FOOD CONTAINER WITH GUARANTEE SEAL

Abstract: A food container (1) with guarantee seal (9) includes a lid (5) and a tray (2), made of synthetic material, which are joined along peripheral edges (6, 7), and a removable seal (9) which is suitable to prevent the lifting of the lid (5), and which clearly indicates the integrity of the package. The seal (9) consists of a removable portion of the edge of the tray, which is joined to the rest of the tray by thin tabs (13). In the closed position, the edge of the tray (6) perfectly adheres to, and blends with, the edge of the lid (7) so that it has no protrusions or slits. The edge of the lid (7) has a portion (29) which simply rests on the seal (8) to allow its removal by radial outward pulling and can be folded elastically upward to allow to pull the seal (8) in the same direction.

Description: FOOD CONTAINER WITH GUARANTEE SEAL The present invention relates to a food container with guarantee seal which comprises a lid and a tray, joined along a peripheral edge, and at least one removable seal which is suitable to prevent the lifting of the lid, clearly indicating the integrity of the package at the time of purchase. Containers of the above described type are commonly used to package and preserve widely used solid, semisolid or pasty food products such as creams, butter, margarine, ice creams, confectionery products and the like. Some of the fundamental requirements for these containers are the preservation of aromas, the absence of transfer of tastes and odors, biodegradability, watertightness, resistance to shocks and to low temperatures, aesthetic appeal, size and stackability. Thes e requiremen ts are ach i eved by us ing f ood-grade thermoplastic synthetic materials which comply wi th the current ly applicable hygi enic and sani tary s ta tutory provisions , such as polyethylene , clear or shock-resistant polystyrene , and degassed polypropylene (premilene) . If the containers are used for several servings , for example with a capacity of one or more liters , the contents are meant to be used at different times and therefore it is necessary to provide a double closure system : one which seal s the package until its first use and one which closes it during the period of use. An example of these systems is constituted by ultrasound- welded trays and lids ? this system is very economical but scarcely reliable, because if the welding is weak it does not ensure tightness, while if it is too strong it leads to the breakage of the lid or of the tray during initial opening, with the consequence that the cor.. >πer is unusable. Another example is constituted by trays covered by a plastic film or by a sheet of aluminum with a removable lid; this system is more reliable than the preceding one but it is rather complicated and expensive. All these methods, however, do not meet the primary requirement of allowing the consumer to easily see the integrity of the package at the time of purchase. This extremely important requirement is generally termed "guarantee seal", "evident closure" or "Tamper Evident Packaging". Some producers meet this requirement by wrapping the entire package with a light cardboard sheath which is torn off when the package is opened for the first time. This system entails additional costs, more complicated packaging and a certain possibility of wear before sale. Other systems provide for the gluing of a label on the lid so that it partially overlaps the tray. Another and more advantageous example of "evident closure" is constituted by a type guarantee seal similar to the bottle caps. The lid is applied in a snap-on manner onto the tray and the seal does not allow to access and lift the lid unless the seal itself is broken or removed. After initial opening, the container can be closed again to preserve the product until it is used completely. In a conventional container of the above described type, the guarantee seal is constituted by a corner of the edge of the tray, which is folded upward and joined to the rest of the tray by a pre-fracture line or by yielding tabs. The seal fully surrounds the corner of the lid which it faces, so that the consumer cannot act on the lid until the seal has been broken and can check the integrity of the package by the presence of the seal. In order to break the seal it is necessary to press down the corner of the container which is superimposed thereon, or it can be sufficient to act on the edge of the tray at the pre-fracture line. Although this known container is a considerable improvement in ensuring the integrity of the package, it has some acknowledged problems: firstly, there is a possibility of unwillingly breaking the seal in handling the container, for example by interference with a protruding body. Furthermore, the shape of the edge of the tray does not offer the maximum assurances of hygiene, since moisture can penetrate in the interspaces between the lid and the tray after the seal has been removed. An aim of the present invention is to eliminate the problems described above by providing a container of the type with evident closure which offers the maximum assurances of reliability and