SEALING MACHINE WITH A REMOVABLE CHASSIS

Abstract

The present invention relates to a sealing machine (10) for sealing by thermal welding a film (14) on containers (12) and a product (16) contained in each container (12).The machine (10) comprises: - an enclosure (28) having an upper bell (22) and a lower bell (20) arranged to be moved vertically relative to each other between an open position and a closed position, - an ejection device (34) for a container (12) mounted movably vertically relative to the lower bell (20) between a lower position, called the retracted position, and a higher position, called the ejection position, characterized in that the lower bell (20) has a removable frame (40) which delimits at least one receptacle (42) in which a base (44) is mounted, the base (44) being shaped to support the container (12) when the ejection device (34) is in the retracted position, and the base (44) having a bottom (46) provided with a window (48) allowing the passage of the ejection device (34). Figure for the abridged version: fig.1.

Description

Title of the invention: SEALING MACHINE COMPRISING A REMOVABLE FRAME Technical field of the invention

[0001] The present invention relates to a machine for sealing containers, in particular plastic trays, making it possible to heat-seal a film on the containers and their contents, in particular for vacuum packaging of products, in particular food products.

[0002] The invention relates more particularly to a sealing machine capable of operating with several types of container to carry out several types of sealing. The invention also relates to a corresponding sealing method. The machine and the method of the invention are particularly suitable for skin packaging. Technical background

[0003] Skin packaging, or "skin packaging" according to the Anglo-Saxon expression, is a technique for packaging a product in plastic film, the plastic film conforming to the shape of the product, like a "second skin". Skin packaging involves a vacuum-sealing operation of the packaging.

[0004] Document FR3056195A1 describes and represents an example of a sealing machine allowing film coating.

[0005] To improve this type of machine, it would be desirable to facilitate the change of tool to allow packaging with different types of container to be produced with the same machine. It would be desirable, for example, to be able to use on the same machine tray-type containers where the thermal welding is carried out on the edge of the tray, with a mechanical welding joint on the edge of the tray, and flat plate-type containers, where the welding is carried out by vacuum and heating of the film so that the film is pressed against the product placed on the plate.

[0006] There is also a need to improve the ergonomics of the machine by facilitating tool changes and packaging format changes. Summary of the invention

[0007] The invention provides a solution to solve the problems mentioned above.

[0008] To this end, the invention proposes a machine for sealing containers in a sealed manner, making it possible to heat seal a film on the containers and the product. contained in each container, in particular for vacuum packaging of products, particularly food products, the sealing machine comprising: - an enclosure comprising an upper bell and a lower bell arranged to be moved vertically relative to each other between an open position and a closed position, - an ejection member for a container mounted to move vertically relative to the lower bell between a low position, called the retracted position, and a high position, called the ejection position, - a heating block arranged in the upper bell, - a vacuum source which is intended to be connected to the enclosure in order to allow the packaging to be vacuum-sealed, - a cutting device designed to cut the film after thermal welding, the upper bell forming with its heating block a first sealing tool, characterized in that the lower bell comprises a removable frame which delimits at least one receptacle in which a base is mounted, the base being shaped to support the container, when the ejection member is in the retracted position, and the base comprising a bottom provided with a window allowing the passage of the ejection member from its retracted position, which is located at a height less than or equal to the height of the bottom of the base, towards its ejection position.

[0009] According to other characteristics of the invention:

[0010] - the machine comprises at least two separate bases capable of being mounted interchangeably in the capping machine and to cooperate with the first capping tool so as to allow, without changing the first capping tool, several types of capping, the bases being chosen from: — a first base whose upper face is shaped to receive a hollow container intended for sealing by thermal welding on the edges of the container with a product not protruding, — a second base whose upper face is shaped to receive a hollow container intended for sealing by thermal welding on the container and on a protruding product, — a third base whose upper face is shaped to receive a container in the form of a flat plate intended for thermal sealing in which the sealing film covers the container and the product;

