EP1440887A1

EP1440887A1 - Method, apparatus and container for vacuum and/or protective atmosphere packaging

Info

Publication number: EP1440887A1
Application number: EP04000962A
Authority: EP
Inventors: Attilio Vignoni
Original assignee: Vacuum Pump SpA
Current assignee: Vacuum Pump SpA
Priority date: 2003-01-23
Filing date: 2004-01-19
Publication date: 2004-07-28
Anticipated expiration: 2024-01-19
Also published as: ES2358902T3; EP1440887B1; ITMI20030099A1; DE602004030735D1; ATE493339T1

Abstract

A method for packaging in a vacuum and or in a protective atmosphere is described, which comprises the following steps: feeding of a plurality of containers (100) comprising a tray (101) and a lid (103) integral with/hinged to the tray (101), introducing into the tray (101) of the product to be packaged, partial closing of the lid on the tray so as to leave a gap for discharging air and/or for introducing gas, sucking air from and/or introducing gas from/into said container (100), and complete closing, heat-sealing and/or sealing of the lid on the tray to close the container hermetically and to avoid possible tampering.

An apparatus (1) to carry out said method and a container (100) that can be used in said method are also described.

Description

The present invention refers in general to the field of vacuum and/or protective atmosphere packaging and in particular to a method and to an apparatus for packaging products, in particular food products, in a vacuum and/or in a protective atmosphere, as well as to a container particularly suitable to be used for vacuum and/or protective atmosphere packaging.
There are currently known in the art systems for vacuum and protective atmosphere packaging that provide for the use of containers in the form of thermoformed plastic trays open at the top. Such a tray is filled with the product to be packaged, the air is evacuated to create the vacuum and it may be filled with gas to create a protective atmosphere. Finally, the tray is closed and sealed by means of a plastic film.
Said packaging system according to the prior art has various drawbacks. In fact, once the tray is opened by the end user by removing the covering film, the contents of the tray must be consumed because the tray cannot be closed again.
The object of the present invention is to overcome the drawbacks of the prior art by providing a method for vacuum and/or protective atmosphere packaging that is versatile, efficient and able to allow high-speed, continuous production.
This object is achieved in accordance with the invention with the method listed in appended independent claim 1.
Another object of the invention is to provide an apparatus for vacuum and/or protective atmosphere packaging that is simple to make.
This object is achieved according to the invention with the apparatus listed in appended independent claim 5.
Yet another object of the present invention is to provide a container for vacuum and/or protective atmosphere packaging that is easy to package and that can be closed again after opening by the end user.
This object is achieved, in accordance with the invention, with the container listed in appended independent claim 9.
Advantageous embodiments of the invention are apparent from the dependent claims.
The peculiar characteristic of the invention is represented by the use of a container comprising a tray with a lid integral with/hinged to the tray. In this manner closing of the container takes place simply by lowering the lid on the tray. For this purpose the process of packaging must provide a first stage of semi-closing of the lid so as to leave a gap for removal of the air and/or for introduction of gas into the container, and a second stage of complete closing of the lid and of heat-sealing or sealing thereof to avoid tampering with the container and/or the product.
Such a package according to the invention offers the end user the possibility of opening and of subsequently closing it by wedging of the lid into the tray.
Further characteristics of the invention will be made clearer by the detailed description that follows referring to purely exemplary and therefore non limiting embodiment thereof illustrated in the appended drawings, in which:

Figure 1 is a diagrammatic top plan view of the apparatus for packaging in a vacuum and/or in a protective atmosphere according to the invention;
Figure 1A is an enlarged detail, enclosed in the circle A of Figure 1, better illustrating the arrangement of the containers on the apparatus of Figure 1;
Figure 2 is a longitudinal sectional view of the apparatus according to the invention, taken along the section plane II-II of Figure 1;
Figure 2B is an enlarged detail, enclosed in the circle B of Figure 2, which better illustrates the arrangement of the containers on the apparatus of Figure 2; and
Figure 3 is a longitudinal sectional view like Figure 2, illustrating the apparatus according to the invention, completed with a reel of plastic film for sealing of containers without a lid.

