WO2024032993A1

WO2024032993A1 - Labeling module with correction system

Info

Publication number: WO2024032993A1
Application number: PCT/EP2023/068963
Authority: WO
Inventors: Mattia Giuliani; Marco Ferri; Cristian ANDREATO
Original assignee: Sidel Participations
Priority date: 2022-08-12
Filing date: 2023-07-10
Publication date: 2024-02-15

Abstract

There is described a labeling module (6) for labeli ng containers (4) by means of labels (2) obtained from a web (3) of labeling material, and comprising: a feeding system (8) for feeding the web (3) along a feed path (P) a nd including a feed roller (14) rotatably motorized ab out its own central axis (X) and actuatable in rotation abo ut its own central axis (X) to advance the web (3) along t he feed path (P); a transfer device (12) arranged along the feed path (P) downstream of the feeding system (8) for receiving labeling material therefrom and configure d to apply labels (2) obtained from the labeling materia l on respective containers (4) at an application station (A); wherein the feeding system (8) is movable with resp ect to the transfer device (12), so as to cause a variatio n of the tilt of the central axis (X) of the feed roller (14) with respect to the transfer device (12), for corre cting the positioning of the labels (2) on the containers (4).

Description

TITLE: “LABELING MODULE WITH CORRECTION SYSTEM” ***** TECHNICAL FIELD The present invention relates to a labeling module for a labeling machine configured to label containers adapted for containing a pourable product, preferably of food type, in particular a labeling machine for applying labels obtained from a web of labeling material on the aforesaid containers. The present invention also relates to a method of labeling containers adapted for containing a pourable product, preferably of food type. BACKGROUND ART Labeling machines are known which are commonly used to prepare, convey and apply labels on containers, in particular bottles, jars or the like, made of plastic or glass, adapted for containing, or destined to be filled with, a pourable product, preferably of food type. The use of glued labels, obtained from a web of labeling material initially wound in the form of a continuous strip on one or more reels, is particularly widespread. In detail, this web is cut into portions of equal size, to which glue is applied. The glue is applied using gluing means, for example rollers, spray or injection systems, or the like. The labels thus obtained are then transferred and glued on the external lateral surface of the respective containers. Another particularly widespread type of labeling involves the production of sleeve labels, produced from a web of heat-shrink film initially wound in the form of a continuous strip on one or more reels; these sleeve labels are applied with a certain slack on the respective containers and then heated in an oven to obtain shrinking and perfect adhesion thereof to the lateral surfaces of said containers. This type of label does not involve the use of glue. Regardless of the type of label used, a labeling machine typically comprises: - a carousel rotatable about a vertical axis and configured to convey a series of containers along a horizontal labeling path in the form of an arc of circle; - an input station, in which the containers to be labeled are fed to the carousel; - an output station, in which the labeled containers leave the carousel; and - one or more labeling modules arranged peripherally with respect to the carousel and configured to feed respective pluralities of labels to the carousel itself at an application station, in order to apply these labels to the respective containers. Generally, the labeling module comprises: - a feeding system for unwinding the web from the respective reel of labeling material, typically supported by a corresponding shaft mounted rotatable on the labeling module, and for advancing the web along a feed path; - a plurality of support rollers for supporting and guiding the web unwound from the reel along the feed path; - a cutting device configured to repeatedly cut the web to obtain therefrom a sequence of single portions of labeling material defining the labels; and - a label transfer device, configured to receive, retain and advance each label previously obtained and feed this label to the carousel at the application station. In the case of sleeve labels, the labels are wound in a tube around respective forming spindles advanced by the carousel and carrying above the containers to be labeled; the labels are then welded at the overlapping ends; at this point, the spindles are withdrawn inside the base of the carousel to allow the containers to be inserted with slack inside the respective sleeve labels; subsequently, the containers with the slack labels are sent to the heating oven to obtain heat-shrinking of the labels and perfect adhesion of the latter on the containers themselves. Typically, the