ITMI20100471A1 - MACHINE TO CARRY OUT THE PACKAGING, BY SEALING WITH SYNTHETIC FILM, OF PRODUCTS, IN PARTICULAR FOOD PRODUCTS, IN CONTAINERS OF THE TYPE OF TRAYS, TRAYS OR SIMILAR, WITH HIGH FLEXIBILITY OF USE. - Google Patents

Description

"MACHINE FOR PACKAGING, BY SEALING WITH SYNTHETIC FILM, OF PRODUCTS, IN PARTICULAR FOOD PRODUCTS, IN CONTAINERS OF THE TYPE TRAYS, TRAYS OR SIMILAR, WITH HIGH FLEXIBILITY OF USE"

DESCRIPTION

The present invention relates to a machine for carrying out the packaging, by sealing with synthetic film, of products, in particular food products, in containers such as tubs, trays or the like.

Machines are known for packaging products, in particular food products, inside pre-formed containers, such as trays, trays or the like, by applying, usually performed by heat sealing or similar techniques, a synthetic film placed to close the mouth of the containers.

These known machines generally comprise a support surface which extends from a container loading station to a packaging station and along which the containers are pushed by means of suitable handling means inside lateral guides that delimit laterally the path of advancement of the containers. In correspondence with the packaging station, a packaging chamber is generally arranged which consists of a lower hood, open at the top and an upper hood open at the bottom and facing the lower chamber. In the lower bell, at least one support plate is arranged for at least one container and a lower mold which can be engaged with the protruding edge that delimits the mouth of the container or containers to be sealed, while in the upper bell there is an upper mold which is provided of means for effecting the sealing of the synthetic film which is positioned between the lower hood and the upper hood. The lower bell can be lifted to lift the container towards the upper mold and to engage with the upper bell going to delimit a compartment which is sealed to the outside and which, depending on the type of packaging to be carried out, can be simply connected to a vacuum pump (vacuum packaging) or, in succession, to a vacuum pump and to a gas or gas mixture supply line (modified atmosphere packaging).

The sealing film unwinds from a feed reel to a waste winding roller passing, in the packaging station, between the lower hood and the upper hood.

The upper mold is movable vertically relative to the upper hood to engage with the lower mold and perform the welding, generally heat sealing, of the film that passes between the two molds.

When the lower bell has been raised against the upper one and the desired degree of vacuum has been obtained or the atmosphere in the compartment delimited by these two bells has been modified, the upper mold, closing on the lower mold, carries out the sealing of the film on the edge that defines the mouth of the container or containers carried by the lower mold, as well as the cut of the film along the edge of the container or containers.

These machines are able to carry out the packaging of a container or a group of containers, as many as can be housed in the packaging chamber.

Machines for large productions are also known in which, in the packaging station, two packaging chambers are provided. In these machines, the same sealing film is used for both packaging chambers, which unwinds, similarly to machines with a single packaging chamber, from a feed reel to a roll for wrapping the scrap and the two packaging chambers. they are used simultaneously, achieving the advantage of doubling the productivity of the machine compared to machines with a single packaging chamber.

Known machines are not free from problems and drawbacks.

In fact, these machines are not very flexible in use since, when a format change is required, or when the format of the containers to be packaged is changed, it is necessary to replace the molds, adjust the side guides, often also replace the film. of sealing, to recall the program in the command and control unit that supervises the operation of the machine, and to the heating of the mold or of the upper molds, with the use of time and manpower.

Even greater difficulties are encountered when the sealing operation requires two distinct phases in which it is necessary for the machine to operate in a different way, such as when a so-called "skin" seal is required followed by further sealing. This type of packaging requires, in fact, a first phase of vacuum packaging with preheating of a particular sealing film so that it adheres (like a skin) to the product placed in the containers and then a second phase in which a further sealing without a “skin” effect, which for simplicity and clarity we will define as “traditional sealing”, of the mouth of the containers using another type of sealing film.

In this case, with machines of the known type, it is necessary to carry out the two packaging phases on two separate machines, or, having only one machine, in two passes on the same machine after replacing the sealing film between the two passages. The double loading of the containers on the same machine or on two separate machines and the replacement of the film in the case of a single machine require the use of manpower and significantly affect the overall production times.

