EP2077965B1

EP2077965B1 - Vapour diffusion device and equipment for the application of labels on containers using said device

Info

Publication number: EP2077965B1
Application number: EP07825567A
Authority: EP
Inventors: Silverio Tagliaferro
Original assignee: Clever Srl-Unipersonale
Current assignee: Clever Srl-Unipersonale
Priority date: 2006-10-31
Filing date: 2007-10-26
Publication date: 2010-07-14
Anticipated expiration: 2027-10-26
Also published as: ATE473924T1; WO2008053335A1; EP2077965A1; ITVI20060321A1; DE602007007798D1

Abstract

A device (1) for the diffusion of vapour comprising a shaped casing (2), which, on the side wall (2a), has a plurality of first pass-through openings (3) through which heated vapour is discharged, a supply duct (4), associated with the shaped casing (2), for conveying the vapour to be overheated to the shaped casing (2) and heating means (5), situated inside the shaped casing (2), suitable for overheating the vapour. The supply duct (4) is equipped with an outlet mouth (4a) which communicates with the heating means (5) for introducing the vapour directly in contact with the heating means (5).

Description

The present invention relates to a vapour diffusion device according to the preamble of claim 1 and known from US 2,880,522 , suitable for being used especially for the application of labels on containers.
The present invention also relates to equipment for the application of labels on containers using the above device, also known in the field as lance.
In particular, the above device and equipment allow labels to be applied on the outer wall of various kinds of containers, exploiting the thermoshrinkability of the material of which they are made.
Under certain temperature conditions, in fact, this material shrinks, favoring a perfect and correct adhesion to the containers.
It is known that containers such as glasses, basins, bowls and the like, made for example of plastic or glass, are generally subjected to a labelling process before being sold or filled with the product to be consumed.
Variously shaped labels are formed immediately before being applied to the container or, alternatively, they are conveyed already preformed, preferably in tubular form, close to the same container.
One of the techniques for applying labels to containers of the known type, mainly adopted if the labels are made of plastic or synthetic resin, envisages advancing the containers aligned with each other on a horizontally moveable conveyor belt.
The conveyor belt is situated above a supporting structure belonging to more complex equipment.
The labels, formed on a tubular structure associated with the conveyor belt and having a diameter larger than the maximum encumbrance of the container, are moved in a vertical direction by driving gears to be positioned in line with the relative containers, positioned externally.
The labels are applied to the containers by means of a process known in the field as "thermoshrinking", inside a tunnel located on a transporting conveyor belt, through which the containers pass in succession.
This process consists in insufflating or distributing vapour in the tunnel at a certain temperature, depending on the type of plastic material of which the label is made, causing the perfect adhesion of this to the outer surface of the container.
The vapour is diffused by a pair of devices, associated with the supporting structure, forming the above tunnel as they are opposite and facing one each other and at a distance from the conveyor belt.
Each device comprises a shaped casing which, on the side wall, has a plurality of pass-through openings through which the vapour exits. The device also comprises a supply duct and a discharge duct, connected to the shaped casing, the first suitable for introducing the vapour into the shaped casing, the second suitable for sending the condensate which is produced therein outside the casing.
In the most recent embodiment procedures of the thermoshrinking process the vapour, before being directed against the containers passing through the tunnel on the conveyor belt, is heated by the diffusion device.
The purpose of this is to reduce the degree of humidity of the vapour entering the thermoshrinking tunnel and consequently to limit the formation of condensate or drops on the outer surface of the container, capable of causing degradation phenomena of the same, such as the creation of surface mildew.
The heating of the vapour is effected by heating means, situated in each of the vapour diffusion devices to raise the temperature.
The heating means consist, for example, of a tube through which hot air passes, communicating with the interior of the shaped casing, or a cylindrical resistance, contained in a hollow body interposed between the shaped casing and the same resistance and having a plurality of pass-through holes on the side surface.
The vapour diffusion devices of the known art, however, are not without drawbacks.
A first disadvantage derives from the fact that the heating means installed in the known vapour diffusion devices do not ensure the complete elimination or reduction to minimum levels of the depositing of condensate or water drops on the containers.
As already mentioned, this phenomenon causes the formation of mildew on the containers capable of deteriorating not only the specific container involved but also those with which it comes into contact.
This aspect is particularly evident and harmful considering that, in most cases, after being labelled, the containers are stacked one upon each other.
Under stacking conditions, moreover, the drops of water or condensate present on the containers cause, over a long period of time, reciprocal adherence between the containers stacked and brought closer in the pile, with the obvious disadvantages which this implies.
