EP1006056B1 - Container for foodstuff and medicaments which is easy to open and reclosable - Google Patents

Abstract

The sealed impermeable cavity (8) of the packaging accommodates a solid, fluid or viscous food, or a medical product (19). It is surrounded by bonded layers (3, 7) of the tray (2) and cover (3) respectively. A welded bead (4) increases package (1) sealing. It maintains the seal up to the use-before date, before the package is first opened.

Description

The invention relates to packaging according to the preamble of claim 1 and for the packaging of solid food products. liquids or pastes such as dairy products, cold meats and meats, and medical products.

It will find its application in the film manufacturing industries food, packaging, and packaging of food products that will then made available to consumers in stores.

For a long time, we know the use of packaging for products solid or pasty food. They consist for example of a tray and a cover also called cover, made from a thermoformable film, suitable for contact food.

le rouleau de film plastique est déroulé, puis thermoformé pour donner forme à la barquette. La barquette est ainsi remplie de produit alimentaire à conditionner. On ferme alors le couvercle sur la barquette par soudure, après avoir injecté un gaz neutre pour la conservation du produit alimentaire.

Food products can be packaged in the following stages:

the plastic film roll is unrolled, then thermoformed to give shape to the tray. The tray is thus filled with food product to be packaged. The lid is then closed on the tray by welding, after injecting a neutral gas for the preservation of the food product.

When opening the packaging when consuming the food product, the seal is broken by the user, and the cover comes off the tray. It is then impossible to close the cover on the tray, which requires the user to either consume the product at once, or use a protective film to keep the product in a good state of freshness or to prevent product odors do not spill in the refrigerator.

It is known in the state of the art to produce packaging for food products, fitted with a device for closing the lid on the tray.

The tray is made by thermoforming from a rigid film or flexible plastic such as PVC or polyester or other.

• une couche soudante intérieure, soudée suivant un cordon contre le bord de l'ouverture de la barquette,
• une couche extérieure qui constitue à la fois l'élément rigide du couvercle et une protection à l'oxygène pour la conservation de l'aliment,
• une couche adhésive intermédiaire à effet permanent.

The cover currently used on the market is made from a film consisting of three layers:

• an inner sealing layer, welded along a bead against the edge of the opening of the tray,
• an outer layer which constitutes both the rigid element of the cover and an oxygen protection for the preservation of the food,
• an intermediate adhesive layer with a permanent effect.

During the first use, the weld bead is torn off from the weldable layer and remains integral with the tray. The adhesive layer is then discovered on the cover at the weld bead. This authorizes the reclosing of the packaging after the first use and therefore allows the product to be consumed several quantities, for several days or several hours.

During the welding operation of the lid on the tray, it has noted the creation of "chimneys" on the adhesive layer which let escape the gas neutral for the preservation of the food product, and allow oxygen to enter packaging which oxidizes food and shortens its shelf life.

Indeed, the adhesive layer being located before the protective layer to oxygen, the "chimneys" eliminate all efficiency and all the properties of the layer oxygen barrier. This therefore means that solid or pasty food products become perishable before their first consumption and the expiration date consumption of solid or pasty food products cannot be given precisely.

These "chimneys" are created on the packaging during the welding of the lid on the tray, because of temperature variations of thermoforming machines and welding pressures are too high or too low. It is also known from the prior art a package according to the preamble of the claim disclosed by document EP A 0 306 982.

The present invention overcomes these disadvantages and his goal main is to present a packaging for the packaging of food products whose manufacture allows the neutral preservative gas to be kept perfectly inside packaging, and therefore to guarantee precisely the shelf life of the product before first use, and therefore before the food consumption deadline.

Another object of the present invention is to enclose the product food, solid or pasty type, inside a pocket to keep the product packed in its entirety and without any deterioration thereof.

Another aim is to no longer involve the disadvantages due to "chimneys" on the adhesive layer which let out the preservative neutral gas and penetrate oxygen. Indeed, in the present invention, the "chimneys" on the layer adhesive no longer open into the pocket which then remains waterproof and impermeable.

So we have more flexibility when using machines to thermoform. In fact, variations in temperature and welding pressure no longer have as much importance and consequence, and machines no longer require temperature and pressure regulations as strict as before. This is intended to simplify the technology used for regulation control, and therefore reduce its cost.

Another aim is to carry out the packaging without any modification of the automatic thermoforming machines on the market, the manufacturing process packaging and packaging of the food product being identical to that existing currently.

