondary labelling device so that it applies at least one test label to a test product, for example to a test blank, in order to obtain a labelled test product, in particular a labelled blank 2, and to adjust the secondary labelling device if the test label optically checked in the labelled test product is applied in a non-conforming way.
The actuating device is configured to control the main labelling device so that it applies labels 4 to respective products, during adjustment of the secondary labelling device.
Thanks to the condition of adjusting the labelling unit 5, the actuating device can correct the application of the test labels by the secondary labelling device whilst the main labelling device can continue to apply labels 4 to the products as if it were in a labelling unit 5 production condition.
In this way, when the actuating device establishes that the main labelling device must be paused, for example for a reel change, and that the secondary labelling device must become the new main labelling device, the adjustment of the application of the labels 4 in the relative blanks 2 by the secondary labelling device has already been performed and therefore there is no longer any need to adjust it again, thereby greatly increasing production efficiency.
The term "test label" applied to a "test product" means a label 4 applied by the secondary labelling device, when the latter is in the adjusting condition, on a product, for example on a blank 2, fed by the conveying unit 6, which is considered as a test product for testing a correct application of the label 4 on it.
It should be noticed that, if the product is a blank 2, the conveying unit 6 is a single labelling wheel, which conveys blanks 2, and that the first labelling device 501 and the second labelling device 502 are positioned one after the other along the feed wheel 601.
The actuating device is configured to pause the main labelling device before application of the test label by the secondary labelling device.
In this way, the actuating device ensures that a single test label is applied to the test product, for example the test blank, and also follows conveying of the labelled test product as far as the optical inspection device 7, to optically check the labelled test product and assess any adjustments of the secondary labelling device.
After application of the test label and during the step of adjusting the secondary labelling device, the actuating device is configured to activate the main labelling device in such a way that it applies labels 4 to respective products.
In order to optically assess the labelled test product, what was previously said applies, that is to say, the optical inspection device 7 is configured to acquire an image of the labelled test product and to process it, comparing it with the reference labelled product.
In detail, the check unit comprises a processing device (not illustrated) for comparing a position of the test label in the labelled test product, detected by the optical inspection device 7, with the reference position and for controlling a movement of the secondary labelling device based on said comparison.
As previously illustrated in detail, in the case of the blank 2, the reference position may be compared by considering the predetermined first distance D1 from the lower edge 207 and the predetermined second distance D2 from the transversal edge 208.
The actuating device is configured to adjust the secondary labelling device and to control the application of a plurality of further test labels, consequently adjusting the secondary labelling device, until a test label applied in a conforming way is detected.
The labelling apparatus comprises a rejection device (not illustrated) suitable for rejecting a product labelled in a non-conforming way, whether this is a product labelled with the label 4 by the main labelling device or a test product, labelled with a test label by the secondary labelling device.
In the case of blanks 2, the rejection device is placed in the conveying unit 6 at a rejection station (not illustrated).
The processing device (not illustrated) is additionally configured to track the labelled blank 2 which has been optically checked by the optical inspection device 7 during feed in the feed path P, in such a way that the actuating device can operate the rejection device when the blank 2 labelled in a non-conforming way is at the rejection station.
The rejection station is positioned upstream of the delivery station 603, that is to say, rejection of the blanks labelled in a non-conforming way occurs as they are fed in the feed path P.
It should be noticed that labelled test blanks, that is to say, on which test labels have been affixed by the secondary labelling device, are alternated with labelled blanks, in which the labels 4 have been applied by the main labelling device.
In use, a method is provided for applying labels 4 on products of the tobacco industry, for example on rigid blanks 2 having an extraction opening 201 which are intended for making wrappers 3 of smoking articles, by folding the blank 2.
Despite the method being described in particular with reference to the apparatus 1, configured to apply the labels 4 on blanks 2, the same method may be used without difficulty to apply labels to other products, as has previously been said and for brevity will not be repeated here.
The method comprises the following steps:

