FR2718711A1 - Closing device for a container with easy opening. - Google Patents

Abstract

The container has a metal lid with a central portion (5) and an outer edge designed to form a seal (18) with the upper rim of the container. A plastics cover (7) fits over the top of the container, and is made with an outer skirt (11) and an inner toothed ring (16) to separate the central portion of the metal lid along a scored line (25). The skirt of the plastics cover can act as a guarantee strip for the container, with a flange (14) around its inner surface preventing the cover from being depressed until the skirt has been removed. In addition, the toothed ring can have a groove (21) to hold the edge of the lid's central portion once it has been separated.

Description

DEVICE FOR CLOSING AN EASILY OPENING CONTAINER

FIELD OF THE INVENTION

  The invention relates to the field of packaging, and more particularly that of easy-opening containers, typically containers for the packaging of food products (canned goods) .10 "Easy opening" means the implementation of means of closure such that the end consumer can open the

  container by hand, without using additional means, such as a can opener.

STATE OF THE ART

  Containers have been known for several decades.

  easy opening. There are all kinds of them, based on various principles, but the most commonly used means is the use of an easy open metal lid (COF abbreviated).

  Such a cover must, in general, meet contradictory requirements in that it must, firstly have a mechanical strength high enough to browse25 without significant deformation under penalty of damaging the aesthetics of the container, and without loss of tightness on pain of bacterial contamination, the entire economic circuit of the product, from the packaging manufacturer to the final consumer, via a packaging step, including30 most often a relatively demanding sterilization phase with respect to concerns the mechanical strength of containers and lids, and secondly offer a great ease of opening to the final consumer. To achieve this purpose, COF, made from a protective layer-coated metal strip, comprises a center pad and an edge for forming a sealing edge with the edge of the container, and further encircling

  said central area, an incision line of the metal constituting the cover, and a ring integral with the central area located at the right of the incision, so as to be able, by tilting the ring and pulling, to make the opening manual container.

  Usually, the ring is assembled at the central beach by a metal rivet obtained by the local deformation of the central range of the lid. See Figure 1.10

PROBLEMS POSED

  The COF known to those skilled in the art poses certain problems to each of the actors involved in the economic circuit of the COF and the container it closes: - problems posed to the manufacturer of COF, because the manufacture of a rivet requires a large number of passes, and consequently, a succession of tools of high precision and thus expensive. The production rates of lids would be significantly higher if the production did not include a rivet manufacturing step. More importantly, the manufacture of a rivet limits the supply of metal to relatively ductile alloys capable of being very deformed without appearance of defects (breaks, cracks, ...). The absence of rivet would allow to widen the choice of alloys and thus to choose

  less expensive alloys, and possibly reduce the thickness of the lid.

  - problems with the food conditioner which must guarantee a certain shelf life of the packaged food product, because, in terms of corrosion, the area of the rivet is the part of the lid - and the entire container - which is the most sensitive and the most likely

  to corrode in contact with food products, depending on the acidity and salinity of the latter.

  In the absence of a rivet, the conditioner would increase its margin of safety a lot and it could also condition5 "more aggressive" products, ie more acidic or more salt-laden, and / or considerably increase the service life. packaged products. problems posed to the distributor of food products packed in these containers with COF, because the handling, typically in pallets, and the stacking of these pallets over a great height can cause an accidental opening of

  COF which, after storage periods that may exceed several months, can pollute and corrode a whole pallet.

  - problems posed to the final consumer, especially if he is not familiar with containers with COF, or if they are children, because the opening of such containers may present some difficulties and some risks. Indeed, it is important to realize the opening in two stages: it is first necessary to tilt the ring forward to perforate the incision located at the end of the end (beak) of the ring, then only pull back to detach the center panel. If, instead of this succession of movements, the consumer pulls on the ring, he may tear it off without opening the container. The risks associated with the opening of containers with COF are twofold: * risks of injury by the cutting edge resulting from tearing of the incision line, mainly the edge of the detached central panel,

  * risk of splashing and staining due to a spring effect of the central panel.

  Finally, it is important to note that containers of large capacity, generally more economical if we consider only the price per kilo, are not very adapted to the needs of the individual consumer, who wishes to consume in several

  The food contained in a large capacity container, therefore, feels the need to be able to close the container in an unsealed (gas) manner, but sufficient for a limited period of storage in a refrigerator.