hygiene both upon first opening and during subsequent use. Within this aim, an object of the invention is to provide a seal structure which is suitable to avoid the involuntary separation of the seal during handling and transport. Another object is to provide a container at low cost and optimum aesthetic appearance. This aim, these objects and others, which will become apparent to those skilled in the art, are achieved by a food container with guarantee seal, comprising a lid and a tray made of synthetic material, said lid and tray being adapted to be joined along their peripheral edges, and at least one removable seal, said removable seal being adapted to prevent the lifting of the lid, clearly indicating the integrity of the package, wherein said seal comprises a removable portion of the edge of the tray, said removable portion being joined to the rest of the tray by thin tabs or by pre- fracture lines, characterized in that in closure position the edge of the tray perfectly adheres to, and uniformly blends with, the edge of the lid so as to have no protrusions or slits with respect to said lid edge. Preferably, the edge of the lid has a portion which simply rests on the removable portion of the tray to allow said portion to be pulled radially outward, causing the breakage of at least part of the tabs. Also, the lid portion which simply rests on the removable portion of the tray has such a shape that it is elastically folded upward to allow traction in the same direction as the removable portion of the tray, causing the breakage of at least part of the tabs. The edge of the tray generally comprises a flat region which blends with the side walls of the tray and is stiffened outward by a ridge which has a substantially U-shaped cross- section with an outer peripheral groove. The removable portion of the edge of the tray is separated from the rest of the tray by a pre-fracture line which consists of a continuous or discontinuous void of material, which comprises a central portion which is substantially parallel to the outer edge of the tray and two end portions arranged at right angles to said edge. The edge of the tray and the edge of the lid have complementarily shaped fastening means which are suitable to ensure, upon closure, the contact of the edges along at least two flat regions. With a container of the above described type, the consumer can check the absolute integrity of the package, avoiding, or in any case substantially reducing, the risk of unwilling breakage of the seal. Further characteristics and advantages of the invention will become apparent from a reading of the detailed description of a preferred but not exclusive embodiment of a container according to the invention, illustrated only by way of a non- limiting example in the accompanying drawings, wherein: FIG. 1 is a top view of the container and of the lid inserted, according to the invention, in a first embodiment; FIG. 2 is a partially sectional side view of the container of FIG. ϊ, taken along a vertical plane designated by II-II; FIG. 3 is an enlarged-scale sectional view of a detail of FIG. 1, taken along a vertical plane designated by III-III; FIG. 4 is an enlarged-scale sectional view of a detail of FIG. 1, taken along a vertical plane designated by IV-IV; FIG. 5 is an enlarged-scale top view of a detail of the tray of the container of FIG. 1; FIG. 6 is an enlarged-scale top view of a detail of the lid of th container of FIG. 1; FIG. 7 is an enlarged-scale view of a detail of FIG. 1 during a step of the breakage of the seal; FIG. 8 is an enlarged-scale view of a detail of FIG. 1 during a step of the lifting of the lid. FIG. 9 is a top view of a detail of the tray and of the lid according to a second aspect of the invention; FIG. 10 is a sectional view of the detail of FIG. 9, taken along a plane designated by X-X; FIG. 11 is a sectional view of the detail of FIG. 9, in open position, taken along a plane designated by XI-XI; FIG. 12 is a view of the detail of FIG. 11 in closure position. With reference to the figures, the container according to the invention, generally designated by the reference numeral 1, comprises a tray 2, which has slightly inclined side walls 3 and a substantially horizontal bottom 4, and a lid 5. In the drawings, the tray and the lid have a substantially rectangular shape, viewed from above; however, this shape may be considerably different without thereby abandoning the scope of the invention. The materials employed may be thermoplastic synthetic resins, such as polyethylene, clear or shock-resistant polystyrene, premilene and other food-grade resins approved by the currently applicable national and international statutory provisions. The tray 2 and the lid 5 have respective edges 6 and 7 which can be sealingly coupled so as to tightly close the container. There is a guarantee seal, generally designated by the reference numeral 8, which is suitable to prevent the lifting of the lid and ensure the integrity of the package. In particular, the seal 8 can be constituted by a portion 9 of the edge of the tray which is separated from the rest of the tray by a line of discontinuity in the material formed