ES2452516T3 - Device for vacuum packaging, in particular food products - Google Patents

Abstract

Packaging device (1a, 1b), in particular, for manual or automatic packaging of trays containing food products or technical materials that can be inserted, by means of a loading platform (13), between longitudinally folded parts of a folded film once (7) and comprising some means for thermal bonding or heat sealing for sealing, and at least one nozzle for producing a vacuum and / or introducing the gas or mixture, and a vacuum chamber (3), characterized in that said film Once folded (7) is fixed and said vacuum chamber (3) is transversely movable with respect to the direction of insertion of said trays (12) and comprises at least one presser, movable on said once folded film (7), which it is forced to be disposed on said trays (12) and is provided with means adapted to transport air and / or gas streams, with the return of air in said vacuum chamber (3) by means of a series of holes provided between a heat sealing crossbar, which constitutes said thermally joining means, and the wall of said vacuum chamber that is parallel thereto.

Description

Device for vacuum packaging, in particular food products.

Technical field

The present invention relates to a packaging device, in particular for food products and technical materials.

Prior art

Machines of this type are known, for example, from US Patent No. 5,155,969.

In addition, vacuum machines are known which feature a bell-shaped chamber and comprise a vacuum pump coupled to a chamber, also known as a vacuum chamber, and inside which a preformed pocket, normally open on three sides, is normally arranged, placing a food product inside it.

In machines of the known type, the preformed pocket, with the product already inside, is then placed in the vacuum chamber and then a vacuum is generated inside the chamber; Next, heat sealing of the free side of the preformed pocket is carried out.

This known technology implies the need to use preformed pockets, which therefore have a dimension that is compatible with the dimensions of the product; In addition, a lot of work is required.

Therefore, there are some stages of operation that extend the time necessary to achieve a vacuum packaging of the product; in addition, if the packaging is carried out in a controlled environment, most of the gas is worn out because the gas disperses not only in the pocket but, and mainly, inside the vacuum chamber.

EP 603 704 is also known in which the packaging of food products is carried out using a plastic film, which is transported through a bending station in order to obtain a double layer, and then is subjected to heat sealed to define the pockets.

These pockets are achieved according to the desired or desired size or capacity before they are filled and sealed.

The heat sealing and forming stages are followed by filling and closing and cutting the pockets obtained in this way; However, this solution is complex because it involves a multitude of separate stations to perform the individual operations to which the plastic material film must be subjected sequentially.

In addition, the above solution involves hot or cold forming of the plastic film and filling, by means of a nozzle, of liquid products, flours or fine granule materials, and therefore it is not possible to consider the solution illustrated for solid products with predetermined volumes such as sliced meats, meat, portioned cheeses, and trays containing food and non-food products.

In the known solution described, in addition, in order to achieve the closure of the pocket, it is necessary to make said pocket go through several stages of operation, with the consequent need to center the pocket as much as possible in each station in order to allow Optimal and desired processing.

Also known is EP 0 405 718 which describes a solution illustrating a packaging device, in particular for packaging food products or technical materials that can be introduced between longitudinally folded parts of a once folded film, from an open side of the same, the device comprising means for thermal bonding or heat sealing, which have a substantially L-shaped shape in order to seal the film both on the open longitudinal side and on its transverse sides, and at least one nozzle to generate a vacuum and / or to introduce the gas or mixture.

Also known is EP 0 832 819 B1 whose priority is the Italian patent application AL 960002 dated September 26, 1996, and illustrating a packaging device comprising a vacuum chamber that can be opened to receive a length of at least one film folded once with the material to be packed in it and which can be sealed tightly, and then the vacuum can be generated and / or the gas or mixture can be introduced with the portion or length of film that it adopts a pocket-like form, also providing heat sealing means that are arranged to operate inside the vacuum chamber, the at least one nozzle being arranged in the vacuum chamber to be oriented, once closed, towards the open longitudinal and / or transverse sides of the film length.

This solution also suffers from some drawbacks, since it has been seen that micro-folds are formed during the heat sealing stage of the film, and this can cause problems in the seal which worsens the aesthetic appearance of the packaging.

In addition, the gas flow inside the film is not optimal, and this reduces the effectiveness of the device.

Finally, when the operator removes the sheet, said sheet may assume an incorrect arrangement.

Another problem is noted: when a vacuum is generated in a hood, and therefore inside the pocket that is being formed, then it is necessary to partially compensate the vacuum with gas; however, if the compensation is excessive, the bell opens during the heat sealing stage.

