FR3110149A1 - Metal tin can comprising a metal can body and a metal lid, assembled by a peel-off tab - Google Patents

Abstract

The present invention relates to a metal can comprising: - a metal can body (2), - a metal lid (3), and - a peelable tab (4) which is sealed, by a heat-sealing material, around the circumference of the can. a peripheral skirt (31) of the metal cover (3) and a second end (212) of the side wall (21) of the metal box body (2). The roll (25) of said second end (212) of the side wall (21) faces outward, away from an access opening (23); and said peelable tab (4) has a strip (41, 411) which partially covers said roll (25), in a sealed manner, to seal said metal can (1). Figure for abstract: 2

Description

Metal tin can comprising a metal tin body and a metal lid, assembled by a peelable 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 metal can body and a metal lid 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 tin cans include:

- a metal can body comprising a side wall, a first end of which is connected to a bottom and a second end of which delimits an access opening, which second end comprises a roll which ends in a free border,

- a metal cover adapted to close off 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-sealing material, on the circumference of the peripheral skirt of the metal cover and of the second end of the side wall of the box body.

Metal parts typically include a protective coating (e.g. a varnish) to make them inert with respect to chemical reactions, in particular with the contents.

The free edge of the metal parts (can body and lid) is often very sharp, with a significant risk of cuts for the user handling the can.

To protect these free edges, they are conventionally shaped into a loop called “rolled”. This roll is generally made by rolling the material on itself.

This free edge generates a second problem: due to the manufacturing process, the metal of this same free edge is bare (uncoated/coated, for example devoid of varnish).

Depending on the structure of the can, this free edge then likely to interact chemically with the contents of the can, then leading to possible phenomena of corrosion and/or sulfuration likely to contaminate this content and make the unacceptable visual aspect by this contamination with a dark deposit on the can and/or on the product.

Considering the foregoing, there is a need for a solution suitable for protecting the free edge of the roll so as to avoid the phenomena of chemical reactions likely to occur at this free edge of the roll.

Presentation of the invention

In order to remedy the aforementioned drawback of the state of the art, the present invention proposes a new can structure comprising a metal can body and a metal lid, assembled by a peelable tab.

More particularly, according to the invention, a metal can comprising:

- a metal can body comprising a side wall, a first end of which is connected to a bottom and a second end of which delimits an access opening, which second end comprises a roll which ends in a free border,

- a metal cover adapted to close off 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-sealing material, on the circumference of the peripheral skirt of the metal cover and of the second end of the side wall.

And, according to the invention, the roll of said second end of the side wall is oriented outward, opposite the access opening.

And said peelable tab comprises a strip which partially covers said roll, in a sealed manner, to ensure the sealing of said metal tin can.

The present invention proposes a new metal can structure in which the free edge of the metal parts is protected against chemical interactions with the contents of the can (thus avoiding corrosion and/or sulfuration problems).

In particular, the roll of the can body is isolated from the contents of the can thanks to the peelable tab.

In addition to maintaining the lid on the can body, this peelable tab thus prevents interactions between the free edge of the can body and the contents of the can.

This solution is thus particularly effective in avoiding chemical reactions between the free edge of the can body and the environment (in particular the contents of the can).

According to a preferred embodiment, the peelable tab is sealed by means of two annular sealing zones, namely:

- an upper sealing zone which is inserted between, on the one hand, an upper strip of said peelable tab and, on the other hand, a sealing strip of the peripheral skirt of said metal cover, and

- a lower sealing zone which is inserted between, on the one hand, a lower band of said peelable tab and, on the other hand, said second end of the side wall of the box body.

Preferably, at the level of the second end of the side wall of the box body, the lower sealing zone covers the roll and/or a sealing strip, advantageously of constant circular or oblong section, connected to said roll.

More preferably, at the level of the second end of the side wall of the box body, the lower sealing zone comprises a configuration chosen from:

(i) two sealing sub-zones:

- a first sealing sub-zone, partially covering the roll, and

- a second sealing sub-zone covering the sealing strip,

Or

(ii) a sealing area partially covering the roll, only,

Or

(iii) a sealing area covering the sealing strip, only.