transfer device is defined by a vacuum drum rotatable about a central axis and configured to receive the previously cut labels on an external lateral surface thereof, to retain them by means of suction and, after a rotation by a given angle about its central axis, to release these labels at the application station, so that they are applied on the respective containers or on the forming spindles. More precisely, the vacuum drum comprises, at its external lateral surface, a plurality of reception sectors configured to receive and retain one label at a time and each angularly delimited by a pair of “pads”, i.e. a front pad and a rear pad, which grip and retain, in use, the longitudinal ends of each label. In the case of labels that use glue, the labeling module further comprises at least one gluing roller arranged substantially tangent to the vacuum drum to spread glue on at least the longitudinal ends of each single label. Typically, the feeding system comprises: - a feed roller rotatable about a first axis and actuatable in rotation to control the advance of the web by means of gripping on an external lateral surface thereof; and - a pinch roller rotatable about a second axis, generally parallel to the first axis, and opposed in pressure to the feed roller, so that the external lateral surface thereof presses against the external lateral surface of the feed roller, with interposition of the web being unwound. In detail, the feed roller is active, i.e., motorized about a first axis, to control the aforesaid unwinding, while the pinch roller is passive, i.e. rotates idle about the second axis driven by the feed roller, and presses against the feed roller so as to define an counter-roller for the latter and allow correct unwinding of the web from the related reel, and feed thereof along the aforesaid feed path. The possibility of erroneous, non-nominal or incorrect positioning of the labels on the containers is known in the field. To solve this problem, a solution is known according to which the labeling module further comprises a correction system of the positioning and/or of the trajectory of the web. Typically, this correction system comprise an idle roller, generally one of the supporting rollers, operatively arranged downstream of the feeding system (more precisely of the feed roller) and upstream of the cutting device, along the feed path, and movable between: - an idle position, in which it simply supports the web fed by the feed roller during unwinding, and in which its axis is in a nominal position; and - a correction position, in which it is tilted, i.e., its axis is tilted, with respect to the nominal position, in order to locally (and temporarily) tilt the web and make the correction of the trajectory thereof upstream of the cutting device. In this way, a correction of the positioning of the subsequent labels on the vacuum drum can be obtained. Although functionally valid, the Applicant has observed how labeling modules of the type described above are susceptible to further improvements, in particular with regard to management of tensioning of the web during feeding, the total number of components, the architecture and the compactness of the module, and the precision, reliability, efficacy and repeatability of the positioning correction. SUBJECT MATTER AND SUMMARY OF THE INVENTION The object of the present invention is to provide a labeling module, and a related method, which are highly reliable and have a limited cost, and which allows at least some of the problems specified above and related to prior art labeling modules to be overcome. According to the invention, this object is achieved by a labeling module as claimed in claim 1. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, a non-limiting preferred embodiment thereof is described below, purely by way of example and with the aid of the accompanying drawings, wherein: - Fig. 1 is a schematic top view, with parts removed for clarity, of a labeling machine comprising a labeling module produced according to the present invention; - Figs. 2 and 3 are schematic side views, in enlarged scale and with parts removed for clarity, of a feeding system of the labeling module of Fig. 1 during two distinct operative conditions; and - Figs. 4 and 5 are schematic side views, in enlarged scale and with parts removed for clarity, of a transfer device of the labels of the labeling module of Fig. 1, during two distinct operative conditions. DETAILED DESCRIPTION With reference to the accompanying figures, the reference numeral 1 indicates as a whole a labeling machine configured to apply labels 2 obtained from a web 3 of labeling material on containers 4 adapted for containing a pourable product, preferably of food type (for example water, beer, wine, carbonated beverages, fruit juices, tea, milk, or the like). For the sake of simplicity, reference will be made hereinafter to a labeling machine 1 operating with labels 2 