IT201800003190A1 - LABELING MACHINE AND METHOD FOR APPLYING LABELS ON CONTAINERS - Google Patents

Description

DESCRIPTION

of the patent for industrial invention entitled:

"LABELING MACHINE AND METHOD FOR APPLYING LABELS ON CONTAINERS"

The present invention relates to a labeling machine for applying labels to containers.

Advantageously, the invention also relates to a labeling method for applying labels to containers.

Various technologies are known for applying labels to containers, such as for example bottles, containers or the like. One of these technologies involves the conveying of a tape of a material for labels, the cutting of the tape to obtain individual labels, the application of glue on the individual labels and the application of the labels thus obtained on respective containers during the conveyance of the containers themselves. along a predetermined path. Such labels are known as "roll-fed labels".

The application of labels according to this technology is obtained through the use of automatic labeling machines.

A typical labeling machine includes:

- a conveying device for conveying the containers along a first path;

- conveying means adapted to convey a tape of material for labels along a second path from an initial station to a labeling station;

- a cutting unit suitable for cutting single labels from the aforementioned tape at a cutting station interposed between the initial station and the labeling station along the second path; and

- a transfer drum, which is arranged between the initial station and the labeling station along the second path and is able to rotate around a first axis, to receive the individual labels at a transfer station and to transfer the single labels at the labeling station to apply the single labels on respective containers; and

- a glue application unit positioned adjacent to the transfer drum and suitable for applying glue to the individual labels before transferring them to the respective containers.

It is known that the transfer drum comprises an external lateral surface and suction means for retaining the individual labels on said external lateral surface during their conveyance from the transfer station to the labeling station.

In further detail, the transfer drum, in particular the external lateral surface, comprises a plurality of retention segments, angularly equally spaced around the first axis and able to retain respective labels during their conveyance from the transfer station to the transfer station. labeling.

It is known that each retention segment is provided with a plurality of suction openings for retaining the respective label by suction.

More specifically, each retention segment includes:

- a respective retention section, usually delimited by two interaction elements ("pads") protruding from the external lateral surface and one of which is configured to interact with a respective initial portion of the individual labels and the other is configured to interact with a respective final portion of the individual labels;

- and a respective transition section on which each label slides, in use, during its transfer from the auxiliary drum to the transfer drum, or towards the respective retention segment, and before being retained on the respective retention section.

It is also known that a typical glue application unit comprises a gluing roller extending along a central axis, adapted to rotate around said central axis, and arranged peripherally adjacent to the transfer drum at the application station. The glue roller is configured to apply glue from its outer side surface to individual labels.

In particular, the gluing roller is spaced from the transfer drum in such a way that the glue is transferred from the outer side surface only to the initial and final portions of the individual labels (in other words, the portions of the individual labels that interact with the elements of interaction of the transfer drum).

However, a drawback of such labeling machines lies in the fact that the respective transition sections are covered by the respective label only during a limited time span.

In particular, during the application of the glue on the labels, the respective transition section is free. As a result, the transition sections are easily contaminated with residues of glue, dust and other unwanted particles. Such contaminations prevent the transfer drum from functioning properly and therefore frequent cleaning is required.

Furthermore, a further drawback lies in the fact that the labeling drum requires the presence of the interaction elements to allow the application of the glue on well-defined portions of the individual labels.

There is therefore a need in the sector to improve the labeling machines and the respective labeling method, in particular to overcome at least one of the aforementioned drawbacks.

The object of the present invention is to provide a machine and a labeling method which allow to overcome at least one of the aforementioned drawbacks in a simple and economical way.

The aforesaid object is achieved by the present invention, since it relates to a machine for labeling containers as defined in claim 1.

Furthermore, the aforesaid object is achieved by the present invention, since it relates to a labeling method according to claim 8.

Alternative preferred embodiments are protected in the dependent claims.

For a better understanding of the present invention, three preferred embodiments are described below, purely by way of non-limiting examples and with reference to the attached drawings, in which:

- Figure 1 schematically illustrates and in top view a first embodiment of a labeling machine according to the invention, with parts removed for clarity;

- Figure 2 schematically illustrates and in top view a second embodiment of a labeling machine according to the invention, with parts removed for clarity;

- Figures 3a to 3d illustrate a detail of the labeling machine during different operating phases, with parts removed for clarity; And

- Figure 4 illustrates a third embodiment of a labeling machine according to the invention, with parts removed for clarity.