Another object of the present invention is to present a packaging with easy opening and closing of the lid on the tray, which saves the use of protective films to preserve the product when it is not consumed entirely on first use. The resealing of the packaging also to maintain the odors of the food product in the packaging, and not to spread in the refrigerator.

Other objects and advantages of the present invention will become apparent during of the following description which is however only given as an indication and which is not intended aim to limit it. The goals and advantages are achieved by a package with the characteristics of claim 1.

• la figure 1, en vue de coupe transversale fortement agrandie, schématise l'emballage (1) pour les produits alimentaires solides ou pâteux (19) avant sa première utilisation,
• la figure 2 représente une vue de coupe détaillée de la constitution des couches soudantes et la soudure de ces éléments,
• la figure 3 schématise, en vue de coupe avec une partie réduite, l'emballage (1) après la première ouverture du couvercle (3),
• la figure 4 schématise l'emballage (1) en vue de dessus.

The invention will be better understood on reading the following description, accompanied by the accompanying drawings, among which:

• FIG. 1, in a greatly enlarged cross-section view, shows diagrammatically the packaging (1) for solid or pasty food products (19) before its first use,
• FIG. 2 represents a detailed sectional view of the constitution of the welding layers and the welding of these elements,
• FIG. 3 shows diagrammatically, in sectional view with a reduced part, the packaging (1) after the first opening of the cover (3),
• Figure 4 shows schematically the packaging (1) in top view.

The present invention relates to a packaging (1) for the packaging of solid or pasty food products (19) such as dairy products, cold meats or meats. It will find its application in particular in the manufacturing industries packaging and packaging of food and medical products which will then be made available to consumers in commercial areas or pharmacies. It can be used for other hardware type products.

Figure 1 shows the packaging (1) of food products (19). The packaging (1) consists of a tray (2) and a cover (3), also called lid, these two elements being assembled by a weld (4). The welding (4) of cover (3) is made over the entire periphery of the tray (2) as shown in the figure 4.

• une couche support (5) extérieure,
• une couche adhésive (6) intermédiaire,
• une couche soudante (7) intérieure qui sera en contact avec le produit alimentaire.

The tray (2) is produced by means of a thermoformable structure in the form of film. The film is composed for example of at least three layers:

• an outer support layer (5),
• an intermediate adhesive layer (6),
• an inner sealing layer (7) which will be in contact with the food product.

The outer support layer (5) is produced in a mode of preferred but non-limiting embodiment, in an amorphous polyester with a thickness which can vary from ten to five hundred micrometers or more depending on stiffness. resistance, or the flexibility of the tray (2) that one wishes to obtain.

In another embodiment, it may be carried out in materials such as PVC, polypro, polyethylene, expanded polyester, polyamide, polycarbonate or polystyrene.

The intermediate adhesive layer (6) is produced by means of a resin adhesive or another material of the thermoplastic synthetic type. She should have a almost permanent adhesive effect to present bonding properties allowing opening and close the lid several times when consuming the product in several quantities. Its thickness will preferably be fifteen to twenty micrometers to ensure the bonding properties with permanent effect, and ensuring the connection between the welding layer (7) inner and the outer support layer (5).

The inner sealing layer (7) is produced by means of a polyethylene preferably composed of five layers (9, 10, 11, 12 and 13), shown schematically at Figure 2, the total thickness of which is greater than twenty five micrometers. She must have good weldability and fusion with another weldable layer as well nature. It must have a sufficiently wide range of weldability and fusion to accept variations in temperature and pressure.

The cover (3) of the packaging (1) is of the same type and structure identical to the sealing layer (7) of the tray (2). It is preferably composed of five layers (14, 15, 16, 17 and 18), shown schematically in Figure 2, in polyethylene of thickness greater than thirty micrometers and these characteristics must be identical to those of the welding layer. It should have good dimensional characteristics allowing it to support the printing of ink and text or image representative of the solid or pasty food product (19) contained in the package (1).

The thermoformable structure of the tray (2) is produced, by example, by hot applying the adhesive layer (6) with a permanent effect of synthetic type thermoformable on the support layer (5) of amorphous polyester by a process of coating carried out at a temperature of approximately 160 ° C., then by rolling on this adhesive layer (6) of the welding layer (7) of polyethylene.

The assembly is then wound up so as to form a reel ready for cutting for the thermoforming packaging machine.

Another technique, used to make the thermoformable structure, consists in hot extruding the adhesive resin, constituting the adhesive layer (6), between the support layer (5) and the welding layer (7).