conveying the products to be labelled along a feed path P through a labelling unit 5;
providing a first labelling device 501 and a second labelling device 502 of the labelling unit 5, which are positioned along the path P;
applying to each product 2 a relative label 4 by means of at least one of the two labelling devices 501; 502;
optically checking each labelled product at least at the label 4 and identifying any labelled products in which the label 4 is applied in a non-conforming way compared with a reference labelled product 2; in a condition of adjusting the labelling unit 5 the method comprises the following steps:
selecting one of the two labelling devices 501, 502 as the main labelling device for applying labels to respective products and selecting the other labelling device 502; 501 as the secondary labelling device;
applying at least one test label to a product by means of the secondary labelling device, obtaining a labelled test product;
adjusting the secondary labelling device if the test label optically checked in the labelled test product is applied in a non-conforming way;
performing said step of adjusting the secondary labelling device during application of labels by means of the main labelling device.

Thanks to the method according to this invention, in the condition of adjusting the labelling unit 5 it is possible to correct the application of the test labels by the secondary labelling device when the main labelling device continues to apply labels.
The method comprises the step of pausing the main labelling device 501, or 502, before application of the test label by the secondary labelling device 502, or 501.
The method also comprises the step of activating the main labelling device 501, or 502 for applying labels to respective products, after application of the test label and during the step of adjusting the secondary labelling device 502, or 501.
In other words, advantageously, the step of applying the test labels by the secondary labelling device 502, or 501, takes place when the main labelling device 501, or 502, is temporarily paused, as it is activated only after application of the test label, when the secondary labelling device 502, or 501 is adjusted.
The step of adjusting the secondary labelling device 502, or 501 may comprise the step of moving the secondary labelling device transversally relative to the direction of detachment of the labels 4, that is to say, transversally relative to the feed path P.
After application of the test label and before moving the secondary labelling device 502, or 501 transversally, the step of adjusting the secondary labelling device comprises the step of pausing the secondary device. Thanks to the fact that the secondary labelling device 502, or 501 is paused and is not in the operating condition of applying labels to the blanks, adjusting of the secondary labelling device 502, or 501 can take place precisely and in the necessary time and even if that adjusting is slow, there is no impact during the labelling machine productive step.
For example, the whole secondary labelling device may be moved transversally manually, by an operator, or automatically, if a movement actuator is provided.
If the product is the blank 2, which has an extraction opening 201, the method comprises the step of conveying the blanks 2 to be labelled, having a main longitudinal axis A of extension, along the feed path P in such a way that the axis A is transversal to the feed path P.
The step of applying labels 4 comprises applying labels 4 at the extraction opening 201 of the blank 2.
By moving the secondary labelling device 502, or 501 transversally relative to the direction of detachment of the labels 4, and therefore transversally relative to the feed path P, it is possible to correct the application of a test label to a test blank longitudinally relative to the axis A.
Advantageously, the labelled blanks 2 are conveyed as far as the delivery station 603 and the optical check of each labelled blank is performed upstream of the delivery station 603, that is to say, when the labelled blank is still conveyed by the conveying unit 6, that is to say is still in the feed wheel 601 which constitutes the conveying unit 6.
Moreover, adjustment of the secondary labelling device may comprise the step of bringing forward, or delaying, application of a test label for correcting application of the test labels parallel to the direction of detachment, that is to say, parallel to the feed path P.
If the product is the blank 2, bringing forward, or delaying, application of a test label on the respective extraction opening 201 of a test blank, corrects application of the labels 4 transversally relative to the longitudinal axis A of the blanks 2.
In this case, although the step of pausing the secondary device is not necessary, it is in any case advantageous for the secondary labelling device to not be in the operating step, preferable for guaranteeing precision in the application of the labels 4 in the case of a manual or automatic operation.
In order to identify any labelled test products in which the test label is applied in a non-conforming way, the labelling method also comprises the further step of comparing a position of the test label in the labelled test product with a reference position in the reference labelled product, in such a way as to calculate an application error on which to base adjustment of the secondary labelling device.
In addition to assessment of a labelled test product on which a test label is applied, the method may also comprise the step of applying a plurality of test labels in a plurality of further products in order to obtain labelled test products; comparing the positions of the further test labels in the respective labelled test products with respective reference positions in such a way as to calculate an average application error based on the plurality of test labels applied.
The adjustment of the secondary labelling device may be based on the average application error.
Advantageously, by applying multiple test labels to as many products and obtaining labelled test products, and by calculating the average application error, the secondary labelling device is adjusted only at the end of a test label application interval and in this way variations over time in application of the test labels can be considered.
The step of moving the secondary labelling device transversally relative to the direction of detachment, that is to say, transversally relative to the feed path P may be based on the application error, or on the average application error.