With reference to Figure 1, the numeral 1 indicates as a whole a labeling machine for applying labels 2 to containers, such as bottles 3, containers or the like.

The following description will refer without any limitative intent to a machine 1 suitable for applying labels 2 to containers which can be filled or are filled with a pourable product, in particular a pourable food product, for example carbonated liquids (sparkling water, soft drinks, beer, etc.), non-carbonated liquids (natural water, fruit juices, wine, etc.), emulsions, suspensions, high viscosity liquids and beverages containing pulp.

Furthermore, the following description will refer without any limitative intent to bottles 3, in particular made of a thermoplastic polymer such as for example polyethylene terephthalate. However, the bottles 3 can also be made of a different material, for example glass, aluminum etc.

Each bottle 3 extends along a longitudinal axis and comprises a hollow body delimiting an internal space of the bottle 3 itself.

With particular reference to Figure 1, the machine 1 comprises:

- a conveying device 4 for conveying the bottles 3 along a first path P, in particular having an arched shape; and

- a labeling apparatus 5 for applying at least a respective single label 2 to each bottle 3 at a labeling station 6 during the conveyance of the bottles 3 along the path P.

In greater detail, the device 4 comprises a conveying carousel 8 adapted to rotate around an axis A, in particular having a vertical orientation, and a plurality of retention units (per se known and not illustrated) arranged on the conveying carousel 8 and each capable of retaining a respective bottle 3 during its conveyance along the path P.

Preferably, the conveying carousel 8 rotates, in use, at a constant rotation speed.

More specifically, each retention unit is also adapted to rotate the respective bottle 3 around the respective longitudinal axis at least during the application of the respective label 2, in particular to allow the respective label 2 to be wound onto the bottle 3 itself.

Preferably, the retention units are equally spaced and spaced from each other around the A axis.

With particular reference to Figure 1, the apparatus 5 is suitable for:

- conveying a tape 12 of label material along a second path Q from an initial station 13 towards the labeling station 6;

- applying glue selectively on at least certain portions of the belt 12 at an application station 15 arranged downstream of the initial station 13 along the path Q;

- cutting the web 12 during its conveyance along the path Q itself at a cutting station 16, arranged downstream of the application station 15, to obtain single labels 2; And

- apply each label 2 on the respective bottle 3 at the labeling station 6.

In particular, the tape 12 is made of polymeric material or paper material. Even more particularly, the tape 12 comprises a repeated decorative motif, in which each repetition corresponds to the extension of a single label 2.

In further detail, apparatus 5 includes:

- conveying means 17 adapted to convey the tape 12 along the path Q from the initial station 13 towards the labeling station 6, in particular to a transfer station 18;

- a glue application unit 19 configured to apply glue on at least certain portions of the tape 12 at the application station 15;

- a cutting unit 20 for cutting the individual labels 2 from the tape 12 at the cutting station 13; and

- a transfer device, arranged between the initial station 13 and the labeling station 6 and able to advance each label 2 along a path R from the transfer station 18 to the labeling station 6 and to transfer the individual labels 2 to the labeling station 6 itself on the respective bottles 3; in particular, the transfer drum 21 is able to rotate around an axis B, in particular parallel to axis A, even more particularly having a vertical orientation.

Preferably, the apparatus 5 also comprises a storage unit suitable for containing the belt 12 and feeding it at the starting station 13.

In greater detail, the magazine unit is configured to contain at least one reel 26, on which the tape 12 is wound. In particular, the reel 26 is rotatable about an axis C, in particular parallel to the axis B, to allow unrolling the tape 12.

More specifically, the magazine unit comprises a housing seat (known per se and not illustrated) for the coil 26 and an actuation unit (per se known and not illustrated) able to control the rotation of the coil 26 around the axis C.

With particular reference to Figure 1, the transfer drum 21 is arranged adjacent to the device 4, in particular peripherally adjacent to the conveying carousel 8 at the labeling station 6.

In greater detail, the transfer drum 21 comprises an external lateral surface 27, on which the individual labels 2 are retained, in use, in particular by means of suction means. In particular, the suction means comprise a plurality of suction holes. disposed on the surface 27, at least one suction unit for applying the suction and at least one control device for selectively controlling the suction through the suction holes.

