Process for manufacturing a bottle-shaped metal container

Abstract

The present invention relates to a method for manufacturing a metal container (1) in the shape of a bottle. The method comprises a step of forming a tubular part (16), to form a threaded neck (3). This manufacturing method comprises, prior at least to an operation of forming a roll (7), preferably prior to said step of forming said tubular part (16), a localized annealing step which is carried out to impart an annealed state to the tubular part (16), at least over the height of a downstream strip (162) of said tubular part (16) intended to be formed into a roll (7). Figure for abstract: 4

Description

Title of the invention: Method for manufacturing a bottle-shaped metal container Technical field of the invention

[0001] The present invention relates to the technical field of bottle-shaped metal packaging.

[0002] It relates in particular to methods for manufacturing such bottle-shaped metal packaging, the neck of which comprises at least one roll, a thread and a transport ring. State of the art

[0003] Some bottle-shaped packages have a threaded neck which is hermetically sealed, after filling, by means of a cap.

[0004] The design of such packaging must take into account the constraints linked to its manufacture, but also to its numerous handling operations at the filler from its reception to the final packaging operations.

[0005] However, depending on their constituent material, the packaging is obtained by manufacturing techniques which generate structural constraints leading to the implementation of conveyor installations dedicated to them.

[0006] In this respect, the tubular part forming the neck of packaging made of plastic (such as bottles or flasks) generally comprises an annular crown, projecting on the circumference and designated under the name of "transport ring", useful for their individual handling.

[0007] These plastic packagings can thus be held, handled and / or transferred by positioning a handling member in the general shape of a fork, resting under this transport ring.

[0008] In practice, for such plastic packaging, the neck and its transport ring are formed simultaneously, for example on a preform (semi-finished part obtained by injection) before finishing by injection-blow molding or by extrusion-blow molding.

[0009] Packaging made from a metallic material, for example steel or aluminum, is often devoid of such a transport ring due to the technical constraints linked to the forming of the metal.

[0010] The manufacture, handling and filling of such metal packaging thus leads to the implementation of dedicated handling means.

[0011] Consequently, for the filler, the transition from plastic packaging to metal packaging requires significant investments, particularly for the transformation of handling equipment.

[0012] To overcome this problem, there are developments in metal packaging whose threaded neck, including in particular a terminal roll and a transport ring, would be suitable for handling within an installation usually dedicated to plastic packaging.

[0013] But, in practice, the technical constraints linked to the forming of the metal generate fragilities during the forming of this threaded neck. The threaded neck of the metal bottle must also be able to withstand the capping forces, while allowing a reduction in the thickness of the metal.

[0014] In view of the above, there is a need for a technical solution which would allow the manufacture of metal bottles which would have a threaded neck adapted to receive a cap and which would be compatible with plastic bottle filling lines, while allowing a reduction in the thickness of its metal wall. Presentation of the invention

[0015] In order to overcome the aforementioned drawback of the state of the art, the present invention provides a method for manufacturing such bottle-shaped metal packaging, the neck of which comprises at least one roll, a thread and a transport ring.

[0016] More particularly, the invention proposes a method for manufacturing a bottle-shaped metal container, said metal container comprising a body connected to a threaded neck by means of a shoulder.

[0017] The method according to the invention comprises:

[0018] - a step of manufacturing a preform comprising a tubular part, defining a longitudinal axis and a free downstream edge, which tubular part is connected to a body by means of a shoulder, and

[0019] - a step of forming said tubular part, to form said threaded neck.

[0020] The forming step comprises forming operations adapted to form single-block structures on said tubular part:

[0021] - an operation of forming a roll within a downstream strip of said part tubular, terminated by said downstream edge, to form a roll at the level of the downstream edge of the threaded neck,

[0022] - an operation of forming a thread within an intermediate strip of said tubular part, and

[0023] - an operation of forming a transport ring within an upstream strip of said tubular part, on the shoulder side, intended to cooperate with a handling member (said transport ring advantageously comprising at least one molding which is arranged on a plane extending perpendicular to said axis longitudinal and on the circumference of the tubular part, which at least one molding has a lower and / or upper surface against which a handling member is intended to come to bear).

[0024] And according to the invention, the manufacturing method comprises, at least prior to said operation of forming the roll, preferably prior to said step of forming said tubular part, a localized annealing step which is carried out to confer an annealed state to the tubular part, at least over the height of the downstream strip of said tubular part.

[0025] The present invention thus offers a technical solution which would allow the manufacture of metal bottles comprising a threaded neck adapted to receive a cap and which would be compatible with plastic bottle filling lines, while allowing a reduction in the thickness of its metal wall.

[0026] In fact, the roll is formed, above the thread, at the end of the tubular part of the preform. Frequently the metal which has been stretched to form the preform is then contracted to form the threaded neck; however, the applicant has found that the metal is likely to tear during the shaping of the roll. This causes a significant proportion of the production to be scrapped.