DESCRIPTION OF THE INVENTION

  The invention consists of a closure device providing a solution to all the problems mentioned above. According to the invention, the closure device of an easy-opening container comprises, a) a metal cover comprising a central area and an edge for cooperating with the edge of said container to form a sealing edge, b) a blister plastic material comprising a central panel and a side skirt, integral with said panel, surrounding said sealing edge, characterized in that, so as to guarantee the inviolability of the container, protect the lid from possible shocks and make it easy to open. said cover, 1) said metal cover has a thickness of metal, at least locally along a closed peripheral line situated at the edge of said central area, between 40 and 120 μm, 2) said blister skirt comprises: - a connected upper part said panel, - a lower part, connected to said upper part by a weakening line, comprising an inner shoulder r intended to bear on said sealing edge, part forming a secured strip of guarantee35 of the skirt of said container under said sealing edge, 3) said central panel of the blister comprises: - means for easy opening of said beach central cover arranged opposite and to the right of said peripheral line, means activatable by simple vertical pressure after removal of said guarantee strip, - means for retaining said central area, so as to secure said central area and said central panel. Thus, following its work, the Applicant has designed the closure device according to the invention, a device that provides all the functions to be performed to achieve all the objectives of the invention, functions sometimes performed by the metal cover, sometimes by the blister , but most often by the latter: - the metal cover provides the sealing function and mechanical strength of the container, for example the holding at the

  internal pressure during a sterilization phase.

  - The blister ensures the opening function previously assigned to the ring, significantly simplified opening compared to that of a traditional COF. But the blister also provides the following functions that did not exist with a conventional COF: it provides the retention function of the central range of the lid by joining the central panel of the blister, and ipso facto a consumer protection function since it subtracts it from any direct contact with the potentially injurious edges of the central panel. Moreover, this fastening prevents any spring effect of said central area. - It provides the protective function of the metal cover and more specifically of its closed peripheral line o the metal may be thin (40-120 pm). The blister, thanks to its inner shoulder that rests on the sealing edge, is designed to absorb the "normal" shocks encountered in the handling of containers. - it ensures the function of inviolability thanks to its band of

  guarantee, which contributes to increased consumer protection.

  - it ensures for the consumer, and in the case of a large capacity container (> 500 ml) the contents of which are

  consumed in several times, the sealing function of the container.

  Certainly, blisters were known in themselves in the art

  formerly for certain types of packaging, but with functions, generally limited to an overwrapping function, also involving no means of cooperation between the blister itself and another means of closure, as is the case in the present invention.

DESCRIPTION OF THE FIGURES

  Figures la to if describe a COF (28) of the prior art

  and its manufacture. FIG. 1a shows schematically a metal strip (26) for producing a cover blank (27) shown in section in FIG. 1b, and a ring (24) shown in FIG. 1c in plan view.

  On the blank (27) of Figure lb have been shown its main elements: the central region (5) carrying the rivet blank (23a), the crimping edge (6) and, in between, an incision ( 25) Figure ld is similar to Figure lb, after riveting of

  the ring (24). Figure if is a top view of the COF (28) shown in section in Figure ld. This view from above makes it possible to visualize the incision line (19) separating the removable central area (5) during opening and the crimping edge (6).

  Figure 1c shows an enlarged sectional view of the assembly of the ring (24) and the central area (5) by the rivet (23), the end of the ring (24) being at the right of the incision (25).

  Figures 2 and 3 show perspective views of two blisters manufactured according to the invention (see examples), sectioned along an axial plane. These blisters have a lateral skirt (11) whose upper part (12) is integral with the central panel (8) of the blister bearing the easy opening means (16, 17) and the retention means (21), and whose lower part (13), connected to the upper part (12) by a weakening line (15) and serving as a guarantee band, has a shoulder (14) and an inner bead (29) hooking. Said upper portion (12), said easy opening means (16,17) and said shoulder (14) define an annular space (30) for cooperating with said sealing edge (18), after removal of the sealing strip. guarantee (13) by the final consumer. FIG. 2 represents a first embodiment of the invention in which the means for easy opening of the central area of the cover (5) consist of 4 teeth (16) integral with the central panel. blister, and angularly spaced 90 (3 teeth are shown in Figure 2). These tapered teeth are provided with slits (21) oriented towards the inside of the blister giving these teeth a retention function, comparable to the function of a harpoon. FIG. 3 represents another form of blister according to the invention in FIG. wherein the means for easy opening of the central range of the cover (5) are constituted by a circular blade with tapered end (17), integral with the central panel of the blister. The blister comprises a movable part (22) whose end has

  the shape of a harpoon (21), constituting a means for retaining the central area of the lid (5).