of the aforesaid glued label type, to which the present description will refer, without loss of generality. Nonetheless, what is described and claimed hereunder is equally applicable in the case of labels of the sleeve type described above. Preferably, the containers 4 are defined by bottles, made of plastic or glass. The machine 1 comprises: - a carousel 5 rotatable about an axis Z, preferably vertical, and configured to convey a succession of containers 4 to be labeled along a preferably horizontal labeling path in the form of arc of circle; - an input station (not visible), in which the containers 4 to be labeled are fed to the carousel; - an output station (not visible), in which the labeled containers 4 leave the carousel 5; and - a labeling module 6 arranged peripherally with respect to the carousel 5 and configured to prepare, transport and feed a plurality of labels 2 to the carousel 5 itself at an application station A, in order to apply these labels 2 to the respective containers 4. Preferably, the web 3 is initially wound in the form of a continuous strip on a reel 3a. In particular, the labeling module 6 comprises: - a storage portion including at least one support shaft 7 mounted rotatable to the module 6 for supporting one said reel 3a at a time; - a feeding system 8 for progressively unwinding the web 3 from the reel 3a and feeding it along a feed path P; - a plurality of support rollers 10 (only one of which is illustrated) for supporting and guiding, in use, the web 3 along a feed path P; - a transfer device 12 arranged along the feed path P downstream of the feeding system 8, for receiving the labeling material therefrom, and configured to apply labels 2 obtained from the labeling material on respective containers 4 at the application station A. According to this preferred embodiment, the module 6 further comprises a cutting device 11 (of known type and not described in detail) arranged along the feed path P downstream of the feeding system 8 and upstream of the transfer device 12 and configured to repeatedly cut the web 3 so as to obtain a sequence of labels 2 therefrom. Preferably, the transfer device is defined by a vacuum drum 12 of the known type, having a central axis W, preferably parallel to the axis Z, having an external lateral surface 12a, and configured to receive, retain and advance, on this surface 12a, each label 2 previously separated from the web 3 by means of the cutting device 11, and to feed this label 2 to the carousel 5 at the application station A. In detail, the surface 12a includes a plurality of receiving sectors 12b (three in the case illustrated) configured to receive and retain one label 2 at a time and each angularly delimited by a pair of known pads, in particular a front pad and a rear pad, which in use grip the longitudinal ends of each label 2. In an alternative embodiment, not illustrated, the cutting device 11 could be integrated into the vacuum drum 12, for example in the form of a blade or knife extractable from the surface 12a. In light of the above, the vacuum drum 12 is configured to receive labeling material (in the case illustrated the labels 2), to retain this material by means of suction and, after a rotation through a given angle about its axis W, to release the labels 2 obtained from the labeling material at the application station A, so that they are applied on the respective containers 4. Moreover, the vacuum drum 12 is configured to space the labels 2 received from one another so as to adapt to the distance between the containers 4. According to this preferred embodiment, the labeling module 6 comprises at least one gluing roller 13 arranged substantially tangent to the vacuum drum 12 upstream of the application station A, to spread glue on at least the ends of each single label 2 before its application on the respective container 4. As visible in Fig. 1, and more in detail in Figs. 2 and 3, the feeding system 8 comprises: - a feed roller 14 which is rotatably motorized about its own central axis X, having an external lateral surface 14a for supporting the web 3, and actuatable in rotation about the axis X to advance the web 3 along the feed path P; - a pinch roller 15 having an external lateral surface 15a opposable in pressure against the external lateral surface 14a of the feed roller 14, with interposition of the web 3, for pressing the web 3 against the feed roller 14 and maintaining it gripped on the external lateral surface 14a, the pinch roller 15 being rotatable about its own central axis Y parallel to the axis X. In practice, the pinch roller 15 is radially opposed to the feed roller 14 to aid the latter during unwinding of the web 3 from the reel 3a and during advance of the web 3 along the feed path P. In particular, the pinch roller 15 is rotatable in an idle manner (i.e., in a passive manner) about its axis Y, rotated by the feed roller 14, which is motorized (i.e., active). From the above, the