On the other hand, when the containers are under stacking conditions, the drops of water possibly present thereon, over a short period of time cause a certain instability of the pile.
A second drawback, which is a direct consequence of the previous aspect, of the known devices in question is due to the fact that, in order to avoid or at least limit the negative phenomena mentioned above, it is necessary to have adequate drying systems of the containers downstream of the thermoshrinking tunnel.
If, on the one hand, this allows containers to be obtained which are practically intact, on the other hand, it increases the constructive complexity and relative costs of the equipment for the application of labels on containers.
Another disadvantage of the known art consists in the construction complexity of the vapour diffusion devices, regardless of the necessity of installing drying systems, as they in any case envisage a discharge duct of the condensate produced in the shaped casing.
The present invention proposes to solve the drawbacks of the known art indicated above.
In particular, a primary objective of the invention is to provide a vapour diffusion device used in thermoshrinking processes for labelling containers which prevents or reduces to the minimum the deposit of water drops or condensate on the same containers.
Within this objective, the present invention therefore undertakes to provide a vapour diffusion device which prevents the danger of the formation of harmful phenomena, such as for example mildew, on the containers which damage them.
The invention also undertakes to prevent the containers already labelled, when stacked, from adhering to each other, thus favouring their easy separation, without high risks, which can also be irremediable, of breakage.
A further undertaking of the invention is to increase the stability of the stack of containers, with respect to the known art, in the phases immediately following its formation.
A second objective of the present invention is to provide a vapour diffusion device, in addition to equipment for the application of labels on containers, which has a simpler construction with respect to the equivalent known devices.
A further objective of the invention is to provide a vapour diffusion device which contributes to obtaining an effective application of labels to containers.
The above objectives achieved by means of a vapour diffusion device according to claim 1 enclosed, to which reference should be made for the sake of brevity.
Other detailed characteristics of the vapour diffusion device are indicated in the subsequent dependent claims.
An object of the present invention also relates to equipment for the application of labels on containers according to claim 18 enclosed, to which reference should be made for the sake of convenience.
The vapour diffusion device of the invention advantageously significantly reduces the phenomenon of the deposit of water drops on the containers to which thermoshrinkable labels are applied, with respect to the equivalent known art.
The reason for this is that, at the outlet of the device of the invention for applying labels on containers, through thermoshrinking, the vapour is overheated and particularly dry.
The invention consequently eliminates or significantly reduces the risk of the appearance of harmful phenomena on the containers, with respect to the known art, such as for example the formation of mildew, capable of also irreparably modifying the functionality.
Furthermore, in this way, with respect to the present state of the art, those cases in which water drops jeopardize the integrity of various containers in contact with each other, for example when stacked one upon each other, are eliminated or are greatly reduced.
The almost total elimination of water drops or condensate on the containers on the part of the device of the invention also makes the stack of containers, normally formed after labelling, more stable with respect to the state of the prior art, thus facilitating its moving.
The device of the invention consequently improves the drying degree of the containers after labelling by means of thermoshrinking.
Again advantageously, the vapour diffusion device and equipment for applying labels on containers of the invention have a simpler construction with respect to the known art.
Due to the high overheating of the vapour obtained therein, in fact, the device of the invention does not comprise the discharge duct of the condensate, typical, on the contrary, of the known devices.
In addition, the equipment for applying labels on containers of the invention reaches the same qualitative results as the known art without, however, having to install drying systems downstream of the vapour diffusion device.
The invention also advantageously allows labels to be effectively applied to containers by means of the thermoshrinking process.
Furthermore, the vapour diffusion device of the invention is advantageously more economical with respect to similar known devices, the other factors involved being identical.
The above objectives and advantages and others which will be defined in the present result, will appear more evident from the description of a preferred embodiment, provided for illustrative but non-limiting purposes with reference to the enclosed drawings, in which:

figure 1 is a simplified front view of the device according to the invention;
figure 1a is an enlargement of a detail of figure 1;
figure 2 is a transversal section of figure 1;
figure 2a is an enlargement of a detail of figure 2;
figure 3 is a plan view of figure 1;
figure 3a is an enlargement of a detail of figure 3.