  FIGS. 4a to 4d are axial sections schematically illustrating the invention in the case of a cover (4), provided with a peripheral incision line (19) intended to be crimped to the edge to be crimped (2). ) of the skirt (3) of a container, and in the case of the use of a blister (7) according to Figure 2.5 In Figure 4a is shown the cover (4) - free

  ring - placed on the container, in crimping position.

  Figure 4b shows the crimped container: formation of the

  sealing edge (18) in relief with respect to the central area (5) of the cover.

  Figure 4c shows the complete closure device

  after snapping the blister (7) onto the sealing edge (18) of the crimped container of FIG. 4b. The inner shoulder (14) presses on the sealing edge (18).

  FIG. 4d shows the position of the blister (7a) after tearing off the lower part (13) of the blister strip as a guarantee strip, and after pressing up and down on the blister - which corresponds to the opening of the container by the

final consumer.

  FIGS. 5a to 5d are axial sections schematically illustrating the invention in the case where the closure of the container is made with a cover of thickness between

  and 120 pm, and in the case where a blister according to Figure 3 is used.

  FIG. 5a shows the lid (4) sealed at the edge (2) of the skirt top (3) of the container, so as to form the border

  sealing member (18), in relief with respect to the central area (5) of the cover.

  FIG. 5b shows the complete closure device, the blister (7) being snapped onto the sealing edge (18)

of the container of Figure 5a.

  FIG. 5c, analogous to FIG. 4d, shows the opening

  and the retention of the central area (5) of the lid, when the consumer opens the container by pressing on the moving part (22), which first harpoon the central area (5) and then provides the peripheral cutting of the lid by action of the blade (17).

  Figure 5d shows the central area (5) of the cover

  secured to the blister (7a) when the blister is separated from the container.

  DETAILED DESCRIPTION OF THE INVENTION

  According to a first possibility of the invention, said metal cover (4) has a metal thickness of between 120 and 250 μm and has an incision (25), forming said closed line (19), whose residual thickness of metal, thoroughly

  incision, is between 40 and 120pm.20 The 4a to 4c illustrate the use of such a metal cover.

  According to another possibility of the invention, said metal cover (4) has a metal thickness of between 40 and 120 μm. These two possibilities generally correspond to two modes

  The first possibility which uses a relatively thick cover but has an incision line (19) is generally associated with a crimp closure mode, as illustrated in FIGS. 4a to 4c.

  At the second possibility which uses a thinner cover than the previous one is often associated a sealing closure mode. Sometimes the "cover" name is reserved for a crimp closure on the end (crimped edge (2) ) of the skirt (3) of a container, and the name of "lid" to a sealing means sealed to the edge to be sealed (2) of the skirt (3) of a

  container. The invention applies in particular to the case of a closure5 by "operculum" non-peelable.

  Whatever option is chosen, it is important for the

  periphery of said central area (5), the thickness of the metal layer is, at least locally, between 4010 and 120 pm so as to reconcile sufficient mechanical strength and ease of opening of the cover.

  According to the invention, the material constituting the lid is known per se and generally consists of a metal layer (Al, Fe alloy, etc.) coated with protective layers (varnish, thermoplastic film, etc.). But one can also find multilayer materials formed by stacks of various materials (metal, plastic, varnish, paper ...) already known to be able to form lids. The material constituting the blister (7) is preferably chosen from thermoplastic materials (PE, PP, etc.) that are both relatively economical and capable of being shaped, typically by injection-molding. Easy opening may be in various forms: Non-limitingly, they may consist of teeth (16), regularly spaced in line with said closed peripheral line (19), the end of which preferably forms an acute angle, so that by simply pressing

  exerted on the blister (7) after removal of the guarantee band (13), said teeth (16) can separate said central area (5) from said edge (6) of the cover (4). Typically, 3 to 8 teeth, regularly spaced, are enough to obtain a correct opening.

  They can also be constituted by an incision blade (17) in line with said closed peripheral line (19), the end of which preferably forms an acute angle, so that, by simple pressure exerted on the blister ( 7) after removal of the guaranty strip (13), said teeth (16) can disengage said central range (5) from said edge

(6) of the lid (4).

  According to a modality relating to these easy opening means, the height of said opening means (16, 17) is chosen so as to concentrate the opening pressure locally and

  thus facilitate the initial perforation of said central area. For example, when four teeth (16) are used, two opposing teeth may have a height a few mm greater than the other two opposite teeth.