Since it works with a particularly variable equilibrium system, there is no precise control of the volume of gas that is introduced into the pocket that is being formed.

The amount of gas in absolute values and in real values (%) that remains inside the pocket that is being formed is therefore extremely variable and difficult to control, and this produces a series of pockets or packages that are swollen or deflated. to a greater or lesser extent, according to each individual case.

The problem worsens if it is necessary to change the packaging format often.

Another problem is observed during the heat sealing stage of the film that is subjected to heat sealing and cut on the transverse side, with respect to the direction of advance of the film itself: since said film is often made of heat shrinkable material, then It can shrink, reducing its width, and this can prevent it from accommodating a tray that is arriving.

Therefore the tray can arrive and find insufficient space to stay, and this causes it to be redirected towards the open side of the pocket, and ends up in the heat sealing bar, which causes hours of machine downtime and lost time in cleaning it.

Finally, it is noted that the return of air in the hood or vacuum chamber occurs, due to construction reasons, usually in an area away from the heat seal bar, or coincides with the vacuum port through a three-way valve, but this does not optimize the transport of the flow inside the hood.

Exhibition of the invention

The objective of the present invention is to solve the aforementioned technical problems, eliminating the drawbacks of the aforementioned prior art, by providing a device that allows to obtain vacuum packaging or compensated vacuum packaging of technical products or food products such as meat in slices, meat, portioned cheeses, and trays containing food and non-food products, which therefore allows optimizing the gas inside the pocket so that swollen pockets can be obtained.

Within this purpose, an objective of the present solution (invention) is to provide a device that can be used even by an operator who has not received special training in the adjustments of the format changes.

Another objective is to provide a device that allows the optimal introduction of the tray into the folded film once, previously heat sealed and cut on the transverse side.

Another objective is to provide a device that allows the optimal introduction of the tray into the pocket, thus avoiding hours of machine downtime and wasted time to clean it.

Another objective is to provide a device that adds to the above characteristics that of presenting a simple, reliable and safe use structure.

This purpose and these objectives are achieved, as well as others that will be revealed below, by means of a packaging device, in particular manual or automatic packaging of trays containing food products or technical materials that can be introduced, by means of a platform loading, between longitudinally folded parts of a film once folded and comprising means for thermal bonding or heat sealing for sealing, and at least one nozzle for generating a vacuum and / or for introducing the gas

or the mixture, and a vacuum chamber, characterized in that said folded film once is fixed and said chamber can be displaced transversely to the direction of insertion of said trays and comprises at least one presser, movable on said folded film once, forced to be disposed on said trays and is equipped with means adapted to transport the air and / or gas streams, producing the return of

air in said vacuum chamber by means of a series of holes made between a heat sealing crossbar, which constitutes said thermal joining means, and the wall of said vacuum chamber that is parallel thereto.

Brief description of the drawings

Other features and advantages of the present invention will become more clearly apparent from the detailed description given below of four specific embodiments, illustrated by way of non-limiting example in the accompanying drawings, in which:

Figure 1 represents a perspective view of a device in its embodiments;

Figure 2 represents a sectional view of the device, according to line II-II of Figure 1, in the condition in which the vacuum chamber is open;

Figure 3 represents a view, similar to the previous one, of the condition in which, when the vacuum chamber is open, the tray placed inside the folded film is inserted once;

Figure 4 represents a view, similar to the previous one, of the condition in which the vacuum chamber is closed and the presser is placed on top of the folded film once;

Figure 5 represents a sectional view, along the line V-V of Figure 4;

Figure 6 represents a top view of the device in which, for the sake of understanding the drawing, the pair of supports for the folded film once has been omitted;

Figure 7 represents a partially sectioned top view of the tray disposed in the vacuum chamber and of the means adapted to transport the air and / or gas streams therein;

Figure 8 represents a sectional view of the device, according to line II-II of Figure 1, in the condition in which the vacuum chamber is open;

Figure 9 represents a view, similar to the previous one, of the condition in which, when the vacuum chamber is open, the tray placed inside the folded film is inserted once;

Figure 10 represents a view, similar to the previous one, of the condition in which the vacuum chamber is closed and the presser is placed on top of the folded film once;

Figure 11 represents a sectional view, along the line XI-XI of Figure 10;

Figure 12 represents a top view of the device in which, for the sake of understanding the drawing, the pair of supports for the folded film once has been omitted;

Figures 13 to 15 partially represent partially sectioned top views of the vacuum chamber, the tray being arranged inside it during the different stages of packaging, and of the means adapted to conduct the air and / or gas currents inside. .

