SPLICING OPERATION IN THE CASE OF SELF-ADHESIVE LABELS

TECHNICAL FIELD

The present invention relates to a labelling machine to label containers adapted to contain a pourable product , preferably of food type , with self-adhesive labels obtained from a web of labelling material .

The present invention also relates to a reel of labelling material comprising a support web on which there are attached self-adhesive labels configured to be detached from the support web and applied on respective containers .

BACKGROUND ART

Labelling machines are known, which are commonly used to prepare , transport and apply labels to containers , in particular bottles , flasks , j ars or the like , made of plastic or glas s , configured to contain, or dest ined to be filled with, a pourable product , preferably of food type .

The use of label s known as "glued labels" , obtained from a web of labelling material in the form of a continuous strip initially wound on one or more reels , is particularly widespread .

In detail , this web is cut into portions of the same size to which glue is applied . The glue is applied using gluing means , such as rollers , spray or in j ection systems , or the like . The labels thus obtained are then trans ferred and glued onto the outer lateral surface of the respective containers .

Another particularly widespread type of labelling provides for the production of tubular labels , known as " sleeve labels" , produced from a web of heat-shrink film initially wound 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 adhe sion thereof to the lateral surfaces of these containers . This type of labels does not require the use of glue .

A further type of labelling known as "PSL" provides for the use of self-adhesive labels initially arranged attached on a support web from which they must then be separated to be glued directly on the respective containers to be labelled .

In detail , by pas sing the support web over a deflector plate that obliges the web to make a very narrow angle , the various labels are detached from the support web to be applied directly to the containers .

The depleted support web, i . e . without the self- adhesive labels , is then fed to a recovery device operatively arranged downstream of the deflector plate .

Regardles s of the type of label used, a labelling machine typically comprises :

- a carousel rotatable about a vertical axis and configured to convey a series of containers along a horizontal labelling path in the form of an arc of circle ;

- a feeding unit , typically defined by a pair of rotating shaft s supporting corresponding webs of labelling material in the form of continuous strip wound in respective reels ;

- a plurality of unwinding rollers that support , in use , the web unwound from the reel and guide it along a feed path; and

- a label trans fer device , configured to receive each label and feed this label to the carousel at the application station .

In the aforesaid case in which P SL labels are used, the trans fer device is defined by the afore-mentioned deflector plate , which causes , through a deflection of the support web with a very narrow angle , the label s to be sequentially detached from the support web and each label to be sent towards the related article .

The support web has a first face to which the self- adhesive labels are removably attached, and a second face opposite the first , on which no labels are present . For the purpose of avoiding to stop the labelling machine each time a reel finishes and hence reduce machine downtime , the need to automatically splice the end ( or terminal ) portion of a first ( depleting) web being unwound from a first reel ( reel in use ) with the initial ( free end) portion of a second (new) web wound on a second reel (new reel ) is known in the art .

To this end, labelling machines of the known type comprise a well-known splicing device ( or splicer ) operatively arranged between the feeding unit and the unwinding rollers and configured to splice the end portion of the first depleting web with the initial portion of the second new web .

Typically, the splicing is carried out by interposing a biadhesive element between the two webs .

In more detail , the biadhesive element is initially arranged on the initial free end portion of the second web ; this portion is then arranged at a splicing station in which the splicing device is positioned .

In the case in which labels of PSL type are used, the splicing operation can present some problems .

More in detail , there are no particular dif ficultie s in the case in which the depleting web has it s second face facing the new web at the splicing station, or in the case in which the labels supported by the depleting web are facing the opposite side with respect to the new web . In this case, splicing takes place so that the first face of the new web is superimposed on the second face of the depleting web .

The case in which the labels supported by the depleting web are facing the new web, and therefore towards the second face of the new web is dif ferent . In this case , splicing takes place so that the second face of the new web is superimposed on the first face of the depleting web .

In fact , in this case , the presence of labels of the new web on the labels of the depleting web, along the initial portion of the new web, can also give rise to, due to the action of the deflector plate , a detachment of the labels of the depleting web . This can cause detachment between the initial portion of the new web and the end portion of the depleting web .

SUBJECT AND SUMMARY OF THE INVENTION

The ob j ect of the present invention is to produce a labelling machine which is highly reliable and has a limited cost , and allows at least some of the drawbacks specified above and related to prior art labelling machines to be overcome .