For the manufacture of the packaging (1) and the packaging of the product (19), the structure is for example preheated to a temperature of 100 to 120 ° C for a duration of about two seconds, then it is formed on air impressions and suction to obtain the tray (2).

Then, the tray (2) is filled with the food product or medical device (19) and inject a neutral gas suitable for preserving the product before closing the tray (2) by the cover (3) by welding at 160 ° C for a period 1.5 seconds at a pressure of 2.5 bars on the periphery of the tray (2) by a cord welding (4) with a width L of 4 to 8 mm.

Parameters that can be changed depending on the type of machine thermoformer used, which do not undergo any modification since the process of packaging manufacturing remains identical to those existing previously for packaging traditional.

The welding is carried out between the welding layer constituting the cover (3) and the sealing layer (7) of the tray (2).

Given the characteristics of the two welding layers, these merge over the entire periphery of the tray (2) and over the entire width of the bead solder (4).

The packaging (1) then has a pocket (8) waterproof and oxygen or gas tight. This pocket (8) is delimited by the welding layer of the cover (3), the sealing layer (7) of the tray (2), and the weld bead (4) on the entire periphery of the packaging (1). It therefore contains the food or medical product (19) and the neutral gas suitable for preserving the product.

The welding layer constituting the cover (3) and the welding layer (7) are preferably composed of five layers (14, 15, 16, 17 18) respectively (9, 10, 11, 12, 13), the layers (11 and 16) being high barrier layers with oxygen. Thus, the pocket is obtained by the connection and the combination of the high film barrier on the cover (3), high barrier film on the welding layer (7) and the bead welding (4), which ensures its sealing and impermeability function. Neutral gas therefore remains contained in the pocket which prevents, at the same time, the penetration of oxygen.

Thus, permeability to oxygen or gas. that is to say the amount of oxygen entering the package or the amount of inert gas escaping from the package will be at most 5 cm3.m ^2/24 hours.

In this way, the manufacturer can accurately determine the deadline consumption of the product (19) and ensuring the quality of food products (19) distributed in commercial areas.

The cover (3) and the welding layer (7) must be made up of at least minus three layers of which the central layer, in a preferred embodiment, will be the film high oxygen barrier.

During the welding operation, the thermoforming machines undergo variations in temperature and pressure. In the state of the art, these variations created on the adhesive layer "chimneys" (21) in the radial direction of the tray (2) which allow oxygen to enter the packaging (1) and escape the preservative neutral gas. These "chimneys" (21) on the adhesive layer (6) still exist, but these are located on the adhesive layer (6) outside the sealed pocket (8) comprising a film high oxygen barrier. In this way, the "chimneys" (21) have no disadvantages on the packaging (1) since they do not open into the pocket (8)

The neutral gas is correctly stored inside the pocket (8) hermetic, without any penetration of oxygen therein. Thus, the quality of solid, liquid or pasty, or medical food products (19) is therefore preserved until their expiration date.

In addition, these "chimneys" (21) on the adhesive layer (6) no longer having the drawback on the packaging of solid, liquid or pasty food products, or medical (19), packaging manufacturers therefore have more flexibility in variations in temperature and pressure in thermoforming machines. The devices temperature and pressure regulation on the machines can be simplified or less precise, which will make the cost of control devices in regulation lower.

When opening the packaging (1) for consumption for the first time solid or pasty food product (19), the consumer, by exerting an effort sufficiently large, detach the weld bead (4) from the tray (2) at least on part of the periphery of the packaging (1) and separates the cover (3) from the tray (2), as shown in figure 3.

To carry out this operation, the consumer has on the packaging (1) a tongue (20) produced on the cover (3) which promotes better grip for pull the cover (3) and detach it from the tray (2), as shown in figure 4. In detaching the weld bead (4) from the tray (2) the consumer releases the layer adhesive (6) with permanent effect on the weld bead (4) around the entire periphery of the packaging (1), and it opens the pocket (8) which then loses its sealing characteristics and impermeability.

The solid or pasty food product (19) is then in contact with oxygen, and the preservative neutral gas is no longer effective. The consumer must therefore consume the food product (19) within a few days after which it will have lost its quality, flavor, and will be perishable.