[0011] - the machine comprises at least two separate chassis, each chassis being shaped to receive one of the at least two bases so as to allow the bases to be changed in the sealing machine by changing the chassis without it being necessary to change the first sealing tool;

[0012] - the machine comprises, in a lower part, a transverse housing provided to receive the chassis by transverse insertion;

[0013] - the machine comprises, in an upper part, a rotating barrel, the barrel rotary comprising at least two faces, a first face carrying the first sealing tool and a second face carrying a second sealing tool, so as to allow a sealing tool to be selected from among several sealing tools available by rotating the barrel;

[0014] - the machine comprises a support member for the base which is mounted movably, by relative to the lower bell, between a low position, called the rest position, and a high position, called the welding position, which allows the container to be positioned at a height suitable for thermal welding of the film;

[0015] - the chassis comprises at least two receptacles, each receptacle receiving a base, so as to allow the simultaneous sealing of two containers;

[0016] - the first sealing tool comprises two heating blocks arranged respectively opposite the two receptacles.

[0017] The invention also proposes a method for sealing containers tightly, making it possible to seal by thermal welding a film on the containers and the product contained in each container, in particular for vacuum packaging of products, in particular food products, the method being characterized in that it uses a sealing machine according to one of the preceding characteristics, in that it comprises at least a first packaging sequence during which a first type of container is sealed and a second packaging sequence during which a second type of container is sealed, and in that between two packaging sequences, a first chassis equipped with a base provided for the first type of container is removed from the sealing machine and then replaced by a second chassis equipped with a base provided for the second type of container. Brief description of the figures

[0018] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0019] [Fig-1] is a cross-sectional view along plane II which schematically represents a sealing machine produced in accordance with the teachings of the invention and equipped with a chassis provided for a first type of container with high edges;

[0020] [Fig.2] is a side view which schematically represents the sealing machine of [Fig.l];

[0021] [Fig.3] is a partial view of the capping machine of [Fig.l] which schematically illustrates a stage of operation during which the lower and upper bells are in the open position and the ejection members are in the high position, each carrying a container with high edges;

[0022] [Fig.4] is a view similar to that of [Fig.3] which schematically illustrates a stage of operation during which the ejection members are in the low position and the containers rest in the bases equipping the chassis;

[0023] [Fig.5] is a view similar to that of [Fig.3] which schematically illustrates a stage of operation during which the lower and upper bells are in the closed position and the bases are placed in a raised welding position by means of movable support members;

[0024] [Fig.6] is a view similar to that of [Fig.3] but with a container with narrow edges and product extending beyond the edges of the container;

[0025] [Fig.7] is a view similar to that of [Fig.4] for the narrow-sided container of [Fig.6];

[0026] [Fig.8] is a view similar to that of [Fig.5] for the narrow-sided container of [Fig.6];

[0027] [Fig.9] is a view similar to that of [Fig.3] but with a container in the form of a flat plate carrying a product;

[0028] [Fig. 10] is a view similar to that of [Fig.4] for the container of [Fig.9];

[0029] [Fig. 11] is a view similar to that of [Fig.5] for the container of [Fig.9];

[0030] [Fig. 12] is a perspective view showing a chassis equipped with a pair of bases suitable for receiving containers with narrow edges, and which represents two pairs of replacement bases suitable for receiving containers with narrow edges of different heights. Detailed description of the invention

[0031] In the following description, identical, similar or analogous elements will be designated by the same reference numbers.

[0032] In Figures 1 and 2, a machine 10 for sealing containers 12 is shown, making it possible to seal a film 14 in a leaktight manner by thermal welding on the containers 12 and the product 16 contained in each container 12. The sealing machine 10 is also described with reference to Figures 3 to 5, which shows a part of the sealing machine 10 in several stages of its operation.

[0033] The sealing machine 10 is particularly suitable for producing vacuum packaging of products 16, particularly food products, presented in trays or on cardboard plates.

[0034] The sealing machine 10 comprises a frame 18 on which the various components which enable the sealing machine 10 to operate are mounted. All of these components are not described in detail since the operating principle of such a sealing machine 10 is described and represented in the document FR3056195A1.

