WO2022003036A1

WO2022003036A1 - Metal preserving can comprising a metal can body and a metal lid which are joined together by a peelable tab

Info

Publication number: WO2022003036A1
Application number: PCT/EP2021/068027
Authority: WO
Inventors: Fabrice Leboucher; Bernard Deltour; Julien Chevalier
Original assignee: Trivium Packaging Group Netherlands B.V.
Priority date: 2020-07-03
Filing date: 2021-06-30
Publication date: 2022-01-06
Also published as: EP4175890A1; EP4175890B1; FR3112125A1; EP4175890C0; FR3112125B1

Abstract

The present invention relates to a metal preserving can comprising a metal can body (2), a metal lid (3) and a peelable tab (4) which is sealed by means of a hot-melt adhesive material. The peelable tab (4) comprises: - a first longitudinal segment (45) of which an inner face (451) is sealed with the pair consisting of the metal lid (3) and the metal can body (2), - a second longitudinal segment (46) which covers an upstream portion (453) of said first longitudinal segment (45), the inner face (461) of said second longitudinal segment (46) being sealed to an outer face (4532) of said upstream portion (453) of said first longitudinal segment (45), which peelable tab (4) comprises a transverse portion (47) that acts as a spacer and corresponds to the transition between said first longitudinal segment (45) and said second longitudinal segment (46), and said metal preserving can (1) comprises sealing means (6) which are arranged so as to close off a transverse space (E1) created between the inner face (471) of said transverse spacer portion (47) and the pair consisting of the metal lid (3) and the metal can body (2).

Description

Metal tin can comprising a metal can body and a metal cover, assembled by a peel-off tab

Technical field of the invention

The present invention relates to the technical field of metal cans.

It relates in particular to metal cans comprising a can body and a metal cover adapted to close an access opening of said can body, assembled by a peelable tab.

State of the art

Metal cans are commonly used for packaging foodstuffs. Such cans can also be used for packaging other industrial products, such as paints.

Some metal cans include:

- a metal box body comprising a side wall, a first end of which is connected to a bottom and a second end of which defines an access opening,

- a metal cover adapted to close said access opening, which metal cover comprises a peripheral skirt which comprises an interlocking strip adapted to cooperate by interlocking with said second end of the side wall, and

- a peelable tab which is sealed, by a heat-bonding material, on the circumference of the peripheral skirt of the metal cover and of the second end of the side wall of the metal box body.

The seal between the can body and the metal lid is often essential to ensure optimal preservation of the product packaged in the canister.

In practice, it is advantageous to ensure this seal directly by means of the peelable tab.

However, current solutions for positioning the peelable tab unfortunately do not provide optimum sealing over the entire circumference of the can body.

It would thus be interesting to offer a metal tin can in which the peelable tab would provide an effective seal over the entire circumference.

Presentation of the invention In order to remedy the aforementioned drawback of the state of the art, the present invention proposes a new structure of a metal tin can in which the peelable tab provides effective sealing over its entire circumference.

More particularly, according to the invention there is provided a metal tin can comprising:

The peel-off tab features:

- a first longitudinal section, an inner face of which is sealed with the metal cover / metal box body pair, and

a second longitudinal section covering an upstream portion of said first longitudinal section, the interior face of said second longitudinal section being sealed with an exterior face of said upstream portion of said first longitudinal section.

This peelable tongue also comprises an intermediate transverse portion, corresponding to the transition between said first longitudinal section and said second longitudinal section.

And said tin can comprises sealing means which are provided to close a transverse space which is formed between the inner face of said intermediate transverse portion and the metal cover / metal can body pair.

Such an arrangement of the peelable tab thus ensures optimum sealing over the entire circumference of the metal tin can, including within the transverse space.

Other non-limiting and advantageous characteristics of the product / process according to the invention, taken individually or in any technically possible combination, are as follows:

- the peelable tongue has two longitudinal edges, parallel, the upstream portion of said first longitudinal section has a transverse edge extending non-perpendicularly with respect to said longitudinal edges and the sealing means are formed by the heat-bonding material which fills the transverse space; the transverse edge of the upstream portion of said first longitudinal section advantageously comprises at least one Vee portion, preferably a Vee portion or two juxtaposed Vee portions;

- The sealing means are formed by at least one molding (preferably at least two or three moldings) provided at least in the intermediate transverse portion, which at least one molding consists of a convex molding on the side of the inner face; said intermediate transverse portion advantageously comprises several parallel moldings, distributed over the circumference of said peelable tongue; the parallel moldings are preferably inclined with respect to the two longitudinal edges;

- The sealing means comprise an additional heat-sealing material added at least in the space provided between the inner face of the intermediate transverse portion and the metal cover / metal box body pair; which additional heat-sealing material is also advantageously attached between the inner face of the second longitudinal section and the outer face of said upstream portion of said first longitudinal section; the additional heat-sealing material is advantageously attached in a localized manner, or in a homogeneous manner, on the circumference of the metal cover / metal box body pair;