The part of the adhesive layer (6), released on the periphery of the packaging (1), has a width L equal to that of the weld bead (4). Its width L will be in a preferred mode of four to eight millimeters. So the consumer can close the cover (3) several times on the tray (2) thanks to the permanent effect of the adhesive layer (6). Reclosing the packaging (1) therefore maintains the share of the product food (19) remaining protected from moisture in the refrigerator, and also prevents spread odors from the product (19) in the refrigerator.

In this way, the consumer no longer has to use a protective film to remedy its drawbacks, or it is no longer obliged to consume the product in one one time.

To allow the weld bead (4) to come off the tray (2) and not the cover (3), the resistance of the weld bead (4) on the cover (2) must be greater than that on the tray (2). That is to say, we must favor the tearing of the weld bead (4) at the level of the tray (2).

To achieve this, a clamping pressure is exerted on the cord solder (4) at a given temperature, which favors the deformation (22) of the layer seal (7) and the cover (3). This deformation becomes permanent when the weld cools. These two elements are deformed by the fact that they merge and undergo a pressure. On the other hand, the support layer (5) of the tray (2) undergoes almost no deformation due to the nature of the material used, which melts very little at temperature exercised.

It is therefore necessary to promote the deformation of the layer (7) to the deformation of the cover (3), to promote the tearing of the weld bead (4) on the tray (2). To strengthen this point, it is also possible to take a greater thickness for the welding layer constituting the cover (3) as for the welding layer (7). So the resistance will be greater on the cover (3) than on the sealing layer (7) at weld bead level (4) when the consumer opens the packaging (1) for the first time.

Other implementations of the present invention, within the scope of the Man of the Art, could have been envisaged without departing from the framework of the present invention defined by the appended claims

Claims (10)

1. Container (1) for packaging of solid, liquid or pasty food products (19) or the packaging of medical products, allowing easy opening and reclosing of the container, which is composed of:

   a rigid or flexible tray (2) using a thermoformable structure formed from:

   an outer support layer (5) made of amorphous polyester or other material,

   an intermediate adhesive layer (6) of permanent effect,

   an inner welding layer (7) of polyethylene; and

   a lid (3) formed from:

   a polyethylene welding layer or a thermoformable structure similar to that of the tray (2) ,

   the container (1) having an impermeable and sealed pocket (8) that houses the medical product or solid, liquid or pasty food product (19), said pocket being bounded by:

   the welding layer (7) of the tray (2);

   the welding layer constituting the lid (3); and

   the weld bead (4) that is produced between these two welding layers (7, 3),

   characterized in that the welding layer (7) of the tray (2) and the welding layer constituting the lid (3) are made of multilayer polyethylene that includes a high oxygen barrier film.
2. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to Claim 1, characterized in that the welding layer (7) of the tray (2) and the lid (3) possess at least three layers and in that the central layer is the high oxygen barrier film.
3. Container (1) according to Claim 1 or 2, characterized in that the lid (3) of the container is of the same nature as and has an identical structure to the welding layer (7) of the tray (2).
4. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to one of Claims 1 to 3, characterized in that the welding layer (7) of the tray (2) and the welding layer constituting the lid (3) are fused together and now form only a single layer around the periphery of the tray (2) level with the weld bead (4), thereby sealing the pocket.
5. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to one of Claims 1 to 4, characterized in that opening the container (1) for the first time detaches the weld bead (4) from the tray (2) and frees part of the adhesive layer (6) of permanent effect on the tray (2) and opens the hermetically sealed pocket, in order to allow the product to be consumed in several quantities and allowing the lid to be closed again on the tray several times.
6. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to Claims 1 to 5, characterized in that the weld bead (4) has a greater tear strength within the lid (3) than within the welding layer (7) on the tray (2) when the container (1) is being opened.
7. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to one of Claims 1 to 6, characterized in that the adhesive layer (6) of permanent effect is freed around the periphery of the tray (2) and has a width L corresponding to that of the weld bead (4).
8. Container (1) according to one of Claims 1 to 7, characterized in that the support layer (5) is made of material such as PVC, polypropylene, polyethylene, expanded polyester, polyamide, polycarbonate or polystyrene.
9. Container (1) for the packaging of medical products or solid, liquid or pasty food products (19) according to Claims 1 to 8, characterized in that the thermoformable structure has a total thickness of greater than forty micrometers and in that the welding layer (7) of the tray (2) and the welding layer constituting the lid (3) have a thickness of several tens of micrometers.
10. Container (1) according to one of Claims 1 to 9, characterized in that the thickness for the welding layer constituting the lid (3) is greater than that for the welding layer (7) of the tray (2).

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