The aim of the present invention is to solve the problems and to obviate the aforementioned drawbacks, realizing a machine which can be adapted, in an extremely simple and rapid way, to the various requirements of use.

Within this aim, an object of the invention is to provide a machine which can rapidly pass from packaging containers of one format to packaging containers of a different format.

Another object of the invention is to provide a machine which, when required, can increase its productivity.

A further object of the invention is to provide a machine which can perform, in a single step, two distinct packaging steps, as required for example in packaging with a "skin" type seal followed by a traditional seal.

Yet another object of the invention is to provide a machine which has a high reliability and operating precision.

This task, as well as these and other purposes which will appear better below, are achieved by a machine for carrying out the packaging, by sealing with synthetic film, of products, in particular food products, in containers such as tubs, trays or the like, comprising means handling of the containers, in which the products to be packaged are placed, along a direction of advancement from a container loading station to a container unloading station; between said loading station and said unloading station, a packaging station being arranged provided with means for positioning a sealing film on the upper side of the containers to be sealed and with sealing means for said sealing film on the containers, characterized by the fact that, in said packaging station, at least two packaging chambers are provided, each of said packaging chambers being served by relative means for positioning a sealing film which can be used independently with respect to those serving another packaging chamber located in said packing station.

Further characteristics and advantages of the invention will become clearer from the description of two preferred, but not exclusive, embodiments of the machine according to the invention, illustrated, by way of non-limiting example, in the accompanying drawings, in which:

Figure 1 is a schematic view of the machine according to the invention, in a first embodiment, partially sectioned and with the packaging chambers open;

Figure 2 schematically illustrates the machine according to the invention, in a second embodiment, partially sectioned and with the packaging chambers open;

Figure 3 schematically illustrates the machine according to the invention, in the second embodiment, with the packaging chambers closed.

With reference to the aforementioned figures, the machine according to the invention, generally indicated in the two embodiments with the reference numbers 1a, 1b, comprises, in a per se known manner, a support structure 2 which is provided with supporting feet a ground and supporting means 3 for moving the containers 60, in which the products to be packaged are placed, along a direction of advance 4 from a loading station 5 to an unloading station 6 for the containers 60.

Between the loading station 5 and the unloading station 6, there is a packaging station 7 which is provided with positioning means 8, 9 of a sealing film 10, 11 on the upper side to be sealed of the containers 60 and of means of sealing film 12, 13 of the sealing film 10, 11 on the containers 60.

According to the invention, at least two packaging chambers 14, 15 are provided in the packaging station 7 and each of these packaging chambers 14 or 15 is served by relative positioning means 8, 9 of a sealing film 10, 11 which they can be used independently of those serving another packaging chamber 15 or 14 located in the packaging station 7.

More particularly, each packaging chamber 14, 15 comprises a lower bell 16, 17, open at the top, which houses at least one support plate 18, 19, which defines a substantially horizontal support surface for a relative container, and a lower mold 20, 21, made in a per se known manner, which is engageable with the edge that surrounds the mouth of the containers 60 and protrudes outwards. The lower mold 20, 21 is substantially constituted by a frame, which is shaped correspondingly to the shape of the container or containers 60 with which it must engage. In practice, the support plates 18, 19, which are arranged inside the lower bell 16, 17 and which are intended to support a container or a group of containers 60, correspond to the zone or zones that are delimited or that are delimited by the frame which constitutes the lower mold 20, 21 and which is connected to the upper edge of the relative lower bell 16, 17.

Each packaging chamber 14, 15 also comprises an upper bell 22, 23, open at the bottom and facing the lower bell 16, 17, which houses an upper mold 24, 25, facing the lower mold 20, 21 and provided with welding means , of a known type and not visible in the figures, of the relative sealing film 10, 11 on the edge that delimits the mouth of the container or containers 60 positioned or positioned in correspondence with the relative packaging chamber 14, 15. More particularly, these means of welding can consist, in a per se known way, of electrical resistances applied to the upper mold 24, 25 and operable to heat the upper mold 24, 25 to a temperature suitable for welding the relative sealing film 10, 11 on the edge of the container or containers 60.