- the metal tin can comprises an adhesive strip which is attached between the inner face of the second longitudinal section and the outer face of said upstream portion of said first longitudinal section, or even in the space provided between the inner face of the intermediate transverse portion and the metal cover / metal box body pair;

the peelable tab and the metal cover / metal box body pair together define at least one chamber; a filling seal fills said at least one chamber at least over the length of the intermediate transverse portion; the filling seal advantageously further extends opposite the inner face of the first longitudinal section and / or between the inner face of the second longitudinal section and the outer face of said upstream portion of said first longitudinal section;

- the second longitudinal section is extended by an end section to form a traction element for the user (possibly including a through hole or embossing).

The present invention also includes a process for manufacturing a metal tin can.

The manufacturing process according to the invention comprises:

(i) a step of supplying the following parts:

- the metal box body comprising a side wall, a second end of which defines an access opening, - the metal cover, adapted to close said access opening, and

- the peelable tab,

(ii) a step of closing said metal tin can during which:

- said metal cover is positioned at said access opening of the metal box body, and

- the metal cover is sealed at the level of the access opening of the metal box body, by heat sealing said peelable tab on the circumference of the peripheral skirt of the metal cover and the second end of the side wall of the box body metal, which peelable tab is arranged to include:

- a first longitudinal section, an inner face of which is formed opposite and on the circumference of the metal cover / metal box body pair,

a second longitudinal section covering an upstream portion of said first longitudinal section, the interior face of said second longitudinal section being sealed with an exterior face of said upstream portion of said first longitudinal section, and

an intermediate transverse portion, corresponding to the transition between said first longitudinal section and said second longitudinal section.

The method further comprises a sealing step designed to close the transverse space formed between the inner face of said intermediate transverse portion and the metal cover / metal box body pair.

Preferably, the sealing step is chosen from one of the following steps:

(i) a step of providing a peelable tab, the upstream portion of the first longitudinal section of which has a transverse edge extending non-perpendicularly to said longitudinal edges,

(ii) a step of molding the peelable tongue to form at least one molding provided at least in the intermediate transverse portion,

(iii) a step of filling a longitudinal chamber with the filling seal (again advantageously to serve as a support and meet the conditions for optimal heat sealing; preferably, the filling seal adheres to the other elements),

(iv) a step of applying an additional heat-sealing material, advantageously localized or homogeneous.

Of course, the different characteristics, variants and embodiments of the invention can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive.

Detailed description of the invention In addition, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate non-limiting embodiments of the invention and in which:

[Fig. 1] is a general and schematic view, along a transverse sectional plane, of a metal tin according to the invention;

[Fig. 2] is a schematic, partial and enlarged view of the metal tin can according to FIG. 1, showing the peelable tab sealed on the circumference of the metal cover / metal can body pair;

[Fig. 3] is a partial and enlarged schematic view of the peelable tongue, along a longitudinal section plane, at its intermediate transverse portion;

[Fig. 4] is a schematic view illustrating variants (4A., 4B., 4C. And 4D.) Of the upstream transverse border of the peelable tongue, covered by the intermediate transverse portion;

[Fig. 5] is a very schematic view which illustrates the heat sealing operation of the peelable tab on the circumference of the metal cover / metal box pair;

[Fig. 6] is a schematic view showing (6A., 6C. Or 6D.) Moldings made in particular in the intermediate transverse portion of the peelable tongue and (6B.) A tool suitable for obtaining such moldings;

[Fig. 7] is a schematic, partial and enlarged view of the metal tin can according to FIG. 1, showing a filling seal which fills the chambers formed between the peelable tab and the metal cover / metal can body pair;

[Fig. 8] is a schematic, partial and enlarged view of the metal tin can according to Figure 1, showing a filling seal which extends between the second longitudinal section and the upstream portion of the first longitudinal section;

[Fig. 9] is a partial and enlarged schematic view of the peelable tongue, along a longitudinal section plane, at its intermediate transverse portion and in which an adhesive strip is attached between the second longitudinal section and the upstream portion of said first longitudinal section.

It should be noted that, in these figures, the structural and / or functional elements common to the different variants may have the same references.

The metal tin can 1 according to the invention, illustrated in particular in Figures 1 and 2, comprises:

- a metal box body 2 (also called "box body 2") comprising a side wall 21 connected to a bottom 22 and having an access opening 23, - a metal cover 3 (also called "cover 3") adapted to cooperate by interlocking with the side wall 21 of said metal box body 2 to close said access opening 23, and

- a peelable tab 4 which is sealed, by a heat-bonding material, on the circumference of the pair formed by the metal cover 3 / the side wall 21 of the box body 2.

