IT201900015650A1 - DEVICE TO SEPARATE LABELS FROM A STRIP OF LABELING MATERIAL AND METHOD FOR APPLYING LABELS TO ITEMS - Google Patents

Description

DESCRIPTION

of the patent for industrial invention entitled:

"DEVICE TO SEPARATE LABELS FROM A STRIP OF LABELING MATERIAL AND METHOD FOR APPLYING LABELS TO ITEMS"

TECHNICAL FIELD

The present invention relates to a device for separating, preferably for sequentially separating, labels from a strip of labeling material, in particular labels configured to be applied to articles in an automated labeling process, for example containers suitable for containing a pourable product , preferably of food type.

The present invention also relates to a method for applying labels obtained from a strip of labeling material to articles in an automated labeling process, in particular containers suitable for containing a pourable product, preferably of the food type.

STATE OF THE ART

There are known labeling machines configured to treat a labeling material in an automated labeling process and commonly used to prepare, transport and apply labels to articles, in particular bottles, containers, jars, vials or the like, made of glass, plastic or metal, suitable to contain a pourable food product, preferably of the food type ("pourable food product").

Particularly widespread is the use of glued labels, known as "glued labels", obtained from a strip of labeling material initially wound on one or more reels.

In detail, this strip is cut into portions of equal size to which glue is applied. The glue is applied by gluing means, for example rollers, spray systems, injection systems, or the like. The labels thus obtained are then transferred and glued to the external lateral surface of the respective articles.

Another particularly widespread type is that of tubular labels, known as "sleeve labels", made from a strip of heat shrinkable film wound on one or more reels; these tubular labels are applied with a certain play on the respective articles and then heated in an oven to obtain their restriction and perfect adhesion to the lateral surfaces of the articles themselves. This type of labels does not require the use of glue.

Regardless of the type of label used, a labeling machine typically includes:

- a rotatable carousel around a vertical axis and configured to convey a plurality of successive articles along a horizontal path in the form of an arc of a circle;

- an entry station, in which the articles to be labeled are fed to the carousel;

- an exit station, where the labeled articles leave the carousel; and

- one or more labeling modules arranged peripherally with respect to the carousel and configured to feed respective plurality of labels to the carousel itself at an application station, in order to apply said labels to the respective articles.

Generally, a known type of labeling module comprises:

- one or more storage units, normally revolving rollers around which corresponding reels of labeling material are wound in the form of a continuous strip;

- a plurality of unwinding rollers which, in use, support the strip of labeling material unwound from the respective reel and guide it along a feed path; And

- a device for transferring the labels, for example a vacuum drum, configured to receive each label and feed said label to the carousel at the application station.

In the case of labels of the "glue labels" and "sleeve labels" type, the labeling module further includes a separation device ("parting device") configured to separate, in particular to sequentially separate, the labels from the respective strip of material labeling that is carried out, in use, by the relative reel.

The separation device essentially comprises a blade member, for example a knife, configured to separate, or cut, at a separation or cutting station, a sequence of single labels having the same length from the strip of labeling material.

The separation devices typically used in labeling modules of the type described above are of the rotary type. In detail, they include:

- a first rotary element, usually a support roller of the blade member, mounted rotatably around an axis, carrying the blade member and configured to convey the blade member along a circular cutting path around the aforementioned axis; And

- a second rotary element, usually a check roller for the blade member, rotatably mounted around an axis typically parallel to the axis of the first rotary element, arranged peripherally to the first rotary element, so as to be substantially tangential to the path of cutting, and configured to define an abutment stop for the blade member and to support the strip of labeling material and convey it towards the separation (cutting) station, at which the strip is cut by the blade member.

In practice, the strip is, in use and in correspondence with the separation station, interposed between the support roller and the feedback roller, the latter acting sequentially as an abutment stop - or as an "anvil" - for the organ blade when cutting. More precisely, the blade member, conveyed rotationally along the cutting path, cooperates in contact with the strip to be cut at the separation station, completing the cutting process by striking against a lateral abutment surface of the abutment roller. , sequentially.