Other non-limiting and advantageous characteristics of the product in accordance with the invention, taken individually or in all technically possible combinations, are the following:

- The free edge is protected within said roll;

- the roll comprises an inner portion, located on the side of the access opening, and an outer portion, located opposite said inner portion and connected to the free edge; the peelable tab, where appropriate via the lower sealing zone, is sealed with said outer portion; preferably, the peelable tab comprises a curved band which hugs at least part of the outer portion of the roll; more preferably, the inner portion and the outer portion of the roll are curved or parallel to each other, where appropriate, the parallel portions each extend parallel to a longitudinal axis or at an angle relative to the longitudinal axis whose dimensions in section decrease in a direction oriented towards the bottom of the box body or whose dimensions in section increase in a direction oriented towards the bottom of the box body;

- at the level of the metal can body, the second end of the side wall comprises an end band, advantageously a constant circular or oblong section, connected to said roll, and said end band and said roll define identical external dimensions, or at least approximately identical, with respect to each other; preferably the end band and the roll are connected by a recessed portion, oriented towards the access opening;

- at the level of the metal cover, the interlocking strip has a concave surface which is complementary to at least part of the roll, if necessary at least to its inner portion; preferably, at the level of the metal lid, the sealing strip is connected to the interlocking strip to come in the extension of the roll and to cooperate with the peelable tab by means of the upper sealing zone;

- at the level of the cover, the sealing strip has a vertical section parallel to the longitudinal axis 3', for example cylindrical or oblong parallelepiped, or with an angle relative to the longitudinal axis 3', the section dimensions of which increase in a direction oriented towards the bottom of the box body or whose section dimensions decrease in a direction oriented towards the bottom of the box body;

- the metal cover comprises a disc extended by the peripheral skirt which extends from the side of an upper face of said disc;

- the metal tin can comprises a seal, optionally formed by an annular sealing zone, which is provided between adjoining surfaces of said second end of the side wall and of said interlocking strip of the metal cover;

- the peelable tab is associated with an elongated member, which is formed between the two sealing zones, if necessary, to allow the division of said peelable tab by means of traction applied to said elongated member;

- the bottom of the can body is made in one piece with the side wall, or attached to the side wall;

- the peelable tab and the roll together define an overlying chamber and/or an underlying chamber, which chambers are filled, over at least part of the circumference, with a filler seal.

The present invention also relates to the process for the manufacture of a metal tin can according to the invention, which manufacturing process comprises:

(i) a step of supplying the following parts:

- the metal can body comprising a side wall, a second end of which delimits an access opening, which second end comprises a roll which ends in a free edge and which is oriented towards the outside, opposite the 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 of the second end of the side wall of the box body metallic.

Other non-limiting and advantageous characteristics of the process in accordance with the invention, taken individually or in all technically possible combinations, are the following:

- the first end of the can body has a bottom or has a free edge delimiting an access opening;

- the peelable tab is heat-sealed in a single step or in at least two successive steps;

- the peelable tab is sealed with at least one support tool comprising a relief matching at least part of the roll.

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 exclusive of each other.

Detailed description of the invention

In addition, various other characteristics of the invention emerge from the appended description made with reference to the drawings which illustrate non-limiting forms of embodiment of the invention and where:

is a general view, along a vertical sectional plane, of a metal can according to the invention;

is an enlarged view of Detail II in Figure 1, showing in more detail the assembly between the can body and the can lid, locked together by the peel tab, with the can body terminating in a section roll oblong;

is a very schematic view which illustrates a possible arrangement of the sealing zones with the lower sealing zone covering the roll and an underlying sealing strip;

is a very schematic view which illustrates a possible arrangement of the sealing zones with the lower sealing zone covering an underlying sealing strip of the roll;

is a schematic view which illustrates a filling of the chambers, defined by the peelable tab and the roll, with a filler seal;

is a very schematic view which illustrates a possible arrangement of the sealing zones with the lower sealing zone covering only the roll;

is an enlarged view of detail II in Figure 1, showing in more detail a variation of the can body and can lid assembly, locked by the peel tab, with the can body terminating in a circular section roll ;

is a view similar to Figure 7, in which the peelable tab has a curved strip which hugs at least a portion of the outer portion of the roll;

is a schematic view showing a can body disposed next to a combination backer tool for peel tab sealing;

is a schematic view which shows a support tool comprising a relief matching at least part of the roll;

is an enlarged view of detail II in Figure 1, showing in greater detail an alternative embodiment of the canister body and the metal lid, locked together by the peelable tab.