In general, the heat-sealing material is also called “heat-sealing material”.

By "heat-bonding material" is also meant a material capable of being activated to provide a sealing (or bonding) function when it is subjected to heating (for example local heating by conduction or induction).

This heat-sealing material is for example chosen from polypropylene or polyethylene (for example in the form of a heat-sealing varnish which advantageously consists of a polymer matrix and a dispersion of polypropylene).

Such a peelable tongue 4 is thus advantageously attached to the pair formed by the metal cover 3 / the side wall 21 of the box body 2, by an action combining heat and pressure, for a suitable time.

The opening of the tin can 1 will advantageously consist of exerting traction on the peelable tab 4, advantageously at an end portion (forming a gripping / traction member) described below.

During this traction, the peelable tab 4 gradually detaches from the circumference of the tin can 1 by crack propagation, by a phenomenon of cohesive or adhesive rupture (depending on the nature and composition of the heat-sealing material used).

Once the peelable tab 4 has been detached, the metal cover 3 is released and can be separated from the metal box body 2.

According to the invention, the peelable tab 4 here also provides effective sealing over the entire circumference of the metal converse box 1.

These various technical characteristics of the metal tin can 1 according to the invention are described below in relation to the figures.

Metal box body

The metal box body 2, generally illustrated in Figures 1 and 2, therefore comprises a side wall 21, defining a longitudinal axis 2 ’, delimited by two ends:

- a first end 211 is connected to the bottom 22, and

- A second end 212 delimits the access opening 23 (opposite the bottom 22). The side wall 21 may for example have a generally cylindrical or parallelepiped / oblong shape.

The side wall 21 and the bottom 22 can be in one piece (forming a two-piece box). Alternatively, the bottom 22 is attached to the side wall 21, for example by crimping (forming a three-piece box).

The second end 212 of the side wall 21 (opposite the bottom 22) advantageously comprises a roll 25 (Figure 2).

The term “rolled” is understood to mean in particular a winding of the material on itself.

The roll 25 of the side wall 21 is here oriented (also called "rolled up") outward (of the tin can 1).

Alternatively, not shown, the roll 25 of the side wall 21 can be oriented (also called "rolled up") inward (of the tin can 1).

The second end 212 may also include an end strip 26, advantageously of constant horizontal circular or oblong section (perpendicular to the longitudinal axis 2 '), connected to the roll 25. This end strip 26 is thus underlying the rolled 25.

This end strip 26 advantageously has a general shape identical to the side wall 21, for example a generally cylindrical or parallelepiped / oblong shape.

This end strip 26 advantageously forms a sealing strip 26, which can be sealed with the peelable tab 4.

Indeed, the second end 212 of the side wall 21 (via the roll 25 and / or the end strip 26) is advantageously intended to be sealed with a lower strip 41 of the peelable tab 4.

Metal cover

The metal cover 3 is adapted to close the access opening 23 of the metal box body 2.

This metal cover 3, illustrated in Figures 1 and 2 in particular, comprises a peripheral skirt 31, defining a longitudinal axis 3 ′, which comprises:

- an interlocking strip 311, adapted to cooperate by interlocking with the second end 212 of the side wall 21 of the canister body 2 and, preferably,

- a sealing strip 312 intended to be sealed with an upper strip 42 of the peelable tab 4.

The interlocking strip 311 advantageously has a general shape complementary to the roll 25 of the can body 2, for example a generally circular or oblong shape. The interlocking strip 311 here comprises a concave surface 311a (outer), here male, which is complementary to at least part of the roll 25 of the box body 2.

The sealing strip 312 of this metal cover 3 advantageously has a general shape identical to the side wall 21 of the can body 2, for example a generally cylindrical or parallelepiped / oblong shape.

This sealing strip 312 (overlying) is preferably connected to the interlocking strip 311 (underlying) and extends in the extension of the roll 25 of the box body 2 (or even in the bulk of the strip. end 26 of the gearbox body 2).

The interlocking strip 311 then forms a constriction relative to the sealing strip

312.

Still generally, the metal cover 3 comprises a disc 34 extended by the peripheral skirt 31.

This disc 34 has two opposite faces:

- a lower face 341, intended to be oriented towards the inside of the metal tin can 1, and

- an upper face 342, intended to be oriented towards the outside of the tin can 1.

The peripheral skirt 31 extends here advantageously from the side of the upper face 342 of the disc 34, together to form a metal cover 3 in the form of a cup.

This metal cover 3 is advantageously produced by forming operations on a metal sidewall.

Still generally, the peripheral skirt 31 ends in a roll 37 (upper).

Here again, the term “rolled” is understood to mean in particular a winding of the material on itself.

This roll 37 advantageously has, seen from above, a general shape identical to the peripheral skirt 31, for example a generally circular or oblong shape.

