FR2609451A1 - SEALED CONTAINER FOR USE IN PARTICULAR FOOD - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS A CONTAINER FOR FOOD USE IN PARTICULAR, SUCH AS A TRAY INCLUDING A BODY-FORMING ELEMENT PROVIDED WITH A NON-CIRCULAR UPPER EDGE AND A COVER-FORMING ELEMENT WITH A GROOVE INTENDED TO RECEIVE IN ITS BOTTOM, AND INCLUDES BODY A THROAT RADIALLY EXTERNAL TO THE SAID GROOVE, PROJECTING BELOW IT INTO THE INSIDE OF THE BODY AND COMING IN CONTACT WITH ITS RIM IN THE CLOSED POSITION OF THE CONTAINER. ACCORDING TO THE INVENTION THROAT 6 HAS A SHOWER DEPTH IN THE PARTS WITH LOW RADIUS OF CURVATURE, SUCH AS THE PARTS FORMING ANGLE A, THAN IN THE LATERAL PARTS L OF THE LID WITH LARGER RADIUS OF CURVATURE, OR SENSITIVELY STRAIGHT. THE INVENTION FOUND IN PARTICULAR APPLICATION IN THE FOOD INDUSTRY.

Description

The present invention generally relates to a container for use in particular

  foodstuff, and essentially relates to a tray of the type comprising a body member provided with an upper rim of non-circular shape and a cover member having a groove for receiving in

its bottom said rim.

  The invention finds particular application in the food industry and in particular for the preparation of vacuum-packed dishes intended for

  to be reheated in their packaging before consumption.

  In the case of a tray including thermoformed, the technique of vacuum packaging of food products requires the use of a perfectly sealed lid. When the upper rim of the container body is circular, there is no particular problem. However, when this flange is of non-circular shape, it is difficult to simultaneously obtain a good seal and a

ease of opening.

  Thus, we have already manufactured substantially rectangular trays, with rounded corners that are perfectly sealed. However it is impossible to open such trays without damaging the lid; which leads to a bad presentation of the product. To solve this problem, that is to say ensure both a perfect seal of the container and a clean and easy opening thereof, we used an additional plastic film forming a lid, placed between the lid of the container and his body. Such a film, for sealing the container is generally made of a complex multilayer plastic material, and requires an additional operation of heat sealing or self-adhesive

to the container body.

  When total sealing is not achieved, the shelf life of the packaged products decreases considerably. The object of the present invention is to solve the aforementioned problems by proposing a container of the above-mentioned type, of simpler design which makes it possible to package food products in a perfectly tight manner, which can be easily opened without damaging the lid and which does not require not

an additional operculum.

  The solution according to the present invention, to solve this technical problem, consists of a container of the type comprising a body member provided with an upper rim of non-circular shape and a cover member having a groove for receiving at its bottom. said flange of said body, and comprising a groove radially external to said groove, projecting therein inwardly of said body and coming into contact with said flange of the body in the closed position of the container, characterized in that the groove has a smaller depth in the low radius of curvature portions, such as the corner portions, than in the side portions of the lid of greater radius of curvature, or

substantially rectilinear.

  Such a container is perfectly sealed and allows the foodstuffs to be kept hermetically without any risk of deterioration, and can

  be easily opened without abtmer the lid.

  According to another characteristic of the invention, the depth of the aforementioned groove, in each part of small radius of curvature, is a function of the length of the arc forming said part of small radius of curvature, and in each lateral part the depth throat

  is a function of the length of said lateral part.

  Another object of the present invention is to provide vacuum packaging of products, in particular food products, which are not deformed by being placed under vacuum or under a neutral gas. Indeed, when using a thermoformed tray, in a flexible material, it is crushed by the vacuum. The result is a poor presentation and the impossibility of stacking the trays once filled one above the other. Thus, according to a particularly advantageous characteristic, the lid of a container according to the invention comprises a deformable part, preformed, capable of being deformed, during the evacuation, to come to marry the profile of the food contained in the container . This provides a neat and attractive presentation for consumers, the tightness of the tray also ensuring long-term food preservation. In addition, such trays once filled can be easily stacked o a gain of

advantageous place during storage.

  The invention will be better understood, and other purposes, features and details thereof will become more clearly apparent on reading the

  explanatory description which will follow, made with reference

  to the accompanying diagrammatic drawings given solely by way of non-limiting example illustrating several currently preferred embodiments of the invention, and in which: - Figure 1 is a top view of a cover according to the invention; FIG. 2 is a view of a container provided with its lid in the direction II-II of FIG. 1; FIG. 3 is a detail view of FIG. 2, at the level of an upper flange illustrating how the sealing of the container is obtained; - Figure 4 is a sectional view along the line IV-IV of Figure 3, showing more particularly the groove of the lid according to the invention; - Figure 5 shows a container body filled with food products; - Figure 6 is a view similar to the figure showing the filled box body, provided with a deformable cover, in the undeformed state, according to a particular embodiment of the invention; and FIG. 7 is a view similar to FIGS. 5 and 6 of a closed container showing the deformable part of the lid conforming to the profile of the food products contained in the container body, after evacuation. In these figures, there is shown a substantially parallelepiped shaped tray of substantially rectangular longitudinal section made of polypropylene. However, it will be understood that the general principle of the invention is applicable regardless of the shape of the tray, provided that its upper flange is not circular, and whatever the material from which this tray is made. In particular, any plastic material can be used

  such as polystyrene, polyvinyl chloride, etc ...

  as well as any suitable multilayer materials.