More specifically, the transfer drum 21, in particular the surface 27, comprises a plurality of retention segments and each retention segment is adapted to retain a respective label 2 during conveyance along the path R, in particular from the transfer station 18 to the labeling station 6.

Preferably, the retention segments are arranged angularly equally spaced around the B axis. In particular, the distance between the retention segments is defined by the distance ("pitch") between the retention units.

In the illustrated embodiment, the suction means of the transfer drum 21 are configured to allow the retention segments to be defined. In particular, the extension of each retention segment is defined by the control of the suction holes of the suction means.

In greater detail, the conveying means 17 comprise an auxiliary conveyor device 29 arranged between the initial station 13 and the transfer drum 21 and adapted to convey the belt 12 along at least a final portion Q1 and to transfer the belt 12 and / or the individual labels 2 on the transfer drum 21.

In particular, the auxiliary conveyor device 29 is positioned adjacent to the transfer drum 21 at the transfer station 18.

In the illustrated embodiment, the auxiliary conveyor device 29 comprises at least one conveyor belt 30, in particular equipped with respective suction means 31 for retaining the belt 12 on the conveyor belt 30 itself and adapted to convey the belt 12 at least along a portion of the portion final Q1.

Preferably, the auxiliary conveyor device 29 also comprises a conveyor element 32 interposed between the conveyor belt 30 and the transfer drum 21 and adapted to receive at least an initial portion of the belt 12 and to transfer the individual labels 2 to the transfer drum 21.

In a possible embodiment not shown, the auxiliary conveyor device 29 can comprise an auxiliary conveyor drum arranged adjacent, in particular peripherally adjacent, to the transfer drum 21.

Preferably, the conveying means 17 also comprise:

- a feed roller 33 able to rotate around an axis E, in particular parallel to the axis B, even more particularly having a vertical orientation, interposed between the initial station 13 and the transfer station 18 and able to control at least partially the advancement of the belt 12 along the path Q;

- an auxiliary roller 34 arranged adjacent, in particular tangential, to the feeding roller 33 to interpose, in use, the belt 12 between the auxiliary roller 34 and the feeding roller 33; and

- an actuator, in particular an electric motor (per se known and not illustrated) connected to the feed roller 33 and configured to rotate, in particular selectively, the feed roller 33 itself around the E axis.

Preferably, the feed roller 33 is interposed between the starting station 13 and the auxiliary conveyor device 29.

In the embodiment illustrated in Figure 1, the cutting unit 20 is adapted to cut the strip 12 in a non-contact way, for example by means of a laser beam.

In a possible embodiment not shown, the cutting unit 20 could comprise at least one blade and a counter-blade to cut the strip 12 in a contact way.

More specifically, the cutting unit 20 is configured to cut the tape 12 at the respective interfaces between two adjacent labels 2. By cutting, a single label 2 is separated from the tape 12, in particular from the subsequent label 2. Even more specifically, the respective final edge of the first single label 2 and the respective initial edge of the subsequent label 2 are defined by cutting.

Preferably, the cutting unit 20 is configured to cut the tape 12 during the advancement of the tape 12 itself along the final portion Q1.

In the embodiment illustrated in Figure 1, the unit 19 is configured to apply the glue on the tape 12 at the application station 15 in a contactless way.

In particular, the unit 19 comprises at least one nozzle or at least one group of nozzles 38 configured to apply the glue on the belt 12.

Even more particularly, the unit 19, in particular the group of nozzles 38, is configured to apply the glue on defined sections of the belt 12 which are located (following the cutting of the belt 12) in correspondence with the respective final edge and at the respective initial edge of each single label 2.

In a possible embodiment not shown, the machine 1, in particular the apparatus 5, even more particularly the conveying means 17, comprises / comprise a buffer unit adapted to accumulate portions of the belt 12 in a variable manner and arranged between the magazine unit and the feed roller 33.

In use, the machine 1 applies at least one respective label 2 to each bottle 3.