The roll 37 is here oriented (also called "rolled up") outward (of the tin can 1), away from the disc 34 (and the longitudinal axis 2 ’).

Alternatively, not shown, the roll 37 is oriented (also called "rolled up") inward (of the tin can 1), facing the disc 34 (and the longitudinal axis 2 ’). Such an embodiment would reduce the radial size of the metal cover 3.

Peelable tab The peelable tab 4 ensures (or at least "participates in") the assembly, hermetic (to fluids, including gases and liquids), between the metal cover 3 and the side wall 21 of the box body 2.

This peelable tab 4 is therefore sealed, by the heat-bonding material, on the circumference, on the one hand, of the peripheral skirt 31 of the metal cover 3 and, on the other hand, of the second end 212 of the side wall 21 of the gearbox body 2.

The peelable tab 4 can be chosen from the peelable tabs 4 which are conventional per se.

Traditionally, the peelable tongue 4 comprises several layers:

- a base layer, also called "barrier layer", outer, made of a resistant and flexible material, for example aluminum, and

- an inner sealing layer, suitable in particular to ensure the sealing with the metal parts 2, 3 (box body 2 and cover 3) and to ensure the sealing of the metal tab 4 on itself (as described by the continuation in connection with figure 3).

The base layer advantageously has a mechanical structural function (resistance of the two metal parts 2, 3 during sterilization against pressure, preventing untimely perforation, etc.).

This base layer has, for example, an aluminum thickness ranging from 20 to 150 μm.

The sealing layer can be made up of different sublayers (not shown), namely:

- an adhesive sub-layer, consisting for example of polypropylene grafted with maleic anhydride and having a thickness of 2 to 15 micrometers,

- a peel sub-layer, consisting for example of a mixture of polyethylene and polypropylene, having a thickness of 15 to 80 micrometers.

To facilitate its peeling, this peelable tab 4 may also include a gripping or traction tab (FIG. 3), intended to facilitate the separation of the peelable tab 4 from the metal parts 2, 3 by the consumer.

In this case, the term "peelable tab 4" means in particular an elongated member, advantageously of rectangular outline.

The peelable tab 4 is delimited, advantageously, by:

- two longitudinal edges 4a, advantageously parallel to each other (figure 2),

- an inner face 4b, intended to be sealed with the metal cover 3 / side wall 21 pair of the box body 2 and here on an outer face 4c of this peelable tab 4 rolled up on itself (Figure 2),

- the outer face 4c, opposite, aforementioned (Figure 2), and - two transverse borders 4d, called “upstream” 4d1 and “downstream” 4d2 (figure 3).

This peelable tab 4 extends over the entire circumference, and continuously, of the metal cover 3 / box body 2 pair.

In general, this peelable tab 4 advantageously extends in a plane perpendicular to the longitudinal axis 2 ’, 3’ of the metal cover 3 / box body 2 pair.

The peelable tab 4 is thus sealed, by the thermo-adhesive material, on:

- the circumference of the peripheral skirt 31 of the metal cover 3 (advantageously on the sealing strip 312), and

- the second end 212 of the side wall 21 of the can body 2 (advantageously on the end strip 26).

According to the invention, as partially illustrated in Figure 3, the peelable tab 4 is arranged around the circumference of the metal tin can 2 with a partial overlap on itself.

The peelable tongue 4 thus comprises at least two sections:

- a first longitudinal section 45 which is sealed with the metal cover 3 / metal box body 2 pair (via the aforementioned lower 41 and upper 42 bands), and

- a second longitudinal section 46 which partially covers this first longitudinal section 45.

The first longitudinal section 45 extends over the circumference of the metal cover 3 / metal box body 2 pair (advantageously over 360 ° or at least approximately over 360 °).

The first longitudinal section 45 has two opposite faces (Figure 3):

- an inner face 451, sealed with the metal cover 3 / metal box body 2 pair, and

- an opposite outer face 452.

This first longitudinal section 45 also comprises:

- an upstream portion 453 whose outer face 4532 is covered by (sealed with) the second longitudinal section 46, and

- a downstream portion 454 whose outer face 4542 is free (not covered) with respect to the second longitudinal section 46.

This first longitudinal section 45 (and in particular this upstream portion 453) also ends with the upstream transverse border 4d1 of the peelable tongue 4 (FIGS. 3 and 4).

The second longitudinal section 46 has two opposite faces:

- an inner face 461, sealed with the outer face 4532 of the upstream portion 453 of the first longitudinal section 45, and

- an opposite outer face 462. The second longitudinal section 46 is advantageously extended by an end section 48 which is provided to form a traction element for the user.

At least part of this terminal section 48 is advantageously free with respect to the first longitudinal section 45 for its gripping.

This terminal section 48 comprises for this, for example:

- a through orifice, or

- an embossing.