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 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 comprising 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-sealing material, on the circumference of the metal cover 3 and of the side wall 21 of the box body 2.

According to the invention, in addition to maintaining the lid 3 on the can body 2, the metal can 1 is shaped so that the peelable tab 4 prevents interactions between the free edge of the can body 2 and the contents of tin can 1.

Canister body

The can body 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. Alternatively, the bottom 22 is attached to the side wall 21, for example by crimping.

The second end 212 of the side wall 21 (opposite the bottom 22) has a roll 25 which ends in a free edge 251.

The free border 251 can be made of a metal which is not covered; this free border 251 is then likely to interact chemically with the contents of the can 1, with possible phenomena of corrosion and/or sulfuration.

By "rolled" is meant in particular a rolling of the material on itself.

This roll 25 advantageously has, seen from above, a general shape identical to the side wall 21, for example a general circular or oblong shape.

According to the invention, the roll 25 of this second end 212 of the side wall 21 is oriented (also called "rolled up") towards the outside (of the tin can 1), opposite the opening of access 23 (and the longitudinal axis 2').

Roll 25 can thus be divided into at least two portions:

- an interior portion 255, located on the side of the access opening 23, and

- an outer portion 256, located opposite the inner portion 255 and connected to the free edge 251.

The inner portion 255 and the outer portion 256 of the roll 25 may be mutually parallel, advantageously rectilinear/straight and connected by a curved portion, thus defining a section of oblong shape (FIG. 2 in particular).

The inner 255 / outer 256 portions, parallel, can extend:

- parallel to the 2' longitudinal axis (figures 2 to 6), or

- with an angle (non-zero) in relation to the longitudinal axis 2' (figure 11).

In Figure 11, the dimensions of the horizontal section decrease in a direction oriented towards the bottom 22 of the box body 2.

Alternatively, not shown, the dimensions of the horizontal section increase in a direction oriented towards the bottom 22 of the box body 2 (inverse inclination in FIG. 11).

Still alternatively, the inner portion 255 and the outer portion 256 of the roll 25 may be curved (FIGS. 7 and 8).

The roll 25 then has a section of generally circular or cylindrical shape.

Preferably, the free edge 251 is protected within the roll 25.

This protection aims to prevent the user from coming into contact with this free edge 251, so as to eliminate the resulting risk of cutting.

For this, this free edge 251 is advantageously curved between the inner portion 255 and the outer portion 256 of the roll 25.

The second end 212 may also comprise an end band 26, advantageously of constant circular or oblong horizontal section (perpendicular to the longitudinal axis 2'), connected to the roll 25. This end band 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.

This end strip 26 and said roll 25 (in particular its outer portion 256) advantageously define identical external dimensions, or at least approximately identical, with respect to each other.

To this end, the end strip 26 and the roll 25 are advantageously connected by a recessed portion 27, oriented towards the access opening 23.

This recessed portion 27 thus approaches the longitudinal axis 2', with respect to the end strip 26.

In other words, the outer portion 256 of the roll 25 advantageously extends in the extension of the end strip 26; the inner portion 255 of the roll 25 is tapered relative to this end strip 26.

metal lid

The metal cover 3 is adapted to close the access opening 23.

This metal cover 3 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 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 identical to the roll 25 of the box body 2, for example a generally circular or oblong shape.

Preferably, the interlocking strip 311 comprises a concave surface 311a (outer), here male, which is complementary to at least a part of the roll 25 of the box body 2, where appropriate at least of its inner portion 255, female here.

The sealing strip 312 of this metal lid 3 advantageously has a general shape identical to the side wall 21 of the box body 2, for example a general 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 (see the size of the strip end 26 of the box body 2).

The interlocking strip 311 then forms a recess with respect to the sealing strip 312.

This sealing strip 312 of the metal lid 3 then cooperates advantageously with the peelable tab 4 via an upper sealing zone 52 described below.

In general, the sealing strip 312 has a vertical section:

- parallel to the longitudinal axis 3' (figure 2 in particular), for example cylindrical or oblong parallelepipedic, with a constant circular or oblong horizontal section (perpendicular to the longitudinal axis 3'), or

- with an angle (non-zero) relative to the longitudinal axis 3' (figure 11 in particular).

In Figure 11, the dimensions of the horizontal section increase in a direction oriented towards the bottom 22 of the box body 2 - from top to bottom (Figure 11); alternatively, the dimensions of the horizontal section decrease in a direction oriented towards the bottom 22 of the box body 2 – from top to bottom (not shown).