[0035] The sealing machine 10 comprises, in its lower part, a lower bell 20 provided to receive the containers 12 with their products 16 and, in its upper part, an upper bell 22 equipped with two heating blocks 24 and a cutting member 26.

[0036] When the upper bell 22 is pressed against the lower bell 20, the two bells 20, 22 delimit an enclosure 28.

[0037] In addition, a vacuum source 30 is provided to be connected to the enclosure 28 in order to allow the packaging formed by the container 12 sealed by the film 14 with the product 16 to be placed under vacuum.

[0038] The upper bell 22 forms with the heating block 24 and the cutting member 26 a first sealing tool 32.

[0039] The sealing machine 10 also comprises an ejection member 34 for a container 12. The ejection member 34 comprises an ejector plate 36 which is mounted to move vertically relative to the lower bell 20 between a low position, called the retracted position, which is shown in FIGS. 1, 4, and 5, and a high position, called the ejection position, which is shown in [Fig. 3].

[0040] The movement of the ejector plate 36 is controlled here by an ejection actuator 38.

[0041] It is noted that according to the embodiment shown, the sealing machine 10 is designed to produce two packages simultaneously. This is why the lower bell 20 is configured here to receive two identical containers 12 and the upper bell 22 comprises two heating blocks 24. The lower bell 20 here comprises two ejection members 34 capable of allowing the ejection of the two containers 12 simultaneously.

[0042] Advantageously, the lower bell 20 comprises a removable frame 40 which here delimits two receptacles 42 each provided to receive a base 44. Each base 44 is shaped to carry the chosen container 12 when the ejection member 34 is in the retracted position, as shown in FIGS. 1, 4, and 5.

[0043] In addition, each base 44 comprises a bottom 46 provided with a window 48 allowing the passage of the ejection member 38 from its retracted position to its ejection position. In its retracted position, the upper surface of the ejector plate 36, which is provided to carry the container 12, extends here in a plane located under the bottom 46 of the base 44, so that the container can rest on the base 44 by its edges.

[0044] Advantageously, the sealing machine 10 also comprises two support members 50 for the two bases 44 which are mounted to move, relative to the lower bell 20, between a low position, called the rest position, shown in Figures 1, 3, and 4, and a high position, called the welding position, shown in [Fig. 5]. Each support member 50 makes it possible to precisely position the base 44 with its container 12 in height, to allow thermal welding of the film 14 on the container 12. Indeed, it appears that the distance between the container 12, with its product 16, and the film 14, before welding, is decisive for ensuring good quality thermal welding.

[0045] According to the embodiment shown, the chassis 40 is received in a transverse housing 52 which is arranged in the lower part of the sealing machine 10. The transverse housing 52 is here arranged above a lower tank 54 forming a lower part of the lower bell 20.

[0046] The chassis 40 is here in the form of a generally parallelepiped block or frame which can be inserted transversely into the transverse housing 52 and removed transversely to be replaced by another chassis 40.

[0047] Advantageously, the containers 12 shown in Figures 1 to 5 here each correspond to a tray with high edges intended for example to receive a product 16 not protruding beyond the edges of the tray. The bases 44 shown in these Figures 1 to 5 are therefore shaped with high edges and a dimension adapted to receive these trays in a complementary manner.

[0048] In [Fig. 1] there is shown a first chassis 40 mounted in the sealing machine 10 and, next to it, two other chassis 40 provided for containers 12 of different types, capable of replacing the first chassis 40 as will be described later.

[0049] In Figures 6 to 8, the sealing machine 10 is shown when it is equipped with a frame 40 capable of supporting bases 44, distinct from the bases 44 previously described. These bases 44 are shaped to support containers 12 different from those used previously. The containers 12 here consist of trays with narrow edges, designed to receive products 16 which can protrude from the edges. This requires a suitable heating and welding operation, without it being necessary to change the first sealing tool 32.