In practice, as described below in relation to FIG. 5, the heat sealing is advantageously activated by combined actions of heat and pressure, for a suitable time.

Advantageously, the heat sealing of the peelable tongue 4 can be obtained by means of at least one support tool 10, advantageously a support wheel 10.

Said at least one support tool 10 is advantageously intended to travel around the circumference of the peelable tongue 4, along its outer face 4c.

The heat-seal material then advantageously forms a bead of heat-seal material, or an accumulation of heat-seal material, which progresses upstream of this support tool 10.

In practice, the opening of the tin can 1 will advantageously consist of exerting a traction on the peelable tongue 4, at its second longitudinal section 46 (or even, where appropriate, at its end section 48) forming a gripping member. / traction.

During this traction, the peelable tab 4 gradually detaches from the circumference of the tin can 1 by crack propagation, by a phenomenon of cohesive or adhesive rupture (depending on the nature and composition of the heat-sealing material used), from the second longitudinal section 46 then along the first longitudinal section 45.

Intermediate transverse portion and sealing means

According to the invention, the peelable tongue 4 further comprises an intermediate transverse portion 47, corresponding to the transition between the first longitudinal section 45 and the second longitudinal section 46.

This intermediate transverse portion 47 thus forms a kind of step or radial offset.

The intermediate transverse portion 47 thus deviates from / diverges with respect to the metal cover 3 / metal box body 2 pair, from the first longitudinal section 45 to the second longitudinal section 46. This intermediate transverse portion 47 further extends opposite the upstream transverse border 4d1.

The intermediate transverse portion 47 has two opposite faces (Figure 3):

- an inner face 471, facing and away from the metal cover 3 / metal box body 2 pair, and

- an opposite outer face 472.

A transverse space E1 is thus provided between, on the one hand, the inner face 471 of said intermediate transverse portion 47 and, on the other hand, the metal cover 3 / metal box body 2 pair.

The transverse space E1 is still delimited here by the upstream transverse border 4d1 of the peelable tab 4.

This transverse space E1 opens out transversely, at the level of the two longitudinal edges 4a of the peelable tongue 4.

Sealing means 6 are provided to close the transverse space E1.

The term “seal” advantageously means fluid tightness. This seal thus prevents circulation of fluids (air and liquid) through this transverse space E1, between the interior of the metal tin can 1 and the environment.

This circulation within the transverse space E1 is also called "transverse circulation", in a "vertical" direction (coaxial with the general axis 2 ’, 3’ of the tin can 1).

Still according to the invention, the sealing means 6 can also be arranged to participate in closing off a longitudinal space E2 which is defined between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of the upstream portion 453 of the first section longitudinal 45.

These sealing means 6 can be useful for optimizing the heat-sealing of the peelable tongue 4 on itself (between the second longitudinal section 46 and the first longitudinal section 45), in particular in the presence of a lack of support / pressure of heat sealing capable of generating this longitudinal space E2.

By “sealing” is meant here again fluid tightness. This seal thus prevents circulation of fluids (air and liquid) through this longitudinal space E2, between the interior of the metal tin can 1 and the environment.

Such sealing means 6 can take different embodiments, described in relation to the figures below.

These embodiments can be implemented independently of each other, or in combination with each other. According to one embodiment, the sealing means 6 are formed by a particular distribution of the heat-bonding material which fills the transverse space E1.

To this end, as illustrated in Figure 4, the longitudinal tongue 4 advantageously has a particular contour: the upstream transverse border 4d1 extends in a non-perpendicular manner relative to the longitudinal borders 4a.

This embodiment helps to optimize the sealing of the transverse space E1.

Without being limited by any theory, this shape generates an increased local sealing pressure (due to a locally reduced bearing surface), in particular when using the bearing tool 10 (FIG. 5 ); the flow of heat-bonding material is further guided by the upstream transverse border 4d1 of the peelable tab 4, so that it penetrates the interstices and fills the transverse space E1.

Again without being limited by any theory, the transverse space E1 has an increased length; the longer path increases the chance of an effective obturation.

In this sense, as illustrated in Figures 4 and 5, the upstream transverse border 4d1 of the upstream portion 453 of the first longitudinal section 45 advantageously comprises at least one Vee-shaped portion.

By “Vee-shaped portion” is advantageously meant:

- a convex V-shaped portion, the point of which (protruding) ends the upstream transverse border 4d1 (figures 4A. and 4B.), or

- a concave V-shaped portion, the tip (recessed) of which initiates the upstream transverse border 4d1 (FIGS. 4C. and 4D.).

Without being limiting, a concave V-shaped portion allows a convergence of the flow of heat-sealing material towards the tip (as illustrated by the diagrammatic arrows in Figures 4C. And 4D.), Which makes it possible to optimize the seal.