  Given the principle of the device according to the invention, the height of the easy opening means (16, 17) and that of the upper part (12) of the skirt of the blister must be chosen so that said means of opening (16, 17) can not press on said closed peripheral line (19) when the blister (7), provided with its guarantee strip

  (13), is positioned on the cover (4).

  According to the invention, a means for retaining the central area

  (5) of the lid, by the blister, when opening, is always associated with the means of easy opening itself.

  Non-limitingly, said retention means (10) is peripheral and consists of a particular form of said opening means (16, 17) having an end provided with detents (21) with a harpoon function, so that, as said central beach detaches by action of said

  opening means, said central range is retained35 by these same opening means (16, 17) through the notches (21) shaped harpoon. See Figures 4c and 4d.

  According to another embodiment of the invention, said retention means (10) is central, secured to said central panel (8) of the blister, and constituted: either by a movable part (22) along the vertical axis, integral with said panel ledits opening means, and whose lower end is constituted by a harpoon, activatable by simple pressure, after removal of the guarantee strip, so as to drill and harpoon said central area. See FIGS. 5b to 5d.10 - or by any other means, such as a suction cup, or an adhesive portion (for example, a portion of double-sided adhesive

  adhering to the inner face of said central panel), such that there is attachment of the central range (5) of the cover and said central panel (8) of the blister when a vertical pressure is exerted on the blister when opening .

EXAMPLES OF REALIZATION

  The two blister models shown in FIGS. 2 and 3 were manufactured by injection.

  The model of FIG. 2 is intended for 71.5 mm diameter boxes (inside diameter of the boxes), having an outside diameter at the sealing edge (18), also called "crimped", of 74 mm. The model of Figure 3 is for boxes of 86 mm in diameter, having an outer diameter at the sealing embroidery (18) of 89 mm. Nature of the blister material: HDPE30 Inside diameter (lower part of the blister skirt):

  74 mm for the blister of Figure 2 and 89 mm for that of Figure 3.

  Inner diameter (tooth end for blister of FIG. 2): 76 mm inside diameter (end of the incision blade of the

  figure 3): 83 mm. Inside diameter at the inside bead (29): 71 mm for the blister of Figure 2, 855 mm for the blister of Figure 3.

  For the two types of blister of Figures 2 and 3: Total height: 25 mm Height of the upper part (12) of the skirt of the blister: 1210 mm. Height of the lower part (13) of the skirt of the blister: 13

  mm. Thickness of the skirt (11) of the blister: 1.5 mm. Thickness of the central panel (8) of the blister: 2 mm. The weakening line (15) consists of spaced apart plastic bridges.

  These two blisters were used with Al alloy lids devoid of rings, 210 μm thick, and having an incision (25) of residual metal thickness equal to 90 μm and forming an incision line (19). ) circular 67 mm diameter in the case of the blister of Figure 2, and 82 mm in the case of the blister of Figure 3. The top of the blisters form a bowl of inner diameter25 adapted to the outer diameter of the bottom of the container, so

  to allow stacking of the containers.

  In the tests carried out by the applicant, the blisters (7) were snapped onto the hot boxes at the outlet of the sterilizer, so as to take advantage of the heat released by the boxes to soften the blister sufficiently (more

  especially the lower part (13) of the skirt of the blister) and allow snapping "hot". After returning to room temperature, it was observed that the blister could not be detached from the box without apparent breakage of the declines of the line of weakness (15).

  A battery of comparative tests (containers with COF of the prior art / same containers with lid without rivet + blister according to the invention) were made. These are the usual tests carried out before launching any container and / or new content: * vertical compression test, * shock simulation test, * life test * opening test These comparative tests have shown that: * the blisters make the lids totally insensitive to vertical compression and shocks (when the compression

  vertical increases and exceeds a certain threshold, it is the box itself that crashes, but the lid remains intact), whereas on a COF of the prior art, a force of about 1 daN applied to the ring causes the opening of the incision.

  * in terms of the shelf life of the contents, numerous tests carried out on a whole range of food products

  Ph and variable salinity showed that the shelf life was greatly increased.

  * The opening tests performed have shown the efficiency and simplicity of opening of the device according to the invention.

  The applicant has tested various means allowing the consumer to easily achieve the break of the line of weakening (15) and the separation of the lower part (13) of the skirt of the blister, a typical means being

  obtained by providing the bottom portion (13) of the blister skirt with a primer or tongue formed by localized cutting of said lower portion, to be torn by the consumer upon opening.

ADVANTAGES OF THE INVENTION

  The invention solves all the problems posed by the COFs of the prior art. The essentially technical advantages already

will not be repeated here.