In the case of labels that require the use of glue, the labeling module also includes at least one gluing roller configured to sprinkle at least the ends of each individual label with glue, after cutting and before applying them to the related items.

Conveniently, the carousel, the transfer device, the gluing roller, the unwinding rollers and the rollers of the separation device are synchronized in phase, in order to correctly perform the entire labeling process.

Although known separation devices of the type described above are functionally valid, they are susceptible of further improvements.

In particular, the need is felt in the sector to increase the useful life of the blade organ and the second rotary element, components that are particularly subject to wear, while limiting complications to the architecture of the labeling machine.

OBJECT AND SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a separation device for separating labels, configured to be applied to articles intended to contain a pourable product, from a strip of labeling material, which is highly reliable and of limited cost, and allows to satisfy at least some of the requirements specified above and connected to known separation devices.

According to the invention, this object is achieved by a label separation device as claimed in claim 1.

A further object of the present invention is to provide a method for applying labels to articles which is highly reliable and allows to satisfy at least some of the requirements specified above in a simple and economical way.

According to the invention, this object is achieved by a method for applying labels to articles as claimed in claim 11.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, two preferred non-limiting embodiments are described below, purely by way of example and with the aid of the attached drawings, in which:

- Figure 1 is a schematic top view, with parts removed for clarity, of a labeling machine comprising a separation device made according to a preferred embodiment of the present invention;

- Figure 2 is a schematic top view, on an enlarged scale and with parts removed for clarity, of the separation device of Figure 1;

Figures 3a and 3b show, on an enlarged scale, a detail of the separation device of Figure 1 during two different operating conditions;

Figure 4 is a schematic side view, partially sectioned, on an enlarged scale and with parts removed for clarity of the separation device of Figure 1;

Figures 5a-5c schematically illustrate, on an enlarged scale and with parts removed for clarity, a component of the separation device of Figure 1;

Figure 5d illustrates a variant of the component of Figure 5a; And

- Figure 6 is a schematic top view, on an enlarged scale and with parts removed for clarity, of a separation device of the labeling machine of Figure 1 made according to a further preferred embodiment of the present invention.

DETAILED DESCRIPTION

With reference to the attached figures, the reference numeral 1 generally designates a labeling machine configured to process a labeling material in an automated labeling process.

In particular, the machine 1 is configured to apply labels 2 obtained from a strip 3 of labeling material to articles 4 intended to (suitable for) containing a pourable product, preferably of the food type.

More particularly, the articles 4 are defined by bottles, flasks, cans, jars, jars, or the like, each of which is able to receive, during the aforementioned labeling process, a respective label 2 on the relative external lateral surface.

According to this preferred and non-limiting embodiment, the labels 2 are of the type known as "glued labels", ie labels 2 obtained starting from the strip 3, which is initially wound on one or more reels 5 (only one of which is shown in figure 1) and is subsequently cut into portions of equal size to which glue is then applied. The labels 2 thus obtained are then transferred and applied (glued) on the external lateral surface of the respective articles 4.

As can be seen in Figure 1, the machine 1 essentially comprises:

- a carousel 6 rotatable around an axis (not shown), preferably vertical, configured to convey a plurality of successive articles 4 along a path P, preferably horizontal and in the form of an arc of a circle; And

- at least one labeling module 7 arranged peripherally with respect to the carousel 6 and configured to prepare, transport and feed a plurality of labels 2 to the carousel 6 itself, in order to apply them to the respective articles 4 at an application station A.

In an embodiment not shown, the machine 1 comprises two or more labeling modules 7 configured to apply respective pluralities of labels 2 to relative articles 4 at respective application stations A.

In detail, the labeling module 7 includes:

- at least one support shaft 8 fixed to a base of the labeling module 7 and supporting, in use, in a rotatable way at least one aforesaid reel 5;

- a distribution system 10, for example a plurality of unwinding rollers mounted on the base of the module 7, configured to unwind the strip 3 from the reel 5, support and guide it and / or advance it along a feed path Q, preferably horizontal;

- a separation device 11 configured to separate, in particular to separate sequentially, the labels 2 from the strip 3; And

- a transfer device, for example a vacuum drum 12 of a known type and not described in detail, configured to receive the labels 2 previously separated from the strip 3 by means of the separation device 11 and feed said labels 2 to the carousel 6 at the application station A, for their application to the respective articles 4.