[0050] In Figures 9 to 11, the sealing machine 10 is shown when it is equipped with a frame 40 capable of supporting still different bases 44, these being provided to receive containers 12 in the form of flat plates, for example made of cardboard. This type of container 12 also requires an operation of suitable heating and welding, without the need to change the first sealing tool 32.

[0051] It is noted that the frames 40 are here each adapted to the type of base 44 and to the type of container 12 received. According to an alternative embodiment, a single model of frame 40 could be configured so as to receive all the types of base 44 and therefore all the types of container 12.

[0052] For example, in [Fig. 12], a chassis 40 is shown equipped with bases 44 provided for trays with narrow edges of different heights. Thus, it is possible to select the pair of bases 44 shown in the frame 40, for trays with narrow edges of a first so-called medium height. But it is also possible, using the same frame 40, to replace the pair of bases 44 with the pair shown on the left which has edges of lower height, or with the pair shown on the right which has edges of higher height.

[0053] Advantageously, the first sealing tool 32 is here mounted on one face of a rotating barrel 56. This rotating barrel 56 here comprises four faces which allow the mounting of four separate sealing tools. This allows, when necessary, to change the first sealing tool 32 for another tool which is for example adapted to another container format 12. The sealing tools mounted on the other faces are for example provided for smaller and / or larger containers 12. The sealing tools can also be equipped with different heating blocks 24 making it possible to adapt to different types of containers 12 and products 16.

[0054] The rotary barrel 56 is here mounted to rotate around a transverse axis XI and it can be controlled in one of the four angular positions corresponding to the four faces by means of a suitable drive device 58.

[0055] According to the embodiment shown, the lower part of the sealing machine 10 comprises a main actuator 60 which is provided to control the movement of the lower bell 20 with the frame 40 towards the upper bell 22 to move into the closed position, and in the other direction to move into the open position.

[0056] According to an alternative embodiment, the main actuator 60 could control the movement of the upper bell 22 towards the lower bell 20.

[0057] An example of a sealed sealing method is now described which implements the sealing machine 10 according to the invention. More particularly, a sealing cycle is described with reference to FIGS. 3 to 5. This sealing cycle is intended to be repeated several times during a packaging sequence.

[0058] In a step of receiving the container 12, the upper bell 22 and the lower bell 20 are in the open position, as illustrated in [Fig. 3]. The film 14 is brought between the two bells 20, 22 by driving a reel 62. The film 14 is preferably pressed against the lower edges of the upper bell 22 so as to close the enclosure of the upper bell 22. The cutting member 26 is in the retracted position.

[0059] To save time and limit the possible creation of folds, the heating blocks 24 are advantageously in the low position and suction is carried out so as to hold the film 14 against the heating blocks 24. In the lower bell 20, the ejection members 34 are in the high position, each capable of receiving a container 12 on an ejector plate 62 in order to support the container 12 by its lower face. Each container 12 and its product 16 is conveyed onto the ejector plate 62, for example by means of a conveyor 64 shown in [Fig.2].

[0060] Each ejection member 38 is then moved to the low position until each container 12 comes to rest by its edges on the edges of the associated base 44, as illustrated by [Fig. 4], then the enclosure 28 is closed by moving the lower bell 20 until the upper bell 22 is in contact with the edges of the chassis 40.

[0061] In a welding step, each support member 50 is controlled so as to raise each base 44 with its container 12 to a high position called the welding position, which is illustrated by [Fig. 5]. In this welding position, the heating blocks 24 are controlled to produce a weld bead along the edge of each container 12.

[0062] In a step of cutting the film 14, the cutting member 26 is controlled so as to cut the film 14 around the edges of each container 12. Two sealed containers 12 are thus obtained.

[0063] In a step of ejecting each container 12, the upper 22 and lower 20 bells are returned to the open position for the purpose of removing each sealed container 12, and for the purpose of loading other containers 12 to be sealed. The ejection members 34 are placed in the high position in order to eject the sealed containers 12 from the chassis 40. The sealed containers 12 are then recovered, for example by the conveyor 64.