feed roller 14 and the pinch roller 15 define between them a gripping station K at which the web 3 is gripped between them during its unwinding. In an alternative embodiment, not illustrated, the feeding system 8 is not provided with the pinch roller 15 and only includes the feed roller 14. Advantageously, the module 6 further comprises a detection device 16 configured to detect a positioning of the labeling material with respect to the vacuum drum 12, or a positioning of each label 2 applied with respect to the respective container 4, and to generate a signal correlated with the detection of an incorrect positioning of the label on the container (or with the detection of an incorrect positioning of the labeling material with respect to the vacuum drum 12). Preferably, the detection device comprises a position sensor 16, for example an optical sensor. Preferably, the optical sensor could be arranged at the external lateral surface 12a of the vacuum drum 12 and configured to sequentially inspect the receiving sectors 12b to detect the aforesaid positioning of the labels 2 retained thereby. Alternatively, the optical sensor could be arranged close to the application station A, to directly detect an incorrect positioning of the label 2 on the container 4. In use, when the sensor 16 detects a non-nominal or erroneous positioning of a label 2 on the respective receiving sector 12b, it generates the aforesaid signal. Figs. 4 and 5 illustrate non-limiting examples of different positionings of the label 2 with respect to the vacuum drum 12. It is specified that Figs. 4 and 5 could similarly be considered as schematically referred also to different respective positionings of the label 2 applied with respect to the respective container 4. Generally, the aforesaid incorrect positioning can depend at least on the trajectory and/or on the geometrical configuration assumed by the web 3 during feeding of the latter to the cutting device 11. According to an aspect of the present invention, the feeding system 8 is movable with respect to the transfer device 12, as a function of said signal, so as to cause a variation of the tilt of the axis X of the feed roller 14 with respect to the transfer device 12, and therefore also a variation of the tilt of the web 3. In this way, a variation of tilt of the web 3 and consequently, a variation of the positioning of the labeling material (in the case of the labels 2) on the vacuum drum 12 and/or a correction of the positioning of the label 2 on the container 4, is obtained. In any case, the main aim is that of obtaining a correction of the positioning of the labels 2 on the containers 4, in the case in which this positioning is incorrect. Incorrectness of the positioning of the labels 2 on the containers 4 is detected either by indirectly detecting the positioning of the labeling material on the vacuum drum 12, or by directly detecting the incorrect positioning of the labels on the containers. The movement of the feed roller 14, which is motorized, makes the correction effect particularly precise. Moreover, by moving the feed roller 14 with respect to the vacuum drum 12, it is not necessary also to tilt the vacuum drum 12. Therefore a labeling module 6 is provided that allows manual and/or automatic correction of the positioning of the labels 2 on the containers 4 of reduced mechanical complexity. The movement of the feed roller 14 that causes a variation of tilt of its central axis X comprises a rotational component about a rotation axis that is transversal to the central axis X of the feed roller 14. The aforesaid variation of tilt of the axis X of the feed roller 14 with respect to the vacuum drum 12 corresponds to a variation of tilt of the axis Y of the pinch roller 15 with respect to the transfer device 12. In this way, by controlling the tilt of the feeding system 8 comprising the feed roller 14 and the pinch roller 15, which move the web 3 maintaining it gripped between them, the effect of variation of tilt of the web 3 can be obtained more accurately, and therefore also the effect of variation of the positioning of the labeling material on the transfer device 12 and therefore also the effect of correction of the positioning of the label 2 on the container 4. The movement of the pinch roller 15 that causes a variation of tilt of its central axis Y comprises a rotational component about a rotation axis that is transversal to the central axis Y of the pinch roller 15. In particular, the feed roller 14 is movable between a first position, shown in Fig. 2, and at least a second position, shown in Fig. 3. In detail, the module 6 comprises an automatic correction system for correcting the positioning of the labels 2 on the containers 4 (in particular by means of correction of a trajectory of the web 3 along the feed path P), this correction system including: - the sensor 16, - an actuator (not illustrated) arranged at the feeding system 8 and