EP0406109B1 - Thermoplastic package which is opened by means of partially peeling a multilayer lid sealed at the edge of the package as well as a film of multilayer lids - Google Patents

Description

The present invention relates to a multilayer thermoplastic container with partial peeling opening of a multilayer heat-sealed cover on the rim of said container and comprising, from bottom to top, a simple or complex tear-resistant internal sheet permanently heat-sealed on the rim of said container, a sheet simple or complex intermediate provided with an access opening or a curved line of incision or opening weakening and firmly adhering to said internal sheet at least outside the zone delimited by said access opening or curved incision line at least partially closed, as well as an external sheet, simple or complex, adhering, on the one hand, in a peelable manner, to the intermediate sheet outside said zone delimited by the access opening or the curved line of incision formed in this intermediate sheet, and, on the other hand, in a firm and non-peelable manner, either directly to a part of the internal sheet passing through said access opening, ie to the intermediate sheet inside the zone delimited by said incision line, said container further comprising a peel primer to facilitate gripping of the external sheet on the edge of said thermoformed container from a multi-layer thermoplastic strip.

In the case of known containers of this type, the internal sheet of the multilayer cover is hermetically sealed on the layer of thermoplastic material of the same nature on the rim of the container with a complex wall, so that it is difficult, if not difficult, or even impossible, to grasp the edge of said cover in order to peel the outer sheet to uncover the access opening of the container.

To facilitate gripping of the outer sheet, and the start of peeling thereof, it has already been proposed (FR-A-2 503 036) practice in a corner of the rim of the container provided with its lid, from the underside of said rim, a weakening notch making it possible to break by folding said corner up to the outer sheet and to peel it from the intermediate sheet of said cover. This procedure does not make it easy to predict the peel initiation anywhere on the rim of the container and, moreover, the cutting or partial incision operation for making the notch cannot be made separately from the container cutout and independently of it.

Another known proposal for making a peel primer (FR-A-2 551 031) consists in forming on an edge of the cover between the intermediate sheet and the outer sheet thereof, a zone of non-adhesion by a special treatment. of non-adhesion of one or the other of these two sheets. This non-stick treatment is expensive and the desired effects of it are often destroyed when the lid is heat sealed on the rim of the container.

The edge of the cover is crimped by the effect of the cutting punches, in particular with the cutting profile necessary for multilayers.

An object of the present invention is to eliminate, or at least mitigate these drawbacks and to provide a container of the type initially mentioned whose outer cover sheet can be gripped and peeled easily.

This object is achieved in accordance with the invention, because the peeling primer comprises at least one shallow notch formed either in the multilayer cover or in the rim of the container from the heat sealing plane of the cover on said rim , so as to define between the latter and the inner sheet of the cover a narrow gripping cavity open on the superimposed edges of the cover and the rim and delimited by the inner sheet of the cover and an inner layer of the container made of an adherent thermoplastic material firmly by heat sealing to the inner sheet of the cover and that opposite the junction zone between the inner sheet of the cover and the inner layer of the container, the intermediate sheet of the cover has a tearing edge facilitating the tearing of the inner sheet of the cover in the primer area peeling, and peeling the outer sheet of said cover to release the access opening.

Thanks to this design, the outer sheet of the cover can be grasped without difficulty and be peeled after the inner sheet of said cover has been torn in the peeling primer area.

The invention also relates to a complex strip containing a plurality of multi-layer contiguous covers and comprising from bottom to top: a single or complex layer of tearable thermoplastic capable of being heat-sealed permanently on the rim of a thermoplastic multi-layer container , at the location of the inner layer thereof; a simple or complex intermediate layer provided, above the mouth of the container, with an access opening cut out in said intermediate layer or delimited by a curved incision line at least partially closed and firmly adhering to said internal layer of said complex strip, at least outside the zone delimited by said access opening or said incision line, as well as a single or complex external layer adhering, on the one hand, peelably to the intermediate layer in outside the zone delimited by the access opening or the curved line of incision formed in this intermediate layer, and, on the other hand, in a firm and non-peelable manner, either directly to a part of the internal layer passing through said access opening, either to the intermediate layer inside the zone delimited by said curved line of incision, said complex strip comprising, in addition, in the marginal zone of each cover, a e primer peeling made accessible after cutting the cover and the rim of the container on which said cover is heat sealed.