  The tray that was made and will be described here is made of polypropylene, and can undergo without

  damage of the temperatures of the order of 120 to 130 C.

  Thus, the food products contained in such trays can be quickly cooked or reheated for example in a microwave oven, and can be

  consumed immediately after cooking.

  Referring to Figure 2, a tray 1 according to the invention comprises a body 2 provided with an upper flange 3 of non-circular shape and a cover 4 having on its inner surface a groove 5 of substantially U-shaped cross-section. intended to receive at its bottom the flange 3, also of substantially U-shaped cross-section. This rim is connected to the trunk 11 of the body 2 by an angular portion 12 intended to come into contact with the bottom of the cover 4 during the closing of the

  container thereby forming a sealing point.

  The lid 4 comprises a groove or peripheral groove 6 radially external to the groove 5 projecting therebelow inwardly of the container body 2. The groove 6 comes into contact with the flange 3, at the end 9 thereof, in the closed position of the container. Specifically, the throat 6

  bears under the end 9 of the flange 3.

  This is where the perfect

tightness of the tray.

  As shown in FIG. 4, the groove 6 has a smaller depth in the parts of small radius of curvature, such as the portions forming angle A, than in the side portions L of the lid, of larger

  radius of curvature or substantially rectilinear.

  The invention is indeed based on the discovery that differences in depth of the groove between the corners and the rest of the periphery of the groove 6 ensure both a perfect seal and the possibility of removing

  easily the lid without deterioration of the latter.

  The depth of the groove 6 in each part forming an angle A is chosen as a function of the length of the arc forming said portion at an angle A. Thus, the depth of the groove is greater than the length of the arc. formed is important. In general, this depth h is of the order of 0.3 to 0.8 mm, and preferably 0.3 to 0.4 mm in the example shown, where the length of the arc A is about 35 to mm. In the same way, in each lateral part L, the depth of the groove is a function of the length of said lateral part. In general, this depth can be of the order of 0.8 to 1.1 mm and in the example shown the depth of the groove in the lateral parts of greater length (approximately mm) is 1, 1 mm while it is about 0.8 mm in the side parts of weaker

length (about 70mm).

  Between each portion of small radius of curvature and the portion of larger adjacent radius of curvature is a connecting portion of the groove R which has a concave profile followed by a convex profile. Advantageously, the length of each connecting portion R is chosen, in particular as a function of the length of the arc formed by the portion of small associated radius of curvature A. Thus, the depth of the groove in a connecting portion is all the more important that the length of the arc formed by the associated corner portion A is large. In the example shown, for a length of the part of small radius of curvature A of about 35 to 40 mm, each connecting portion extends over a length of about 12 to mm. As shown in particular in Figure 3, the cover 4 comprises a peripheral end edge 10 and substantially horizontal plane facilitating the gripping of the

  lid so the opening of the closed container.

  FIGS. 5 to 7 show a particular embodiment of the invention which finds particular application in the packaging of products packaged under deep vacuum. The lid comprises a deformable portion 8 preformed, may be deformed during the evacuation, to come to marry the profile of food P contained in the container. The deformable portion 8 is a curved wall of convex shape in the undeformed state which can be obtained easily by molding. The tray obtained after filling and evacuation (Figure 7) has various advantages. In particular, in addition to a good presentation of the finished product, these full trays can be easily stacked from where an appreciable space saving during

storage.

Claims (10)

  1. Container for particular food use such as a tray, of the type comprising a body member provided with an upper rim of non-circular shape and a cover member having a groove for receiving at its bottom said rim of said body, and comprising a groove radially external to said groove, projecting therefrom inwardly of said body and coming into contact with said flange of the body in the closed position of the container, characterized in that said groove (6) has a greater depth low in the low radius of curvature portions, such as the corner portions (A), as in the side portions (L) of the larger radius lid,   curvature, or substantially rectilinear.   2. Container according to claim 1, characterized in that in each portion of small radius of curvature (A), the depth of the groove (6) above is a function of the length of the arc forming said portion of small radius of curvature , and in that in each lateral part (L) the depth of the groove is   function of the length of said lateral part.   3. Container according to claim 1 or 2, characterized in that the depth of the groove (6) above is of the order of 0.3 to 0.8 mm for a length arc length of about 35 to 40 mm.   4. Container according to one of claims 1 to   3, characterized in that each connecting portion of the groove between a portion of greater radius of curvature and the portion of small radius of curvature adjacent has a concave profile followed by a convex profile. 5. Container according to claim 4, characterized in that the length of each aforementioned connecting portion is selected in particular according to the length of the arc formed by the low radius of curvature portion. Container according to claim 5, characterized in that each said connecting portion has a length of about 12 to 15 mm, for a length of the portion of small radius of curvature. above about 35 to 40 mm.   Container according to one of claims 1 to   6, where said upper rim (3) is of substantially rectangular shape, characterized in that the depth of said groove (6) is 0.8 to 1.1 mm on the lateral parts (L) of the lid and 0.3 to 0.4 mm in areas of small radius of curvature forming angle (A).   Container according to one of claims 1 to   7, characterized in that it is made of a material   thermoplastic, such as in particular polypropylene.   Container according to one of claims 1 to   8, intended in particular for the sealed packaging of food products, characterized in that the aforementioned lid member (4) has a deformable portion (8) preformed, capable of being deformed under the effect of vacuum, to come and marry the profile of the foods contained in said container.   10. Container according to claim 8, characterized in that the deformable portion (8) above the lid is a curved wall of convex shape to the undistorted state.