EP0631941B1 - Plastic container comprising a rigid receptacle and a lid - Google Patents

Description

The invention relates to a new type of plastic packaging box, formed of a rigid container and a lid.

For the packaging of a wide variety of materials, in particular food materials, packaging boxes are already known which are formed of a rigid tray which has an opening delimited by a peripheral rim in the shape of an inverted U, formed of two branches respectively internal connected to the tray itself and external, and a cover comprising a similar peripheral rim, also in the shape of an inverted U, intended to be fitted onto the peripheral rim of the tray (see for example document GB-A-1 473 905) . When it is desired to store a food product in a sealed manner in this container, it is known to apply a seal on the opening of the container. However, this complex operation requires appropriate tools, which increases the cost of packaging.

In document US-A-2 998 158, it has been proposed to provide, directly from molding, on each of the two external branches of the rim of the tray and of the lid respectively, a flexible peripheral annular lateral band, the area where the section of connection to the external branch presents a series of notches or incipient fractures. These two peripheral lateral annular bands are then welded together by any appropriate means, such as heat-welding, induction, ultrasound, glue, etc. This gives an excellent seal. When you want to open the box, just detach the two welded side strips by breaking the caps of rupture. Unfortunately, this initial opening operation is not easy and during use, the opening and replacing of the cover, and therefore access to the packaged product, are inconvenient.

The invention overcomes these drawbacks. It relates to a packaging box of the type in question, the tray and the cover having detachable welded side bands to ensure good sealing to the assembly, but in which access to the conditioned product remains easy, in particular after having detached the bands. side.

• . la barquette présente une ouverture délimitée par un rebord périphérique en forme de U inversé, formé en section de deux branches respectivement interne, reliée au corps de la barquette proprement dite et externe, et dans laquelle la branche externe est entourée par une première bande annulaire latérale venue de moulage, dont la zone de raccordement à la branche externe présente une entaille d'amorce de rupture ;
• . le couvercle comporte un rebord périphérique également en forme de U inversé complémentaire du U de la barquette, destiné à être emboité sur le rebord périphérique de cette barquette, dont la branche externe est également entourée par une seconde bande annulaire venue de moulage, dont la zone de raccordement à la branche externe présente une entaille d'amorce de rupture coopérant avec l'entaille d'amorce de rupture de la bande annulaire de la barquette,

et dans laquelle :

• . les deux bandes annulaires sont superposées de manière à ce que les entailles de chaque bande soient superposées, puis sont soudées entre elles sur toute leur bordure périphérique extérieure pour assurer l'étanchéité de la boite ;
• . et l'empilement des deux bandes annulaires soudées présente une première ligne de rupture, qui s'étend transversalement du bord externe de l'empilement jusqu'au voisinage de la zone comportant les entailles d'amorce de rupture pour permettre de déchirer et détacher cet empilement ;

se caractérise en ce que sur un côté de la barquette et du couvercle, les entailles d'amorce de rupture sont interrompues pour ainsi définir dans l'empilement une zone non-détachable destinée, après déchirure de la bande détachable, à former charnière d'articulation du couvercle sur la barquette.This plastic packaging box, formed of a rigid tray and a cover, in which:

• . the tray has an opening delimited by a peripheral rim in the shape of an inverted U, formed in section of two respectively internal branches, connected to the body of the tray proper and external, and in which the external branch is surrounded by a first lateral annular band coming from molding, the connection area of the external branch of which has a break initiation notch;
• . the cover has a peripheral rim also in the form of an inverted U complementary to the U of the tray, intended to be fitted onto the peripheral rim of this tray, the external branch of which is also surrounded by a second annular strip coming from molding, the area of which connecting to the external branch has a rupture initiation notch cooperating with the rupture initiation notch of the annular strip of the tray,

and in which:

• . the two annular bands are superimposed so that the notches of each band are superimposed, then are welded between them over their entire outer peripheral border to ensure the tightness of the box;
• . and the stack of the two welded annular bands has a first rupture line, which extends transversely from the external edge of the stack to the vicinity of the zone comprising the incisions of initiation of rupture to allow tearing and detaching this stacking;

is characterized in that on one side of the tray and of the lid, the incipient fracture notches are interrupted so as to define in the stack a non-detachable zone intended, after tearing of the detachable strip, to form a hinge articulation of the cover on the tray.