Still generally, the metal cover 3 comprises a disc 34 (lower) 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 metal tin can 1.

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

The disc 34 and the interlocking strip 311 are here connected by an annular molding 35 which is oriented on the side of the lower face 341 (projecting from the side of the lower face 341).

This metal cover 3 is advantageously produced by forming operations of a metal side.

Again generally, the peripheral skirt 31 ends in a roll 37 (upper) opposite the disc 34.

Here again, by "rolled" is meant in particular a rolling 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 general circular or oblong shape.

The roll 37 is here oriented (also called "rolled") outward (of the tin can 1), opposite the disk 34 (and the longitudinal axis 2').

Alternatively, not shown, the roll 37 is oriented (also called "rolled up") inwards (of the tin can 1), opposite 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, advantageously 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 a heat-sealing material T (illustrated schematically in particular in FIG. 3), 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 the box 2.

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

Traditionally, the peelable tab 4 comprises several layers:

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

- an inner sealing layer, adapted in particular to ensure sealing with the metal parts 2, 3 (box body 2 and cover 3).

The base layer advantageously has a mechanical structural function (holding 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 100 µm.

The sealing layer can be composed of different sub-layers (not shown), namely:

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

- a peeling underlayer, 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 pulling tab (not shown), intended to facilitate the separation of the peelable tab 4 from the metal parts 2, 3 by the consumer.

In this case, "peelable tab 4" means in particular an elongated member, advantageously of rectangular outline, delimited in particular by:

- two longitudinal borders 4a,

- an inner face 4b, intended to be sealed with the metal lid 3 and the side wall 21 of the box body 2, and

- an outer face 4c, opposite.

This peelable tab 4 advantageously extends over the entire circumference, and continuously, of the metal lid 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.

According to the invention, the peelable tab 4 comprises at least one strip 41 (or portion of width) which partially covers, and in a fluidtight manner, the roll 25 of this second end 212 of the side wall 21 of the body of the box 2.

This strip 41 thus interacts with the roll 25 to prevent any fluid circulation between the peelable tab 4 and the roll 25, sealing the metal tin can 1, advantageously both with regard to incoming flows and outgoing flows. .

Such an interaction advantageously includes:

- a fusible material binding the peelable tab 4 and the roll 25,

- a sealed contact, without heat-adhesive material, capable of preventing fluid circulation.

More specifically, according to the invention, the peelable tab 4 advantageously comprises several superimposed bands (or portions of width):

- an upper strip 42 assembled with the sealing strip 312 of the peripheral skirt 31 of the metal cover 3, and

- a lower band 41 assembled at the second end 212 of the side wall 21 of the box body 2.

The lower strip 41 of the peelable tab 4 then has a width adapted to cover the roll 25 and, preferably, the sealing strip 26.

In general, the strips 41, 42 of this peelable tab 4 (rectangular in shape) advantageously extend in planes perpendicular to the longitudinal axis 2', 3' of the metal cover 3/box body 2 couple, parallel to the longitudinal edges 4a of this peelable tab 4.

According to a preferred embodiment, the peelable tab 4 is sealed with the pair metal cover 3 / box body 2 by means of two annular sealing zones 5, which are made of the heat-sealing material T, namely:

- a lower sealing zone 51 which is inserted between, on the one hand, the lower band 41 of the peelable tab 4 and, on the other hand, the second end 212 of the side wall 21 of the box body 2, and

- an upper sealing zone 52 which is inserted between, on the one hand, the upper strip 42 of said peelable tab 4 and, on the other hand, the sealing strip 312 of the peripheral skirt 31 of the metal cover 3.

At the level of the second end 212 of the side wall 21 of the box body 2, the lower sealing zone 51 advantageously covers:

- the roll 25 and the sealing strip 26 (Figure 3), or

- the sealing strip 26, only (figure 4), or

- the roll 25, only (Figure 6).

In this context, the lower sealing zone 51 advantageously comprises a configuration chosen from:

(i) two sealing sub-zones 511, 512 for optimal closure (FIG. 3):

- a first sealing sub-zone 511, partially covering the roll 25, at the level of a first lower sub-band 411 of the peelable tab 4, and

- a second sealing sub-zone 512 covering the sealing strip 26 of the can body 2, at the level of a second lower sub-strip 412 of the peelable tab 4,

Or

(ii) a single sealing zone 512 covering the sealing strip 26 only (FIG. 4), or

(iii) a sealing zone 511, unique, partially covering the roll 25, only (FIG. 6).