In greater detail, the labeling process, in particular during the operation of the machine 1, comprises the following phases:

- advance the bottles 3 to be labeled along the path P;

- feeding the tape 12 along the path Q from the initial station 13 towards the labeling station 6, in correspondence with which at least a single label 2 is applied on each bottle 3 advancing along the path P;

- applying the glue on the tape 12 advancing along the path Q at the application station - cutting the tape 12 at the cutting station 16 to obtain the individual labels 2; And

- transfer the tape 12 and / or the respective individual labels 2 (in the specific case illustrated the individual labels 2) on the transfer drum 21 rotating around the axis B; And

- applying each single label 2 from the transfer drum 21 to the respective bottle 3 at the labeling station 6.

Preferably, the machine 1 is operated continuously. In other words, during the operation of the machine 1, the steps of advancing, feeding, applying the glue, cutting, transferring and applying each label 2 are repeated.

In further detail, during the advancing step, the device 4, in particular the conveying carousel 8, advances the bottles 3 along the path P.

Preferably, during the advancing step, the bottles 3 rotate, at least during the step of applying the respective labels 2, around the respective longitudinal axis. In particular, each retention unit activates the rotation of the respective bottle 3 around the respective longitudinal axis.

In greater detail, during the feeding step, the conveying means 17 advance the belt 12 along the path Q from the initial station 13 towards the transfer station 6, in particular towards the transfer station 18.

More specifically, during the feeding step, the auxiliary conveyor device 29, in particular the conveyor belt 30, advances the belt 12 along the final portion Q1.

Preferably, during the feeding step, the web 12 advances between the feed roller 33, rotating around the axis E, and the auxiliary roller 34. In particular, the feed roller 33 at least partially controls the advancement of the web 12, even more particularly from the auxiliary roller 34 itself to the auxiliary conveyor device 29.

In further detail, during the cutting step, the tape 12 is cut at the cutting station 16 in such a way as to obtain a single label 2 from the tape 12. In particular, by cutting the tape 12 at the cutting station 13, the respective final edge of the label 2 is obtained, which is transferred onto the transfer drum 21, and the respective initial edge of the subsequent label 2 to be transferred.

In particular, the cutting step is performed during the advancement of the belt 12 along the final portion Q1.

In the embodiment illustrated in Figure 1, during the cutting step, the web 12 is cut in a non-contact manner, in particular by means of a laser beam.

In an embodiment not shown, during the cutting step, the strip 12 is cut by means of a blade which interacts with a counter-blade.

In further detail, during the transfer step, the tape 12 and / or the individual labels 2, in this specific case the individual labels 2, are transferred to the transfer drum 21 by means of the auxiliary conveyor device 29.

Preferably, the individual labels 2 are transferred to the transfer drum 21 by the conveying element 32.

In the embodiment described, during the transfer phase, the transfer drum 21 rotates around the axis B, receives the individual labels 2 at the transfer station 18 and advances the individual labels 2 along the path R.

In greater detail, the invention described here lies in the fact of applying the glue on the tape 12 before cutting the tape 12 itself. In particular, the glue is applied to those sections which define the respective initial and final edges of the individual labels after cutting 2.

Preferably, during the step of applying the glue, the unit 19, in particular the group of nozzles 38, applies the glue on the belt 12 in a non-contact way.

Even more particularly, the glue is applied to defined sections of the tape 12 which correspond (following the cutting of the tape 12) to the respective final edge and to the respective initial edge of each single label 2.

In figure 2, 1 'indicates a second embodiment of the machine according to the present invention. The machine 1 'is similar to the machine 1 and for this reason it is described below limitedly to the differences with respect to the machine 1 itself, indicating with the same reference numbers parts that are the same or equivalent to parts already described.

In particular, the main difference lies in the fact that the machine 1 'includes the unit 19' for applying the glue.

Unit 19 'includes:

- a glue feeding device 39;

- at least one, preferably a plurality of transfer elements 40, each configured to receive glue from the device 39 at a receiving station 41 and to transfer the glue onto the belt 12 at the application station 15; and

- a conveying device 42 configured to convey the transfer elements 40 along a third annular feed path S through the receiving station 41 and the applying station 15.

More specifically, the device 39 comprises:

- a glue roller 43 extending along a respective central axis F, having a first external lateral surface 44 and able to rotate around the respective axis F; and

- a glue feed unit configured to feed and / or distribute the glue on the outer lateral surface 44 of the glue roller 43.

Preferably, the conveying device 42 is configured to control the advancement of the transfer element (s) 40 along the path S so that the transfer element (s) 40 apply, in use, the glue on the belt 12 at the sections of the latter which define, following the cutting of the tape 12 itself, the respective initial edges and the respective final edges of the single labels 2.