configured to control the movement of the feeding system with respect to the vacuum drum 12, and thus the tilt of the axis X of the feed roller 14 and the tilt of the axis Y of the pinch roller 15 with respect to the vacuum drum 12, and - a control unit 17 configured to receive said signal from the sensor 16 and to automatically control the actuator as a function of said signal, so as to vary the positioning of the labeling material on the external lateral surface 12a of the vacuum drum 12 and/or to correct the positioning of the label 2 on the container 4. More precisely, the actuator is configured to control the movement of the feed roller 14 at least between the first position and the second position. It is specified that the correction system is configured to correct the trajectory of the web 3, by means of tilting of the web 3 itself through the aforesaid tilt of the axis X of the feed roller 14, in order to attempt to correct the positioning of the labels 2 subsequent to the label 2 for which the sensor 16 detected a non-nominal or erroneous positioning. Preferably, this label 2 for which the sensor 16 detected a non-nominal or erroneous positioning is discarded, or the container 4 on which it is applied is discarded. The first position of the feed roller 14 corresponds to a first position of the pinch roller 15, and the second position of the feed roller 14 corresponds to a second position of the pinch roller 15. In more detail, the actuator is configured to control a simultaneous and mutually parallel variation of tilt of the central axis X of the feed roller 14 and of the central axis Y of the pinch roller 15, so as to cause a variation of the local tilt of the web 3 at the gripping station K, as illustrated in Fig. 3. More precisely, the simultaneous and mutually parallel tilt of the axes X and Y causes a local tilt of a portion of web 3 at, and immediately downstream of, the gripping station K, thus determining a correction of the trajectory of the web 3 upstream of the cut thereof, which in turn causes a variation of the positioning of the labels 2 fed to the vacuum drum 12. Advantageously, the feed roller 14 and the pinch roller 15 are movable to determine a simultaneous variation of the tilt of the respective central axes X, Y, along the ideal plane containing the center distance I between the central axes X, Y themselves. In other words, the tilt of the axes X and Y is such that the tilt of the web 3 takes place about the longitudinal ideal straight line of the web 3 itself, at the gripping station K, so as to laterally tilt the web 3 in the direction of the pinch roller 15 or, as illustrated in Fig. 3, in the direction of the feed roller 14. Preferably, the module 6 comprises a base (not illustrated) defining a support plane, preferably horizontal. The aforesaid tilts of the central axis X of the feed roller 14 and of the central axis Y of the pinch roller 15 are to be considered also with respect to the support plane. The vacuum drum 12 is advantageously rotatably mounted on the base with its own central axis W orthogonal or transversal to the support plane. The feeding system 8 is mounted on the base so that the feed roller 14 can rotate on the base with its own central axis X orthogonal or transversal to the support plane. In particular, also the pinch roller 15 is rotatable on the base with its own central axis Y transversal or orthogonal to the support plane. In the first position, the tilt of the central axis X of the feed roller 14 with respect to the support plane assumes a respective first value. In the first position, the tilt of the central axis Y of the pinch roller 15 with respect to the support plane assumes a respective first value. In the second position, the tilt of the central axis X of the feed roller 14 with respect to the support plane assumes a respective second value, which is different from the respective first value. In the second position, the tilt of the central axis Y of the pinch roller 15 with respect to the support plane assumes a respective second value, which is different from the respective first value. The first value and the second value assumed of the tilt of the axis X of the feed roller 14 respectively in the first position and in the second position of the feed roller 14 could be respectively the same as the first value and the second value assumed by the tilt of the axis Y of the pinch roller 15, respectively in the first position and in the second position of the pinch roller 15. From the above, it is clear how with the module 6, and in particular with the labeling machine 1, it is possible to implement a method of labeling containers suitable to contain a pourable product, the method comprising the steps of: a) conveying the containers along a labeling path; b) advancing a web of labeling material along a feed path; c) repeatedly cutting the web to obtain a sequence of labels therefrom; d) transferring the labels obtained