[0064] The sealing machine 10 according to the invention thus makes it possible to carry out a first packaging sequence with a type of container 12 such as a tray with high edges at a very high speed. It therefore makes it possible to package a large number of products 16 in succession.

[0065] The sealing method described with reference to figures 3 to 5 corresponds to a package in which the film is sealed on the edge of the container 12.

[0066] When it is desired to change the type of container 12, for example to package 16 different products or different quantities of product per container 12, it It is sufficient to stop the sealing machine 10 and then only change the chassis 40 with its bases 44.

[0067] Thus, an operator can remove the chassis 40 installed in the transverse housing 52 by transverse sliding, in the manner of a drawer. He can then select the chassis 40 and the appropriate bases 44, and insert this new chassis 40 into the transverse housing 52 in the opposite direction.

[0068] It is not necessary to change other parts in the sealing machine 10. The ejection members 34 and the support members 50 are compatible with the different frames 40 and their bases 44, by virtue of their design with the window 48 provided in each base 44 which allows the ejector plate 36 of each ejection member 38 to pass through.

[0069] After changing the chassis 40 and the bases 44, a second packaging sequence begins.

[0070] In the embodiment described above, the sealing machine 10 is designed to package two containers 12 simultaneously. Of course, the invention also applies to a sealing machine 10 configured to package a single container 12 or more than two containers 12.

[0071] Figures 6 to 8 show the same steps of the sealing process as for Figures 3 to 5, but applied to a type of container 12 with narrow edges, for which the product 16 protrudes from the edges.

[0072] The main steps are similar, once the correct chassis 40 with the adapted bases 44 has been inserted into the transverse housing 52.

[0073] However, the sealing method is distinguished by a step of heating the film 14 during which each heating block 24 is in the low position and the suction is maintained so as to hold the film 14 against the heating block 24. Each heating block 24 then transmits heat to the film 14 to increase the latter's capacity to deform. Suction is also carried out in the lower bell 20 in order to obtain a pressure difference on either side of the film 14 so as to prevent the film 14 from forming folds.

[0074] In a step of vacuuming the packaging, the suction in the lower bell 20 is maintained until a set vacuum level is obtained, i.e. at a pressure lower than atmospheric pressure.

[0075] In a welding step, each heating block 24 is moved to a high position and each support member 50 is controlled so as to raise each base 44 with its container 12 to a high position called the welding position, which is illustrated by [Fig. 8]. In this welding position, the product 16 contained in each container 12 is then in contact with the film 14 while remaining distant from the heating block 24 in order to limit the exposure of the product 16 to heat.

[0076] A gas, advantageously air, is introduced into the upper bell 22 to create a pressure difference on either side of the film 14. The pressure in the upper bell 22, that is to say the pressure in the portion of the enclosure 28 located above the film 14, then becomes greater than the pressure in the lower bell 20, that is to say in the portion of the enclosure 28 located below the film 14. Under the effect of the pressure difference, the film 14 is pressed against each product 16 and the edges of the associated container 12 so as to match its shape like a second skin. As it cools, the film 14 is pressed against each product 16 and seals tightly to the associated container 12.

[0077] The sealing process is similar for a container 12 of the plate type, as shown in Figures 9 to 11. The frame 40 and the adapted bases 44 are positioned in the lower part of the sealing machine 10 and film heating and welding steps are carried out as for the previous type of container 12 of Figures 6 to 8.

[0078] LEGEND

[0079] 10: lidding machine 12: container 14: movie 16: product 18: frame 20: lower bell 22: upper bell 24: heating block 26: cutting organ 28: pregnant 30: source of depression 32: first sealing tool 34: ejection organ 36: ejector plate 38: ejection actuator 40: chassis 42: receptacle 44: base 46: background 48: window 50: support organ 52: transverse housing 54: lower tank 56: rotating barrel 58: drive device 60: main actuator 62: coil 64: conveyor XI: transverse axis