The upper mold 24, 25 is also provided, in a per se known manner, with blades for cutting the sealing film 10, 11 around the edge of the container or containers 60.

Below each lower bell 16, 17, lifting means 26, 27 are provided, in a per se known manner, to lift the lower bell 16, 17 and the lower mold 20, 21 towards the upper bell 22, 23 of each packaging chamber 14, 15. More specifically, these lifting means 26, 27 comprise, for each lower bell 16, 17, a fluid-dynamic cylinder 28, 29, with a vertical axis, which is connected with its body to the support structure 2 and with the upper end of its piston rod to the underside of its lower bell 16, 17.

Each upper mold 24, 25 is connected to the lower end of the piston rod of a relative fluid-dynamic cylinder 30, 31, with vertical axis, which is connected with its body to the relative upper bell 22, 23. This fluid-dynamic cylinder 30, 31 it can be operated to cause the relative upper mold 24, 25 to be lowered towards the lower mold 20, 21 or to cause its lifting, as will become clearer later on.

In proximity to each packaging chamber 14, 15, sensors 32, 33 are provided, in a per se known manner, for detecting the arrival, inside each packaging chamber 14, 15, on the support plates 18, 19, of a container or group of containers 60. These sensors 32, 33 are suitably arranged outside the overall dimensions of the upper hood 22, 23 and of the lower hood 16, 17 in such a way as not to hinder the opening and closing operations. closing of the packaging chambers 14, 15 following the raising and lowering of the lower bells 16, 17 relative to the upper bells 22, 23.

For each packaging chamber 14, 15, the relative lower bell 16, 17 and the relative upper bell 22, 23, once closed against each other, delimit a compartment which is able to contain a container or a group of containers 60 and which can be connected, in a per se known way, to a vacuum pump and / or to a gas supply line or a gas mixture depending on whether vacuum packaging is required or if packaging with atmosphere is required. modified.

The positioning means 8, 9 of a sealing film 10, 11 comprise, for each of the packaging chambers 14, 15, a feed reel 34, 35 of the sealing film 10, 11, a roll for winding the scrap 36, 37 of the sealing film 10, 11 and return rollers 38, 39 which define, for the sealing film 10, 11, a path that develops from the supply reel 34, 35, to the waste winding roller 36, 37. This path of the sealing film 10, 11 develops, for a stretch, between the lower bell 16, 17 and the upper bell 22, 23 of the relative packaging chamber 14, 15.

More particularly, the waste winding roller 36, 37 is driven by a gearmotor 40, 41 and the unwinding of the sealing film 10, 11 from the supply reel 34, 35 is assisted by a motorized roller 42, 43, possibly connected to the same gearmotor 40, 41 or driven by an autonomous gearmotor 44, against which a pressure roller 45, 46 acts.

Possibly, along the path followed by each sealing film 10, 11 from the supply reel 34, 35 to the relative packaging chamber 14, 15, a centering unit 47, 48 for the print, if present, can be provided, known per se. on the sealing film 10, 11.

In the second embodiment of the machine according to the invention, illustrated in Figures 2 and 3, which refers to a machine for carrying out a packaging with sealing of the "skin" type followed by a traditional sealing, between the supply reel 34 and the first packaging chamber 14, i.e. the packaging chamber which is first encountered by the containers 60 in their advancement path from the loading station 5 to the unloading station 6, a heating plate 49 of the sealing film 10, 11 is provided.