According to the invention, this ob j ect is achieved by a labelling machine as claimed in claim 1 . A further object of the present invention is to provide a reel of labelling material which is highly reliable and has a limited cost, and allows at least some of the drawbacks specified above to be overcome.

According to the invention, this object is achieved by a reel as claimed in claim 9.

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 labelling machine produced according to the present invention;

- Figs. 2a, 2b and 2c are schematic top views, in enlarged scale and with parts removed for clarity, of part of the labelling machine of Fig. 1;

- Fig. 3 is a schematic side view of a reel of labelling material for use in the labelling machine of Fig. 1; and

- Fig. 4 is a cross section of a support web of which the reel of Fig. 3 is formed.

DETAILED DESCRIPTION

With reference to Fig. 1, the reference number 1 indicates as a whole a labelling machine configured to label containers 2 adapted to contain a pourable product, preferably of food type, with self-adhesive labels 3.

The labels 3 are self-adhesive labels of "PSL" type, initially attached to a support web 4 and longitudinally spaced on it, as can be seen in Fig. 3. The support web 4 thus defines a web of labelling material.

The containers 2 are preferably defined by bottles, jars or flaks, made of plastic or glass.

The machine 1 comprises:

- a carousel 5 rotatable about a preferably vertical axis (not illustrated) and configured to convey a series of containers 2 to be labelled along a preferably horizontal labelling path in the form of an arc of circle;

- a feeding unit 6 configured to feed the support web 4 along a feed path Q;

- a plurality of unwinding rollers 7 that support, in use, the web 4, and guide it along the feed path Q; and

- a separation device, in the case in question a deflector plate 8 configured to interact, in a known manner, with the web 4, so as to oblige it to make a sudden curve with a very narrow angle.

Through this change in direction, the self-adhesive labels 3 are sequentially separated, i.e., detached, from the support web 4, to then be applied directly on the containers 2 at an application station A.

The depleted web 4, i.e., without the self-adhesive labels 3, is then fed to a recovery device 50 operatively arranged downstream of the deflector plate 8.

The web 4 has a first face 12a on which the labels 3 are removably attached, and a second face 12b opposite the first. No labels are present on the second face 12b. The second face 12b is facing the opposite side with respect to the first face 12a.

The first face 12a can be provided with a non-stick covering, such as a silicone coating, to facilitate detachment of the labels 3 at the deflector plate 8.

Advantageously, the feeding unit 6 supports at least two support webs 4a, 4b and comprises for this purpose at least two support shafts 10, each configured to support a respective web 4a, 4b.

In more detail, each of the webs 4a, 4b is initially contained, in the form of continuous strip, in a respective winding, so as to define a respective reel 11a, lib.

More precisely, one reel 11a, lib at a time is unwound from the feeding unit 6. Therefore, with reference to the situation shown in the accompanying figures, the reel 11a defines a reel in use 11a, and the reel lib defines a new reel lib. Consequently, one web 4a, 4b at a time is selectively fed, in use along the feed path Q . Therefore, with reference to the situation shown in the accompanying figures , the web 4a defines a web in use or a depleting web 4a, and the web 4b defines a new web 4b .

In the example described the machine 1 comprises the reels 11a and l ib .

Each support web 4a, 4b has an initial portion 13a and an end or terminal portion 13b .

For the purpose of avoiding the stop of the machine 1 each time a reel 11a in use finishes , the machine 1 also comprises a splicing device 14 , operatively interposed between the feeding unit 6 and the deflector plate 8 , more in particular between the unit 6 and the unwinding rollers 7 , and configured to splice the end portion 13b of the depleting web 4a with the initial portion 13a of the new web 4b .

The splicing device 14 is of known type and therefore is only illustrated schematically in the accompanying figures and will not be described in detail .

Preferably, splicing is performed by interposing a biadhesive element 15 between the two webs .

In more detail, the biadhesive element 15 is initially arranged on the initial portion 13a of a free end of the new web 4b; this initial portion 13a is then arranged at a splicing station G in which the splicing device 14 is positioned .

Hereinafter, the case in which the labels of the web in use 4a are facing the new web 4b, and in particular facing the second face 12b of the new web 4b, will be examined . The first face 12a of the web in use or depleting web 4a is facing the second face 12b of the new web 4b . Therefore, in the case illustrated in the accompanying figures , the splicing device 14 splices the depleting web 4a with the new web 4b so that the second face 12b of the new web 4b is superimposed on the first face 12a of the depleting web 4a .