[0027] The applicant has found that annealing this area, by improving its formability, makes it possible to reduce the rate of cut necks.

[0028] Other non-limiting and advantageous characteristics of the method according to the invention, taken individually or in all technically possible combinations, are the following:

[0029] - the localized annealing step is performed to impart an annealed state over a height at least 3 to 7 mm from the downstream band of said tubular part;

[0030] - the localized annealing step is performed to impart an annealed state only to the level of said downstream band, only at the level of the downstream band and the upstream band, so as to keep at least part of the height of the intermediate band in an unannealed state, or at the level of the downstream band, the intermediate band and the upstream band;

[0031] - the localized annealing step is performed to impart an annealed state over the height of the upstream band of said tubular part, advantageously over a height of 5 to 15 mm;

[0032] - the step of manufacturing the preform comprises a phase of deformation of a metal part for obtaining a primary preform comprising a bottom extended by a tubular wall, for example chosen from stamping and / or drawing and / or reverse extrusion, for example by stamping and / or drawing a metal blank for, for example, a thickness ranging from 0.2 mm to 0.7 mm, advantageously by a technique chosen from stamping / drawing or stamping and re-stamping (Drawing and Wall Ironing (DWI) or Draw and Re Draw process (DRD)) or reverse spinning from a 2 to 15 mm pin, a trimming phase, to form a downstream edge of said primary preform, and a shrinking step, to form said tubular part of a secondary preform; and said localized annealing step is applied to the tubular wall of the primary preform, before said shrinking step;

[0033] - the localized annealing step is implemented by an induction technique, advantageously within a tunnel inductor, advantageously with rotation of the preform;

[0034] - the method comprises an operation of shrinking the downstream strip of the tubular part prior to the roll forming operation; said roll forming operation is adjusted to form said roll outwardly and such that the outside diameter of said roll is less than or equal to the thread root diameter;

[0035] - the operation of forming the transport ring is carried out before the operation of forming the roll; the transport ring is advantageously used for holding the tubular part during said roll forming operation;

[0036] - the thread forming operation is applied to an intermediate strip present a height of 10 to 25 mm;

[0037] - the step of forming the tubular part also comprises a forming operation of a tamper-evident counter-ring within an additional band of the tubular part, located between the intermediate band and the upstream band, forming a tamper-evident counter-ring groove between said tamper-evident counter-ring and said transport ring;

[0038] - the method also comprises a varnishing phase, preferably a phase of exterior varnishing and an interior varnishing phase implemented after the localized annealing step;

[0039] - the metal packaging is made from an aluminum alloy of the 3000 series or 5000, for example an aluminum alloy 3104;

[0040] - the operation of forming the transport ring is chosen from a technique of molding, for example by internal pressure exerted by a pressurized fluid or by the compression of an elastomer, which causes the wall to take the shape of a mold, or a direct mechanical action by a moving tool, for example by pushing the metal by rotating a wheel on the internal face of the tubular part while an external wheel, opposite the first, holds the metal, or an overlying and underly-shrinking technique;

[0041] - the operation of forming the transport ring includes a calibration phase to give a definitive shape to said transport ring; in this case, preferably, the calibration phase advantageously consists of bringing the upper connection radius and the lower connection radius of the ring of transport, in contact with each other, or to obtain an upper connection radius and a lower connection radius of the transport ring which are radially offset from each other, with said lower connection radius which is advantageously in abutment against the upper surface of the transport ring, in particular to ensure the transfer of the axial force towards the transport ring during capping, and / or to bring the external radius of the transport ring to a minimum radius acceptable by the constituent material; the calibration phase is advantageously carried out by pinching the annular deformation between two calibration rings which are coaxial with the longitudinal axis of the tubular part, or by two knurling wheels rotating around the tubular part, with advantageously the introduction into the tubular part of a centering mandrel during calibration to ensure the concentricity of the overlying and underlying parts of the tubular part;

[0042] - during the forming operation of the transport ring, an axial load is exerted on the metal packaging to accompany the metal in its deformation and avoid thinning and breakage;

[0043] - the method also comprises a step of placing a metal capsule on the neck threaded.

[0044] The present invention also relates to the metal packaging, in the form of a bottle, resulting from a method according to the invention.