by a central portion 10 which is substantially parallel to the edge and by two end portions 11 and 12 which are substantially perpendicular to the edge. In a per se known manner, the portion 9, which forms the edge seal, is joined to the rest of the tray by a series of tabs 13. Tabs 13 have a limited stress resistant cross-section, so as to allow the separation of the seal with a minimal tangent and/or normal effort. According to the invention, in closure position the edge 6 of the tray perfectly adheres to, and is aligned with, the edge 7 of the lid without protruding at all from the outer profile of said lid. As shown in ξ G. 4, the edge of the tray 6 is formed by a flat portion 14 which blends with the side wall 3 of the tray and is substantially parallel to its bottom 4. The flat portion 14 is stiffened outward by a ridge 15 which has an external lip 16 and an internal wall 17 which are joined downward by a curved bottom 18, so as to define a groove 19 which has a substantially U-shaped transverse cross-section. The edge 7 of the lid has a flat portion 20 which is peripherally stiffened by a flange or lip 21. Lip 21 is shaped so that it can be inserted in the groove 19 of the ridge 15 of the tray edge and is provided with an external step 22. External step 22 has a horizontal side 23 which forms an abutment for the top of the lip 16 of the tray. The flat portion 20 is also connected to the central portion 24 of the lid by a corrugation 25 which has an approximately U-shaped transverse cross-section. Corrugation 25 has an outer wall 26 which has the same inclination as the side wall 3 of the tray. Both the edge of the lid and the edge of the tray have means for snap-together coupling, constituted by protruding and opposite ribs 27 and 28. Ribs 27 and 28 are formed respectively along the internal surface of the lip 16 and along the outer rim of the lip 21 and have approximately trapezoidal cross-sections with rounded edges. For closing the container, the lip 21, of the edge 7 of the lid, may simply be inserted in the corresponding U-shaped cavity of the tray edge, then applying a certain p...ssure on the lid to produce the snap-together overlap of the ribs 27 and 28, moving the upper edge of the outer lip 16 so that it abuts against the side 23 of the step 22. Thus, the flat portion 26 of the lid perfectly adheres to the wall 3 of the tray, and the flat portion 20 of the lid is in contact with the flat portion 14 of the tray. Contact is also ensured at the ribs 27 and 28, minimizing the possibility of infiltrations of fluids and impurities inside the container. In this condition, the outer lip 16 of the edge of the tray is perfectly aligned with the lip or flange 21 of the edge of the tray so that it does not have any protrusion, which may engage external objects or be gripped by a user, and has no slits which allow the infiltration of moisture and dirt. Therefore, the edges of the lid and of the tray, once coupled, appear as a single perfectly uniform and blended edge, with a high functional and aesthetic value. Upon closure, a corresponding portion 29 of the edge of the lid can be superimposed on the removable portion 9 of the edge of the tray which constitutes the seal. In this region, the portion 29 of the lid and the corresponding portion 9 of the tray have the following structural differences, shown in FIG. 3. First of all, there are no coupling means, because the edges do not have the protrusions 27 and 28. Also, the edge of the lid does not have the flange 21 and is shaped so that it is simply rested on the underlying portion of the tray 9. In this manner, the underlying portion of the tray can be separated from the rest of the tray by means of a radial outward traction. Also, the flat region 14 of the edge of the tray 9 is slightly depressed at the region 30 with respect to the rest of the edge, and the lid also has an equally depressed region 31 which is in contact with the corresponding region 30 of the seal when the lid is closed again. The flat region 31 of the edge of the lid is blended with the ridge 25 by means of a curved edge 32. Because of its particular configuration, curved edge 32 has a slight elasticity and possibility of flexing the lid upward but is substantially rigid if pressed downward. This allows the edge of the tray to flex upwardly in this particular region and, at the same time, also the removable portion 9 of the edge of the tray to flex upwardly. Therefore, if the container is inadvertently compressed at the seal, for example during its stacking or transport, its lid cannot fold downward due to its substantial rigidity in this direction, preventing the breakage of the tabs 13 and thus of the seal. If required, it is possible to insert instructions for the consumer, such as the word "PULL", in the flat depression 31. A user can grip the seal 8, together with the corresponding portion of the lid, between his thumb and index, folding them upward until the tabs 13 break and the seal separates. The seal can be separated completely from the rest of the tray, allowing the insertion of a finger below the edge of the lid so as to allow to lift it and open the