In greater detail, the vacuum drum 12 (schematically illustrated in Figure 1) is mounted on the labeling module 7, rotatably around a Z axis, preferably vertical, and is configured to receive the labels 2, retain them on its own surface external lateral 13 by means of suction, according to a known modality and not described in detail, and transfer them to the related articles 4 after a rotation of a predetermined angle about the axis Z.

As illustrated in Figure 2, the separation device 11 is of the rotary type and essentially comprises:

- a first rotary element, for example a first support roller 14 mounted on the labeling module 7 rotatably around an X axis, preferably vertical, and configured to receive the strip 3 from the distribution system 10 and to support and advance it along the feed path Q; And

- a second rotary element, for example a second support roller 15 mounted on the labeling module in a rotatable way around a Y axis, preferably vertical, and carrying a blade member 16 configured to cooperate sequentially in contact with the strip 3 in correspondence of a cutting station T interposed between the first roller 14 and the second roller 15 itself.

In detail, the second roller 15 is arranged peripherally to the first roller 14 and advances, in use, the blade member 16 along a cutting path R, conveniently having a substantially circular shape.

In greater detail, the first roller 14 is arranged in such a way that the cutting path R is substantially tangent to an external lateral surface 17 of the first roller 14 itself, at the cutting station T.

In practice, the strip 3 is interposed, in use, during its advancement along the feeding path Q and at the cutting station T, between the first roller 14 and the second roller 15.

Preferably, the first roller 14 is provided with a series of holes 18 provided on the external lateral surface 17, connected to a known vacuum source and not described in detail and configured to hold the strip 3 by suction against the external lateral surface 17, during its progress along the feed path Q.

This ensures adequate tensioning of the strip 3 during the subsequent cut and allows to avoid slipping of the strip 3 itself along the feed path Q.

According to an alternative embodiment not shown, the strip 3 is held against the outer lateral surface 17 by electrostatic or any other suitable means.

Advantageously, the first roller 14 also comprises a recess 20 obtained on the external lateral surface 17.

According to this preferred and non-limiting embodiment, the recess 20 is defined by a longitudinal slot extending on the external lateral surface 17 of the first roller 14 parallel to the X axis.

In particular, this slot is through, i.e. it extends for the entire axial length of the roller 14, as can be seen in particular in Figure 4.

In practice, the recess 20 defines a radial recess of the external lateral surface 17 towards the inside, or towards the X axis.

Conveniently, the recess 20 is configured to be engaged by the blade member 16, according to the method described below.

Conveniently, the strip 3 comprises a plurality of predetermined cutting portions 19, normally equidistant along the longitudinal direction of the strip 3 itself and configured to be cut by the blade member 16.

In use, the first roller 14 advances the recess 20 sequentially at the cutting station T, by rotating on itself around the X axis; furthermore, the first roller 14 supports and advances, by suction through the holes 18, the strip 3 in such a way that the cutting portions 19 cover, one at a time, at least part of the recess 20 at the cutting station T.

According to the invention, the blade member 16 is also arranged on the opposite side of the strip 3 with respect to the first roller 15, or on the opposite side of the strip 3, and therefore of the feed path Q, with respect to the recess 20, and is configured to sequentially cooperate in contact with one cutting portion 19 at a time.

In detail, the blade member 16 is movable through the strip 3 and through the recess 20 to sequentially cut each cutting portion 19 of the strip 3 at the cutting station T, thus separating the labels 2 from the strip 3 itself.

This is shown in detail in Figures 3a and 3b. In greater detail, the blade member 16 sequentially cuts, in particular at each revolution made around the Y axis, a cutting portion 19 of the strip 3, while this cutting portion 19 covers the recess 20, i.e. while the cut 19 is positioned circumferentially along a radial line which ideally joins the X axis with the recess 20.

To this end, the blade member 16 is mounted on the second roller 15 so as to protrude from an external lateral surface 22 of the second roller 15 itself.