[0045] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0046] Furthermore, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate non-limiting forms of embodiment of the invention and where:

[0047] [Fig. 1] is a general and schematic view of a bottle-shaped metal packaging, resulting from the manufacturing process according to the invention;

[0048] [Fig.2] is a schematic and partial view of the metal packaging according to the [Fig.l], illustrating in more detail its threaded neck;

[0049] [Fig.3] is a schematic view, in section, of a step of placing a capsule metallic on the threaded neck;

[0050] [Fig.4] is a schematic view illustrating the main phases / steps of the process manufacturing method according to the invention for manufacturing the bottle-shaped metal packaging;

[0051] [Fig.5] is a schematic view of the localized annealing step which is applied on a preform during the manufacturing process according to the invention;

[0052] [Fig.6] is a schematic view of the operation of forming the transport ring by means of an elastomer compression molding technique;

[0053] [Fig.7] is a schematic view of the operation of forming the transport ring by means of a molding technique by internal pressure exerted by a pressurized fluid;

[0054] [Fig.8] is a schematic view of the operation of forming the transport ring by direct mechanical action using expandable segments;

[0055] [Fig.9] is also a schematic view of the operation of forming the transport ring by direct mechanical action by pushing back the metal by rotation of an internal wheel / external wheel pair;

[0056] [Fig. 10] is a schematic view illustrating an axial load exerted on the metal packaging, during the operation of forming the transport ring;

[0057] [Fig. 11] is a schematic view illustrating the operation of forming the transport ring by overlying and underlying necks applied in the tubular part;

[0058] [Fig. 12] is a schematic view of a phase of calibrating the transport ring, to give a definitive shape to said transport ring, by the implementation of two calibrating rings;

[0059] [Fig. 13] is a schematic view of a phase of calibrating the transport ring, to give a definitive shape to said transport ring, by the implementation of two rotating wheels;

[0060] [Fig. 14] is a schematic, partial and sectional view of a threaded neck after the calibration phase, the upper connecting radius and the lower connecting radius of the transport ring of which are in contact with each other;

[0061] [Fig. 15] is also a schematic, partial and sectional view of a threaded neck after the calibration phase, the upper connecting radius and the lower connecting radius of the transport ring of which are offset relative to each other.

[0062] It should be noted that, in these figures, the structural and / or functional elements common to the different variants may have the same references.

[0063] Figures 1 to 3 thus represent a metal packaging, in the form of a bottle, resulting from the process according to the invention.

[0064] Generally speaking, such metal packaging is advantageously made of aluminum or steel.

[0065] Solely by way of example, the metal packaging 1 is made from an aluminum alloy of the 3000 or 5000 series, for example an aluminum alloy 3104.

[0066] Such a metal packaging 1 advantageously consists of a container or receptacle, intended to receive for example a liquid product (in particular drinks), pasty or solid (in particular powders or granules).

[0067] This metal packaging 1 consists for example of a bottle, a flask or a can.

[0068] This metal packaging 1 is advantageously intended to be hermetically sealed, after filling, by means of a metal capsule C which is advantageously conventional in itself (described below in relation to [Fig.3]).

[0069] Generally speaking, such a metal capsule C advantageously comprises:

[0070] - a bottom Cl provided with a compressible seal C2,

[0071] - a skirt C3, intended to cooperate with a thread, and

[0072] - advantageously a C4 tamper-evident ring.

[0073] The metal packaging 1, in the form of a bottle, advantageously comprises a body 2 (or belly) which is connected to a threaded neck 3 (or neck) by means of a shoulder 4.

[0074] The threaded neck 3 defines a longitudinal axis 3', here oriented vertically and advantageously coaxially with the body 2.

[0075] This threaded neck 3 is constituted by a single-piece metal wall 5 which defines its circumference and which delimits an internal conduit T terminated at the level of a downstream opening 6 opposite the shoulder 4 (figures 2 and 3).

[0076] The general horizontal section of this threaded neck 3, perpendicular to the longitudinal axis 3', is here of circular shape; it could just as easily be oval, rectangular or square for example.

[0077] The threaded neck 3 of this metal packaging 1 comprises a succession of single-piece structures, illustrated in particular in figures 2 and 3, namely:

[0078] - a roll 7, at the level of the downstream opening 6 of the threaded neck 3, advantageously intended to cooperate with the bottom Cl of capsule C (see in particular [Fig.3]),

[0079] - a thread 8, advantageously intended to cooperate with the skirt C3 of capsule C,

[0080] - a transport ring 9, on the side of the shoulder 4, intended to cooperate with a member handling (not shown), and

[0081] - possibly a tamper-evident counter-ring 10, forming a counter-groove tamper-evident ring 11 with the transport ring 9, advantageously intended to cooperate with the tamper-evident ring C4 of capsule C.

[0082] The downstream opening 6 of the tubular part 1 is constituted here by the roll 7 which is oriented towards the outside, delimiting this downstream opening 6 of the internal conduit T (figures 1 and 2).

[0083] The thread 8 forms means for receiving a stopper or a capsule ([Fig.3]), in this case in the form of a helical thread.

[0084] The transport ring 9 advantageously comprises at least one molding 9 which is arranged on a plane extending perpendicular to the longitudinal axis 3' and on the circumference of the threaded neck 3.