In greater detail, the conveying device 42 is configured to control the speed of advancement of the transfer element or elements 40 as a function of the length of the individual labels 2. In this way it is possible to adapt the unit 19 'to a format change without significant modifications of the 19 'unit itself.

Preferably, the conveying device 42 comprises a transfer roller 45 extending along a respective central axis G, in particular (substantially) parallel to the respective central axis F; the transfer roller 45 is rotatable around the axis G and carries the transfer element (s) 40, which or which protrudes or protrudes from a respective external lateral surface 46 of the transfer roller 45 itself. In particular, the transfer element or elements 40 is or are, in use, advanced or advanced along the path R, having a circular shape, by means of the rotation of the transfer roller 45.

Preferably, the transfer roller 45 is peripherally arranged adjacent to the glue roller 43 at the receiving station 41 and is spaced from the glue roller 43 so that, in use, during the rotation of the transfer roller 45 around the respective axis G, the transfer element or elements 40 is adapted or are adapted to receive the glue from the external lateral surface 44 at the receiving station 41 and to apply the glue on the belt 12 at the application station 15.

In a possible embodiment not shown, the conveying device 42 comprises a conveyor belt carrying the transfer element or elements 40.

The operation of the machine 1 'is similar to the operation of the machine 1 and for this reason it is described below limitedly to the differences with respect to the operation of the machine 1 itself.

In particular, the main difference lies, as shown in particular in Figures 3a to 3d, in the way in which the step of applying the glue is carried out.

More specifically, during the glue application step, in particular during a first sub-step (see for example Figure 3b), the transfer element or elements 40 receives or receives the glue from the device 39 at the receiving station 41 and, in particular during a second sub-phase (see for example Figure 3c) following the first sub-phase, the transfer element or elements 40 applies or applies the glue on the belt 12 at the application station 15.

In particular, during the step of applying the glue, the transfer element or elements 40 applies or applies the glue on respective sections of the belt 12 which define (form), following the cutting step, the respective initial flaps and the respective flaps. endings of the individual labels 2.

In further detail, during the step of applying the glue, the transfer element or elements 40 advances or advances along the path S.

Preferably, during the step of applying the glue, the transfer element or elements 40 contacts or contact the glue present on the external lateral surface 44 of the glue roller 43 rotating around the axis F at the receiving station 41 to allow the transfer glue on the transfer element (s) 40 themselves.

In particular, the conveying device 42, specifically the transfer roller 45, advances the transfer element or elements 40 along the path S.

Preferably, the conveying device 42, in particular the transfer roller 45, controls the speed of advancement of the transfer element (s) 40 as a function of the length of the individual labels 2.

In further detail, during the glue application phase, the glue roller 43 rotates around the F axis and receives the glue from the power supply unit. In particular, the glue feed unit feeds the glue onto the outer side surface 44.

In figure 4, 1 '' indicates a second embodiment of the machine according to the present invention. Machine 1 'is similar to machine 1 and machine 1' and for this reason it is described below limitedly to the differences with respect to the latter, indicating with the same reference numbers parts equal or equivalent to parts already described.

In particular, the main difference lies in the fact that the machine 1 'includes the unit 19' for applying the glue.

Unit 19 'includes:

- a glue dispensing device 50;

- at least one interaction element 51, preferably a plurality of interaction elements 51, each configured to selectively interact with the web 12 in such a way as to selectively direct a section of the web 12 against an external surface 52 of the device 50, to transfer the glue present therein on the aforementioned section of the belt 12; and

- an actuation device 53 configured to advance the interaction element or elements 51 along an advancement path T.

In particular, the interaction element or elements 51 is arranged or are arranged in such a way that, in use, the tape 12 is interposed between the device 50 and the interaction element or elements 51.

The device 50 is similar to the device 39 and is described hereinafter limitedly to the differences with respect to the device 39 itself.

In particular, these differences reside in the fact that the respective glue roller 43 is configured to apply the glue on the respective section of the tape 12 which is, in use, directed by the respective interaction element 51 against the outer surface 52, in particular the surface external 52 corresponding to the external lateral surface of the respective glue roller 43.

In greater detail, in the embodiment illustrated in Figure 4, the actuation device 53 is configured to advance the interaction element or elements 51 along the annular path T and comprises a conveyor, in particular a conveyor belt 54, carrying the or the elements of interaction 51.