The handling means 3 of the containers 60 comprise a pair of chains 50 which are side by side and arranged laterally, on opposite sides, relative to a vertical median plane parallel to the direction of advance 4 and towing elements 51 which are arranged perpendicular to the direction 4 and which are fixed to the chains 50. Between the loading station 5 and the packaging station 7, a substantially horizontal support surface 52 is provided, fixed to the support structure 2. On this support surface 52, there are provided , in a per se known manner, lateral guides, not visible in the figures, which laterally delimit the path of advancement of the containers 60. The distance of these lateral guides can be varied, in a per se known manner, to adapt it to the dimensions of the containers 60. The chains 50 engage with relative pinions 53 which are supported, in a rotatable way around their axes, arranged horizontally and orientated perpendicular to the direction of advancement 4, by the support structure 2. These pinions 53 are arranged in such a way that the chains 50, in correspondence with the supporting plane 52, are arranged with their branch laterally and on opposite sides with respect to each other. resting areas of the containers 60 on the supporting surface 52. At least one of these pinions 53 is driven with a rotary motion around its axis by a relative gearmotor 54 in such a way as to cause the advancement of the chains 50 along their closed path and therefore the advancement of the pulling elements 51, fixed to the chains 50, with consequent advancement of the containers 60 from the loading station 5 to the unloading station 6 passing through the packaging station 7.

Conveniently, at the unloading station 6, the beginning of a conveyor belt 55 is provided by means of which the packaged containers 60 are removed from the machine.

The operation of the machine according to the invention is as follows.

In the first embodiment, illustrated in Figure 1, which refers to a machine 1a for vacuum or modified atmosphere packaging, with traditional sealing, of products inside preformed tray-shaped containers 60, the containers 60 are positioned on the support surface 52 in correspondence with the loading station 5 which can also act as a station for filling the containers 60 with the products to be packaged. With the two packaging chambers 14, 15 open, as shown in Figure 1, the actuation of the chains 50 causes the advancement of the containers 60 placed on the support surface 52 until a container or group of containers 60 is positioned on the relative plate. support 18 or 19 located inside the packaging chamber 14 or the packaging chamber 15. From time to time, a portion of sealing film 10, 11 is unwound from the relative supply reel 34, 35 and positioned between the bell upper 22, 23 and lower bell 16, 17 ready to be used. At this point, by means of the actuation of the fluid-dynamic cylinder 28, 29, the lower bell 16, 17 is raised towards the upper bell 22, 23 in such a way as to raise the relative container or group of containers 60 and to close the packaging chamber 14, 15. At this point, the interior of the packaging chamber 14, 15 can simply be put into communication with a vacuum pump so as to achieve the desired degree of vacuum inside the container or group of containers 60 or , in sequence, to a vacuum pump and a supply line for a gas or a gas mixture to modify the atmosphere inside the container or group of containers 60. The upper mold 24, 25 is then lowered and brought into contact with the lower mold 20, 21 by sealing the sealing film 10, 11 on the edge of the container or containers 60 and cutting the sealing film 10, 11 around the edge of the container or d and containers 60. Finally, the lower bell 16, 17, by means of the actuation of the fluid-dynamic cylinder 28, 29, is lowered in such a way as to open the packaging chamber 14, 15 again. The chains 50 are then activated again, causing the passage of the packaged container or containers 60 from the packaging station 7 to the unloading station 6, where they are removed from the machine 1a, for example by means of the conveyor belt 55.

Depending on the requirements, the two packaging chambers 14, 15 can be equipped with identical lower 20, 21 and upper 24, 25 molds, i.e. designed to be used with the same format of containers 60 so that they can be used simultaneously for double the productivity of the machine when required. Alternatively, the two packaging chambers 14, 15 can be equipped with different molds so as to be able to handle containers 60 of different sizes. In this case, only one packaging chamber 14 or 15 is used, the one capable of packaging the required format, while the other packaging chamber 15 or 14 is intended to be used as an alternative, extremely quickly, when the format change is requested.

In the second embodiment, illustrated in Figures 2 and 3, which refers to a machine 1b for carrying out a packaging with sealing of the "skin" type followed by a traditional sealing, the containers 60 to be packed are positioned on the supporting surface 52 and they are made to advance, by means of the actuation of the chains 50, towards the packaging station 7. In this second embodiment, the two packaging chambers 14, 15 are used in sequence.