[0085] Said at least one molding 9 comprises a lower surface 91 and / or upper surface 92 against which a handling member (not shown) is intended to come to bear.

[0086] This handling member (not shown) advantageously has a fork shape, of the type conventionally encountered in the field of handling plastic bottles fitted with a transport ring.

[0087] By “molding” is meant in particular a ribbing in the single-piece metal wall 5 (commonly referred to in English as “bead”), hollow or in relief, obtained for example by striking or by embossing.

[0088] The molding 9 is here continuous, extending over the entire circumference of the threaded neck 3.

[0089] The molding 9 is here arranged to project towards the outside of the threaded neck 3.

[0090] The vertical section of this molding 9 is advantageously identical or at least approximately identical on its circumference, without geometric break.

[0091] Generally, the lower 91 and upper 92 surfaces of said at least one molding 9 advantageously have a crown shape.

[0092] Said at least one molding 9 is further defined by different radii:

[0093] - a lower connecting radius 93, on the side of the shoulder 4,

[0094] - an upper connecting radius 94, on the side of the thread 8,

[0095] - an external radius 95, connecting the two lower surfaces 91 and upper surfaces 92.

[0096] Advantageous characteristics relating to the shape of this molding 9, as well as its forming and its calibration, will be described in more detail later in relation to figures 6 and following.

[0097] Generally, the present invention relates to the method for manufacturing such a bottle-shaped metal packaging 1.

[0098] As illustrated in [Fig.4], the manufacturing method according to the invention comprises successive steps:

[0099] - a step of manufacturing a preform 15 comprising a tubular part 16 (intended to be subsequently formed to constitute the threaded neck 3) which is connected to the body 2 by means of a shoulder 4 (items A and B of [Fig.4]), then

[0100] - a step of forming this tubular part 16, to form the threaded neck 3 (items C to F of [Fig.4]).

[0101] In particular, the tubular part 16, intended to form the threaded neck 3 after forming, defines a longitudinal axis 16' and a free downstream edge 161.

[0102] For the manufacture of the threaded neck 3 in this tubular part 16, the forming step comprises operations of forming the single-piece metal wall 5 which are adapted to form the different single-piece structures 7, 8, 9 and 10 of the threaded neck 3 within superimposed strips of the tubular part 16.

[0103] In this case, as further illustrated in [Fig.4], the forming operations include:

[0104] - an operation of forming the roll 7 within a downstream strip 162 of the part tubular 16, terminated by the downstream edge 161, to form the roll 7 at the level of this downstream edge 161 of the threaded neck 3 (items E and F of [Fig.4]),

[0105] - an operation of forming the thread 8 within an intermediate strip 163 of the tubular part 16 (items D and E of [Fig.4]), and

[0106] - an operation of forming the transport ring 9 within an upstream strip 164 of the tubular part 16, on the side of the shoulder 4, by a fold of metal forming an annular deformation (items B to D of [Fig.4]), and possibly

[0107] - an operation of forming the tamper-evident counter-ring 10 within a strip additional 165 of the tubular part 16, located between the intermediate strip 163 and the upstream strip 164.

[0108] According to a particular embodiment, the step of forming the tubular part 16 comprises an operation of shrinking the downstream strip 162 of the tubular part 16, prior to the operation of forming the roll 7 (see item B of [Fig.4]).

[0109] The operation of forming the roll 7 is then advantageously adjusted to form the roll 7 outwards and so that the outside diameter of this roll 7 is less than or equal to the thread bottom diameter 8 (see in particular [Fig.3]).

[0110] According to the embodiment illustrated in [Fig.4], the operation of forming the transport ring 9 (items C and D) is implemented before the operation of forming the roll 7 (item F).

[0111] This arrangement of operations makes it possible to use the transport ring 9 for holding the tubular part 16 during the operation of forming the roll 7, or even also during the operation of forming the subsequent thread 8.

[0112] Without being limiting, and independently of one another, the forming operations are applied to the following respective heights:

[0113] - a downstream band 162 of 3 to 7 mm,

[0114] - an intermediate strip 163 of 10 to 25 mm, and

[0115] - an upstream band 164 of 5 to 15 mm.

[0116] Preferably, the manufacturing method may also comprise a step of placing a metal capsule C on the threaded neck 3 ([Fig.3]).

[0117] This operation is implemented by a classic technique in itself.

[0118] The capsule C is made integral with this threaded neck 3 by a rotating capping head R.

[0119] For example, the rotary capping head R performs three simultaneous operations:

[0120] - the central tip of the rotary capping head R, by applying a load axial on the capsule C, compresses the seal C2 on the upper part of the rolled 7 of the metal packaging 1 and re-stamped the upper corner of the capsule C to apply the seal C2 to the external face of the roll 7,

[0121] - wheels rotating around the skirt C3 of the capsule C apply a force axial which pushes the metal of the skirt C3 into the hollows of the thread 8, thus creating the thread of the skirt C3, and

[0122] - rotating wheels around the C4 tamper-evident ring crimp it under the protruding from the tamper-evident counter-ring 10.