By means of the aforesaid splicing, a splicing area 16 is defined on the end portion 13b of the depleting web 4a .

In particular, the splicing area 16 is defined by a longitudinal sector of the end portion 13b of the depleting web 4a having a determined extension along the longitudinal direction of the depleting web 4a .

According to an aspect of the present invention, the depleting web 4a includes a covering strip, band or tape 17 , which is fixed at its end portion 13b to cover the splicing area 16 .

Due to this solution, when the aforesaid "problematic" splicing of the depleting web 4a with the new web 4b in which the depleting web 4a has it s first face 12a facing the second face 12b of the new web 4b at the splicing station G is performed, a detachment of the new web 4b from the depleting web 4a once the splicing area 1 6 reaches the deflector plate 8 is prevented .

In practice , the initial portion 13a of the new web 4b is spliced with the end portion 13a of the depleting web 4a at the splicing area 1 6 , with interposing of the strip 17 (Fig . 2 c ) .

The strip 17 is preferably defined by a portion of a further web, positioned to cover the web 4a .

Advantageously, the strip 17 has a longitudinal extension greater than or equal to the longitudinal extension of the splicing area 1 6 ( as shown schemat ically in Fig . 3 ) .

This ensures that the splicing area 1 6 pas ses at the deflector plate 8 without detachment of the new web 4b from the depleting web 4a occurring . In fact , the label 3 or the labels 3 present along the splicing area 1 6 of the depleting web 4a are prevented from detaching f rom the web 4a, as they are covered and held in position by the strip 17 .

Advantageously, the strip 17 has a first portion 17a that transversely covers the first face 12a of the depleting web 4a, and a second portion folded on the web 4a so as to cover at least part of the second face 12b of the depleting web 4a, as shown in Fig . 4 . The first portion 17a is applied to the first face 12a of the depleting web 4a , and the second portion 17b is applied to the second face 12b of the web in use 4b .

In this way, a firm and strong fixing of the strip 17 to the splicing area 1 6 is ensured, so that the strip 17 withstands the detachment force transmitted by the deflector plate 8 , maintaining the labels 3 below in position attached to the web in use 4a, and ensuring splicing .

In light the above , the strip 17 has an inner face 18b which is applied, in particular attached, to the web 4a and an outer face 18a which is opposite the inner face . The inner face 18b faces the web 4 a, while the outer face 18a is facing the opposite side with respect to the inner face 18b .

Advantageously, at least the outer face 18a is configured for attachment of the new web 4b . The outer face 18a is configured so that the second face 12b of the new web 4b can be attached to said outer face 18a . Therefore , no non-stick covering is present on the outer face 18a, while instead said non-stick covering can be present on the first face 12a of the web in use 4a .

In this way, the new web 4b is spliced firmly to the depleting web 4a by the strip 17.

Preferably, the inner face 18b has no non-stick covering either. In this way, fixing of the strip 17 to the web 4a is further improved.

According to a further aspect of the present invention, the strip 17 defines a reference element on the respective web 4a, 4b, said reference element being detectable to control splicing between the web 4a and the web 4b.

In particular, the machine 1 comprises:

- a sensor 19 configured to detect the reference element, i.e., the strip 17, on the web 4a, 4b, and to generate a trigger signal when the reference element is detected (Fig. 2a) ;

- a control unit 20 configured to receive said trigger signal and to control the splicing device 14 to perform the splice between the depleting web 4a and the new web (4b) as a function of said trigger signal (Fig. 2c) .

Preferably, the strip 17 has, at its outer face 18a and its first portion 17a, an aesthetic pattern different from that of the labels 3 supported by the respective web 4a, 4b, so as to be easily detectable by the sensor 19 with respect to the labels 3. In this case, the sensor 19 is an optical sensor, such as a video camera or a fibre optic sensor. In this way, the choice of a suitable pattern of the covering strip can allow more accurate detection .

Alternatively, the strip 17 could include a magnetic or electromagnetic portion. In this case, the sensor 19 is a sensor capable of detecting a magnetic or electromagnetic field. In this way, an increase in the detection speed is obtained.

Alternatively, the sensor 19 could be configured to detect a thickness variation, so as to be able to detect the presence of the strip 17. In fact, the strip 17 determines an increase of the thickness of the element which comprises thickness and strip. In this case, the sensor 19 could be an ultrasonic sensor, which allows high precision.