In case (ii) according to Figure 4, the first lower sub-band 411 of the peelable tab 4 cooperates with the roll 25 by means of a sealed contact (without sealing by the heat-sealing material T).

In general, these sealing zones 5 advantageously extend over the entire circumference, and in a continuous manner, of the pair metal cover 3 / box body 2.

Still in general, these sealing zones 51, 52 advantageously extend in a plane perpendicular to the longitudinal axis 2', 3' of the metal cover 3/box body 2 pair.

Still generally, the peelable tab 4, if necessary via the lower sealing zone 51, is sealed with the outer portion 256 of the roll 25.

In other words, the peelable tab 4 advantageously comes opposite (preferably heat-sealed on) a face of the roll 25 coming in the extension of an inner face 21a of the side wall 21 which is oriented outwards because of the winding of the roll 25.

In general, the peelable tab 4 can have a rectilinear section or one made up of several straight segments.

In particular, the first lower sub-band 411 of the peelable tab 4, partially covering the roll 25, can be straight (FIGS. 3 and 7 in particular).

Alternatively, the lower strip 41, and in particular its first lower sub-strip 411, hugs at least part of the outer portion 256 of the roll 25 (FIG. 8 in particular).

In the case of a circular roll, this lower strip 411 then has a curved shape, with a vertical section in the form of an arc of a circle.

This embodiment aims to optimize the contact surface between the first lower sub-strip 411 of the peelable tab 4 and the outer portion 256 of the roll 25.

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

The term “fusible material” also means a material capable of being activated to perform 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).

In practice, the opening of the tin can 1 will advantageously consist in exerting traction on the peelable tab 4 at the level of a free portion forming a gripping/pulling member (not shown).

During this traction, the peelable tab 4 gradually detaches from the circumference of the tin can 1 by spreading the degradation of the sealing zones 5.

Once the peelable tab 4 is “peeled off”, the metal cover 3 is released and can be separated from the metal box body 2.

According to a particular embodiment, illustrated schematically in FIG. 2, the peelable tab 4 can be associated with (or even integrate) an elongated member 45 to allow the division/tearing of this peelable tab 4 by means of traction applied to said elongated member 45.

Such an elongated member 45 consists for example of a wire incorporated in the thickness of the peelable tab 4.

If necessary, this elongated member 45 is advantageously provided between the two sealing zones 5 (the lower sealing zone 51 and the upper sealing zone 52) to divide the peelable tab 4 into a lower band 41 and an upper band 42.

Seal (s)

As shown schematically in Figure 2, the metal can 1 may also include a seal 6, possibly formed by an annular sealing zone, which is formed between the adjoining surfaces, on the one hand, of the second end 212 of the side wall 21 of the box body 2 and, on the other hand, of the interlocking strip 311 of the metal cover 3.

This seal 6 thus aims to participate in the fluidic sealing (including gas and liquid) of the metal tin can 1, in addition to the peelable tab 4.

Still generally, as described below in relation to Figure 5, the peelable tab 4 and the roll 25 can together define at least one chamber 7:

- an overlying chamber 71, above the roll 25 (between the roll 25 and the metal cover 3), and/or

- An underlying chamber 72, below the roll 25 (facing the necking portion 27 of the metal can body 2).

Advantageously, the chambers 7 are filled, over at least part of the circumference, with a filler joint 8.

In particular, these filler seals 8 confer various advantages:

- these filler joints 8 provide an additional sealing / heat-sealing surface for the peelable tab 4,

- the filler seal 8 in the overlying chamber 71 participates in the sealing of the metal tin can 1,

- the filler seal 8 in the underlying chamber 72 contributes to the tightness of the roll 25 and to the protection of the free edge 251.

Examples of embodiments, not limiting

Several non-limiting embodiments may result from the invention.