In practice, according to the invention, the blade member 16, when it is in correspondence with the cutting station T, penetrates the strip 3, transversely to the feed path Q, entering the recess 20 and, therefore, without coming into contact with the first roller 14.

The entry of the blade organ 16 into the recess 20 does not therefore involve the completion of the radial distance that defines the depth of the recess 20, according to the radial direction from the external lateral surface 17 to the X axis.

In other words, the cutting of each cutting portion 19 and the separation of the relative label 2 from the strip 3 take place without a physical feedback from the first roller 14.

In the light of what has been described above, the separation device 11 is configured to cut the strip 3 for each rotation of the second roller 15 by 360 ° around the Y axis and for each rotation of the first roller 14 by 360 ° around the X axis

Conveniently, the first roller 14 and the second roller 15 rotate around the respective axes X and Y so as to ensure the condition that the recess 20 is in correspondence with the cutting station T whenever the blade member 16 is at the cutting station T.

Conveniently, the distribution system 10 is equally configured to respect the above condition and ensure that the cutting portions 19 are in correspondence with the cutting station T at the appropriate time.

According to this preferred and non-limiting embodiment, the labeling module 7 further comprises at least one gluing roller (not shown) configured to sprinkle at least the ends of each single label 2 with glue, after cutting and before their application. related articles 4.

As can be seen in particular in Figures 2, 3a and 3b, the separation device 11 further comprises an elastomeric element 21 carried by the second roller 15, in particular mounted on the external lateral surface 22 of the second roller 15 itself, and configured to cooperate sequentially in contact with the strip 3 so as to temporarily block a movement of the strip 3 along the feed path Q.

In particular, the elastomeric element 21 consists of a flat body that covers, as a layer, the portion of the external lateral surface 22 surrounding the blade member 16.

More precisely, the elastomeric element 21 is mounted on the external lateral surface 22 so as to be arranged on opposite sides of the blade member 16, i.e. upstream and downstream of the blade member 16, considering the direction of rotation of the second roller 15.

In use, the elastomeric element 21 cooperates sequentially, at each revolution of the roller 15 around the Y axis, with the strip 3 pressing it against the outer lateral surface 17 of the first roller 14, at the cutting station T.

In other words, the strip 3 is interposed, at the cutting station T, between the elastomeric element 21 and the external lateral surface 17 of the first roller 14.

The interaction of the elastomeric element 21 with the strip 3 at the cutting station T involves the aforementioned temporary locking of the strip 3 along the feed path Q and, therefore, a further tensioning of the cutting portions 19 at the moment of the cut performed from the blade member 16, as visible in figure 3b.

This results in an easier breaking of the strip 3, that is, in a better, cleaner and more effective cut.

According to a further aspect of the present invention, the blade member 16 comprises a serrated blade 23 ("serrated blade") extending along a longitudinal direction, in particular along a vertical direction parallel to the X and Y axes, and having a plurality of teeth 24 with a triangular profile and arranged in a row along the aforementioned longitudinal direction (Figure 4).

With reference to Figures 4, 5a, 5b and 5c, some constructive parameters of the serrated blade 23 identified by the Applicant as the optimal parameters are listed below in order to perform the aforementioned cut as effectively as possible, without however affecting the generality of what described.

In particular, the serrated blade 23 according to the present invention can encompass all or any combination of these constructive parameters.

In detail:

- the distance B (figure 5b) between the free vertices of each pair of successive teeth 24 is between 0.5mm and 2mm, preferably 1mm; and / or

- the thickness H (figure 5c) of the serrated blade 23, measured at the base of each tooth, is between 0.75mm and 1.5mm, preferably 1mm; and / or

- each tooth 24 comprises two lateral surfaces 25 (Figure 5c) intersecting in the relative free vertex and inclined, with respect to an ideal plane K passing through the free vertexes of all the teeth 24, by an angle α having an amplitude equal to 60 °; that is, the two lateral surfaces 25 identify between them an angle α having an amplitude equal to 60 °; and / or

- the adjacent lateral edges 26 (Figure 5b) of each pair of successive teeth 24, which edges 26 define the profile of the serrated blade 23, identify between them an angle β having an amplitude equal to 90 °; and / or

- the aforementioned ideal plane K passing through the free vertices of all the teeth 24 is inclined with respect to the aforementioned longitudinal direction with a slope of 1/50 (Figure 5a); that is, this ideal plane K identifies with the longitudinal direction an angle γ with an amplitude equal to 1.15 °.