Ways to practice the invention

Referring to Figures 1 to 7, reference number 1a designates the packaging device, in particular for technical materials or food products, which are designated by reference number 2.

The device 1a comprises a bell-shaped vacuum chamber, designated with the reference number 3, which is essentially constituted by a lower container 4 and an upper lid 5, closable; tapes or seals 6 for the tightness are arranged in the perimeter of the container 4 and the lid 5.

The device uses a film folded once 7, which therefore has a first longitudinal side 8 that is closed and a second longitudinal side 9 that is open.

A first L-shaped heat sealing bar 10 is disposed inside the bell-shaped vacuum chamber 3, with a side adjacent to the inlet 11 of the food product; an essentially L-shaped blade (not shown) is arranged laterally, adjacent to the first heat seal bar 10 and the lines of the L are respectively arranged in a parallel direction to, and at right angles to the first heat seal bar 10.

The technical materials or food products 2 are stored in an adapted tray 12, which is placed on a loading platform 13 which is conveniently motorized or movable on means

suitable, such as, for example, a roller bank.

The film folded once 7 is kept open thanks to the presence of a pair of supports 14a, 14b, between which the loading platform 13 is arranged; This pair of supports 14a, 14b can be moved closer together by means of a suitable handwheel 15 adapted to adjust their mutual position.

The device 1a comprises at least some means adapted to pull the folded film once 7, said means being constituted by a suitable motor 16 that drives a roller 17 cooperating with a complementary roller 18, where the film folded once 7 is it passes between said rollers.

The motor 16, the roller 17 and the complementary roller 18 are supported by a suitable arm, which protrudes from a suitable fixed base 19.

The pair of supports 14a, 14b and the handwheel 15, as well as the loading platform 13, are also fixed with respect to the base 19, so that the film folded once 7, during use, can only slide along of an axis that is the axis of the loading platform 13, but is fixed with respect to other possible movements.

However, the vacuum chamber 3 can move along an axis that is transverse to the direction of advance of the folded film once 7, which coincides with the insertion direction of the tray 12.

The bell-shaped vacuum 3 is arranged in a suitable frame 20 constituted by a pair of uprights 21a, 21b and a pair of crossbars 22a, 22b, the latter supporting a pair of first cylinders 23a, 23b adapted to move the upper cover 5 and a guide 24 suitable to allow the sliding of the frame 20 where there is a complementary guide 25 that forms a single piece with the base 19.

An elevated shelf 26 is provided inside the lower container 4, adjacent to the end of the loading platform 13, and is adapted to support the tray 12 within the vacuum bell 3.

Where the upper cover 5 is located, at least one presser 27 is provided inside, movable by a pair of suitable second cylinders 28a, 28b, which are externally connected together to the upper cover 5 in an area adjacent to the crossbar superior 22a.

A third pair of cylinders 29a, 29b and a pair of fourth cylinders 30a, 30b are also arranged on the outer surface of the upper cover 5, are arranged in mutually perpendicular directions and are adapted to drive a second heat sealing bar 31, arranged with specular symmetry with respect to the first heat seal bar 10.

The presser 27 is provided with means adapted to transport the air and / or gas streams, said means being constituted by a plurality of ribs 32 protruding therein in the direction of the tray 12 and are arranged transversely to the forward direction of the movie folded once.

Said ribs 32 are preferably made of rubber, so that they can adhere to the edges 33 of the tray 12, thereby defining channels 34 adapted to allow the passage of air and / or gas.

Advantageously, the presser 27 moves together with the opening and closing of the bell-shaped vacuum chamber 3. The shape and function of the presser 27 make it possible to better create the vacuum inside the container 35 and they allow a better and more constant introduction of the gas inside.

In addition, the movement of the presser makes it possible to adapt to the height of the tray 12 and prevents, during the introduction of the gas, the corner 36 of the container 35, which swells like a balloon, reaches the upper level of the tray 12; therefore the formation of a visible heat seal 37 in the upper window of the container 35 is avoided, which avoids an aesthetic appearance of very poor quality that, in any case, can be observed in the prior art.

The packaging device is further constituted by means adapted to transport the air and / or gas streams, said means being constituted by a nozzle 38, which forms a single piece with the bell-shaped vacuum chamber 3 and is hermetically housed. in a cajiform appendix 39 arranged in two half-shells protruding laterally with respect to the bell-shaped vacuum chamber 3 along an axis perpendicular to the advance axis of the folded film once.

In this way, the film folded once 7 is trapped, the free end 40 being of the second longitudinal side 9, which is open, trapped above and below the nozzle, forcing the gas, when introduced, to enter the bag that constitutes the container 35, sweeping the interior and then leaving in the form of a flow into the bell-shaped vacuum chamber 3.