container. Alternatively, the seal 8 can be pulled radially outward, for example toward one of its ends, by pivoting about the opposite end, causing the breakage of the adjacent tabs and keeping intact those which are further away, which may be stronger and retain the seal partially coupled to the rest of the tray, as shown in broken lines in FIG. 5. In order to improve the effectiveness of the closure and clearly indicate the integrity of the seal, an alternate embodiment of the removable portion of the tray edge and of the region which faces the lid edge is provided. These portion and region are illustrated in FIGS. 9 to 12, wherein like reference numerals denote similar features to those of the preceding figures. In particular, a means for automatic coupling between the removable portion 9 of the tray edge and the facing portion 7 of the lid edge is provided. This automatic coupling means can be constituted, for example, by a flared opening 33 which is formed on the flat region 14 of the removable portion 9 of the tray edge and has a side wall 34 which is substantially shaped like a truncated cone and is provided with radial notches 35. Notches 35 form V-shaped tabs or sectors 36 which yield elastically downward but not upward. This shape allows to insert an object with an enlarged head by simple pressure but prevents its retraction once the tapered portion formed by the V-shaped tabs 36 hass been passed. An elongated structure 37 is provided on the flat portion 20 of the edge of the lid 7 which faces the removable portion 9 of the tray edge. Structure 37 is constituted by a central body with radial longitudinal ribs 38. Radial ribs 38 are joined to the lid proximate to the radial ends 39, leaving passages 40 through the flat portion 20, and with an enlarged head 41 which is substantially shaped like a truncated cone and has a maximum diameter which is greater than the minimum distance between the tips of the V-shaped tabs 36. Ribs 38 are aligned with radial notches 35 so as to be able to pass through them freely. Upon the closure of the lid on the tray, the pressure applied on the lid in a downward direction forces the head 41 of the structure 37 to flex the tabs 36, allowing the passage of the ribs 38 in the notches 35. After the complete insertion of the head 41, the tabs 36 can return toward the center elastically, blocking the upward return movement of the head 41, as shown in broken lines in FIG. 12. In this manner one achieves the double object of increasing the adhesion of the lid to the tray, making it more difficult to insert sharp objects in their separation line, and of clearly indicating the separation of the seal once the container has been opened. It is also noted that by means of this non-disengageable coupling means the removable portion of the tray is prevented from inadvertently falling into the tray, contaminating its contents, once the seal has been broken. In order to make the integrity of the package even more evident , it is possible to use di f f erent lid and tray colorings so as to easily indicate the presence or absence of the seal . The container can have a seal structure at one or more corners of the edge. In the illustrated cases, there are two seals at two opposite corners of the tray but it is possible to provide seals at each corner of the tray. From what has been described above, it is apparent that the container according to the invention achieves the intended aim and objects-- The configuration of the seal should be noted in particular: it has high reliability and prevents involuntary breakage by lifting or compression of the edge. The container according to the invention is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept. All the details may furthermore be replaced with other technically equivalent elements. In practice, the materials employed, as well as the dimensions, may be any according to the requirements. Having thus described one particular embodiment of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements as made obvious by this disclosure are intended to be part of this disclosure though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention is limited only as defined in the following claims and the equivalents thereto. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: CLAIMS 1. Food container with guarantee seal, comprising a lid (5) and a tray (2) made of synthetic material, said lid and tray being adapted to be joined along their peripheral edges (6, 7) , and at least one removable seal (8) , said removable seal being adapted to prevent the lifting of the lid, clearly indicating the integrity of the package, wherein said seal (8) comprises a removable portion (9) of the edge of the tray (6) , said removable portion being joined to the rest of the tray by thin tabs (13) or by pre-fracture lines, characterized in that in closure position the edge of the tray (6) perfectly adheres to, and uniformly blends with, the edge of the lid (7) so as to have no protrusions or slits with respect to said lid edge. 2. Container according to claim 1, characterized in that the edge of the lid (7) has a portion (29) which simply rests on the removable portion of the tray (9) to allow said removable tray portion to be pulled radially outward, causing the breakage of at least part of said tabs (13). 