According to an alternative embodiment illustrated in Figure 5d, the distribution system 11 comprises a serrated blade 23 'including compound teeth 27, each formed by a plurality of teeth 24 of the type described above.

In detail, the compound teeth 27 have a substantially triangular profile and are arranged in a row along the aforementioned longitudinal direction.

In more detail:

- the half-distance D between the free vertices of each pair of successive compound teeth 27 is between 5mm and 15mm, preferably 10mm; and / or - the compound lateral edges 28 of each compound tooth 27, defining the profile of the serrated blade 23 ', are inclined, with respect to an ideal plane (not shown) passing through the free vertices of all compound teeth 27, of a angle δ having an amplitude comprised between 10 ° and 25 °, preferably 15 °.

According to this embodiment, the aforementioned ideal plane is parallel to the longitudinal direction.

The operation of the labeling machine 1 and of the separation device 11 made according to the present invention will be described below, with particular reference to an initial condition in which the strip 3 is conveyed and advanced by the distribution system 10, the blade member 16 and the recess 20 are located in correspondence with the cutting station T and a respective cutting portion 19 of the strip 3 covers, at least partially, the recess 20.

In this condition, the blade member 16 faces the recess 20, i.e. the free vertices of the teeth 24 of the serrated blade 23 face and face the recess 20 (Figure 4).

At this point, since the blade member 16 protrudes from the external lateral surface 22 of the second roller 15, the teeth 24 penetrate into the strip 3, cutting it and separating the relative label 2 from the strip 3 itself.

This operation is facilitated by the elastomeric element 21, which causes further tensioning, as described above, of the strip 3.

Conveniently, the teeth 24 are housed in the recess 20, without abutting against the bottom of the recess 20 itself.

At this point, the first roller 14 and the second roller 15 continue to rotate around the respective X and Y axes, in order to sequentially perform other separations of labels 2, one after the other and with the same methods described above.

With reference to Figure 6, 11 'indicates as a whole a device for separating the labels 2 from the strip 3 of labeling material made according to an alternative embodiment of the present invention.

Since the separation device 11 'is similar in structure and operation to the separation device 11 described above, only the distinctive characteristics between the two will be highlighted below, indicating with the same references, where possible, identical or corresponding parts .

In particular, the separation device 11 'differs from the separation device 11 in that it comprises a second roller 15' carrying, in addition to the blade member 16 configured to cut first cutting portions 19 of the strip 3, a further member to blade 30 configured to sequentially cut second cutting portions 19 of strip 3, distinct from first cutting portions 19.

Conveniently, the blade member 30 is arranged in a diametrically opposite position to the blade member 16, with respect to the Y axis.

Consequently, the separation device 11 'is configured to perform a cut of the strip 3 for each rotation of the second roller 15' by 180 ° around the Y axis.

According to an alternative embodiment not shown, the further blade member 30 is arranged in a different position, not necessarily diametrically opposite with respect to the blade member 16.

Conveniently, the second roller 15 'comprises a seat 29 housing the further blade member 30; in particular, the further blade member 30 is selectively removable from the seat 29, along a radial direction, to cut the aforementioned second cutting portions 19 of the strip 3.

In the latter case, if only the blade member 16 is used during the cutting process, the additional blade member 30 can be kept retracted inside the seat 29.

Preferably, the separator device 11 'comprises a first roller 14' having two or more recesses 20 of the type described above.

In one embodiment, the first roller 14 'comprises a first recess 20, configured to be engaged by the blade member 16 at the cutting station T and a second recess 20, conveniently arranged in a position diametrically opposite to the first recess 20, with respect to the X axis, and configured to be engaged by the blade member 30 at the cutting station T.