In this way we manage to ensure the vacuum and subsequent filling and replacement of the air in the bag that contains the product, where using a long nozzle you can easily modify the size of the bag that constitutes the container 35 by fitting the folded film a time 7 or so on the nozzle 38 while the drag system of the film folded once 7 remains stationary.

Obviously, the force of the cylinders that keep the bell-shaped vacuum chamber 3 closed is 5 greater than the strength of the heat sealing cylinders, and the frame 20 that supports them has the shape of a closed cage.

In this way, a complete or partial vacuum can be produced and compensated with gas to atmospheric pressure, while avoiding, as in the prior art, working with extremely unstable pressures to fill the bag with the gas, using the presser that It makes it possible to obtain containers that are identical throughout the batch.

The device also has a plurality of holes 41 for the return of air into the bell-shaped vacuum chamber 3, in order to return it to atmospheric pressure after heat sealing of the container 35. 15 Said holes 41 are provided between the first heat seal bar 10a and the adjacent wall 42 of the bell-shaped vacuum chamber 3.

In this way, it is possible to cool the heat seal 37 immediately after heat sealing, which prevents shrinkage of the container 35.

20 Referring to Figures 8 to 15 cited above, reference number 1b designates the device for packaging, in particular technical materials or food products, which are designated with reference number 2.

The device 1b comprises a bell-shaped vacuum chamber, designated with the reference number 3, consisting essentially of a lower container 4 and an upper lid 5, which can be closed; tapes or seals 6 for the tightness are arranged in the perimeter with respect to the container 4 and the lid 5.

The device uses a film folded once 7, which therefore has a first longitudinal side 8 that is closed, and a second longitudinal side 9 that is open.

A first heat seal cross bar 10a is arranged in the vicinity of the bell-shaped vacuum chamber inlet 3 and, more precisely, inside, with a side adjacent to the inlet 11 of the food product; a blade (not shown) is arranged laterally, adjacent to the first bar

35 transverse heat seal 10a.

The technical materials or the food products 2 can be stored in a suitable tray 12, arranged on a loading platform 13 which, conveniently, is motorized or movable on suitable means, such as for example a roller bank.

40 Alternatively, the technical materials or food products 2 can be arranged directly on the loading platform 13 in order to provide direct packaging without using tray 12.

The film folded once 7 is kept open thanks to the presence of a pair of supports 14a, 14b, between which 45 the loading platform 13 is interposed, the pair of supports 14a, 14b being mutually movable closer by means of a suitable steering wheel 15 adapted to adjust their mutual position.

The device 1b further comprises at least some means adapted to pull the folded film once 7, said means being constituted by a suitable motor 16 that drives a roller 17 cooperating with a complementary roller 18, where the film folded once 7 is passed between said rollers.

The motor 16, the roller 17 and the complementary roller 18 are supported by a suitable arm, which protrudes from a suitable fixed base 19.

55 The pair of supports 14a, 14b and the handwheel 15, as well as the loading platform 13, are also fixed with respect to the base 19, so that the film folded once 7, during use, can only slide at along an axis than the axis of the loading platform 13, but is fixed with respect to other possible movements.

However, the vacuum chamber 3 can move along an axis that is transverse to the direction of advance of the folded film once 7, which coincides with the insertion direction of the tray 12.

The bell-shaped vacuum 3 is arranged in a suitable frame 20 constituted by a pair of uprights 21a, 21b and a pair of crossbars 22a, 22b, the latter supporting a pair of first cylinders 23a, 23b adapted to move the upper cover 5 and a guide 24 suitable to allow the sliding of the frame 20 where it is located

65 a complementary guide 25 forming a single piece with the base 19.

An elevated shelf 26 is provided inside the lower container 4, adjacent to the end of the loading platform 13, and is suitable for supporting the tray 12 inside the vacuum bell 3.

In the upper cover 5 there is provided at least one presser 27, movable by a pair of suitable second cylinders 28a, 28b, which are coupled together and externally to the upper cover 5 in an area adjacent to the upper cross member 22a.

Alternatively, the film folded once 7 can remain stationary and the bell-shaped vacuum chamber 3 moves relative to the film folded once 7.

Once again on the outer surface of the upper cover 5, a third pair of cylinders 29a, 29b adapted to drive a second heat seal cross bar 31a, arranged with specular symmetry with respect to the first heat seal cross bar 10a, is provided.