Some examples of implementation are illustrated through the figures, namely:

- Figure 3 illustrates a box body 2 comprising a roll 25 with an oblong section and a peelable tab 4 attached to the box body 2 by two sealing sub-zones 511, 512 (a first sealing sub-zone 511 covering partially the roll 25 and a second sealing sub-zone 512 covering the sealing strip 26 of the can body 2);

- Figure 4 illustrates a box body 2 comprising a roll 25 with an oblong section and a peelable tab 4 attached to the box body 2 by a single sealing zone 512 covering the sealing strip 26 only;

- Figure 5 illustrates a box body 2 comprising a roll 25 with an oblong section and a peelable tab 4 attached with the lower sealing zone 51 covering the roll 25 and/or the sealing strip 26, and whose chambers 7 are filled by the filler joint 8;

- Figure 6 illustrates a box body 2 comprising a roll 25 with an oblong section and a peelable tab 4 attached to the box body 2 by a single sealing zone 511, partially covering the roll 25, only (the peelable tab 4 covers only the roll 25, without descending to the sealing strip 26);

- Figure 7 illustrates a box body 2 comprising a roll 25 of circular section and a peelable tab 4 attached so that the lower sealing zone 51 covers the roll 25 and / or the sealing strip 26 and that the first sub- lower strip 411 is tangent to the roll 25 of the box body 2;

- Figure 8 illustrates a box body 2 comprising a roll 25 of circular section and a peelable tab 4 attached so that the lower sealing zone 51 covers the roll 25 and/or the sealing strip 26 and that the first sub- lower band 411 marries the roll 25 of the box body 2;

- Figure 11 illustrates a box body 2 comprises an oblong roll 25 (dimensions in section decreasing towards the bottom of the box body 2) and a cover 3 comprising an oblong sealing strip 312 (dimensions in section increasing towards the disc 34 of this metal cover 3).

Such embodiments are in no way limiting. Other combinations are possible within the scope of the invention (section of the roll 25, arrangement of the lower sealing zone 51, etc.).

Process for the manufacture of the metal tin can

The present invention also relates to the process for the manufacture of the metal can according to the invention.

This manufacturing process, described in relation to FIGS. 9 and 10, comprises:

(i) a step of supplying the following parts:

- the metal can body 2 comprising a side wall 21, a second end 212 of which delimits an access opening 23, which second end 212 comprises a roll 25 which ends in a free edge 251 and which is oriented outwards, opposite the access opening 23,

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

- the peelable tab 4 (not shown in Figure 10), advantageously bearing the heat-sealing material T,

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

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

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

During the supply step, the first end 211 of the box body 2 may include a bottom 22.

The filling of this box body 2 is implemented before the step of closing by the metal cover 3.

Alternatively, during the supply step, the first end 211 of the box body 2 may include a free border delimiting a second access opening.

In this case, the filling of the box body 2 is advantageously implemented after the step of closing by the metal cover 3. The bottom 22 is then attached, for example by crimping, at the level of the first end 211 of the body of the box. box 2 to finish metal tin can 1.

Before the closing step, at least one of the chambers 7 is advantageously filled with the filler joint 8.

Generally, during the closing step, the peelable tab 4 is heat-sealed/heat-sealed in a single step or in at least two successive steps (advantageously with at least one heat-sealing/heat-sealing step per sealing zone 5).

Heat sealing is advantageously activated by combined actions of heat and pressure.

The heating is advantageously carried out from the outer face 4c of the peelable tab 4, to generate the sealing zones 5 by means of a phenomenon of thermal conduction or induction.

For example, as shown in figure 9, the heat sealing of the peelable tab 4 can be obtained by means of a series of support tools 9 which are each dedicated to a sealing zone 5.

In this case, three support tools 9 are provided:

- a first support tool 91 intended for heat-sealing the upper sealing zone 52,

- a second support tool 92 intended for heat sealing the second sealing sub-zone 512 of the lower sealing zone 51 (covering the sealing strip 26 of the can body 2), and

- a third support tool 93, intended for heat-sealing the first sealing sub-zone 511 of the lower sealing zone 51 (partially covering the roll 25).

Preferably, these support tools 9 are implemented successively so as to heat seal the successive sealing zones 5 from top to bottom, or vice versa, to avoid the forces on the peelable tab 4.

Alternatively, these support tools 9 are implemented successively so as to heat seal:

- initially, the upper sealing zone 52 (first support tool 91) and the second sealing sub-zone 512 of the lower sealing zone 51 (second support tool 92),

- secondly, the first sealing sub-zone 511 of the lower sealing zone 51 (third support tool 93).