An apparatus for packaging in a vacuum and/or in a protective atmosphere according to the invention, denoted as a whole with reference numeral 1, is described with reference to Figures 1 and 2.
The apparatus 1 comprises a conveying station 2, a filling station 6, a semi-closing station 3, a station 4 for creating the vacuum and/or the protective atmosphere and for heat-sealing and a discharging station 5.
The conveying station 2 comprises a horizontal conveyor belt 20 supported by a main frame 21 resting on the ground. A plurality of containers 100, able to contain the products destined to be put in a vacuum and/or in a protective atmosphere, is fed on the conveyor belt 20.
As shown better in Figures 1A and 2B, according to the invention each container 100 is a tray 101 of thermoformed plastic material, open at the top.
A lid 103, able to close the tray 101 hermetically, is connected integrally to a portion 102 of the upper edge of the tray 101. In this manner the connecting portion 102 behaves as a hinge and the lid 103, rotating around the hinging axis 102, can pass from an opening position to a closing position of the tray 101.
The lid 103 is thermoformed together with the tray 101 and in normal conditions the lid 103 remains in the open position with respect to the tray 101.
The upper edge of the tray 101 and the peripheral edge of the lid 103 are able to engage mutually with each other by interference, to maintain the lid 103 in the closing position.
As shown in Figures 1 and 2, the empty containers 100 are conveyed from the conveyor belt 20 toward the filling station 6, disposed in two parallel rows, with the lids 103 completely open and disposed towards the outside. Even if in the Figures the containers 100 are shown disposed on two rows, they can be disposed on one or more rows.
The conveyor 20 has two side bars 23 integral with the sides of its frame. The side bars 23 are parallel to each other and horizontal. In this manner the lids 103 of the containers as they pass through the filling station 6 remain above the horizontal side bars 23.
Special means (per se known and therefore not shown in the figures) suitable to fill the trays 101 with the products destined to be packaged will be provided in the filling station 6. Clearly filling of the trays 101 can also take place manually.
The filled containers 100 continue their transfer on the conveyor belt 20 towards the semi-closing station 3. During this transfer the side bars 23 of the conveyor continue with two guide bars 31, convergent and inclined upwards. In this manner the bars 31 cause raising of the lids 103 of the containers bringing them towards the closing position.
As a result, in the semi-closing station 3 a partial closing of the lid 103 on the tray 101 occurs, so as to leave a gap between the lid 103 and the upper edge of the tray 101 able to allow the discharge of air from the container and/or the introduction of gas into the container 100.
Semi-closing of the container 100 takes place by means of shaped guides 34 suitably inclined downwards or by means of mechanical or pneumatic actuators 32 which are responsible for lowering the lid 103 onto the tray 101.
At this point the filled and semi-closed containers 100 continue on the conveyor belt 20 towards the station 4 for creating a vacuum and/or a protective atmosphere and for heat-sealing. During this transfer, the lids 103 of the containers remain beneath the parallel horizontal bars 33 which serve to keep the lids 103 in their semi-closed position.
In the station 4 for creating a vacuum and/or a protective atmosphere and for heat-sealing there is provided a press comprising a lower half-mould 41 and an upper half-mould 42. On the upper half-mould 42, pneumatic means 43 for suction and introduction of gas and thermal means 44 for heat-sealing are provided.
The suction means 43 suck the air from the inside of the container 100 so as to create the vacuum.
The introduction means 43, on the other hand, introduce suitable gases into the container so as to create a protective atmosphere. According to the characteristics of the product contained in the containers 100, gases such as oxygen O₂, carbon dioxide CO₂ and nitrogen N₂ can be introduced.
After the protective atmosphere has been created inside the container 100, in the station 4 for creating a vacuum and/or a protective atmosphere and for heat-sealing, the edge of the container 100 is sandwiched between the lower half-mould 41 and the upper half-mould 42, closed hermetically and sealed by means of the thermal heat-sealing means 44, so as to avoid tampering with the container 100 and the product, before it reaches the end user.
The container 100 is made of particular plastic materials (easy open) which allow heat-sealing and easy opening of the container 100. In this way, if the consumer intends to use up the product in more than one time, there is the possibility of closing again by wedging the lid 103 of the container.
As shown in Figure 3, the apparatus 100 can provide a reel 70 of plastic film 71 which can be used in a per se known manner for closing of the trays 101, if said trays are not provided with a reclosable lid. The reel 70 is disposed above and upstream of the station 4 for creating a vacuum and/or a protective atmosphere and for heat-sealing, whilst the waste film 71' is collected by a winder 42 disposed downstream of the station 4.
On leaving the station 4 for creating a vacuum and/or a protective atmosphere and for heat-sealing, the product is perfectly packaged in a vacuum and/or in a protective atmosphere inside the container 100. The container 100 is then discharged from the apparatus 1 though a slide 50 or a conveyor belt of the discharge station 5 to be sent for transport and/or storage.
Numerous variations and modifications of detail within the reach of a person skilled in the art can be made to the present embodiment of the invention without departing from the scope of the invention as set forth in the appended claims.