Alternatively, the first heat seal cross bar 10a and the second heat seal cross bar 31a may be arranged outside the bell-shaped vacuum chamber 3.

Thus, a thinner structure could advantageously be achieved, the third cylinders 29a, 29b being arranged outside the bell-shaped vacuum chamber 3, in order to be able to increase the useful volume that can be used inside of the bell-shaped vacuum chamber 3.

Inside the bell-shaped vacuum chamber 3, a first heat seal cross bar 10b is provided, to correspond to the open longitudinal side 9 of the film folded once 7 of the food product, in order to intersect the heat sealed by means of the heat sealing cross bars 10a.

A blade is provided laterally and adjacent to the first longitudinal heat sealing bar 10b, and on the outer surface of the lid 5 there are a pair of fourth cylinders 30a, 30b adapted to drive a second longitudinal heat sealing bar 31b, arranged symmetrically speculate with respect to the first longitudinal heat sealing bar 10b.

In this way, multiple heat sealants can be made, one followed by another, of the film folded once 7 along the transverse direction with respect to the sliding direction thereof, in order to prepare multiple trays 12 before making the vacuum operation, and then said vacuum operation is carried out with an individual longitudinal heat sealing that intersects all the transversal heat sealing.

The presser 27 is provided with means adapted to transport the air and / or gas streams, said means being constituted by a plurality of ribs 32 protruding therein in the direction of the tray 12 and are arranged transverse to the direction of advance of the folded film once 7.

Preferably, said ribs 32 are made of rubber in order to be able to adhere to the edges 33 of the tray 12, defining channels 34 adapted to allow the passage of air and / or gas.

The presser 27 advantageously moves together with the opening and closing of the bell-shaped vacuum chamber 3. The shape and function of the presser 27 make it possible to better create the vacuum inside the container 35 and allow an introduction better and more constant gas inside.

In addition, the movement of the presser makes it possible to adapt to the height of the tray 12 and prevents, during the introduction of the gas, the corner 36 of the container 35, which swells like a balloon, reaches the upper level of the tray 12; therefore the formation of a visible heat seal 37 in the upper window of the container 35 is avoided, which avoids an aesthetic appearance of very poor quality that, in any case, can be observed in the prior art.

The packaging device is further constituted by means adapted to transport the air and / or gas streams, said means being constituted by a nozzle 38, which forms a single piece with the bell-shaped vacuum chamber 3 and is hermetically housed. in a cajiform appendix 39 arranged in two half-shells protruding laterally with respect to the bell-shaped vacuum chamber 3 along an axis perpendicular to the advance axis of the folded film once 7.

In this way, the film folded once 7 is trapped, the free end 40 being of the second longitudinal side 9, which is open, trapped above and below the nozzle, forcing the gas, when introduced, to enter the bag that constitutes the container 35, sweeping the interior and then leaving in the form of a flow into the bell-shaped vacuum chamber 3.

In this way it is possible to ensure the vacuum and subsequent filling and replacement of the air in the bag containing the product, where using a long nozzle the size of the bag that constitutes the container 35 can be easily modified by fitting the folded film once 7 or so on the nozzle 38 while the drag system of the folded film once 7 remains stationary.

Obviously, the force of the cylinders that keep the bell chamber vacuum chamber 3 closed is greater than the strength of the heat sealing cylinders, and the frame 20 that supports them has the shape of a closed cage.

In this way, a complete or partial vacuum can be produced and compensated with gas to atmospheric pressure, while avoiding, as in the prior art, working with extremely unstable pressures to fill the bag with the gas, using the presser that makes make it possible to obtain containers that are identical throughout the batch.

The device also has a plurality of holes 41 for the return of the air into the bell-shaped vacuum chamber 3, in order to return it to atmospheric pressure after heat sealing of the container 35. Said holes 41 are provided between the First heat seal bar 10a and the adjacent wall 42 of the bell-shaped vacuum chamber 3.

In this way, it is possible to cool the heat seal 37 immediately after heat sealing, which prevents shrinkage of the container 35.

In practice it has been seen that the invention has achieved the purpose and objectives pursued, having devised a device that, when using a film folded once, can achieve a vacuum package or with a modified atmosphere in which the gas inside the bag or pocket that constitutes the container, so that the packages are swollen uniformly, and that also allows the operation of vacuum in multiple trays at the same time.

The possibility of moving the vacuum chamber in the form of a bell 3 allows changing the size of the bag or pocket that constitutes the container 35, quickly and easily, since the operator in this case only has to move the position of the frame 20 and therefore also the complexity of elements associated with the bell-shaped vacuum chamber 3 as a function of the width of the tray 12 to be packaged, and this without touching anything else, with the consequence of virtually no machine downtime .