Similarly, even bringing forward or delaying application of the test labels, may be based on the application error, or on the average application error. The labelling method according to this invention additionally comprises the step of repeating multiple times the step of adjusting the secondary labelling device.
In other words, if the test label detected on the labelled test blank is applied in a non-conforming way, the labelling method comprises again pausing the main labelling device, controlling the secondary labelling device in such a way that it again applies a test label to a respective test blank, again adjusting the secondary labelling device, if the test label detected in the labelled test blank is again applied in a non-conforming way. During the new adjustment of the secondary labelling device, the main labelling device is again made to operate.
Therefore, the step of adjusting the secondary labelling device may be repeated multiple times. However, the method comprises the step of evaluating the secondary labelling device as faulty, if the adjusting step is performed a number of times which exceeds a predefined maximum number.
However, it must be emphasised that such faultiness might not be entirely attributable to the secondary labelling device. If, for example, the secondary labelling device were paused due to a reel change and the machine operator fitted a reel 503', or 503", of the type required for the product to be labelled but with a pitch between labels different relative to that of the reel 503', or 503" previously used or in which the labels are moved transversally in the web, the faultiness of the secondary labelling device would be chiefly due to the reel rather than to an error of the labelling device itself.
The faultiness of the secondary labelling device may therefore be translated into a request for intervention intended for a machine operator.
Advantageously, this occurs during application of labels 4 by the main labelling device which can continue to operate undisturbed. The production efficiency of the labelling apparatus is not reduced, despite adjustment of the secondary labelling device.
If, in contrast, the test label optically checked by the optical inspection device 7 on the labelled test product is applied in a conforming way, then the method comprises the step of ending the condition of adjusting the labelling unit 5. From this moment, the secondary labelling device may be selected to apply labels to the products, that is to say, it may be selected as the main labelling device after the end of the adjusting condition, during a subsequent step of adjusting the labelling unit 5.
The labelling method also comprising the step of rejecting the products labelled in a non-conforming way, which have been optically checked and for which the label is applied in a non-conforming way compared with a reference labelled product, since each product is tracked as it is fed in the path P of the conveying unit 6.
Therefore, thanks to the labelling method and to the related labelling apparatus 1 according to this invention, the production efficiency of the labelling apparatus itself is increased in a simple and inexpensive way.
The method according to this invention comprises the step of activating the condition of adjusting the labelling unit 5 when a reel change is expected, since the reel of the labelling device which is applying labels to the products is ending.
For example, if it is the first labelling device 501 which is applying labels to the products, the first labelling device 501 is selected as the main labelling device and continues applying labels to the products whilst the second labelling device 502, in which the reel has been loaded and is still new, is selected as the secondary labelling device.
The secondary labelling device is adjusted while the main labelling device continues applying labels to the products and therefore the secondary labelling device applies at least one test label to a product, obtaining a labelled test product. The secondary labelling device, that is to say, the second labelling device 502 is adjusted if the test label optically checked in the labelled test product is applied in a non-conforming way.
At the end of the adjusting condition, the second labelling device 502 is ready to start applying labels to respective products. Therefore, the reel change procedure can be activated, and the second labelling device 502 will start applying labels to respective products whilst the first labelling device 501 is paused for substitution of the reel which ended. Since it has already been adjusted, the second labelling device 502 does not require any further adjustment.
The method according to this invention may comprise the step of activating the condition of adjusting the labelling unit 5 even if there is a high frequency of products labelled in a non-conforming way, that is to say, when the quality of application of the labels to the products falls over time since the number of labelled products rejected increases over time.
For example, if it is the first labelling device 501 which is applying labels to the products and the number of rejects is increasing over time, the first labelling device 501 is selected as the secondary labelling device whilst the second labelling device 502 is selected as the main labelling device.
The secondary labelling device, that is to say, the first labelling device 501, is adjusted while the main labelling device continues applying labels to the products, that is to say, the secondary labelling device is activated in such a way that it applies at least one test label to a product, obtaining a labelled test product.
In order to assess a drift over time in the quality of application of labels by the secondary labelling device, multiple test labels are applied to as many products, obtaining respective labelled test products and calculating the average application error. The secondary labelling device, that is to say, the first labelling device 501, is adjusted using the average application error.
In this way, it is possible to solve, for example, a problem linked to a transversal drift of the web on which the labels are applied, which in the detaching zone may be moved relative to a reference position.
At the end of the adjusting condition, the first labelling device 501 is again ready to start applying labels to respective products.
Therefore, it should be noticed that, in a simple and inexpensive way, the method according to this invention may be applied to multiple different products and to labelling apparatuses configured in a different way and is capable of increasing the production efficiency of the apparatus itself and of the automatic machine in which the apparatus is inserted.