[0123] At the end of the manufacturing process, a metal packaging 1 in the shape of a bottle is obtained, as illustrated in Figures 1 to 3. Localized annealing step

[0124] The manufacturing method according to the invention comprises, at least prior to the operation of forming the rolled part 7, a localized annealing step (also called “annealing”) which is carried out to confer an annealed state to the tubular part 16 at least over the height of the downstream strip 162 of the tubular part 16 (illustrated very schematically by item B of [Fig.4]).

[0125] Generally, the localized annealing step is advantageously carried out to impart an annealed state:

[0126] - only at the level of the downstream strip 162 (intended to form the roll 7),

[0127] - only at the level of the downstream band 162 and the upstream band 164 (intended for respectively form the roll 7 and the transport ring 9), so as to keep at least part of the height of the intermediate strip 163 in an unannealed state to give the thread 8 optimal mechanical resistance qualities, or

[0128] - at the level of the downstream strip 162, the intermediate strip 163 and the upstream strip 164, or even over the entire height of the tubular part 16 intended to form the threaded neck.

[0129] Such a localized annealing step has the advantage of modifying the property of the material, the elastic limit, the ductility and the elongation at break, conferring malleability to the material constituting the tubular part 16.

[0130] The annealing step thus allows the threaded neck 3 to be formed, allowing a reduction in the thickness of the body of the metal packaging 1 while maintaining resistance to capping forces.

[0131] For example, the single-piece metal wall 5 has a thickness ranging from 0.2 to 0.5 mm.

[0132] Preferably, the annealing step is still applied before the step of forming the tubular part 16 (i.e. before forming the different monobloc structures 7, 8, 9 and 10 of the threaded neck 3 within the superimposed strips 162, 163, 164, 165 of the tubular part 16).

[0133] Preferably, the localized annealing step is carried out to impart an annealed state over a height of at least 3 to 7 mm to the downstream strip 162 of the tubular part 16, starting from the downstream edge 161.

[0134] Similarly, the localized annealing step is advantageously carried out to impart an annealed state over the height of the upstream strip 164 of said tubular part 16, advantageously over a height of 5 to 15 mm.

[0135] As developed below, the localized annealing step is advantageously implemented on a primary preform 15a comprising a tubular wall 18 of which a downstream section 181 is intended to undergo a constriction to form the tubular part 16 of the preform 15.

[0136] The implementation of this localized annealing step on this downstream section 181, then of shrinking this downstream section 181, has the advantage of conferring interesting mechanical properties for the forming operations of the tubular part 16 (advantageously, the mechanical work in shrinking restores part of the work hardening).

[0137] Generally, the localized annealing step can be implemented to bring other parts of the preform 15, 15a into an annealed state, for example the body 2 or the shoulder 3 to facilitate their forming.

[0138] Still generally, in this localized annealing step, the metal of the preform 15, 15a is advantageously subjected to a high temperature, generally in the range of 150 to 450°C, such as 200 to 400°C and more preferably 200 to 350°C.

[0139] Annealing is carried out at a suitable temperature for a suitable period of time to achieve the desired reduction in yield strength and improvement in ductility and elongation at break.

[0140] Generally, for aluminum, the temperature is between 200°C and 400°C.

[0141] For high temperature annealing, the annealing temperature is higher, for example 350°C to 454°C for a duration of 1 qs (microsecond) to 1 h (hour), for example 0.1 s (second) to 30 min (minutes), 1 s to 5 min or 10 s to 1 min.

[0142] For steel, the annealing temperature range is normally much higher and may be, for example, 500°C to 950°C and the time period may be, for example, 1 qs to 1 h, such as 0.1 s to 30 min, 1 s to 5 min, or 10 s to 1 min.

[0143] The annealing treatment results in a reduction in hardness, a reduction in yield strength and an increase in ductility.

[0144] Generally, as illustrated in [Fig.5], the localized annealing step is implemented by an induction technique.

[0145] This induction technique is advantageously carried out within a tunnel inductor D, advantageously with rotation of the preforms 15, 15a.

[0146] This rotation is for example ensured by means M for rotating each preform 15, 15a around an axis of rotation parallel to its longitudinal axis (for example the longitudinal axis 18' of the tubular wall 18 described below).

[0147] The rotation means M consist for example of a pair of lateral conveyor belts which comprise facing strands sandwiching the preforms 15, 15a and traveling at a relative speed appropriate for generating the rotation of the preforms 15, 15a during the localized annealing step.