3. Container according to claim 1, characterized in that the lid portion (29) which simply rests on the removable portion of the tray (9) has such a shape that it can be folded elastically upward to allow traction, in the same direction, of said removable tray portion (9) , causing the breakage of at least part of said tabs (13) . 4. Container according to claim 3, characterized in that the edge of the tray comprises a flat region (14) which is blended to the lateral walls (3) of the tray and is stiffened outward by a ridge (15) which has a substantially U-shaped transverse cross-section with an external peripheral groove (19) . 5. Container according to claim 4, characterized in that the edge (7) of the lid comprises a flat outer region (20) which can be superimposed on the flat region (14) of the edge of the tray. 6. Container according to claim 5, characterized in that at the seal (8) the flat outer region (20) of the edge of the lid (5) -»s joined to the central region of the lid by means of a curved edge (32) which is suitable to allow the upward flexing, but not the downward flexing, of the flat outer region (20) of the edge of the lid. 7. Container according to claim 7, characterized in that the edge (7) of the lid is peripherally provided with a flange (21) which is substantially perpendicular to the flat region (20) of said lid edge and can be inserted in the peripheral groove (19) of the ridge of the edge of the tray. 8. Container according to claim 7, characterized in that the flat region (14) of the edge of the tray has a slight depression (30) at its removable portion (9) . 9. Container according to claim 8, characterized in that said flat region (20) of the edge of the lid which overlaps the removable portion of the tray (9) has a depression (31) which is similar to the depression (30) of the edge of the tray so as to be in contact therewith-. 10. Container according to claims 1 to 9, characterized in that it has a means for automatic coupling between the removable tray portion (9) and the facing lid region (20) which can be coupled in a snap-together manner upon the closure of the lid on the tray and cannot be disengaged even after breaking the seal and opening the container. 11. Container according to claim 10, characterized in that said automatic coupling means comprises, on the flat region (14) of the edge of the tray, at its removable portion (9) , a flared opening (33) with a lateral wall (34) which is substantially shaped like a truncated cone and is provided with radial notches (35) which are suitable to define, in said wall, V-shaped tabs (36) which yield elastically downward. 12. Container according to claim 11, characterized in that said automatic coupling means comprises, on the flat region (20) of the edge of the lid which faces the removable tray portion (9), an elongated structure (37) which extends downward at right angles to the lid and is aligned with the flared opening (33) of the removable region of the tray (9) . 13. Container according to claim 12, characterized in that the elongated structure (37) is provided with a main body which is formed by radial longitudinal ribs (38) which can be inserted in respective radial notches (35) of the flared opening (33) of the removable portion of the tray (9) , and with a head (41) which is substantially shaped like a truncated cone and can be inserted, in a snap-together manner, in the flared opening (33) of the edge of the tray but cannot be extracted therefrom due to the locking action exerted by the V-shaped tabs (36) of the wall of said flared opening. 14. Container according to claims 1 to 9, characterized in that the edges of the tray and of the lid (6; 7) have, in the regions spaced from the seal (8) , a complementarily shaped engagement means (27; 28) which is adapted to ensure mutual contact of the lid and of the tray along at least two flat regions (3, 14; 26, 20). 15. Container according to one or more of the preceding claims, characterized in that said removable portion (9) of the edge of the tray is separated from the rest of the tray by a void of material which extends along a central portion (10) which is substantially parallel to the outer edge of the tray and along two lateral portions (11, 12) which are substantially at right angles to said edge. 16. Container according to one or more of the preceding claims, characterized in that the flat outer region (20; 31) of the edge of the lid is blended with the central region of the lid by means of a corrugation (25) which has a substantially U-shaped cross-section with an outer wall (26) which has the same inclination as the side wall (3) of the trav. 17. Container according to one or more of the preceding claims, characterized in that it has a polygonal shape, viewed from above, with a seal (9) arranged one or more corners .

Inventors: NUSSIO GUIDO, NUSSIO, GUIDO
Applicants: NUSSIO GUIDO, TECNOWERK SRL, TECNOWERK S.R.L.
Application year: 1992
Main classification: B65D43
IPC codes: B65D43, B65D55