Of course, the device can be controlled by suitable mechanical and / or electronic means to determine the desired position of the frame 20 at one or more predetermined points, so that for each type of package 35 it is possible to fix, for example using a computer, The position of the frame 20 automatically as the package is changed reaches the loading platform 13.

Therefore, the device can also be used by an operator who does not have specific training in the adjustments of the format changes and allows the optimal insertion of the tray into the folded film once, previously sealed and cut on the transverse side, allowing thus the optimal insertion of the tray in the bag and avoiding hours of machine inactivity and time lost in cleaning it.

Finally, the device has a simple, reliable and safe use structure.

Obviously, the invention is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims.

Therefore, it is possible, for example, to consider keeping the frame 20 fixed and making the folded film once 7 movable transversely also with respect to the direction of advancement.

Where the technical characteristics cited in any of the claims are followed by reference signs, said reference signs have been included solely to facilitate the understanding of the claims and consequently, said reference signs have no limiting effect on the interpretation. of each element identified by way of example by said reference signs.

In the examples of embodiments provided below, the individual characteristics that are given in relation to specific examples can in fact be exchanged with other different characteristics that exist in other examples of embodiments.

In addition, it is noted that in the case of finding out, during the patenting process, that some element is already known, it is understood that said element is not claimed and will be subject to a waiver.

The materials used, as well as the dimensions that constitute the individual components of the invention, can obviously be more relevant according to the needs.

The different means to perform different specific functions do not really have to coexist in the illustrated embodiment, but they can exist by themselves in numerous embodiments, including ones that have not been illustrated herein.

The characteristics indicated as advantageous, convenient or similar, can also be omitted, or substituted by equivalent characteristics.

The disclosures in Italian patent application no TV2010A000019 and no TV2010A000117 of which the present application claims its priority, are incorporated herein by reference.

Claims (29)

one.

Packaging device (1a, 1b), in particular, for manual or automatic packaging of trays containing food products or technical materials that can be inserted, by means of a loading platform (13), between longitudinally folded parts of a folded film once (7) and comprising means for thermal bonding or heat sealing for sealing, and at least one nozzle for producing a vacuum and / or introducing the gas or mixture, and a vacuum chamber (3), characterized in that said once folded film (7) is fixed and said vacuum chamber (3) is transversely movable with respect to the direction of insertion of said trays (12) and comprises at least one presser, movable on said folded film a time (7), which is forced to be arranged on said trays (12) and is provided with means adapted to transport the air and / or gas streams, with the return of the air in said vacuum chamber io (3) by means of a series of holes provided between a heat sealing crossbar, which constitutes said thermal joining means, and the wall of said vacuum chamber that is parallel thereto.

2.

Device (1a) according to claim 1, characterized in that said vacuum chamber is a bell-shaped vacuum chamber (3) constituted by a lower container (4) and by a closing top lid (5), being tapes or seals (6) adapted for the sealing provided on the perimeter with respect to said container (4) and said lid (5), said film folded once (7) a first longitudinal side (8) that is closed and a second longitudinal side (9) which is open, said film being folded once (7) held open by the presence of a pair of supports (14a, 14b) between which said loading platform (13) interposed, motorized or movable on means said pair of supports (14a, 14b) being movable so that they approach each other by means of a handwheel (15) adapted to adjust their mutual position.

3.

Device (1a) according to claims 1 and 2, characterized in that it comprises at least some means for pulling said folded film once (7), said means being constituted by a motor (16) that drives a cooperating roller (17) with a complementary roller (18), said folded film being passed once (7) between said rollers, said motor (16), said roller (17) and said complementary roller (18) being supported by an arm protruding from a base fixed (19), with which said pair of supports (14a, 14b), said steering wheel (15) and said loading platform (13) are associated.

Four.

Device (1a) according to claims 1 and 2, characterized in that said bell-shaped vacuum chamber (3) is displaced along an axis transverse to the direction of advance of said folded film once (7), which coincides with the insertion direction of a tray (12) adapted to contain said technical materials or food products (2).

5.

Device (1a) according to claims 1 and 4, characterized in that said bell-shaped vacuum chamber (3) is arranged inside a frame (20) consisting of a pair of uprights (21a, 21b) and a pair of crossbars (22a, 22b), said crossbars supporting respectively a pair of first cylinders (23a, 23b) adapted to move said upper cover (5) and a guide (24) adapted to allow sliding of said frame (20) in a complementary guide (25) forming a single piece with said base (19).