The drawbacks of this type of complex strip with lids have been mentioned previously in relation to the containers known from documents FR-A-2 503 036 and 2 551 031.

Another object of the invention is to provide a complex strip with lids making it possible to produce on the thermoplastic receptacles provided with lids fixed on the rim thereof by heat sealing or autogenous thermosealing, a peel primer which is easy to grip and does not could be destroyed during said heat sealing.

This object is achieved in accordance with the invention because, in the region of the peeling primer, the intermediate layer of the cover strip is notched over its entire thickness, at least at the edge of said primer zone, and that the notch is covered with the inner layer.

In this case, the internal layer of the cover strip not only adheres to the underside of the intermediate layer up to the edge of the cover which will subsequently be cut from the complex strip, but also covers the notch of the intermediate layer, and the gripping cavity is then formed between the cover with a flat lower face and the depression or notch zone formed by thermoforming in the rim of the container at the location of the primer zone.

The above-mentioned object can also be achieved in accordance with the invention, when in the region of the peeling primer, the intermediate layer of the cover strip has a recess extending over the entire thickness of this intermediate layer and the inner layer adheres directly to the outer layer, the side wall of this recess comprising a tear edge for said inner layer.

In this case, the rim of the container may have a completely flat upper surface or include, at the location of the peel initiation zone, a depression or notch zone which deviates from the heat-sealing plane between the lid. and the container rim and which is formed by thermoforming in the latter at the location of said initiation zone.

• la figure 1 est une vue en perspective d'un premier mode de réalisation d'un récipient conforme à l'invention, mode dans lequel la zone d'amorce de pelage est prévue dans un coin du rebord du récipient ;
• la figure 2 est une vue en perspective d'une partie d'un récipient dont la zone d'amorce est prévue au milieu d'un côté du rebord de récipient ;
• la figure 3 est une vue partielle en élévation d'une coupe axiale verticale à travers un récipient de forme parallélépipédique et d'une partie de la bande complexe à couvercles thermoscellés sur le rebord dudit récipient, et montrant un deuxième mode de réalisation de la zone d'amorce ;
• la figure 4 est une vue similaire à la figure 3 mais avec la feuille externe partiellement pelée et la feuille interne déchirée aux endroits de la zone d'amorce et de l'ouverture d'accès ;
• la figure 5 est une vue partielle en élévation d'une coupe axiale verticale à travers un récipient et d'un couvercle complexe thermoscellé sur le rebord dudit récipient, et montrant un troisième mode de réalisation de la zone d'amorce ;
• la figure 6 est une vue similaire à la figure 5 mais avec la feuille externe du couvercle partiellement pelée ;
• la figure 7 est une vue partielle en élévation d'une coupe verticale axiale à travers un récipient et d'une partie du couvercle, montrant le premier mode de réalisation de la zone d'amorce, et
• la figure 8 est une vue similaire à la figure 7 mais avec la feuille externe du couvercle partiellement pelée.

The object of the present invention will be understood more clearly with the aid of the following description of several embodiments, description made with reference to the appended drawings in which:

• Figure 1 is a perspective view of a first embodiment of a container according to the invention, mode in which the peel initiation zone is provided in a corner of the rim of the container;
• Figure 2 is a perspective view of a portion of a container whose initiation zone is provided in the middle of one side of the container rim;
• FIG. 3 is a partial view in elevation of a vertical axial section through a container of parallelepiped shape and of a part of the complex strip with heat-sealed lids on the rim of said container, and showing a second embodiment of the zone primer;
• Figure 4 is a view similar to Figure 3 but with the outer sheet partially peeled and the inner sheet torn at the locations of the primer area and the access opening;
• Figure 5 is a partial elevational view of a vertical axial section through a container and a complex heat-sealed cover on the rim of said container, and showing a third embodiment of the primer area;
• Figure 6 is a view similar to Figure 5 but with the outer sheet of the cover partially peeled;
• FIG. 7 is a partial view in elevation of an axial vertical section through a container and part of the lid, showing the first embodiment of the initiation zone, and
• Figure 8 is a view similar to Figure 7 but with the outer sheet of the cover partially peeled.