Alternatively, the sensor 19 could be a mechanical contact, and configured to detect the strip 17 by mechanical contact. In this way a cost saving is obtained.

Advantageously, the machine 1 comprises a pair of sensors 19, each configured to detect the strip 17 on a respective web 4a, 4b and each arranged adjacent to the web 4a, 4b and operatively between the related support shaft 10 and the splicing device 14.

In this way, a simple and effective system is provided to control the splicing operation of the webs

4a, 4b. From the foregoing, it is evident how with the present invention it is pos sible to provide a reel 11a of labelling material comprising a support web 4a which support s a plurality of self-adhesive labels 3 mutually spaced apart and configured to be applied on containers 2 adapted to contain a pourable product , wherein :

- the web 4a comprises a covering strip 17 which is fixed at the end portion 13b to cover the splicing area 1 6 ;

- advantageously, the strip 17 has a longitudinal extension greater than or equal to the longitudinal extension of the splicing area 1 6 ;

- preferably, the strip 17 has a first portion 17a that transversely covers the first face 12a of the web 4a, and a second portion 17b folded so as to cover at least part of the second face 12b of the web 4a ;

- advantageously, the outer face 18b of the strip 17 does not have the non-stick covering;

- advantageously, the strip 17 defines a reference element on the web 4a detectable by a sensor 1 9 to control , on the basis of the detection, splicing between the web 4a and the web 4b .

From the foregoing, it also evident how with the present invention it is pos sible to implement a use of a covering strip 17 applied to an end portion 13b of a support web 4a of self-adhesive labels 3, configured to be applied on containers 2 adapted to contain a pourable product, to cover a splicing area 16 of said end portion 13b at which the support web 4a is spliced with a further support web 4b.

The operation of the machine 1 according to the present invention will be described below, with particular reference to an initial condition in which the initial portion 13a of the new web 4b is arranged at the splicing station G and the end portion 13b of the depleting web 4a passes in front of the sensor 19.

In this condition, the splicing area 16 and hence the strip 17 passes in front of the sensor 19 (Fig. 2a) . At this point, the control unit 20 controls the splicing device 14 as a function of detection of the strip 17 - i.e., of the reference element - by the sensor 19, in this way controlling splicing of the web 4a with the web 4b (Fig. 2c) when the splicing area reaches the splicing station G (Fig. 2b) . The presence of the strip 17 determines a firm splicing between the two webs 4a, 4b, as explained above.

By examining the features of the machine 1, and of the reel 11a, lib, according to the present invention the advantages that can be obtained therewith are evident.

The labelling machine according to the invention is configured to optimize splicing in the case of selfadhesive labels .

In particular, due to the presence of the covering strip 17 , during splicing of the depleting web 4a with the new web 4b in which the depleting web 4a has it s first face 12a facing the second face 12b of the new web 4b at the splicing station G, unwanted detachment of the new web 4b from the depleting web 4a once the splicing area 1 6 reaches the deflector plate 8 is prevented in a simple and ef fective way .

In fact , the strip 17 covers the labels 3 located at the splicing area 1 6 attaching them to the depleting web 4a and preventing their detachment from the web 4a, and hence the detachment of the initial portion 13a of the web 4b from the end portion 13b of the web 4a .

Therefore , firm splicing between the webs 4a and 4b is ensured, at the same time avoiding more complicated and laborious alternative solutions , such as the installation of a device for removing the labels 3 from the splicing portion 1 6 during the labelling proces s or the removal of these labels prior to the labelling proces s ( solutions which, moreover, are not particularly ef fective due to the non-stick covering in any case present on the first face 12a of the web 4a, which could facilitate detachment of the non-stick element 15 at the deflector plate 8 ) .

Moreover, the use of the strip 17 as reference element to "trigger" the splicing operation makes it pos sible to perform this operation in a simple , automatic and ef fective way .

Naturally, the splicing area 1 6 is equally identifiable on the new web 4b, once this becomes a depleting web 4a .

In other words , each support web 4 has a splicing area 1 6 , given that from time to time each web becomes a depleting web .

As stated above , since the new web 4b also becomes a depleting web 4a, each support web 4a, 4b includes this covering strip 17 to cover the respective splicing area 1 6 .

It is clear that modifications and variant s may be made to the machine 1 and to the reel 11a described and illustrated herein without however departing from the scope of protection defined by the claims .