In particular, the actuation device 53, specifically the conveyor belt 54, is arranged in such a way that, in use, the belt 12 is interposed between the actuation device 53, in particular the conveyor belt 54, and the distribution device of glue 50, especially glue roller 43.

In a possible embodiment not shown, the conveyor is a roller, in particular an elliptical-shaped roller, rotatable around a respective central axis and carrying the interaction element or elements 51. In particular, the roller is configured to advance the interaction elements 51 along an annular path through a rotation about the respective central axis. Still more particularly, the interaction element or elements 51 protrudes or projects from a respective outer lateral surface of the roller.

In another possible embodiment not shown, the actuation device 53 comprises at least one linear actuator connected to the interaction element (s) 51 and adapted to selectively advance the interaction element (s) 51 along a path T having a substantially shape linear.

In particular, the linear actuator is configured to move the interaction element or elements between a first and a second limit position.

The operation of machine 1 'is similar to the operation of machines 1 and 1' and, for this reason, it is described below limitedly to the differences with respect to the operation of machines 1 and 1 'themselves.

In particular, the main difference lies in the execution of the phase of applying the glue.

Preferably, during the step of applying the glue, the interaction element or elements 51 interacts or interact with a respective section or sections of the belt 12 to establish contact between the aforementioned section or sections of the belt 12 and at least the surface 52 of the device 50 so as to transfer the glue on the aforesaid section or on the aforesaid sections of the belt 12 itself.

More specifically, each interaction element 51 is advanced along the path T and interacts with the respective section of the belt 12 to direct the respective section against the outer surface 52 at the application station 15 during the conveyance of the belt 12 itself along the path. P.

Even more specifically, the conveyor belt 54 advances the interaction element or elements 51 along the path T.

In the possible embodiment not illustrated, in which the roller carries the interaction element (s) 51, the roller advances the interaction element (s) 51 along the respective path through a rotation around the respective central axis.

In the other possible embodiment not illustrated, in which the actuation device 53 comprises the linear actuator connected to the interaction element (s) 51, the actuator advances the interaction element (s) 51 along the path T, in particular between a first and a second limit position.

From an examination of the characteristics of the machines 1, 1 'and 1' and of the respective labeling methods implemented according to the present invention, the advantages that the latter allows to obtain are evident.

In particular, machines 1, 1 'and 1' require less frequent cleaning than the currently known labeling machines. By applying the glue on the belt 12, the risk of contaminating the transfer device, in particular the transfer drum 21, due to this application is reduced.

A further advantage lies in the fact that the transfer drum 21 can be made without "pads".

Another advantage, in particular of the machine 1 ', lies in the fact that the glue can be applied with very high precision.

Finally, it is clear that the machines 1, 1 ', 1' and the respective labeling methods described and illustrated here may be subject to modifications and variations that do not go beyond the scope of protection defined by the claims.

Claims (1)