Preferably, the upstream transverse border 4d1 comprises:

- a Vee-shaped portion (Figures 4A. or 4C.), advantageously extending over the entire width of the peelable tab 4, or

- two juxtaposed V-shaped portions (Figures 4B. or 4D.), juxtaposed over the width of the peelable tab 4.

The Vee portion advantageously has an angular dimension ranging from 30 ° to 90 °.

According to one embodiment illustrated in Figures 6A., 6C. or 6D., the sealing means 6 are formed by at least one molding 63 provided at least in (across) the intermediate transverse portion 47.

Said at least one molding 63 consists of a convex molding on the side of the inner face 471 of the intermediate transverse portion 47 (projecting towards the metal cover 3 / metal box body 2 pair). The intermediate transverse portion 47 is advantageously cut by at least one molding 63, more preferably by at least two moldings 63, or even by at least three moldings 63.

Preferably, said at least one molding 63 intersects the intermediate transverse portion 47 at the level of the lower band 41 of the peelable tongue 4 and of the upper band 42 of the peelable tongue 4, so as to optimize the sealing of the space. transverse E1 (top and bottom - on the side of each longitudinal border 4a).

For example, as shown in Figures 6C. and 6D, the intermediate transverse portion 47 is advantageously cut by two or three moldings 63.

This molding 63 thus extends advantageously, for a first part, in the first longitudinal section 45 and, for a second part, in the second longitudinal section 46.

The molding or moldings 63 advantageously extend in a non-perpendicular manner, also called "inclined", with respect to the longitudinal edges 4a of the peelable tongue 4.

In this case, the peelable tongue 4, and in particular the second longitudinal section 46, has several parallel moldings 63 which are distributed over its length / circumference.

The moldings 63 advantageously extend over the entire height of the peelable tongue 4, from one longitudinal edge 4a to the other.

The parallel moldings 63 are preferably inclined with respect to the two longitudinal edges 4a of the peelable tongue 4.

Such moldings 63 have the advantage of closing off, or at least participating in closing off, the transverse space E1, or even the longitudinal space E2.

The moldings 63 can have any other suitable shape, for example a straight line (Figures 6A. Or 6C.), A V-shape (Figure 6D.), A wavy / sinusoidal line (not shown), arranged juxtaposed or interspersed. .

Furthermore, in general, as illustrated in Figure 7, the peelable tab 4 (including its first longitudinal section 45) and the metal cover 3 / metal box body 2 pair optionally together define at least one chamber 7.

A filling seal 8 advantageously fills said at least one chamber 7, preferably at least over the length of the intermediate transverse portion 47.

This filling gasket 8 provides an additional sealing / heat-sealing surface for the intermediate transverse portion 47, thus participating in the sealing means 6 of the transverse space E1.

Preferably, the filling seal 8 further extends:

- facing the inner face 451 of the first longitudinal section 45 (Figure 7) and / or - Between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of the upstream portion 453 of the first longitudinal section 45, forming an intermediate seal (Figure 8).

Such a filling seal 8 also confers various advantages:

- The filling seal 8 provides an additional sealing / heat-sealing surface for the peelable tongue 4, and in particular the inner face 451 of the first longitudinal section 45;

- the filling seal 8 contributes to the sealing of the metal tin can 1;

- The “intermediate” filling seal 8 provides an additional sealing / heat-bonding surface between the second longitudinal section 46 and the upstream portion 453 of the first longitudinal section 45.

The "spacer" filling seal 8 is particularly useful for helping to ensure optimum sealing / heat-sealing in the longitudinal space E2.

The filling joint 8 consists for example, without being limiting, of a polyamide hot glue.

According to yet another embodiment, not shown, the sealing means 6 comprise an additional heat-sealing material which is attached at least in the transverse space E1.

The additional heat-sealing material may be the same, or different, from the heat-sealing material suitable for sealing the peel-off tab 4.

This additional heat-sealing material is preferably added between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of said upstream portion 453 of said first longitudinal section 45.

The additional heat-sealing material then also participates in ensuring optimum sealing / heat-sealing in the longitudinal space E2.

For this, preferably, the additional heat-sealing material is added:

- located on the circumference of the metal cover 3 / metal box body 2 pair, or

- homogeneously over the circumference of the metal cover 3 / metal box body 2 pair or

- Locally, between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of said upstream portion 453 of said first longitudinal section 45.

According to yet another embodiment, illustrated by FIG. 9, an adhesive strip 9 is attached in the longitudinal space E2, between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of the upstream portion 453 of the first section longitudinal 45. This adhesive strip 9 could also extend into the transverse space E1.

Such an adhesive strip 9 helps to ensure optimal assembly in the longitudinal space E2, or even to participate in closing off the transverse space E1.

Such an adhesive strip 9 still allows assembly of the peelable tab 4 on itself, in an easy manner (establishing contact with low / moderate pressure).