As can be seen in the drawing, the thermoplastic container 1 obtained in a known manner by thermoforming from of a complex thermoplastic strip, not shown, comprises a vertical wall 2 and a horizontal rim 3, the wall 2 and the rim 3 consisting of an internal layer 4 and an external layer 5 firmly adhering to each other , the inner layer 4 being for example made of polyethylene and the outer layer 5 of polyester. Of course, the materials of the container 1 can be changed without it being important for the object of the invention provided that the rules of the art are observed.

A complex cover 6 with multiple layers or sheets is heat-sealed on the rim 3 of the container 1 with the exception of a peel initiation zone generally designated by the reference 7. The complex cover 6 is obtained by cutting (see arrow D of FIG. 3) from a complex strip called lids 8, part of which is shown in FIG. 3. The cover 6 or the strip with lids 8 comprising several superimposed sheets or layers which are from bottom to top: an internal heat-sealable thermoplastic sheet or layer 9 of identical or similar nature to that of the internal layer 4 of the container 1, for example made of polyethylene; a sheet or intermediate layer 10, for example of polyester, firmly adhering to said sheet or internal layer 9; and an outer sheet or layer 11 made for example of an aluminum film 11a coated on its underside with a thin film of PVC 11b or other suitable material. The different sheets or layers 4, 5, 9, 10, 11 can be simple or complex layers, that is to say made up of several thin films adhering more or less strongly to neighboring films or layers.

According to the embodiment shown in Figures 1, 7 and 8, the cover 6 and the cover strip 8 comprising a plurality of these covers juxtaposed and joined to each other, have, above the upper mouth 12 of the container 1, preferably near the vertical wall 2 of the latter a curved line of incision 13 at least partially closed on itself and preferably entirely closed or contiguous, line of incision 13 preferably made from bottom to top in the sheet or intermediate layer 10. This curved line of incision 13 preferably extends over the entire thickness of the intermediate sheet 10 and has for example a triangular cross section whose base is covered by the inner sheet 9 like the rest of the underside of said sheet 10. It should be noted that the outer wall of the incision line 13 delimits the access opening 14 inside the container 1, access opening which will subsequently be completely cleared during the peeling of the external sheet 11 of the cover 6, it being understood that the internal sheet 9 tears under the action peeling along one of the tearing edges which constitute the lower and upper edges of the access opening 14. The heat-sealing or heat-sealing plane between the cover 6 and the reb ord 3 of the container is horizontal and is delimited on both sides by the inner layer 4 of the container 1 and the inner sheet 9 of said cover 6. For these layer 4 and sheet 9, preferably, the same thermoplastic material is used allowing to perform an autogenous heat sealing or at least a sealing having the strongest adhesions existing between two neighboring layers or sheets.

At the location of the peel primer 7 which will be provided at the most suitable location and preferably in the immediate vicinity of the access opening 14 and a sufficient distance from the vertical wall 2 of the container to allow sealing correct and tight cover 6 on the rim 3, the latter has a shallow notch or depression 15 relative to the heat sealing plane between the rim 3 and the cover 6, this notch 15 being formed, preferably by thermoforming, in the rim 3 of the container 1 preferably during the forming of the latter (see Figures 1, 2 and 5 to 8).

With this measure, the cover 6 is not sealed on the rim 3 at the location of the notch 15, but is sealed all around the latter, so as to define with said notch 15 a narrow grip cavity 16 open laterally on the superimposed edges of the rim 3 and of the cover 6. In the immediate vicinity of the bottom and sides of this cavity 16, namely at face of the junction area between the inner sheet 9 of the cover 6 and the inner layer 4 of the rim 3, junction area bordering the horizontal periphery of said cavity 16, the intermediate sheet 10 of the cover 6 has a breaking incision 17 which follows the periphery of the cavity 16 and which preferably is of triangular section, the base of which is covered with the internal sheet 9 and at least partially overlaps the bottom of the cavity 16. The wall (external with respect to the periphery of the cavity 16) constitutes by one of these edges a tearing edge on which the inner sheet 9 of the cover 6 is torn (see FIGS. 5 to 8).

Of course, the access opening 14 which in itself is not the subject of the invention can be produced differently, and in particular in the manner indicated in FIGS. 3 to 6. In this case, the access opening 14 is produced by cutting and eliminating a small plate in the intermediate sheet 10. This access opening 14 is covered on one side by the external sheet 11 which remains substantially flat opposite that here, and on the other side, by the internal sheet 9 which penetrates into the opening 14 and adheres firmly over a large part of the cross section of this opening 14, on the underside of the external sheet 11.