More particularly, the containers 60 first pass inside the packaging chamber 14 which is closed, by means of the lifting of the lower bell 16 towards the upper bell 22, carried out by means of the actuation of the fluid-dynamic cylinder 28. In this packaging chamber 14, the the desired degree of vacuum is carried out inside the container or containers 60, so that the sealing film 10, suitably preheated by the plate 49 adheres to the product, obtaining the characteristic "skin" effect. The sealing film 10 is then sealed on the edge of the container or containers 60 and cut around the edge of the container or containers 60 in a similar way to what is described with reference to the first embodiment, i.e. by lowering the upper mold 24 on the lower mold 20. The packaging chamber 14 is then opened by lowering the lower bell 16 by operating the fluid-dynamic cylinder 28 and the container or containers 60 are positioned in correspondence with the second packaging chamber 15 which is then closed by means of the lifting of the lower bell 17, activating the fluid-dynamic cylinder 29. In this packaging chamber 15, the sealing film 11 is carried out on the edge of the container or containers 60 and the sealing film 11 is cut around the edge of the container or of the containers 60 by lowering the upper mold 25 s the lower mold 21. The packaging chamber 15 is then opened and the container or containers 60, by means of the actuation of the chains 50, are brought to the unloading station 6 where they are removed from the machine 1b, for example by means of the conveyor belt 55.

It should be noted that the pulling elements 51, once the container or containers 60 have been positioned on the support plate or plates 18, 19 of a packaging chamber 14, 15, are moved back by actuation, in the opposite direction. to what has been done previously, of the chains 50 in such a way as to bring the driving elements 51 outside the overall dimensions of the lower hood 16, 17 so as not to hinder the lifting of the lower hood 16, 17 of the relative packaging chamber 14, 15.

The machine according to the invention is suitably provided with a command and control member of the programmable electronic type which supervises the operation of the machine. This command and control member manages, in particular, the advancement of the containers 60 along the direction of advancement 4, the opening and closing of the packaging chambers 14, 15 and the operation of the sealing means 12, 13, as well as the positioning of sections of sealing film 10, 11 in correspondence with the relative packaging chamber 14, 15.

According to a variant of the second embodiment of the machine according to the invention, a heating plate similar to the heating plate 49 can be provided between the supply reel 35 and the second packaging chamber 15. This invention can be used to carry out packaging with a skin type seal both in the first packaging chamber 14 and in the second packaging chamber 15.

It is to be emphasized that, in the machine according to the invention, at least two packaging chambers 14, 15 are provided, each served by relative means for positioning the sealing film 10, 11 which can be used for each packaging chamber 14 or 15 in a manner autonomous from the other packaging chamber 15 or 14, a high flexibility of use of the machine is obtained which allows, according to the requirements, to use the two packaging chambers 14, 15 at the same time to seal containers 60 of the same format in a such as to double the productivity of the machine, or to use only one of the packaging chambers 14, 15 keeping the other ready to be used if a format change is required, or they can be used in sequence to carry out two packaging phases distinct, such as required in packaging with a "skin" type seal followed from a traditional sealing.

With the machine according to the invention, when one of the two packaging chambers 14, 15 is kept ready for the packaging of containers 60 of different format, the format change can be carried out extremely quickly simply by selecting the relative program in the command and control that oversees the operation of the machine and simply varying the spacing between the lateral guides to adapt it to the dimensions of the containers 60.

In practice it has been found that the machine according to the invention fully achieves the intended aim, since, due to the fact that it provides at least two packaging chambers, with each of these chambers being served by relative means for positioning the sealing film which can be used independently from those that serve another chamber or other packaging chambers, a high flexibility of use is obtained, capable of satisfying the most varied requirements.

For greater clarity and simplicity, the description of the machine according to the invention has been limited to two preferred embodiments, in which two packaging chambers are provided, but several packaging chambers can be provided, each served by relative means for positioning a sealing films which can be used independently from those which serve another packaging chamber or other packaging chambers, without thereby departing from the scope of protection of the present invention.

The machine thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; moreover, all the details can be replaced by other technically equivalent elements.

In practice, the materials used, as well as the dimensions, may be any according to the requirements and the state of the art.