Manufacturing process

The present invention also relates to the process for manufacturing a metal tin can 1 according to the invention.

This manufacturing process includes:

(i) a step of supplying the following parts:

- the aforementioned metal box body 2, comprising a side wall 21, a second end 212 of which defines an access opening 23,

- the metal cover 3, adapted to close this access opening 23, and

- the peelable tab 4,

(ii) a step of closing the tin can 1 during which:

- the metal cover 3 is positioned at the level of the access opening 23 of the metal box body 2, and

- the metal cover 3 is sealed at the level of the access opening 23 of the metal box body 2, by heat sealing of the peelable tab 4 on the circumference of the peripheral skirt 31 of the metal cover 3 and of the second end 212 of the side wall 21 of the metal box body 2.

As developed previously in relation to FIG. 3, the peelable tongue 4 is arranged to form the first longitudinal section 45 and the second longitudinal section 46, connected by the intermediate transverse portion 47.

The heat sealing is advantageously activated by combined actions of heat and pressure, for a suitable time.

The heating is advantageously carried out from the outer face 4c of the peelable tab 4, to generate the heat sealing by means of a phenomenon of thermal conduction or induction.

The heat-bonding material then advantageously forms a bead of heat-bonding material, also called “a front” or “a wave” or “an accumulation” of heat-bonding material, which progresses upstream of this support tool 10. Preferably and as illustrated in FIG. 5, the peelable tongue 4 is heat-sealed while progressing over its length:

- along the first longitudinal section 45, from its upstream transverse border 4d1, then

- along the second longitudinal section 46, so that it covers the upstream portion 453 of the first longitudinal section 45.

According to the invention, the method according to the invention further comprises a sealing step which is designed to close the transverse space E1, or even also the longitudinal space E2.

In practice, the sealing step can be chosen from different sealing steps, which can be taken alternately or in combination.

According to one embodiment described in relation to FIG. 5, the sealing step is based on a step of providing a peelable tab 4 which comprises an upstream transverse border 4d1 extending in a non-perpendicular manner with respect to at the longitudinal edges 4a.

Without being limited by any theory, this shape generates an increased local sealing pressure (due to a locally reduced bearing surface), in particular when using the bearing tool 10 (FIG. 5 ).

The bead of heat-bonding material, traveling upstream of the support tool 10, is guided by the upstream transverse border 4d1 of the peelable tongue 4, so that it penetrates the interstices and fills the transverse space E1.

According to an embodiment described in relation to FIG. 6, the sealing step is based on a step of molding the peelable tongue 4 to form at least one molding 63 provided at least in the intermediate transverse portion 47.

In this case, as illustrated schematically in FIG. 6, the support tool 10 advantageously comprises at least one rib 101 which is adapted to form the complementary moldings 63 as it travels along the outer face 4c of the peelable tongue. 4.

According to yet another embodiment, not shown, the sealing step is based on a step of applying additional heat-bonding material, advantageously localized or homogeneous.

This additional iron-on material can be added:

- on the metal cover 3 / metal box body 2 pair, just upstream of the upstream transverse border 4d1 of the peelable tab 4, to participate in closing the transverse space E1 by creep, - even between the inner face 461 of the second longitudinal section 46 and the outer face 4532 of said upstream portion 453 of said first longitudinal section 45, to participate in closing the longitudinal space E2 by creep.

Of course, various other modifications can be made to the invention within the scope of the appended claims.

Claims

[Claim 1] Metal tin comprising:

- a metal box body (2) comprising a side wall (21), a first end (211) of which is connected to a bottom (22) and a second end (212) of which defines an access opening (23),

- a metal cover (3) adapted to close said access opening (23), which metal cover (3) comprises a peripheral skirt (31) which comprises an interlocking strip (311) adapted to cooperate by interlocking with said second end (212) of the side wall (21), and

- a peelable tab (4) which is sealed, by a heat-bonding material, on the circumference of the peripheral skirt (31) of the metal cover (3) and of the second end (212) of the side wall (21) of the body of metal box (2), characterized in that the peelable tab (4) comprises:

- a first longitudinal section (45), an inner face (451) of which is sealed with the metal cover (3) / metal box body (2) pair,

- a second longitudinal section (46) covering an upstream portion (453) of said first longitudinal section (45), the inner face (461) of said second longitudinal section (46) being sealed with an outer face (4532) of said upstream portion ( 453) of said first longitudinal section (45), which peelable tongue (4) comprises an intermediate transverse portion (47), corresponding to the transition between said first longitudinal section (45) and said second longitudinal section (46), and in that said metal tin can (1) comprises sealing means (6) which are provided to close a transverse space (E1) formed between the inner face (471) of said intermediate transverse portion (47) and the metal cover pair ( 3) / metal box body (2).