The embodiment of the peel primer 7 as shown in FIGS. 3 and 4 preferably applies to a completely flat rim 3, but can also be used in combination with a rim 3 provided with a notch 15 ( see Figures 5 to 8). According to FIGS. 3 and 4, the cover 6 and the cover strip 8 comprise, at the place where the peel leader 7 is to be located later, a cylindrical or frustoconical recess or the like 18 which is of small diameter and which extends over the entire thickness of the intermediate layer 10 and which will be located astride two contiguous edges of two neighboring containers 1 until the two containers 1 and the corresponding lids are cut out (see arrow D in FIG. 3) . This recess 18 is covered, on the one hand, by the sheet or planar external layer 11 of the neighboring covers 6 or of the strip with covers 8 and, on the other hand, by the sheet or internal layer 9 which at the place of the recess 18 passes through it over a large part of the cross section of said recess 18 and adheres firmly to the underside of the sheet or outer layer 11. After cutting the edges of the two neighboring containers 1 at least at the location of the peel primer 7, as in the previous examples, a gripping cavity 16 is obtained which is open on the superimposed edges of the cover 6 and the rim 3 and delimited by, on the one hand, a part of the internal sheet 9 of the cover 6 and, on the other hand, part of the internal layer 4 of the rim 3, the bottom of this cavity 16 being constituted by the junction by heat sealing of the sheet 9 and the layer 4 and having a rim in the form of U open to the edges of the container 1 e t of the cover 6. It should be noted that one of the edges of the vertical wall delimiting the recess 18 of the intermediate sheet 10 constitutes a tear edge for the internal sheet 9 at the bottom of the gripping cavity 16.

The object of the present invention may undergo a number of modifications without departing from the protective framework defined by the appended claims.

Claims (4)