[0148] Induction annealing is thus carried out by scrolling the preforms 15, 15a in the tunnel inductor D, with concentration of the magnetic field to advantageously obtain partial annealing of the areas of interest of the tubular wall 18 by thermal conduction and / or convection.

[0149] This approach advantageously reduces the loss of axial strength of the thread 8, while improving the formability of the roll 7. Preform manufacturing stage

[0150] Prior to forming the tubular part 16 into a threaded neck 3, the step of manufacturing the preform advantageously comprises:

[0151] - a phase of deformation of a metal part (not shown) to obtain a primary preform 15a comprising a base 17 extended by a tubular wall 18 advantageously having a constant diameter over its height (see item A of [Fig.4]),

[0152] - a trimming phase, to form the downstream edge 161 of the primary preform 15a (item A of [Fig.4]), and

[0153] - a shrinking step, here of a downstream section 181 of the tubular wall 18, to form the tubular part 16 of a secondary preform 15, the tubular part 16 of which is connected to the body 2 by means of a shoulder 4 (items A and B of [Fig.4]).

[0154] The deformation phase is advantageously chosen from among the techniques which are conventional per se, for example from among stamping and / or drawing and / or reverse spinning.

[0155] In particular, the stamping and / or drawing is preferably applied to a metal part consisting of a metal blank having, for example, a thickness ranging from 0.2 mm to 0.7 mm.

[0156] Stamping and / or drawing consist, for example, of a technique chosen from stamping / drawing (also called “Drawing and Wall Ironing” or DWI) or stamping and re-stamping (also called “Draw and Re Draw process” or DRD).

[0157] Reverse spinning is preferably applied from a 2 to 15 mm pin.

[0158] Furthermore, according to the invention and as mentioned previously, the localized annealing step is advantageously applied prior to the step of forming the tubular part 16.

[0159] In this case, this annealing step is applied prior to the shrinking step, preferably between the trimming step and the shrinking step.

[0160] This annealing step is thus advantageously applied to the tubular wall 18 of the primary preform 15a (item A of [Fig.4]), before the shrinking step (item B of [Fig.4]).

[0161] The localized annealing step is preferably applied to at least part of the height (or even the entire height) of the downstream section 181 of the tubular wall 18 (intended to form the tubular part 16), depending on the annealed / unannealed state which is expected at the level of the bands of the tubular part 16.

[0162] In particular, the localized annealing step is advantageously located at the level:

[0163] - only at the level of a downstream portion 182 corresponding, after shrinking, to the strip downstream 162 (intended to form roll 7),

[0164] - only at the level of a downstream portion 182 and an upstream portion 184 corresponds, after shrinking, respectively to the downstream strip 162 and to the upstream strip 164 (intended to form respectively the roll 7 and the transport ring 9), or

[0165] - at the level of the downstream portion 182, of an intermediate portion 183 and of the portion upstream 184 corresponding, after shrinking, respectively to the downstream strip 162, to the intermediate strip 163 and to the upstream strip 164, or even over the entire height of the downstream section 181 intended to be shrinked to form the tubular part 16.

[0166] Generally, the method also advantageously comprises a phase of varnishing the preform 15, 15a, preferably an external varnishing phase and an internal varnishing phase.

[0167] This varnishing phase is preferably implemented after the localized annealing step, or even before the shrinking step (between items A and B of [Fig.4]).

[0168] The varnishing phase, after the localized annealing step, makes it possible to protect the varnish against thermal degradation.

[0169] Conveyor ring forming / calibration operation

[0170] The present invention also relates to the operation of forming, or even calibrating, the transport ring 9.

[0171] The forming operation consists for example of a molding technique (figures 6 and 7).

[0172] In this sense, the molding technique consists, for example, of applying an internal pressure which causes the single-piece metal wall 5 to take on the shape of a mold 20.

[0173] This internal pressure is exerted for example by:

[0174] - the compression of an elastomer 21 ([Fig.6]), or

[0175] - a pressurized fluid which is injected by means of an injection head 22 ([Fig.7]).

[0176] The molding technique can also consist of using extensible segments 23 ([Fig.8]).

[0177] The forming operation can also consist of a direct mechanical action by the rotation of an internal wheel 24 on the internal face of the tubular part 16 while an external wheel 25, opposite the first, holds the metal of the single-piece metal wall 5.

[0178] In this case, the internal wheel 24 preferably comprises a single rib 241; and the external wheel 25 comprises a pair of ribs 251, located on either side of the single rib 241.

[0179] Generally speaking, during the operation of forming the transport ring 9, an axial load F is advantageously exerted on the metal packaging 1, advantageously parallel to the longitudinal axis 16' of the tubular wall 16 ([Fig. 10]).

[0180] This approach has the advantage of accompanying the metal in its deformation and avoiding the phenomena of thinning and ruptures.