In one embodiment, the first roller 14 'and the second roller 15' are configured to rotate at the same speed.

In another embodiment, the first roller 14 'and the second roller 15' rotate, in use, at different speeds. This is the case, for example, in which the second roller 15 'must perform, in a single turn, more cuts than there are blade members 16, 30 present in the second roller 15' itself. For example, the second roller 15 'rotates, in use, faster than the first roller 14' if the second roller 15 'has two blade members 16, 30 and the first roller 15' has more than two configured recesses 20 to be engaged by respective blade members 16, 30 during the same revolution around the X axis.

From an examination of the characteristics of the separation device 11, 11 'made according to the present invention, the advantages that it allows to obtain are evident.

In particular, thanks to the configuration of the blade member 16, more particularly thanks to the fact that the blade member 16 does not come into contact with the first roller 14 and approaches the strip 3 from the outside, or from the opposite side with respect to the first roller 14 supporting the strip 3, it is possible to increase the useful life of the blade member 16 itself, since there is no contact between the blade member 16 and the first roller 14. At the same time, the effectiveness of cutting, since, also thanks to the presence of the elastomeric element 21, the strip 3 is kept under tension during the cutting process.

In fact, as can be seen in particular in Figure 3b, the external edges of the recess 20 act as wedges for the strip 3, allowing a better tensioning of the same.

In addition, the use of a serrated blade 23, 23 'of the type described further increases the effectiveness of the cut.

In particular, the use of a serrated blade 23 having an inclined cutting surface of the angle γ, favors the attachment of the strip 3 by the blade and therefore favors the initiation of the local breaking of the labeling material, with respect to the case where the blade is not tilted.

Furthermore, the presence of a further blade member 30 and, conveniently, of two or more recesses 20, allows to increase the production rate or, alternatively, to increase the adaptability of the separation device 11 ', since labels can be obtained 2 of different sizes by suitably calibrating the speeds of the first roller 14 'and of the second roller 15'.

It is clear that modifications and variations may be made to the separation device 11, 11 'described and illustrated here without thereby departing from the scope of protection defined by the claims.

Claims (1)