Claims

Method for applying labels (4) on products of the tobacco industry, and, that is to say, on blanks (2) for making wrappers (3) of smoking articles, on webs of wrapping material, on wrappers (3) of smoking articles, on partially ready packets or on packets of the tobacco industry, the method comprising the following steps:
- conveying the products (2) to be labelled along a feed path (P) through a labelling unit (5);

- providing a first labelling device (501) and a second labelling device (502) of the labelling unit (5), which are positioned along the path (P);

- applying to each product (2) a relative label (4) by means of at least one of the two labelling devices (501; 502);

- optically checking each labelled product (2) at least at the label (4) and identifying any labelled products (2) in which the label (4) is applied in a non-conforming way compared with a reference labelled product (2); wherein in a condition of adjusting the labelling unit (5) the method comprises the following steps:

- selecting one of the two labelling devices (501; 502) as the main labelling device for applying labels (4) to respective products (2) and selecting the other labelling device (502; 501) as the secondary labelling device;

- applying at least one test label to a product by means of the secondary labelling device, obtaining a labelled test product;

- adjusting the secondary labelling device if the test label optically checked in the labelled test product is applied in a non-conforming way;

- performing said step of adjusting the secondary labelling device during application of labels by means of the main labelling device.
The method according to claim 1, and comprising the step of pausing the main labelling device, before application of the test label by the secondary labelling device.
The method according to claim 1, or 2, and comprising the step of activating the main labelling device for applying labels (4) to respective products, after application of the test label and during the step of adjusting the secondary labelling device.
The method according to one of the preceding claims, wherein the step of adjusting the secondary labelling device comprises the step of moving the secondary labelling device transversally relative to a direction of detachment of the label (4) from a respective detaching zone (505'; 505").
The method according to claim 4, wherein the product is a rigid blank (2) having an extraction opening (201) and the method comprises the step of conveying the blanks (2) to be labelled, having a main longitudinal axis (A) of extension, along the feed path (P) in such a way that the axis (A) is transversal to the feed path (P); wherein the step of applying labels (4) comprises applying labels (4) at the extraction opening (201) and wherein the step of moving the secondary labelling device comprises the step of correcting the application of a test label to a test blank longitudinally relative to the axis (A) of the blank (2).
The method according to claim 4, or 5, and comprising the step of pausing the secondary device, after application of the test label, before moving the secondary labelling device transversally.
The method according to one of the preceding claims, wherein the step of adjusting the secondary labelling device additionally comprises the step of bringing forward, or delaying, application of a test label for correcting application of the test labels parallel to a direction of detachment of the label (4) from a respective detaching zone (505'; 505").
The method according to claim 7, wherein the product is a rigid blank (2) having an extraction opening (201) and the method comprises the step of conveying the blanks (2) to be labelled, having a main longitudinal axis (A) of extension, along the feed path (P) in such a way that the axis (A) is transversal to the feed path (P); and wherein the step of applying labels (4) comprises applying labels (4) at the extraction opening (201) and the step of bringing forward, or delaying, application of a test label to a test blank comprises the step of correcting application of the test label transversally relative to the axis (A) of the blank (2).
The method according to one of the preceding claims, wherein the step of identifying any labelled test products in which the test label is applied in a non-conforming way comprises the step of comparing a position of the test label in the labelled test product with a reference position in the reference labelled product, in such a way as to calculate an application error; said step of adjusting the secondary labelling device being based on said application error.