[0181] This axial load is for example exerted by means of at least one support tool 28 which exerts an axial load on the tubular part 16 during the operation of forming the transport ring 9.

[0182] Said at least one tool 28 can exert an axial load for example at the downstream edge 161 of the tubular part 16 and / or at the bottom of the body 2 (opposite the tubular part 16, at the bottom 17).

[0183] Said at least one tool 28 can exert an axial load which is for example uniform over the entire circumference of the downstream edge 161 or localized on a zone situated on a generatrix passing through the zone during the forming of the transport ring 9.

[0184] This axial load is for example exerted by means of a support tool 28, for example in the form of a crown, which exerts an axial load on the downstream edge 161 (in the direction of the bottom 17 of the body 2).

[0185] According to another embodiment illustrated in [Fig. 11], the operation of forming the transport ring 9 may consist of a technique of overlying and underlying shrinking of the tubular part 16.

[0186] For this, for example, the successive phases are implemented:

[0187] - a shrinking phase overlying the tubular part 16, to form the surface upper 92 of the transport ring 9 (items A and B of [Fig.l 1]), then

[0188] - an underlying shrinking phase, to form the lower surface 91 of the ring transport 9, for example by means of a pair of wheels 29 (items C and D of [Fig.11]).

[0189] Preferably, the operation of forming the transport ring 9 also comprises a calibration phase to give a definitive shape to the transport ring 9.

[0190] This calibration operation is in particular intended to deform the lower 91 and upper 92 surfaces of the transport ring 9 to give it its final shape.

[0191] The calibration phase is for example carried out:

[0192] - by pinching the annular deformation between two calibration rings 30, which are coaxial with the longitudinal axis 16' of the tubular part 16 and which are maneuvered in axial translation towards each other ([Fig.12]), or

[0193] - by two wheels 31 rotating around the tubular part 16 ([Fig. 13]).

[0194] In particular, these calibration rings 30 and the wheels 31 are shaped / profiled / arranged to define, after deformation, the shape of the lower 91 and upper 92 surfaces of the transport ring 9.

[0195] Preferably, a centering mandrel 32 (illustrated in [Fig. 12]) is introduced into the tubular part 16 during calibration to ensure the concentricity of the overlying and underlying parts of the tubular part 16 (on either side of the transport ring 9).

[0196] In practice, as illustrated in [Fig.14], the calibration phase consists for example of:

[0197] - to bring the upper connecting radius 94 and the connecting radius lower 93 of the transport ring 9, in contact with each other, to ensure optimal transfer of the axial force towards the transport ring 9 during capping ([Fig. 14]), and / or

[0198] - to bring the external radius 95 of the transport ring 9 to a minimum radius acceptable by the constituent material.

[0199] Alternatively, as illustrated in [Fig.15], the upper connecting radius 94 and the lower connecting radius 93 of the transport ring 9 are radially offset from each other (while advantageously extending coaxially).

[0200] In this case, the diameter of the upper connecting radius 94 (in a plane perpendicular to the longitudinal axis 16') is advantageously smaller than the diameter of the lower connecting radius 93 (in a plane perpendicular to the longitudinal axis 16') of the transport ring 9.

[0201] The lower connecting radius 93 advantageously bears against the upper surface 92 of the transport ring 9.

[0202] Such an embodiment provides a transport ring 9 whose upper surface 92 and lower surface 91 have different widths (the upper surface 92 is here wider than the lower surface 91).

[0203] This embodiment is for example obtained by a set of adapted wheels 29, similar to [Fig.l 1], for an overlying and underlying shrinking technique of the tubular part 16 which is differential in diameter (the overlying and underlying diameters of the tubular part 16 are different from each other; the overlying diameter is here less than the underlying diameter).

[0204] Of course, various other modifications may be made to the invention within the scope of the appended claims.

Claims

Claims

1. Method for manufacturing a bottle-shaped metal packaging, said metal packaging (1) comprising a body (2) connected to a threaded neck (3) via a shoulder (4), which method comprises: - a step of manufacturing a preform (15) comprising a tubular part (16), defining a longitudinal axis (16') and a free downstream edge (161), which tubular part (16) is connected to a body (2) via a shoulder (4), and - a step of forming said tubular part (16), to form said threaded neck (3), which forming step comprises forming operations adapted to form single-piece structures on said tubular part (16): - an operation of forming a roll (7) within a downstream strip (162) of said tubular part (16), terminated by said downstream edge (161), to form a roll (7) at the downstream edge (161) of the neck threaded (3),- an operation of forming a thread (8) within an intermediate strip (163) of said tubular part (16), and - an operation of forming a transport ring (9) within an upstream strip (164) of said tubular part (16), on the shoulder (4) side, intended to cooperate with a handling member, characterized in that said manufacturing method comprises, prior at least to said operation of forming the roll (7), preferably prior to said step of forming said tubular part (16), a localized annealing step which is carried out to impart an annealed state to the tubular part (16), at least over the height of the downstream strip (162) of said tubular part (16), which localized annealing step is carried out to impart an annealed state: - only at the level of said downstream strip (162), or - only at the level of the downstream strip (162) and the upstream strip (164),so as to retain at least a portion of the height of the interlayer strip (163) in an unannealed state.,

2. A method for manufacturing a bottle-shaped metal packaging (1) according to claim 1, characterized in that the step localized annealing is performed to impart an annealed condition over a height of at least 3 to 7 mm of the downstream strip (162) of said tubular portion (16).