The vapour diffusion device according to the invention is represented in figure 1, where it is indicated as a whole with 1.
It can be observed that the device 1 comprises a shaped casing 2, which, on the side wall 2a, has a plurality of first pass-through openings 3, clearly visible in figure 1a, through which heated vapour is discharged.
The device 1 comprises a supply duct 4, associated with the shaped casing 2, which introduces the vapour to be heated into the shaped casing 2.
The device 1 also comprises heating means, indicated as a whole with 5, situated inside the shaped casing 2, suitable for increasing the temperature of the vapour.
According to the invention, the supply duct 4 is equipped with an outlet mouth 4a which communicates with the heating means 5 to put the vapour directly in contact with the heating means 5.
The device 1 preferably comprises in this case a hollow body 6, interposed between the shaped casing 2 and the heating means 5 and having, on the side surface 6a, a plurality of second pass-through openings 7, more clearly visible in figure 2 and in the enlargement of figure 2a.
The shaped casing 2 and the hollow body 6 are prevalently developed along a longitudinal axis Z.
In the example described, the shaped casing 2 and the hollow body 6 have a U-shaped profile in the longitudinal section and a square-shaped profile in the transversal section.
Both the shaped casing 2 and the hollow body 6 are in fact equipped at one end 2b, 6b, with a bottom wall 2d, 6d and at the opposite end 2c, 6c, with an inlet mouth, not indicated, in correspondence with which the heating means 5 are inserted in the hollow body 6.
The device 1 also includes a closing flange 8 coupled in correspondence with the outlet mouth with the shaped casing 2 and the hollow body 6 by first fixing means, indicated as a whole with 9 and screws, for example.
The shaped casing 2 and the hollow body 6 define an internal chamber 10 which communicates with the outside of the shaped casing 2 by means of the first pass-through openings 3 and with the internal volume of the hollow body 6 by means of the second pass-through openings 7.
The first pass-through openings 3 and the second pass-through openings 7 are substantially distributed for the whole length of the shaped casing 2 and hollow body 6 respectively.
Furthermore, the first pass-through openings 3 and the second pass-through openings 7 are aligned with each other along respective longitudinal directions parallel to each other and to said longitudinal axis Z.
Figure 2 shows that the second pass-through openings 7 of the hollow body 6 face a first section 21a of the side wall 2a of the shaped casing 2 which is opposite to a second section 22a of said side wall 2a in which the first pass-through openings 3 are made.
As explained in more detail further on, this constructive expedient compels the vapour to follow a rather articulated course and remain in the hollow body 6 and subsequently in the shaped casing 2 for a prolonged period of time or in any case sufficiently long to allow the heating means 5 to raise the temperature of the vapour to high values.
This prevents the formation of drops on the containers to be labelled by means of the thermoshrinking process, exploiting the vapour leaving the first pass-through holes 3 of the shaped casing 2.
The supply duct 4 is inserted in a first pass-through hole, not indicated, and made in the shaped casing 2, and in a second pass-through hole, not indicated, coaxial to the first hole and made in the hollow body 6.
The supply duct 4 has an end section 4b contained in the internal chamber 10 whereas its outlet mouth 4a is coupled with the above second pass-through hole 7 made in the hollow body 6.
According to a preferred embodiment of the invention described herein, the heating means 5 comprise a pair of heat resistances 11, 12 of the immersion type, as shown in figure 3.
In other embodiments of the invention, not shown, the number of heat resistances can be different, and can have any value.
More specifically, each of the heat resistances 11, 12 consists of a metallic bar passing through an axial hole, not visible, made in the closing flange 8.
For purely illustrative purposes, the metallic bar has a substantially U-shaped profile according to a longitudinal sectional plane.
Each heat resistance 10, 11 is made up of a main portion 110, contained in the hollow body 6, and a smaller portion 111, protruding from the hollow body 6 and shaped casing 2 and connected to a supporting block 12 suitable for being electrically connected to the electric power supply.
The electric connection at the supporting block 12 outside the components in which vapour is produced, i.e. the shaped casing 2 and the hollow body 6, protects the structural integrity of the heat resistance 10, 11, preventing dangerous overheating and/or short circuits.
The device 1 preferably but not exclusively comprises a plurality of diffusive nozzles 13, each of which is applied outside the shaped casing 2 tin correspondence with one of the first pass-through openings 3.