6.

Device (1a) according to claims 1 and 2, characterized in that an elevated shelf (26) is provided inside said lower container (4), which is adjacent to the end of said loading platform (13), and is adapted to supporting said tray (12) inside said bell-shaped vacuum chamber (3), in said upper cover (5) being arranged internally at least one presser (27), movable by a couple of second cylinders (28a , 28b), which are externally connected together to said upper cover

(5) in an area adjacent to said upper cross member (22a).

7.

Device (1a) according to one or more of the preceding claims, characterized in that it comprises a first L-shaped heat sealing bar (10) and arranged inside said bell-shaped vacuum chamber (3), with an adjacent side at the inlet (11) of the food product; a blade being arranged laterally, adjacent to said first heat sealing bar (10), a pair of third cylinders (29a, 29b) and a pair of fourth cylinders (30a, 30b) being arranged on the outer surface of said upper cover (5 ) and being arranged along mutually perpendicular directions and being adapted to drive a second heat sealing bar (31), arranged with specular symmetry with respect to said first heat sealing bar (10).

8.

Device (1a) according to claims 1 and 7, characterized in that said presser (27) is provided with means adapted to transport the air and / or gas streams, said means being constituted by a plurality of ribs (32) protruding from the same in the direction of said tray (12) and are arranged transversely to the direction of advance of said folded film once (7), said ribs (32) being made of rubber, so as to be able to adhere to the edges (33) of said tray (12), defining channels (34) adapted to allow the passage of air and / or gas.

9.

Device (1a) according to claims 1 and 8, characterized in that said presser (27) moves together with the opening and closing of said bell-shaped vacuum chamber (3).

10.

Device (1a) according to one or more of the preceding claims, characterized in that it comprises means adapted to transport the air and / or gas streams, said means being constituted by a nozzle (38), which forms a single piece with the chamber of bell-shaped vacuum (3) and is tightly housed within a cajiform appendix (39) provided in two half-shells protruding laterally with respect to said bell-shaped vacuum chamber (3) along an axis perpendicular to the axis of advancing said folded film once.

eleven.

Device (1a) according to claims 1 and 2, characterized in that it comprises a plurality of holes (41) for the return of air into said bell-shaped vacuum chamber (3), to return it to atmospheric pressure after heat sealing of said container (35), said plurality of holes being provided between said first heat sealing bar (10) and the adjacent wall (42) of said bell-shaped vacuum chamber (3).

12.

Device (1a) according to one or more of the preceding claims, characterized in that it is controlled by mechanical and / or electronic means to predetermine the desired position of said frame (20) at one or more predetermined points, so that for each type of container (35) can be fixed, by means of a computer, the position of said frame (20) automatically as the package that arrives at said loading platform (13) varies.

13.

Device (1a) according to one or more of the preceding claims, characterized in that said frame (20) is also transversely movable with respect to the direction of advance of said once folded film (7).

14.

Device (1b) according to claim 1, comprising a loading platform (13) that supports a once folded film (7) defining at least two parts that are folded longitudinally to accommodate trays

(12) containing food products and technical materials (2), comprising thermal or heat sealing means that are adapted to seal said folded parts of said folded film once (7) peripherally with respect to said trays (12), and comprising at least one nozzle (38), which is adapted to provide a vacuum and / or adapted to introduce gas or a mixture into a vacuum chamber (3) that houses said trays (12) inserted between said folded parts of said film folded once (7), so that said film folded once (7) and said vacuum chamber (3) are movable with respect to each other transversely to the direction of insertion of said trays (12) in said vacuum chamber (3), characterized in that said thermal or heat sealing means comprise a plurality of independent heat sealing bars (10a, 31a, 10b, 32b), being at least one of them transverse and po r at least one of them longitudinal with respect to the direction of advance of said folded film once (7). 15. Device (1b) according to claim 14, characterized in that said vacuum chamber (3) is bell-shaped and is provided with a lower container (4) and an upper lid (5), which can be closed on said container ( 4), being airtight tapes or seals (6) interposed on the perimeter between said container (4) and said cover (5).

16.

Device (1b) according to one or more of claims 14 and 15, characterized in that it comprises a pair of supports (14a, 14b), which can be approached mutually by means of a steering wheel (15) adapted to adjust their mutual position in order to open said folded film once (7), said loading platform (13) being interposed between said pair of supports (14a, 14b), and said folded film presenting once (7) a first longitudinal side (8) which is closed and a second longitudinal side (9) that is open.

17.