In other words, the invention consists, in a packaging box of the type in question in which the tray and the lid are secured by a welded side band, connected to the assembly by incipient fracture notches, having a transverse rupture line to allow easy tearing of the superimposed lateral sealing strips welded together, to be provided on an appreciable portion on one side, a non-detachable zone intended after detaching the welded lateral strips, to form a hinge for the articulation of the cover on the tray. Thus, the improved packaging box according to the invention is waterproof and once the sealing strip is detached, is easy to use thanks to the articulation of the cover on the tray.

• la charnière caractéristique de l'invention est disposée sur un grand côté du couvercle (et de la barquette), et le côté opposé du couvercle comporte une languette de préhension destinée à saisir le couvercle pour le soulever, aussi bien pour amorcer la rupture que l'ouverture ;
• le couvercle et la barquette sont réalisés par moulage dans la même matière plastique, ce qui permet utilement de souder la périphérie des bandes latérales par tous moyens connus, tels que induction, haute fréquence, ultra-sons, etc .. ;
• les entailles d'amorce de rupture, formant affaiblissement, sont venus de moulage ;
• la zone non-détachable formant charnière est disposée sur partie essentielle du couvercle (et de la barquette) et est délimitée de chaque côté par une amorce de rupture transversale destinée à arrêter le détachement des bandes latérales soudées entre elles ;
• la bande latérale supérieure reliée à la branche externe du couvercle présente, dans la zone d'articulation, des portions espacées de moindre épaisseur destinées à former charnière proprement dite du couvercle sur la barquette ;
• la ligne de rupture transversale est ménagée dans un coin de la barquette et du couvercle.

Advantageously, in practice:

• the characteristic hinge of the invention is arranged on a long side of the lid (and of the tray), and the opposite side of the lid has a gripping tab intended to grip the lid to lift it, both to initiate the rupture and to 'opening ;
• the cover and the tray are made by molding in the same plastic material, which makes it possible to weld the periphery of the side strips by any known means, such as induction, high frequency, ultrasound, etc .;
• the fracture initiation notches, forming weakening, came from molding;
• the non-detachable zone forming a hinge is disposed on an essential part of the cover (and of the tray) and is delimited on each side by a transverse breaking primer intended to stop the detachment of the lateral strips welded together;
• the upper lateral strip connected to the outer branch of the cover has, in the articulation zone, spaced apart portions of lesser thickness intended to form the hinge proper of the cover on the tray;
• the transverse rupture line is formed in a corner of the tray and of the cover.

The manner in which the invention can be implemented and the advantages which result therefrom will emerge more clearly from the embodiment which follows, with the support of the appended figures.

In practice, the packaging box according to the invention is of the type described by the Applicants in document US-A-5 145 088, corresponding to document EP-B-0447 329.

Figure 1 is a summary perspective view of a packaging box according to the invention shown in Figure 2 in the open position.

Figure 3 is a top view of the characteristic cover of the invention.

FIGS. 4 and 5 are sectional views of the cover and the tray along the axes IV-IV 'and V-V' of FIG. 3.

Figure 6 is a sectional view of the lid-tray stack of a preferred version of the invention.

The packaging box according to the invention designated by the general reference (1), consists of a rigid container (2) and a cover (3), both made of injected plastic, for example of food-grade polypropylene. In a variant not shown, the cover (3) has on the edge of the ribs, molded, intended to facilitate stacking and maintaining the boxes (1) filled.