Claims

Claims

1. Sealing machine (10) for containers (12) for sealing by thermal welding a film (14) on the containers (12) and the product (16) contained in each container (12), in particular for vacuum packaging of products (16), in particular food products, the sealing machine (10) comprising: - an enclosure (28) comprising an upper bell (22) and a lower bell (20) arranged to be moved vertically relative to each other between an open position and a closed position, - an ejection member (34) for a container (12) mounted to move vertically relative to the lower bell (20) between a low position, called the retracted position, and a high position, called the ejection position, - a heating block (24) arranged in the upper bell (22), - a vacuum source (30) which is intended to be connected to the enclosure (28) in order to allow the packaging to be vacuum-sealed,- a cutting member (26) provided for cutting the film after thermal welding, the upper bell (22) forming with its heating block (24) a first sealing tool (32), characterized in that the lower bell (20) comprises: - a removable frame (40) which delimits at least one receptacle (42) in which a base (44) is mounted, the base (44) being shaped to support the container (12), when the ejection member (34) is in the retracted position, and the base (44) comprising a bottom (46) provided with a window (48) allowing the passage of the ejection member (34) from its retracted position, which is located at a height less than or equal to the height of the bottom (46) of the base (44), to its ejection position, - a transverse housing (52) provided to receive the frame (40) by transverse insertion and transverse sliding, like a drawer.,

2. Sealing machine (10) according to the preceding claim, characterized in that it comprises at least two separate bases (44) capable of being mounted interchangeably in the sealing machine (10) and of cooperating with the first tool sealing tool (32) so as to allow, without changing the first sealing tool (32), several types of sealing, the bases (44) being chosen from: - a first base (44) whose upper face is shaped to receive a hollow container (12) intended for sealing by thermal welding on the edges of the container (12) with a non-protruding product (16), - a second base (44) whose upper face is shaped to receive a hollow container (12) intended for sealing by thermal welding on the container (12) and on a protruding product (16), - a third base (44) whose upper face is shaped to receive a container (12) in the form of a flat plate intended for sealing by thermal welding in which the sealing film covers the container (12) and the product (16).

3. Sealing machine (10) according to the preceding claim, characterized in that it comprises at least two separate chassis (40), each chassis (40) being shaped to receive one of the at least two bases (44) so as to allow the changing of the bases (44) in the sealing machine (10) by changing the chassis (40) without it being necessary to change the first sealing tool (32).

4. Sealing machine (10) according to any one of the preceding claims, characterized in that it comprises, in an upper part, a rotating barrel (56), the rotating barrel (56) comprising at least two faces, a first face carrying the first sealing tool (32) and a second face carrying a second sealing tool, so as to allow a sealing tool to be selected from among several available sealing tools by rotation of the barrel (56).

5. Lidding machine (10) according to any one of the preceding claims, characterized in that it comprises a support member (50) for the base (44) which is mounted to move, relative to the lower bell (20), between a low position, called the rest position, and a high position, called the welding position, which makes it possible to position the container (12) at a height suitable for thermal welding of the film (14).

6. Lidding machine (10) according to any one of the preceding claims, characterized in that the chassis (40) comprises at least two receptacles (42), each receptacle (42) receiving a base (44), so as to allow the simultaneous sealing of two containers (12).

7. Sealing machine (10) according to the preceding claim, characterized in that the first sealing tool (32) comprises two heating blocks (24) arranged respectively opposite the two receptacles (42).

8. Method for sealing containers (12) in a sealed manner, making it possible to seal by thermal welding a film (14) on the containers (12) and the product (16) contained in each container (12), in particular for vacuum packaging of products, in particular food products, the method being characterized in that it uses a sealing machine (10) according to any one of the preceding claims, in that it comprises at least a first packaging sequence during which a first type of container (12) is sealed and a second packaging sequence during which a second type of container (12) is sealed, and in that between two packaging sequences,a first chassis (40) equipped with a base (44) provided for the first type of container (12) is removed from the sealing machine (10) then replaced by a second chassis (40) equipped with a base (44) provided for the second type of container (12) by transverse insertion and transverse sliding, in the manner of a drawer.,

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