Device (1b) according to one or more of claims 14 to 16, characterized in that it comprises at least some motor means (16) adapted to pull said folded film once (7) and drive a roller

(17)

 cooperating with a complementary roller (18), said folded film being passed once (7) between said rollers, said motor means (16), said roller (17) and said complementary roller being supported

(18)

 by an arm protruding from a fixed base (19) with which said pair of supports (14a, 14b), said steering wheel (15) and said loading platform (13) are associated.

18. Device (1b) according to one or more of claims 14 to 17, characterized in that said vacuum chamber

(3)

 it is arranged in a frame (20) constituted by a pair of uprights (21a, 21b) and a pair of crossbars (22a, 22b), said crossbars respectively supporting a pair of first cylinders (23a, 23b) adapted to move said cover ( 5) and a guide (24) adapted to allow the sliding of said frame (20) in a guide

(25)

 which forms a single piece with said base (19).

19. Device (1b) according to one or more of claims 14 to 18, characterized in that said vacuum chamber (3) it can move along an axis substantially transverse to the direction of advance of said folded film once (7), said axis substantially coinciding with the direction of insertion of said tray (12). 20. Device (1b) according to one or more of claims 14 to 19, characterized in that it comprises less a presser (27), which can move over said folded film once (7), can cooperate with said trays (12) in an upper area, and is provided with means adapted to transport the air currents and / or gas

twenty-one.

Device (1b) according to one or more of claims 14 to 20, characterized in that said means adapted to transport the air and / or gas streams comprise a plurality of ribs (32) projecting in the direction of said tray (12) and they are arranged transversely to the direction of advance of said folded film once (7), said ribs (32) being made of rubber to adhere to the edges (33) of said tray (12), in order to define a plurality of channels (34) adapted to allow the passage of air and / or gas.

22

Device (1b) according to one or more of claims 14 to 21, characterized in that, within said container (4), adjacent to the end of said loading platform (13), an elevated shelf (26) is provided, adapted to support said tray (12) inside said vacuum chamber (3), said presser (27) being disposed internally in said lid (5) and being able to move through a pair of second cylinders (28a, 28b), which are externally connected in a manner joint to said cover (5) in an area that is adjacent to said cross member (22a).

2. 3.

Device (1b) according to one or more of claims 14 to 22, characterized in that said presser (27) can be moved together with the opening and closing of said vacuum chamber (3).

24.

Device (1b) according to one or more of claims 14 to 23, characterized in that it comprises at least one nozzle (38) connected so as to form a single piece with said vacuum chamber (3), said at least one nozzle being said (38) hermetically housed in a cajiform appendix (39) that is formed by two half-shells protruding laterally from said vacuum chamber (3) along an axis perpendicular to the advance axis of said folded film once (7).

25.

Device (1b) according to one or more of claims 14 to 24, characterized in that it comprises a first heat sealing crossbar (10a), arranged in proximity to the inlet (11) of said vacuum chamber (3), being a knife laterally adjacent to said first heat seal cross bar (10a), on the outer surface of said cover (5), a pair of third cylinders (29a, 29b) being adapted to drive a second heat seal cross bar (31a), arranged with specular symmetry with respect to the first heat sealing crossbar (10a).

26.

Device (1b) according to one or more of claims 14 to 25, characterized in that it comprises a first longitudinal heat sealing bar (10b), arranged inside said vacuum chamber (3) in order to correspond to said open longitudinal side (9) of said film folded once (7) of the food product, a blade being laterally adjacent to said first longitudinal heat sealing bar (10b), on the outer surface of said lid (5) a pair of fourth cylinders ( 30a, 30b) adapted to drive a second longitudinal heat sealing bar (31b), arranged with specular symmetry with respect to the first longitudinal heat sealing bar (10b).

27.

Device (1b) according to one or more of claims 14 to 26, characterized in that it comprises a plurality of holes (41) for the return of air into said vacuum chamber (3) in order to return it to atmospheric pressure after heat sealing of said container (35), said plurality of holes (41) being provided between said first heat sealing crossbar (10a) and the adjacent wall (42) of said bell-shaped vacuum chamber (3).

28.

Device (1b) according to one or more of claims 14 to 27, characterized in that it is controlled by mechanical and / or electronic means adapted to predetermine the desired position of said frame (20) at one or more predetermined points, so that for each type of container (35) can be fixed, by means of a computer, the arrangement of said frame (20) automatically, as the package that arrives at the loading platform (13) varies.

29.

Device (1b) according to one or more of claims 14 to 28, characterized in that said frame (20) can move transversely with respect to the direction of advance of said folded film once (7).