Claims

A method for packaging products, in particular food products, in a vacuum and/or a protective atmosphere, comprising the following steps:

feeding of a plurality of containers (100) comprising a tray (101) and a lid (103) integral with/hinged to said tray (101),

introducing the product to be packaged into the tray (101),

partial closing of the lid (103) on said tray so as to leave a gap for discharging air and/or for introducing gas,

sucking air and/or introducing gas from/into said container (100), and

complete closing, heat-sealing and/or sealing the lid (103) on the tray (101) to close the container hermetically and to avoid tampering with the product.
A method according to claim 1, characterised in that said step of complete closing the lid (103) on the tray (101) provides for a closure by wedging.
A method according to claim 1 or 2, characterised in that said step of heat-welding or sealing of the lid on the tray involves heat-sealing on plastic materials (easy open) to allow heat-sealing with easy opening of the container.
A method according to any one of the preceding claims, characterised in that said step of introducing gas into the container (100) provides for the introduction of gases such as oxygen O₂, carbon dioxide CO₂, and nitrogen N₂.
An apparatus (1) for packaging products, in particular food products, in a vacuum and/or in a protective atmosphere, comprising:

a conveying station (2) for conveying containers (100) comprising a tray (101) and a lid (103) hinged to the tray,

a filling station (6) for introducing the product to be packaged into the tray (101),

a station (3) for partial closing of said lid (103) on said tray (101) so as to leave a gap for discharge of the air and/or for introduction of gas;

a station (4) for sucking air and/or for introducing gas from/into said container (100), and for complete closure, heat-sealing and/or sealing of the lid (103) on the tray (101) to close the container hermetically and to avoid possible tampering.
An apparatus according to claim 5, characterised in that said station for partial closing the lid on the tray comprises guide means (31, 34) and/or actuator means (32) to bring the lid close to the tray.
An apparatus according to claim 5 or 6, characterised in that it comprises means (33) for maintaining said lid in a semi-closed position on said tray, disposed upstream of said station (4) for creating a vacuum and/or a protective atmosphere and for heat-sealing.
An apparatus according to any one of claims 5 to 7, characterised in that it further comprises a reel (70) of plastic film (71) and sealing means to apply said film (71) to trays without lids.
A container (100) for packaging of products, in particular food products, in a vacuum and/or in a protective atmosphere, comprising a tray (101) and a lid (103) hinged to said tray (101).
A container according to claim 9, characterized in that the upper edge of said tray (101) and the peripheral edge of said lid (103) are able to engage with each other by interference.
A container according to claim 9 or 10, characterised in that it is made of particular plastic materials (easy open) which allow heat sealing thereof with easy opening.