[Claim 2] Metal tin can, according to claim 1, characterized in that the peelable tab (4) has two longitudinal edges (4a), parallel, in that the upstream portion (453) of said first longitudinal section (45) comprises a transverse border (4d1) extending in a non-perpendicular manner with respect to said longitudinal borders (4a), and in that the sealing means (6) are formed by the thermobonding material which fills the transverse space (E1 ).

[Claim 3] A metal tin can, according to claim 2, characterized in that the transverse edge (4d1) of the upstream portion (453) of said first longitudinal section (45) comprises at least a Vee portion, preferably a portion in Vé or two portions in Vé juxtaposed.

[Claim 4] A metal tin can, according to any one of claims 1 to 3, characterized in that the sealing means (6) are formed by at least one molding (63), preferably at least two or three. moldings (63), formed at least in the intermediate transverse portion (47), which at least one molding (63) consists of a molding (63) convex on the side of the inner face (4c) of the peelable tongue (4).

[Claim 5] A metal tin can, according to claim 4, characterized in that said intermediate transverse portion (47) comprises several parallel moldings (63), distributed over the circumference of said peelable tongue (4), which moldings (63) parallel are preferably inclined with respect to the two longitudinal edges (4a).

[Claim 6] A metal tin can, according to any one of claims 1 to 5, characterized in that the sealing means (6) comprise an additional heat-sealing material added at least in the transverse space (E1), which Additional heat-sealing material is preferably added between the interior face (461) of the second longitudinal section (46) and the exterior face (4532) of said upstream portion (453) of said first longitudinal section (45).

[Claim 7] A metal tin can, according to claim 6, characterized in that the additional heat-sealing material is attached in a localized manner, or in a homogeneous manner on the circumference of the metal cover (3) / can body (2) pair. .

[Claim 8] A metal tin can according to any one of claims 1 to 7, characterized in that it comprises an adhesive strip (9) which is attached between the inner face (461) of the second longitudinal section (46) and the outer face (4532) of said upstream portion (453) of said first longitudinal section (45), or even in the transverse space (E1).

[Claim 9] A metal tin can, according to any one of claims 1 to 8, characterized in that the peelable tab (4) and the metal cover (3) / metal can body (2) pair together define at least a chamber (7), and in that a filling seal (8) fills said at least one chamber (7) at least over the length of the intermediate transverse portion (47).

[Claim 10] A metal tin can, according to claim 9, characterized in that the filling seal (8) further extends:

- facing the inner face (451) of the first longitudinal section (45) and / or

- between the inner face (461) of the second longitudinal section (46) and the outer face (4532) of said upstream portion (453) of said first longitudinal section (45).

[Claim 11] A method of manufacturing a metal tin can according to any one of claims 1 to 10, which manufacturing method comprises:

(i) a step of supplying the following parts:

- the metal box body (2) comprising a side wall (21), a second end (212) of which defines an access opening (23),

- the metal cover (3), adapted to close said access opening (23), and

- the peel-off tab (4),

(ii) a step of closing said metal tin can (1) during which:

- said metal cover (3) is positioned at said access opening (23) of the metal box body (2), and

- the metal cover (3) is sealed at the level of the access opening (23) of the metal box body (2), by heat sealing said peelable tab (4) on the circumference of the peripheral skirt (31) of the metal cover (3) and the second end (212) of the side wall (21) of the can body (2), which peelable tab (4) is arranged to include:

- a first longitudinal section (45), an inner face (451) of which is provided opposite and on the circumference of the metal cover (3) / metal box body (2) pair,

- a second longitudinal section (46) covering an upstream portion (453) of said first longitudinal section (45), the inner face (461) of said second longitudinal section (46) being sealed with an outer face (4532) of said upstream portion ( 453) of said first longitudinal section (45), and

- an intermediate transverse portion (47), corresponding to the transition between said first longitudinal section (45) and said second longitudinal section (46), which method further comprises a sealing step which is designed to close the transverse space (E1 ) formed between the inner face (471) of said intermediate transverse portion (47) and the metal cover (3) / metal box body (2) pair.

[Claim 12] A method according to claim 11, in combination with claim 2, characterized in that the sealing step is a step of providing a peelable tab (4) including the upstream portion (453) of the first section longitudinal (45) comprises a transverse border (4d1) extending non-perpendicularly with respect to said longitudinal edges (4a).

[Claim 13] A method according to claim 11, in combination with claim 4, characterized in that the sealing step is a step of molding the peelable tongue (4) to form at least one molding (63) provided at the less in the intermediate transverse portion (47).

[Claim 14] A method according to claim 11, in combination with claim 9, characterized in that the sealing step is a step of filling a longitudinal chamber (7) with the filling seal (8).

[Claim 15] A method according to claim 11, in combination with claim 6, characterized in that the sealing step is a step of applying an additional heat-sealing material, advantageously localized or homogeneous.