The method according to one of claims 1 to 8, and comprising the step of applying a plurality of test labels in a plurality of respective products in order to obtain labelled test products, comparing the positions of the further test labels in the respective labelled test products with respective reference positions in the reference labelled product in such a way as to calculate an average application error based on the plurality of test labels applied; said step of adjusting the secondary labelling device being based on said average application error.
The method according to claim 9, or claim 10, as appended to one of claims 4 to 6, wherein said adjusting step comprises moving the secondary labelling device transversally based on the application error, or on the average application error.
The method according to claim 9, or claim 10, as appended to claim 7, or 8, wherein said adjusting step comprises bringing forward or delaying the application of test labels based on the application error, or on the average application error.
The method according to one of the preceding claims, and comprising the step of repeating multiple times the step of adjusting the secondary labelling device and of evaluating the secondary labelling device as faulty if said adjusting step is performed a number of times which exceeds a predefined maximum number.
The method according to one or more of the preceding claims, and comprising the step of ending the condition of adjusting the labelling unit (5), if the test label optically checked in the labelled test product is applied in a conforming way; the secondary labelling device being selectable as the main labelling device at the end of the adjusting condition.
The method according to one or more of the preceding claims, and also comprising the step of rejecting the products, or the test products, labelled in a non-conforming way.
The method according to one or more of the preceding claims, and comprising the step of activating the condition of adjusting the labelling unit (5) when a reel change is expected, selecting as the main labelling device the labelling device which is applying labels to the products and in which the reel is ending and as the secondary labelling device the other labelling device in which the reel is still new; or when there is a high frequency of products labelled in a non-conforming way, selecting as the secondary labelling device the labelling device which is applying labels to the products in a non-conforming way and as the main labelling device the other labelling device.
Apparatus (1) for applying labels (4) on products of the tobacco industry, and, that is to say, on blanks (2) for making wrappers (3) of smoking articles, on webs of wrapping material, on wrappers (3) of smoking articles, on partially ready packets or on packets of the tobacco industry, the apparatus comprising:
- a labelling unit (5) configured to apply labels (4) to the products (2);

- a conveying unit (6), which is configured to feed a series of products (2) along a feed path (P), through the labelling unit (5); wherein the labelling unit (5) comprises a first labelling device (501) and a second labelling device (502), which are positioned along the feed path (P), which are configured to apply said labels (4); wherein the apparatus (1) additionally comprises:

- a check unit comprising: an optical inspection device (7), positioned downstream of the labelling unit (5) for optically checking each labelled product (2), at least at the label (4) and for identifying any labelled products (2) in which the label (4) is applied in a non-conforming way compared with a reference labelled product (2);

- an actuating device configured to operate one of the two labelling devices (501; 502) for applying said labels (4); wherein, in a condition of adjusting said labelling unit (5), the actuating device is configured to select one of the two labelling devices (501; 502) as the main labelling device for applying the labels to respective products (2) and the other labelling device (502; 501) as the secondary labelling device and is also configured: to control the secondary labelling device so that it applies at least one test label to a test product to obtain a labelled test product, adjusting the secondary labelling device if the test label optically checked in the labelled test product is applied in a non-conforming way; and to control the main labelling device so that it applies labels (4) during adjustment of the secondary labelling device.