CLAIMS 1.- Labeling machine (1, 1 ', 1') to apply labels (2) on containers (3) including: - a conveying device (4) for conveying the containers (3) along a first path (P); And - a labeling apparatus (5) to apply at least one label (2) to each container (3) at a labeling station (6) during the conveyance of the containers (3) along the first path (P); in which the labeling apparatus (5) includes: - conveying means (17) adapted to convey a tape (12) of label material along a second path (Q) from an initial station (13) to the labeling station (6); - a cutting unit (20) configured to cut single labels (2) from said tape (12) at a cutting station (16) interposed between the initial station (13) and the labeling station (6) along the second path (Q); - a transfer device (21), arranged between the initial station (13) and the labeling station (6) and able to transfer the individual labels (2) to the labeling station (6) on the respective containers (3); characterized in that it also comprises a glue application unit (19, 19 ', 19' ') configured to apply glue on said belt (12) at an application station (15) interposed between the initial station (13) and the cutting station (16) along the second path (Q). 2.- Labeling machine according to claim 1, wherein the conveying means (17) comprise: - a feed roller (33) adapted to rotate around a first axis (E) and interposed between the initial station (13) and the transfer drum (21) along the second path (Q) to feed said belt at least partially (12); - an auxiliary roller (34) arranged adjacent to the feeding roller (33) to interpose, in use, said belt (12) between the auxiliary roller (34) itself and the feeding roller (33); and - an electric motor connected to the feed roller (33) and adapted to selectively rotate the feed roller (33) around the second axis (E). 3.- Labeling machine according to Claim 1 or 2, in which the conveying means (17) comprise an auxiliary conveyor device (29) interposed between the transfer device (21) and the initial station (13) and adapted to guide the advancement of said tape (12) and / or to guide the transfer of the individual labels (2) to the transfer device (21) at a transfer station (18). 4.- Labeling machine according to one of the preceding claims, in which the glue application unit (19 ') includes: - a glue dispensing device (39); - at least one transfer element (40) configured to receive glue from the glue dispensing device (39) at a receiving station (41) and to transfer the glue onto said belt (12) at the application station ( 15); and - a conveying device (42) configured to convey the transfer element (40) along a third path (S) through the receiving station (41) and the application station (15). 5.- Labeling machine according to claim 4, in which the conveying device (39) is configured to control the speed of advancement of the transfer element (40) as a function of the length of the individual labels (2). 6.- Labeling machine according to Claim 4 or Claim 5, wherein the glue dispensing device (39) comprises: - a glue roller (43) extending along a first central axis (F), having a first external lateral surface (44) and able to rotate around the first central axis (F); and - a glue feed unit configured to feed the glue onto the outer lateral surface (44) of the glue roller (43); and wherein the conveying device (42) comprises: - a transfer roller (45) extending along, and rotatable about, a second central axis (G) and carrying the transfer element (40), which protrudes from a second outer side surface (46) of the transfer roller (45); wherein the transfer roller (45) is peripherally disposed adjacent to the glue roller (43) at the receiving station (41) and is spaced from the glue roller (43) such that, in use, during a rotation of the transfer roller (45) around the second central axis (G), the transfer element (40) is able to receive the glue from the first external side surface (44) at the receiving station (41) and to apply the glue on said tape (12) at the application station (15). 7.- Labeling machine according to one of claims 1 to 3, wherein the glue application unit (19 '') comprises a glue dispensing device (50) and at least one interaction element (51) arranged in such that, in use, said tape (12) is interposed between the glue dispensing device (50) and the interaction element (51); wherein the interaction element (51) is configured to interact with said belt (12) in such a way as to selectively direct a section of said belt (12) against an external surface (52) of said distribution device (50) of glue, the external surface of which is at least partially covered with glue at the application station (15) to transfer the glue onto said section of said tape (12). 8.- Method for applying labels (2) on containers (3) comprising the following steps: - advancing the containers (3) to be labeled along a first path (P); - feeding a tape (12) of label material along a second path (Q) from an initial station (13) to a labeling station (6), at which at least one respective single label (2) is applied to each container (3) advancing along the first path (P); - cutting said tape (12) at a cutting station (16) to obtain the individual labels (2); And - transferring said tape (12) and / or a single label (2) to a transfer device (21) at a transfer station (18); - applying each single label (2) from the transfer device (21) to a respective container (3) at the labeling station (6); characterized in that it also includes the step of applying a glue on said belt (12) at an application station (15) interposed between the initial station (13) and the cutting station (16) along the second path (Q ). 9.- Method according to Claim 8, wherein during the feeding step, the said belt (12) advances between a feed roller (33), rotating around a second axis (E), and an auxiliary roller (34) , arranged adjacent to the feed roller (33). 10.- Method according to Claim 8 or 9, wherein during the transfer step, the said tape (12) and / or the individual labels (2) are transferred to the transfer device (21) by means of an auxiliary conveyor device (29). ) interposed between the transfer station (18) and the initial station (13). 11. A method according to one of claims 8 to 10, wherein, during the glue application step, a transfer element (40) receives glue from a glue dispensing device (39) at a receiving station (41) and the transfer element (40) applies the glue on said tape (12) at the application station (15). 12. A method according to Claim 11, wherein, during the step of applying the glue, the transfer element (40) advances along a third path (S) of advancement through the receiving station (41) and the application (15). 13.- Method according to one of claims 8 to 10, wherein, during the glue application step, an interaction element (51) interacts with a section of said tape (12) to establish contact between the aforementioned section of said tape (12) and at least one external surface (52) of a glue dispensing device (50) for transferring the glue onto the aforementioned section of said tape (12).