The tray (2) has an opening (5) delimited by a peripheral rim (6) in the shape of an inverted U, formed (see FIGS. 4 and 5) of two branches, respectively internal (7) connected to the tray (2) properly said, and external (8). The end of the downwardly inclined outer branch (8) is surrounded by a first flexible annular lateral strip (9) which is molded, the connection zone (10) of the branch (8) having a notch breaking point (11), for example of lesser thickness. The connection portion (12) of the two branches (7,8) of the horizontal flange (6) has a support overmolding (13).

The cover (3) comprises (see FIGS. 3, 4 and 5) a peripheral rim (20), also in the form of an inverted U, complementary to the U of the tray, intended to be fitted onto the rim (6) of this tray ( 2). This rim (20) is also formed of two branches respectively one internal (21) connected to the plate (22) of the cover (3), the other external (23) inclined outwards and the bottom corresponding to the branch (8) from the tray. These two branches (21, 22) are connected by a horizontal portion (24) parallel to the portion (12) of the tray, and the internal face of which bears on the overmolding (13). The end (26) of the external branch (23) is also surrounded by a second peripheral annular flexible band (25) peripheral coming from molding. The connection zone forming the end (26) of the lid proper coincides substantially by superposition with the zone (10) of the tray and both have continuous notches of initiation of rupture (27) cooperating in essential part with the notch (11) in the side strip (8) of the tray.

The two horizontal annular bands (9.25) are superimposed and welded together over their entire outer peripheral edge up to the notches (10.26) which are superimposed. These bands (9.25) define a stack designated by the general reference (30), which surrounds the entire box to thereby ensure the tightness of the assembly. Welding is carried out by any known means, in particular those mentioned above. This weld line (31) extends to the plumb of the notches (11,27) at the start of the rupture (11,26) up to point (29) to ensure the tightness of the assembly. .

In a first embodiment shown in FIG. 4, the point (29) of the end of the weld corresponds to the connection end of the two peripheral strips (9.25) on the branches (8.23).

In a second preferred embodiment, shown diagrammatically in FIG. 6, the welded peripheral zone (32) represents only part of the width of the horizontal strips (9,25) superimposed.

The stack (30) of the two lateral flexible bands (9,25) welded (31) together, has a first rupture line (40) disposed in a corner of the cover, for example the lower left corner as seen on FIG. 3. This rupture line (40) extends transversely from the outer edge (32) of the stack to the vicinity of the zones (10, 26) of the fracture initiation notches (11, 27). In practice, the two opposite faces of this breaking line (40) are rounded, as seen in FIG. 3, to facilitate gripping and thereby the tearing operation.

In another embodiment, the breaking line (40) can be arranged in the middle of a large side at the height of the gripping tab (55).

According to a characteristic of the invention, on one side of the cover of the container, and on an essential part on this side, designated by the reference (45), the stack (30) no longer has a breaking notch (see figures 1 and 5). Thus, this zone (45) of the stack (30) forms a portion in which the cover and the tray are welded together by the annular bands (9,25). Therefore, this portion (45) is non-detachable. This zone (45) disposed on an essential part on one side of the cover, is delimited on each side (46,47) by a transverse breaking line similar to (40).

In other words, the horizontal annular peripheral sealing strip (30) essentially comprises (see FIG. 2) three distinct portions, namely a first portion designated by the reference (50) which extends from the first rupture line transverse (40) to the transverse rupture line (46), then a second similar portion (51) extending from (40) to (47), these two portions (50,51) being detachable after tearing as seen in Figures 1 and 2. These two strips (50,51) before tearing, are firmly connected to each other by the area (45) free of break notch. In this way, this zone (45) forms a hinge hinge of the cover (3) on the tray (2).

In a practical embodiment shown in FIG. 5, the articulation zone (45) has spaced apart portions of lesser thickness (59) forming a proper hinge. Advantageously, the side of the cover opposite the hinge (45) comprises a gripping tab (55) (see FIGS. 1, 2 and 3), housed in a space (58) provided for this purpose on the flange (6) of the tray. This tongue (55) is intended to facilitate the opening and pivoting of the cover (3) on the hinge (40).

In a preferred variant, the hinge portion (45) has stops (57, 58) which are molded, intended to facilitate holding the cover (3) in the open position (see FIGS. 2 and 3).