on respective receiving sectors of a transfer device toward an application station; and e) applying each label to a respective container at the application station; wherein the advancing step b) comprises: - supporting the web on an external lateral surface of a motorized feed roller; - actuating in rotation the feed roller about its own central axis to advance the web along the feed path; and wherein the method further comprises the steps of: f) detecting a positioning of each label on the respective receiving sector or of each label applied on the respective container; g) generating a signal correlated with the detection of a non-nominal or erroneous positioning of the label; h) moving the feed roller from the first position to the second position, so as to define a tilt of the web. Preferably, the advancing step b) further comprises: - opposing an idle pinch roller in pressure against the feed roller with interposition of the web, so that an external lateral surface of the pinch roller maintains the web gripping on the external lateral surface of the feed roller. Consequently, the moving step h) further comprises moving the pinch roller from the first position to the second position. Preferably, the moving step h) comprises tilting, in a simultaneously and mutually parallel manner, the central axis of the feed roller and the central axis of the pinch roller along an ideal plane containing the center distance between these central axes. By examining the features of the labeling module 6 and of the labeling method implemented according to the present invention the advantages that can be obtained therewith are evident. In particular, due to the fact that the correction of the trajectory of the web 3 along the feed path P is performed by means of tilting of the feeding system 8, and in particular of the feed roller 14, and more in particular also of the pinch roller 15, it is not necessary to provide a further tiltable correction roller arranged downstream of the feeding system 8 and upstream of the cutting device 11. Therefore, the total number of components is reduced, thus increasing the reliability of the module 6, making its architecture leaner and increasing its compactness, as the feeding system 8 can be positioned closer to the cutting device. This provides further advantages from the point of view of kinematics and of tensioning of the web, above all in the case in which the cutting device 11 comprises a cutting roller of known type, as the Applicant has observed that when the feeding system 8 and this cutting roller are positioned closer to each other this improves the tensioning of the web 3, reducing risks of stretching and improving spacing of the labels 2. The Applicant has also observed how correction of the trajectory of the web 3 and of the positioning of the labels 2 on the containers 4 is more precise and less prone to errors with respect to the known solution, as the tilt of the web 3 is obtained by means of two opposed rollers (i.e. the feed roller 14 and the pinch roller 15) instead of with a single roller. The Applicant has also observed that the increase of the precision of the correction is also accentuated by the fact that the tilt is performed by means of at least one motorized (not idle) roller, which improves the grip and the control on the web 3. It is clear that modifications and variants can be made to the labeling module 6 and to the related method described and illustrated herein without departing from the scope of protection defined by the claims.

Claims

CLAIMS 1.- Labeling module (6) for a labeling machine (1) configured to label containers (4) adapted for containing a pourable product by means of labels (2) obtained from a web (3) of labeling material, the module (6) comprising: - a feeding system (8) for feeding the web (3) along a feed path (P) and including at least one feed roller (14) which is rotatably motorized about its own central axis (X), has an external lateral surface (14a) for supporting the web (3), and is actuatable in rotation about its own central axis (X) to advance the web (3) along the feed path (P); and - a transfer device (12) arranged along the feed path (P) downstream of the feeding system (8), for receiving labeling material therefrom, and configured to apply labels (2) obtained from the labeling material on respective containers (4) at an application station (A); wherein the feeding system (8) is movable with respect to the transfer device (12), so as to cause a variation of the tilt of the central axis (X) of the feed roller (14) with respect to the transfer device (12), for correcting the positioning of the labels (2) on the containers (4); characterized in that the feed roller (14) and the pinch roller (15) are movable so as to cause a simultaneous and mutually parallel variation of the tilt of the respective central axes (X, Y) with respect to the transfer device (12), along an ideal plane containing the center distance (I) between the central axes (X, Y) themselves. 