3. Method for manufacturing a bottle-shaped metal packaging (1), according to any one of claims 1 or 2, characterized in that the localized annealing step is carried out to impart an annealed state over the height of the upstream strip (164) of said tubular part (16), advantageously over a height of 5 to 15 mm.

4. Method for manufacturing a metal packaging (1) in the shape of a bottle, according to any one of claims 1 to 3, characterized in that the step of manufacturing the preform (15) comprises: - a phase of deformation of a metal part to obtain a primary preform (15a) comprising a bottom (17) extended by a tubular wall (18), - a trimming phase, to form a downstream edge (161) of said primary preform (15a), and - a shrinking step, to form said tubular part (16) of a secondary preform (15), and in that said localized annealing step is applied to the tubular wall (18) of the primary preform (15a), before said shrinking step.

5. Method for manufacturing a bottle-shaped metal packaging (1), according to any one of claims 1 to 4, characterized in that the localized annealing step is implemented by an induction technique, advantageously within a tunnel inductor, advantageously with rotation of the preform (15).

6. Method for manufacturing a bottle-shaped metal packaging (1) according to any one of claims 1 to 5, characterized in that the operation of forming the transport ring (9) is carried out before the operation of forming the roll (7), which transport ring (9) is advantageously used for holding the tubular part (16) during said operation of forming the roll (7).

7. Method for manufacturing a bottle-shaped metal packaging (1) according to any one of claims 1 to 6, characterized in that the step of forming the tubular part (16) further comprises an operation of forming a counter- tamper-evident ring (10) within an additional band (165) of the tubular part (16), located between the intermediate band (163) and the upstream band (164), forming a tamper-evident counter-ring groove (11) between said tamper-evident counter-ring (10) and said transport ring (9).

8. Method for manufacturing a metal packaging (1) in the shape of a bottle, according to any one of claims 1 to 7, characterized in that said method further comprises a varnishing phase, preferably an external varnishing phase and an internal varnishing phase carried out after the localized annealing step.

9. Method for manufacturing a metal container (1) in the shape of a bottle, according to any one of claims 1 to 8, characterized in that said metal container (1) is made of an aluminum alloy of the 3000 or 5000 series, for example an aluminum alloy 3104.

10. Method for manufacturing a bottle-shaped metal packaging (1), according to any one of claims 1 to 9, characterized in that the operation of forming the transport ring (9) is chosen from: - a molding technique, or - a direct mechanical action by a mobile tool, or - an overlying and underlying shrinking technique.

11. Method for manufacturing a metal packaging (1) in the shape of a bottle, according to any one of claims 1 to 10, characterized in that the operation of forming the transport ring (9) comprises a calibration phase to give a definitive shape to said transport ring (9).

12. Method for manufacturing a bottle-shaped metal packaging (1) according to claim 11, characterized in that the calibrating phase consists of: - bringing the upper connecting radius (94) and the lower connecting radius (93) of the transport ring (9) into contact with each other, or obtaining an upper connecting radius (94) and a lower connecting radius (93) of the transport ring (9) which are radially offset from each other, with said lower connecting radius (93) which is advantageously in abutment against the upper surface (92) of the transport ring (9), and / or - to bring the external radius (95) of the transport ring (9) to a minimum radius acceptable by the constituent material.

13. Method for manufacturing a bottle-shaped metal packaging (1), according to claim 12, characterized in that the calibration phase is carried out by: - ​​pinching the annular deformation between two calibration rings (30) which are coaxial with the longitudinal axis (16') of the tubular part (16), or - by two knurled wheels (31) rotating around the tubular part (16), with advantageously the introduction into the tubular part (16) of a centering mandrel (32) during the calibration to ensure the concentricity of the overlying and underlying parts of the tubular part (16).

14. Method for manufacturing a bottle-shaped metal packaging (1) according to any one of claims 1 to 13, characterized in that, during the operation of forming the transport ring (9), an axial load is exerted on the metal packaging (1) to accompany the metal in its deformation and avoid thinning and breakage.

15. Method for manufacturing a metal packaging (1) in the shape of a bottle, according to any one of claims 1 to 14, characterized in that it further comprises a step of placing a metal capsule (C) on the threaded neck (3).

Images