In the embodiment shown in FIG. 6, the two characteristic notches of rupture initiation (33 and 34) similar to (27) and (11), are arranged opposite and in the middle of the annular bands (9, 25). The sealing weld (32) is carried out only on the outer peripheral border to the left of the notches (33, 34), for example by means of ultrasound. Thus, after rupture at (35), the socket produced still has a horizontal stacking portion (36) which completes the seal.

In a variant not shown, the characteristic incipient fractures (11,27) follow the shape of a right triangle and are slightly offset by one strip (9) relative to the other (25) to favor the tearing action.

The strips (9.25) can be arranged horizontally, as shown in the figures, or be inclined downwards, even inclined downwards and then connected to a horizontal portion.

The box according to the invention has many advantages compared to those described in the preamble. The fact that it has a hinge portion (45) allows it to be used with convenience. The first transverse breaking line (40) ensures a convenient opening, while allowing, before opening, to ensure a good seal of the assembly, so that it is no longer necessary to use a seal. .

In this way, this type of box can be used advantageously for the packaging of very diverse products, in particular food products.

Claims (7)

1. A plastic packaging box (1) which comprises a rigid tub (2) and a cover (3) wherein :

   - the tub (2) comprises an aperture (5) bounded by a peripheral rim (6) assuming the shape of an upended U and consists of two arms respectively an inner arm (7) linked to the body of the tub proper, and an external arm (8), the external arm (8) being extended by a first injection-molded lateral, annular strip (9), of which the junction zone (10) to the external arm (8) comprises a rupture-initiating notch (11) ;

   - the cover (3) comprises a peripheral rim (20) also assuming the shape of an upended U complementary with the U of the tub, and designed to nest with this tub (2) peripheral rim (6), of which the outer arm (23) also is extended by a second injection-molded annular strip (25), of which the junction zone (26) to the outer arm (23) comprises a second rupture-initiating notch (27);

   and wherein :

   - the two annular strips (8, 25) are superposed in such manner that the notches (8, 27) of each annular strip (9, 25) will de superposed and then the strips are welded together along their entire outer peripheral rim defining a stacked structure (30) to ensure the box is sealed ;

   - the staked structure (30) of the two welded (31, 32), annular strips (9, 25) comprises a first rupture line (40) running transversaly from the outer stacking rim (32) to the vicinity of the zone (10, 26) comprising the rupture-initiating notches (11, 27) to make it possible to tear (50, 51) and separate this staked structure (30);

   is characterized in that on one side of the tub and cover, the rupture-initiating notches (11, 27) are separated by a segment having an absence of notches to define thereby a permanently attached zone (45) within the stacked structure (30) so that, following tearing the detachable strip (40), a hinge shall be formed for the cover (3) to pivot about the tub (2).
2. Packaging box of claim 1 characterized in that the zone (40) forming a hinge extends along a large side of the cover (3) and the tub (2), and in the fact that the side opposite the cover comprises a gripping tab (55) which allows the cover (3) may be gripped to lift.
3. Packaging box of claims 1 and 2 characterized in that the cover (3) and the tub (2) are made in the same plastic.
4. Packaging box of claim 3 characterized in that the rupture-initiating notches (11, 27) are formed by injection-molded.
5. Packaging box of claims 1 to 4 characterized in that the permanently attached zone (45) acting as a hinge is present over a large part of the cover and tub and is bounded on each side by a transverse rupture-initiating line (46, 47) for the purpose of separating the mutually welded lateral, peripheral strips (50, 51).
6. Packaging box of claims 1 to 5 characterized in that the lateral strip (25) of the cover comprises in the vicinity of the inner end (29) of the welded zone (31) thinner and spaced segments (59) which will act as the hinges proper.
7. Packaging box of claims 1 to 6 characterized in that the cover and tub side opposite the side of the permanently attached zone (45) respectively comprise :

   - on the tub rim (6), a housing (56)

   - on the cover (3), a gripper tab (55) housed in a housing (56).

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