CLAIMS 1.- Separation device (11; 11 ') of labels (2) configured to be applied to articles (4) intended to contain a pourable product from a strip (3) of labeling material; said separation device (11; 11 ') comprising: - a first support element (14; 14 '), rotatable around a first axis (X), having at least one recess (20) on its own external lateral surface (17), supporting, in use, said strip (3) on said external lateral surface (17) and advancing it, in use, so that predetermined cutting portions (19) of said strip (3), configured to be cut, cover one by one at least part of said recess (20) at least in correspondence of a cutting station (T); And - a blade member (16; 30), arranged on the opposite side of said strip (3) with respect to said first support element (14; 14 ') and configured to cooperate sequentially in contact with said strip (3) in correspondence with said cutting station (T); said blade member (16; 30) being movable through said strip (3) and through said recess (20) to sequentially cut said cutting portions (19) at said cutting station (T). 2.- Separation device (11; 11 ') as claimed in claim 1, comprising a second support element (15; 15'), rotatable around a second axis (Y) and carrying said blade member (16; 30 ); said second support element (15; 15 ') being configured to sequentially advance said blade member (16; 30) in correspondence with said cutting station (T). 3.- Separation device (11 ') as claimed in claim 2, in which said blade member (16) is configured to cut first cutting portions (19) of said strip (3); and in which said separation device (11 ') further comprises a further blade member (30), carried by said second support element (15') and configured to sequentially cut second cutting portions (19) of said strip (3) distinct from said first cutting portions (19). 4.- Separation device as claimed in claim 3, wherein said further blade member (30) is selectively removable from a seat (29) of said second support element (15 ') to cut said second cutting portions (19 ). 5.- Separation device as claimed in any of the preceding claims, in which said first support element (14 ') has at least two said recesses (20) on said external lateral surface (17). 6.- Separation device as claimed in any one of claims 2 to 4, wherein said first support element (14; 14 ') advances, in use, said strip (3) along a longitudinal feed path (Q) ; said separation device (11; 11 ') further comprising local stop means (21) of said strip (3), carried by said second support element (15; 15') and configured to cooperate sequentially in contact with said strip ( 3) so as to temporarily block a movement of said strip (3) along said feed path (Q). 7.- Separation device as claimed in claim 6, wherein said local stop means comprise an elastomeric element (21) mounted on an outer lateral surface (22) of said second support element (15; 15 ') and configured to cooperating sequentially in contact with said strip (3) so as to temporarily block a movement of said cutting portions (19) along said feeding path (Q) when these are at said cutting station (T). 8.- Separation device as claimed in any one of the preceding claims, wherein said blade member (16; 30) comprises a serrated blade (23; 23 ') extending along a longitudinal direction and having a plurality of triangular profile teeth (24) arranged in a row; and in which: - the distance between the free vertices of each pair of successive teeth (24) is between 0.5mm and 2mm, preferably 1mm; and / or - the thickness of said serrated blade (23), measured at the base of each tooth (24), is between 0.75mm and 1.5mm, preferably 1mm; and / or - each tooth (24) comprises two lateral surfaces (25) intersecting in said free vertex and inclined, with respect to an ideal plane (K) passing through the free vertices of all the teeth (24), of an angle (α) of 60 °; and / or - the adjacent lateral edges (26) of each pair of successive teeth (24) identify an angle (β) of 90 ° between them; and / or - the ideal plane (K) passing through the free vertices of all the teeth (24) is inclined with respect to said longitudinal direction with a slope of 1/50, that is with an angle (γ) of 1.15 °. 9.- Separation device as claimed in claim 8, wherein said serrated blade (23 ') comprises a plurality of compound teeth (27) arranged in a row along the aforementioned longitudinal direction, each formed by a plurality of said teeth (24) and having a triangular profile; and in which: - the half-distance D between the free vertices of each pair of successive compound teeth (27) is between 5mm and 15mm, preferably 10mm; and / or - the compound lateral edges (28) of each compound tooth (27), defining the profile of said serrated blade (23 '), are inclined, with respect to an ideal plane passing through the free vertices of all compound teeth ( 27), by an angle (δ) having an amplitude comprised between 10 ° and 25 °, preferably 15 °. 10.- Labeling machine (1) configured to apply labels (2) obtained from a strip (3) of labeling material to articles (4) intended to contain a pourable product; said machine (1) comprising: - a conveying device (6) which advances, in use, said articles (4) along a conveying path (P); - at least one storage unit (5) configured to store said strip (3) of labeling material; - a distribution system (10) configured to take said strip (3) from said storage unit (5) and advance it along a feeding path (Q); - a separation device (11; 11 ') of said labels (2) from said strip (3) as claimed in any of the preceding claims; And - a transfer device (12) of the labels (2) obtained by means of said separation device (11; 11 '), configured to sequentially receive said labels (2) separated from said separation device (11; 11') and to feed them to said conveyor device (6), to apply them to respective articles (4). 11.- Method for applying labels (2) made from a strip (3) of labeling material to articles (4) intended to contain a pourable product, said method comprising the steps of: i) advancing a plurality of articles (4) along a conveying path (P); ii) sequentially advancing a recess (20) at a cutting station (T); iii) advancing said strip (3) along a feed path (Q) in such a way that predetermined cutting portions (19) of said strip (3) cover one by one at least part of said recess (20) at said station shear (T); iv) sequentially advancing a blade member (16; 30) at said cutting station (T), on the opposite side of said strip (3) with respect to said recess (20); v) sequentially inserting said blade member (16; 30) through said recess (20) at said cutting station (T), so as to sequentially cut each of said cutting portions (19); And vi) apply the labels (2) previously cut during step v) to insert to relative articles (4) at an application station (A). 12.- Method as claimed in claim 11, wherein said step iii) of advancing further comprises the steps of: vii) supporting and advancing said strip (3) by means of a rotating support element (14; 14 ') having said recess (20) on its own external side surface (17); And viii) rotate said support element (14; 14 ') so as to sequentially bring said recess (20) in correspondence with said cutting station (T).