2.- Labeling module as claimed in claim 1, and comprising a detection device (16) configured to detect a positioning of the labeling material with respect to the transfer device (12) or a positioning of each applied label (2) with respect to the respective container (4), and to generate a signal correlated with the detection of an incorrect positioning of the label (2) on the container (4) or with the detection of an incorrect positioning of the labeling material with respect to the transfer device (12); wherein the feeding system (8) is automatically movable with respect to the transfer device (12) as a function of said signal, so as to cause a variation of the tilt of the central axis (X) of the feed roller (14) with respect to the transfer device (12), for correcting the positioning of the labels (2) on the containers (4). 3.- Labeling module as claimed in claim 2, and comprising an automatic correction system for correcting the positioning of the labels (2) on the containers (4), the correction system including: - said detection device (16), arranged adjacent to an external lateral surface (12a) of the transfer device (12) or in proximity to the application station (A); - an actuator arranged at the feeding system (8) and configured to control the movement of the feeding system (8) with respect to the transfer device (12), and thus to control the tilt of the central axis (X) of the feed roller (14); and - a control unit (17) configured to receive said signal from the detection device (16) and to automatically control the actuator as a function of said signal, so as to vary the positioning of the labeling material on the external lateral surface (12a) of the transfer device (12) and/or to correct the positioning of the labels (2) on the containers (4). 4.- Labeling module as claimed in any one of the preceding claims, wherein the feed roller (14) is movable between a first position and at least a second position; wherein the labeling module (6) comprises a base defining a support plane, said tilt also being with respect to the support plane; wherein the transfer device is defined by a vacuum drum (12) having a central axis (W) and rotatably mounted on the base with its own central axis (W) transversal or orthogonal to the support plane; wherein the feed roller (14) is rotatably mounted on the base, the tilt of the central axis (X) of the feed roller (14) with respect to the support plane assuming a first value in said first position; and wherein the feed roller (14) is controllable in at least also said second position, the tilt of the central axis (X) of the feed roller (14) with respect to the support plane assuming, in the second position, a second value which is different from the first value. 5.- Labeling module as claimed in any one of the preceding claims, wherein the feeding system (8) further includes a pinch roller (15) opposable in pressure against opposable in pressure against the feed roller (14) with interposition of the web (3), for pressing the web (3) against the feed roller (14) and maintaining it gripped on the outer lateral surface (14a) of the latter, wherein said pinch roller (15) is rotatable about its own central axis (Y), said variation of tilt of the central axis (X) of the feed roller (14) corresponding to a variation of tilt of the central axis (Y) of the pinch roller (15) with respect to the transfer device (12). 6.- Labeling module as claimed in claims 4 and 5, wherein said tilt of the central axis (Y) of the pinch roller (15) is also with respect to the support plane. 7.- Labeling module as claimed in claims 3 and 5 or 3 and 6, wherein the actuator is configured to control the movement of the feed system (8) with respect to the transfer device (12) and thus also the tilt of the central axis (Y) of the pinch roller (15). 8.- Labeling module as claimed in claim 3 and in one or more of claims 5 or 6 or 7, wherein the feed roller (14) and the pinch roller (15) define between them a gripping station (K) at which the web (3) is gripped between them; and wherein the actuator is configured to control a simultaneous and mutually parallel variation of the tilt of the central axis (X) of the feed roller (14) and of the central axis (Y) of the pinch roller (15), so as to cause a variation of the local tilt of the web (3) at the gripping station (K). 9.- Labeling machine (1) for labeling containers (4) adapted for containing a pourable product by means of labels (2) obtained from a web (3) of labeling material, the machine comprising: - a conveyor (5) for advancing the containers (4) to be labeled along a labeling path; and - a labeling module (6) as claimed in any one of the preceding claims; wherein the transfer device (12) is configured to apply the labels (2) obtained from the labeling material on the respective containers (4) advanced by the conveyor (5), at the application station (A).