Each support tool 9 comprises a peripheral surface adapted to fit a complementary portion of the box body 2 / lid 3 couple.

Preferably, as illustrated in Figure 10, at least one support tool 93, here the third support tool 93, comprises a relief 931 (for example a groove) marrying at least a part of the roll 25.

Such a groove advantageously corresponds, in negative, to the outer contour of the roll 25.

As discussed above, the lower strip 41 of the peelable tab 4, and in particular its first lower sub-strip 411, hugs at least part of the outer portion 256 of the roll 25 (Figure 8 in particular).

This embodiment aims to optimize the contact surface between the first lower sub-strip 411 of the peelable tab 4 and the outer portion 256 of the roll 25.

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

Claims (12)

Tin can including:
- a metal box body (2) comprising a side wall (21) of which a first end (211) is connected to a bottom (22) and of which a second end (212) delimits an access opening (23), which second end (212) comprises a roll (25) which ends in a free border (251),
- 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-sealing 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 the metal box (2),
characterized in that the roll (25) of said second end (212) of the side wall (21) faces outward, away from the access opening (23),
and in that said peelable tab (4) comprises a strip (41, 411) which partially covers said roll (25), in a leaktight manner, to seal said metal tin can (1). Metal tin can according to Claim 1, characterized in that the said peelable tab (4) is sealed by means of two annular sealing zones, namely:
- an upper sealing zone (52) which is inserted between, on the one hand, an upper strip (42) of said peelable tab (4) and, on the other hand, a sealing strip (312) of the peripheral skirt (31) of said metal cover (3), and
- a lower sealing zone (51) which is inserted between, on the one hand, a lower strip (41) of said peelable tab (4) and, on the other hand, said second end (212) of the side wall ( 21) of the gearbox body (2). Metal can according to Claim 2, characterized in that, at the level of the second end (212) of the side wall (21) of the can body, the lower sealing zone (51) covers:
- the roll (25) and/or
- a sealing strip (26) connected to said roll (25). Metal tin can according to any one of Claims 1 to 3, characterized in that the free edge (251) is protected within the said roll (25). Metal tin can according to any one of Claims 1 to 4, characterized in that the roll (25) comprises:
- an interior portion (255), located on the side of the access opening (23), and
- an outer portion (256), located opposite said inner portion (255) and connected to the free edge (251),
and in that the peelable tab (4), if necessary via the lower sealing zone (51), is sealed with said outer portion (256). Metal tin can according to Claim 5, characterized in that the peelable tab (4) comprises a curved strip (411) which hugs at least part of the outer portion (256) of the roll (25). Tin can according to any one of Claims 1 to 6, characterized in that, at the level of the can body (2), the second end (212) of the side wall (21) comprises an end band (26), advantageously a constant circular or oblong section, connected to said roll (25),
and in that said end band (26) and said roll (25) define identical external dimensions, or at least approximately identical, with respect to each other. Metal tin can according to any one of Claims 1 to 7, characterized in that, at the level of the metal cover (3), the interlocking strip (311) comprises a concave surface (311a) which is complementary to the least part of the roll (25), where applicable at least of its inner portion (255). Metal can according to Claim 8 in combination with Claim 2, characterized in that, at the level of the metal lid (3), the sealing strip (312) is connected to the fitting strip (311) to come into the extension of the roll (25) and to cooperate with the peelable tab (4) through the upper sealing zone (52). Metal tin can according to any one of Claims 1 to 9, characterized in that the metal lid (3) comprises a disc (34) extended by the peripheral skirt (31) which extends from the side of an upper face (342) of said disk (34). Metal can according to any one of claims 1 to 10, characterized in that the peelable tab (4) and the roll (25) together define an overlying chamber (71) and/or an underlying chamber ( 72),
which chambers (71, 72) are filled, over at least part of the circumference, with a filler seal (8). A process for manufacturing a metal can according to any of claims 1 to 11, which manufacturing process comprises:
(i) a step of supplying the following parts:
- the metal can body (2) comprising a side wall (21) of which a second end (212) delimits an access opening (23), which second end (212) comprises a roll (25) which ends in a free border (251) and which faces outwards, opposite the access opening (23),
- the metal cover (3), adapted to close said access opening (23), and
- the peelable tab (4),
(ii) a step of closing said metal can (1) during which:
- said metal cover (3) is positioned at said access opening (23) of the metal box body (2), and
- the metal lid (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).