The diffusive nozzles 13 are coupled with a supporting plate 14, connected to the shaped casing 2 by second fixing means, indicated as a whole with 15 and again consisting of screws for example, as shown in figure 3a.
The diffusive nozzles 13 can be preferably regulated in height with respect to the shaped casing 2, to obtain different outlet directions of the vapour from the casing 2 itself.
The diffusion device 1 of the invention thus allows the shape of the container, often variously articulated, to be followed, favouring the effective application of the labels even in those areas of the container which are most difficult to reach.
The vapour diffusion device 1 also comprises connection means, indicated as a whole with 16, associated with the shaped casing 2 and suitable for the connection of the latter with a generic supporting structure.
The connection means 16 comprises two shaped rods 17, 18 which are coupled by joining means of the known type to the supporting structure.
As already specified, the invention also relates to equipment for the application of labels to containers, not illustrated for the sake of convenience.
Said equipment comprises a supporting structure, on which stands a conveyor belt which collects the containers and moves them forward along a pre-established direction.
The equipment for the application of labels to containers comprises a pair of vapour diffusion devices 1, connected to the supporting structure and facing the conveyor belt to define a tunnel for the thermoshrinking of the labels on the side wall of the containers.
Each of the devices 1, opposite to each other and separated by the conveyor belt, has the technical characteristics previously described.
Each container normally consists of a glass, a bowl, a basin or a bottle, made of glass or plastic, not yet filled with the substance of interest.
The labels to be applied to the containers are made of plastic or thermoshrinkable synthetic material, such as film made of polyethylene, polystyrene, polyvinylchloride or polyethylene foams, or laminated film with the outer surface which can be used for the printing of decorative designs.
The thickness of each label depends on the type of thermoplastic material used.
The tunnel extends for a length which is sufficient for allowing an effective and controlled thermoshrinking process, coinciding with that of the shaped casing 2.
Operatively, the vapour is introduced, for example at a temperature of about 120°C, into the hollow body 6 through the supply duct 4, entering directly into contact with the heating means 5.
In this way, the vapour is brought to a particularly high temperature and in any case higher than that reached in the devices of the known type, which do not envisage the direct contact of the vapour with the heating means.
This aspect, which favours the overheating of the vapour, is determined in particular by the type of heating means 5 used by the device 1, consisting, as already mentioned, of suitable heat resistances of the immersion type, suitable for operating in the presence of more or less humid environments.
The vapour overheated by the heating means 5 leaves the hollow body 6 and, passing through the second pass-through openings 7, enters the internal chamber 10.
After externally touching most of the side surface 6a, the overheated vapour passes through the first openings 3 and the diffusive nozzles 13, thus leaving the shaped casing 2.
At the outlet of the shaped casing 2, the vapour immediately enters the tunnel formed on the conveyor belt of the equipment for the application of labels on containers.
In the tunnel, where the containers arrive one at a time, aligned on the conveyor belt, the vapour is used for the thermoshrinking of the labels on the outer wall of the containers.
Immediately before being applied to the containers, the labels are formed in a tubular form on a rotating tower and are obtained from a roll positioned on a feeding drum of the tower.
The labels are cut to size, for a length substantially equal to that of the container, by means of a knife which acts tangentially with respect to the drum.
Each portion of the label thus obtained, joined at the ends so as to form a tube and be applied to the container, is then wound onto a rotating mandrel belonging to the tower, vertically aligned with the relative container.
The label is then transported in a vertical and axial direction towards the container.
The system thus obtained allows substantially dry vapour to be sent towards the tunnel, thus avoiding the formation of condensate in its interior and consequently on the containers to be labelled, with the evident and already mentioned advantages that this implies.
In particular, this derives from the arrangement of a supply duct directly in contact with the heating means, the type of heating means used and the course that the vapour is forced to follow inside the diffusion device according to the invention.
In view of what is specified above, it is consequently clear how the vapour diffusion device and equipment for the application of labels on containers, object of the present invention, achieve the objectives and advantages indicated above.