  In addition to these advantages, it should be noted the interest of blisters to renew the image of the products marketed, to use the blister itself as an attractive element (possibility of coloring in the mass or on the surface - possibility of having opaque or transparent blisters) and as a support for information and decoration. In addition, the use of a warranty tape blister allows the space between the central range of the cover (5) and the central panel of the blister (8) to be used to introduce a promotional element intended to promote sales. (pictures, pins, games, all objects that can constitute a "gift" for the consumer or children). In this case, the end-user consumer will recover his "gift" after breaking the line of weakness (15), and before exerting pressure on the incision (25) of the metal cover which makes the opening easy of the box while

  solidarisant the blister and the central range (5) of the lid.

APPLICATION

  The device of the invention applies to the closure of all

  containers, round or shaped opening, when it is necessary to reconcile both the mechanical strength of the closure means and the ease of opening.25 It applies in particular to cans.

Claims (8)

  1 - Device for closing an easy opening container comprising, a) a metal cover (4) comprising a central area (5) and an edge (6) intended to cooperate with the edge (2) of said container to form a border sealing strip (18), b) a plastic blister (7) comprising a central panel (8) and a side skirt (11), integral with said panel (8), surrounding said sealing edge (18), characterized in that, in order to guarantee the inviolability of the container, to protect the lid from possible shocks and to make it easy to open said lid, 1) said metal lid (4) has a thickness of metal, at least locally in a line closed peripheral (19) located at the edge of said central area (5), between 40 and 120 μm, 2) said skirt (11) of the blister (7) comprises: - an upper part (12) connected to said panel (8) a lower part (13) connected to said upper part (12) by r a weakening line (15), comprising an inner shoulder (14) intended to bear on said sealing edge (18), part forming a guarantee strip secured to the skirt (20) of said container under said border sealing (18), 3) said central panel (8) of the blister (7) comprises: - means for easy opening of said central area (5) of the cover arranged opposite and to the right of said closed peripheral line (19). ), means activatable by simple vertical pressure after removal of said guarantee strip (13), - retention means (10) of said central area (5), so as to secure said central area (5) and said central panel (8).   2 - Device according to claim 1 wherein said metal cover (4) has a thickness of metal included   between 120 and 250 μm and has an incision (25) forming said closed line (19), the residual metal depth of incision being between 40 and 120 μm.   3 - Device according to claim 1 wherein said metal cover (4) has a metal thickness of between 40 and 120 pm.   4 - Device according to any one of claims 1 to 3 wherein said easy opening means are constituted   by teeth (16), regularly spaced in line with said closed peripheral line (19), the end of which preferably forms an acute angle, so that, by simple pressure exerted on the blister (7) after removal of the guarantee band (13), said teeth (16) can separate said central area (5) from said edge (6) of the cover (4).   - Device according to any one of claims 1 to 3 wherein said easy opening means are constituted   by an incision blade (17) in line with said closed peripheral line (19), the end of which preferably forms an acute angle, so that, by simple pressure exerted on the blister (7) after removal of the band of   guarantee (13), said teeth (16) can separate said central area (5) from said edge (6) of the cover (4).   6 - Device according to any one of claims 4 and 5 wherein the height of said opening means (16,17) is   chosen so that said opening means can not press on said closed peripheral line (19) when the blister (7), provided with its guarantee strip (13), is positioned on the cover (4).   7 - Device according to claim 6 wherein the height of said opening means (16, 17) varies (16,17), so   concentrating the opening pressure locally and thereby facilitating the initial perforation of said central area.   8 - Device according to any one of claims 1 to 7 wherein said retention means (10) is constituted by   a particular form of said opening means (16,17) having an end with detents (21) with a harpoon function, so that as said center pad is released by action of said harpoon means; opening,   said central range is retained by these same opening means (16, 17) thanks to the notches (21) shaped harpoon.   9 - Device according to any one of claims 1 to 7 wherein said retention means (10) is central,   secured to said central panel (8) of the blister, and constituted - either by a movable part (22) along the vertical axis, integral with said panel and said opening means, and whose lower end is constituted by a harpoon, activatable by a single pressure, after removal of the guarantee strip, so as to pierce and harpoon said central area, - or by any other means, such as a suction cup, or an adhesive portion (for example, portion of double-sided adhesive adhering to the inner face of said central panel), such   that the central area (5) of the cover and of the central panel (8) of the blister are joined when a vertical pressure is exerted on the blister during the opening.