Claims (10)

CLAIMS 1. Machine for carrying out the packaging, by sealing with synthetic film, of products, in particular food products, in containers such as tubs, trays or the like, comprising means for moving (3) the containers (60), in which the products to be packaged, along a direction of advance (4) from a container loading station (5) (60) to a container unloading station (6) (60); between said loading station (5) and said unloading station (6), being a packaging station (7) provided with positioning means (8, 9) for a sealing film (10, 11) on the upper side to be sealing containers (60) and sealing means (12, 13) of said sealing film (10, 11) on containers (60), characterized in that, in said packaging station (7), at least two packaging chambers (14, 15), each of said packaging chambers (14 or 15) being served by relative positioning means (8, 9) of a sealing film (10, 11) usable independently with respect to those serving a another packaging chamber (15 or 14) located in said packaging station (7). 2. Machine, according to claim 1, characterized in that each of said packaging chambers (14, 15) comprises a lower hood (16, 17), open at the top and an upper hood (22, 23) open at the bottom and facing said lower bell (16, 17); means (26, 27) for lifting said lower bell (16, 17) towards said upper bell (22, 23) with the relative sealing film (10, 11) interposed; said upper bell (22, 23) and said lower bell (16, 17) being mutually engageable to delimit, sealed towards the outside, a compartment suitable for housing said at least one container (60) to be sealed. 3. Machine, according to claims 1 and 2, characterized in that, in the lower bell (16, 17) of each of said packaging chambers (14, 15), at least one support plate (18, 19) is arranged substantially horizontal for at least one container (60) to be sealed and a lower mold (20, 21) engageable with the edge of the mouth of said at least one container (60) arranged on said support plate (18, 19); said lower mold (20, 21) being integral with the relative lower bell (16, 17) in its translation towards or away from the upper bell (22, 23) of the same packaging chamber (14, 15) by the action of said lifting means (26, 27). 4. Machine according to one or more of the preceding claims, characterized in that, in the upper bell (22, 23) of each packaging chamber (14, 15), an upper mold (24, 25) facing the lower mold is arranged (20, 21) of the lower bell (16, 17) of the same packaging chamber (14, 15) and engageable with said lower mold (20, 21) with the relative sealing film (10, 11) interposed; said upper mold (24, 25) being provided with sealing means (12, 13) of the relative sealing film (10, 11) on the edge of the mouth of the at least one container (60) engaged by said lower mold (20, 21) ). 5. Machine according to one or more of the preceding claims, characterized in that said compartment can be connected to a vacuum pump and / or to a gas supply line. 6. Machine according to one or more of the preceding claims, characterized in that said positioning means (8, 9) of a sealing film (10, 11) comprise, for each of said packaging chambers (14, 15), a feeding reel (34, 35) of the sealing film (10, 11), a reel winding roll (36, 37) of sealing film (10, 11) and deflecting rollers (38, 39) defining, for said sealing film (10, 11), a path extending from said feed reel (34, 35) to said scrap winding roller (36, 37), said path developing, for a stretch, between said lower bell ( 16, 17) and said upper bell (22, 23) of the relative packaging chamber (14, 15). 7. Machine according to one or more of the preceding claims, characterized in that heating means (49) for the sealing film (10, 11) are arranged along said path. 8. Machine, according to one or more of the preceding claims, characterized in that said means for moving the containers (60) to be packaged from said loading station (5) to said unloading station (6) comprise a pair of chains (50) side by side and arranged laterally, on opposite sides, relative to a vertical median plane parallel to said direction of advancement (4) and towing elements (51) arranged perpendicular to said direction of advancement (4) and fixed to said chains (50); between said loading station (5) and said packaging station (7), a substantially horizontal support surface (52) being provided for the containers (60) and said chains (50) being arranged with their branch laterally and from parts opposite each other with respect to the resting areas of the containers (60) on said supporting surface (52); said towing elements (51) being engageable with said containers (60) on said support surface (52) to cause their advancement along said direction of advancement (4) from said loading station (5) to said packaging station ( 7) and from said packaging station (7) to said unloading station (6). 9. Machine, according to one or more of the preceding claims, characterized in that it comprises a command and control member of the programmable electronic type adapted to command the use of said at least two packaging chambers (14, 15) alternatively or alternatively simultaneously or in sequence according to preset programs. 10. Machine, according to one or more of the preceding claims, characterized in that, in said unloading station (6), a conveyor belt (55) is arranged for the removal of the packaged containers (60).