Claims

A vapour diffusion device (1) comprising:
- a shaped casing (2) which, on the side wall (2a), has a plurality of first pass-through openings (3) through which said heated vapour is discharged;

- a supply duct (4), associated with said shaped casing (2), for conveying said vapour to be heated to said shaped casing (2);
characterized in that it further comprises:

- heating means (5), situated inside said shaped casing (2), suitable for increasing the temperature of said vapour, and in that said supply duct (4) is equipped with an outlet mouth (4a) which communicates with said heating means (5) to put said vapour directly in contact with said heating means (5).
The device according to claim 1, characterized in that it comprises a hollow body (6), interposed between said shaped casing (2) and said heating means (5), having, on the side surface (6a), a plurality of second pass-through openings (7).
The device according to claim 2, characterized in that said shaped casing (2) and said hollow body (6) define an internal chamber (10) which communicates with the outside of said shaped casing (2) by means of said first pass-through openings (3) and with the internal volume of said hollow body (6) by means of said second pass-through openings (7).
The device according to claim 2, characterized in that said shaped casing (2) and said hollow body (6) are prevalently developed along a longitudinal axis (Z).
The device according to claim 2, characterized in that said shaped casing (2) and said hollow body (6) are equipped at one end (2b, 6b) with a bottom wall (2d, 6d) and at the opposite end with an inlet mouth in correspondence with which said heating means (5) are inserted in said hollow body (6).
The device according to claim 5, characterized in that it comprises a closing flange (8), coupled by first fixing means (9) with said shaped casing (2) and to said hollow body (6) in correspondence with said inlet mouth.
The device according to claim 6, characterized in that said heating means (5) comprise at least one heat resistance (10, 11) of the immersion type, consisting of a metallic bar passing through at least one axial hole situated in said closing flange (8).
The device according to claim 7, characterized in that said heat resistance (10, 11) consists of a main portion (110), contained in said hollow body (6), and a smaller portion (111), protruding from said hollow body (6) and said shaped casing (2), connected to a supporting block (12) suitable for being electrically connected to the electric power supply.
The device according to claim 7, characterized in that said metallic bar has a substantially U-shaped profile according to a longitudinal sectional plane.
The device according to claim 5, characterized in that said shaped casing (2) and said hollow body (6) each have a U-shaped profile in a longitudinal section and a square profile in a transversal section.
The device according to claim 3, characterized in that said supply duct (4) is inserted in a first pass-through hole, situated in said shaped casing (2), and in a second pass-through hole, coaxial to said first hole and situated in said hollow body (6), and has an end section (4b) contained in said internal chamber (10) and said outlet mouth (4a) coupled with said second pass-through hole.
The device according to claim 2, characterized in that said second pass-through openings (7) of said hollow body (6) face a first section (21a) of said side wall (2a) of said shaped casing (2) opposite to a second section (22a) of said side wall (2a) where said first pass-through openings (3) are present.
The device according to claim 2, characterized in that said first pass-through openings (3) and second pass-through openings (7) are substantially distributed for the whole length of said shaped casing (2) of said hollow body (6).
The device according to claim 1, characterized in that it comprises a plurality of diffusive nozzles (13), each of which applied outside said shaped casing (2) in correspondence with one of said first pass-through holes (3).
The device according to claim 14, characterized in that said diffusive nozzles (13) are coupled with a supporting plate (14), connected by second fixing means (15) to said shaped casing (2).
The device according to claim 14, characterized in that said diffusive nozzles (13) can be regulated in height with respect to said shaped casing (2).
The device according to claim 1, characterized in that it comprises connection means (16), associated with said shaped casing (2), suitable for allowing the connection of said shaped casing (2) to a supporting structure.
Equipment for the application of labels to containers comprising a supporting structure, on which stands a conveyor belt suitable for collecting said containers and moving them forward along a pre-established direction, and at least one vapour diffusion device (1) according to claim 1, associated with said supporting structure and facing said conveyor belt to define a tunnel for the thermoshrinking of said labels on the side wall of said containers, and
said discharged heated vapour is sent to said tunnel.