1. Multi-layered thermoplastic container (1) opened by partially peeling back a multi-layered top (6) heat-sealed to the edge (3) of said container (1) and comprising, from bottom to top, a tear-off, simple or complex, internal sheet (9) permanently heat-sealed on the edge (3) of said container (1), a simple or complex intermediate sheet (10) provided with an opening (14) for access or a curved line (13) for incision or weakening for opening and firmly adhering to said internal sheet (9) at least outside the zone defined by said acccess opening (14) or at least partially closed curved incision line (13), as well as a simple or complex outer sheet (11) adhering, on the one hand, in peelable manner, to the intermediate sheet 10 outside said zone defined by the access opening 14 or the curved incision line (13) made in this intermediate sheet (10) and, on the other hand, in firm and non-peelable manner, either directly to a part of the internal sheet (9) traversing said access opening (14), or to the intermediate sheet (10) inside the zone defined by said incision line (13), said container (1) further comprising a peeling tab (7) in order to facilitate grip of the outer sheet (11) on the edge (3) of said recipient (1) thermoformed from a multi-layered thermoplastic band,
   characterized in that
   the peeling tab(7) comprises at least one shallow scalloping 15 made in the edge (3) of the container (1) from the plane of heat-seal of the top (6) on said edge (3), so as to define between the latter and the internal sheet (9) of the top (6) a narrow grip cavity (16) open on the superposed edges of the top (6) and of the edge (3) and defined by the internal sheet (9) of the top (6) and an internal layer (4) of the container (1) constituted by a thermoplastic material firmly adhering by heat-seal to the internal sheet (9) of the top (6) and,
   facing the area where the internal sheet (9) of the top (6) and the internal layer (4) of the container (1) meet, the intermediate sheet (10) of the top (6) presents a tearing edge facilitating tear of the internal sheet (9) of the top (6) in the zone of the peeling tab (7), and peeling of the outer sheet (11) of said top (6) in order to reveal the opening (14) for access.
2. Multi-layered thermoplastic container (1) opened by partially peeling back a multi-layered top (6) heat-sealed to the edge (3) of said container (1) and comprising, from bottom to top, a tear-off, simple or complex, internal sheet (9) permanently heat-sealed on the edge (3) of said container (1), a simple or complex intermediate sheet (10) provided with an opening (14) for access or a curved line (13) for incision or weakening for opening and firmly adhering to said internal sheet (9) at least outside the zone defined by said access opening (14) or at least partially closed curved incision line (13), as well as a simple or complex outer sheet (11) adhering, on the one hand, in peelable manner, to the intermediate sheet (10) outside said zone defined by the access opening (14) or the curved incision line (13) made in this intermediate sheet (10) and, on the other hand, in form and non-peelable manner, either directly to a part of the internal sheet (9) traversing said access opening (14), or to the intermediate sheet (10) inside the zone defined by said incision line (13), said container (1) further comprising a peeling tab (7) in order to facilitate grip of the outer sheet (11) on the edge (3) of said recipient (1) thermoformed from a multi-layered thermoplastic band,
   characterized in that
   the peeling tab (7) comprises a grip cavity (16) defined by the flat edge (3) of the container and by the internal sheet (9) of the top penetrating at the location of the tab (7) in a recess (18) made in the intermediate sheet of the top (6) over the whole thickness of the latter,
   the internal sheet (9) penetrates in this recess (18) and adheres firmly to the outer sheet (11), and facing the area where the internal sheet (9) of the top (6) and the internal layer (4) of the container (1) meet, the intermediate sheet (10) of the top (6) presents a tearing edge facilitating tear of the internal sheet (9) of the top (6) in the zone of the peeling tab (7), and peeling of the outer sheet (11) of said top (6) in order to reveal the opening (14) for access.
3. Complex band (8) containing a plurality of contiguous multi-layered tops (6) and comprising, from bottom to top: a tear-off, simple or complex thermoplastic layer (9) capable of being permanently heat-sealed on the edge (3) of a thermoplastic multi-layered container (1), at the location of the internal layer (4) of the latter; a simple or complex intermediate layer (10) provided, above the opening (12) of the container, with an opening (14) for access cut out in said intermediate layer (10) or defined by a curved line (13) of incision at least partially closed and firmly adhering to said internal layer (9) of said complex band (8), at least outside the zone defined by said access opening (14) or said incision line (13), as well as a simple or complex outer layer (11) adhering, on the one hand, in peelable manner, to the intermediate layer (10) outside the zone defined by the access opening (14) or the curved incision line (13) made in this intermediate layer, and, on the other hand, firmly and in non-peelable manner, either directly to a part of the internal layer (9) traversing said access opening (14), or to the intermediate layer (10) inside the zone defined by said curved incision line (13), said complex band (8) further comprising, in the marginal zone of each top (6), a peeling tab (7) rendered accessible after cutout of the top (6) and the edge (3) of the container (1) on which said top (6) is heat-sealed,
   characterized in that, in the zone of the peeling tab (7), the intermediate layer (10) of the band (8) is notched (notch 17) over the whole of its thickness at least on the border of said tab zone 7, and in that the the base of the notch (17) is covered with the internal layer (9).
4. Complex band (8) containing a plurality of contiguous multi-layered tops (6) comprising, from bottom to top: a tear-off, simple or complex thermoplastic layer (9) capable of being permanently heat-sealed on the edge (3) of a thermoplastic multi-layered container (1), at the location of the internal layer (4) of the latter; a simple or complex intermediate layer (10) provided, above the opening (12) of the container, with an opening (14) for access cut out in said intermediate layer (10) or defined by a curved line (13) of incision at least partially closed and firmly adhering to said internal layer (9) of said complex band 8, at least outside the zone defined by said access opening (14) or said incision line (13), as well as a simple or complex outer layer (11) adhering, on the one hand, in peelable manner, to the intermediate layer (10) outside the zone defined by the access opening (14) or the curved incision line (13) made in this intermediate layer, and, on the other hand, firmly and in non-peelable manner, either directly to a part of the internal layer (9) traversing said access opening (14), or to the intermediate layer (10) inside the zone defined by said curved incision line (13), said complex band (8) further comprising, in the marginal zone of each top (6), a peeling tab (7) rendered accessible after cutout of the top (6) and the edge (3) of the container (1) on which said top (6) is heat-sealed,
   characterized in that, in the zone of the peeling tab (7), the intermediate layer (10) of the top band (8) comprises a recess (18) extending over the whole thickness of this intermediate layer (10) and the internal layer (9) adheres directly on the outer layer (11), the lateral wall of this recess (18) comprising a tearing edge for said internal layer (9).

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