Title - PROCEDURE FOR THE MANUFACTURE OF A METAL CONTAINER IN THE SHAPE OF A BOTTLE

Abstract

The present invention relates to a process for manufacturing a bottle-shaped metal container (1). The process comprises a step of forming a tubular part (16) to create a threaded neck (3). This manufacturing process comprises, prior to at least one operation of forming a rolled flange (7), preferably prior to said step of forming said tubular part (16), a localized annealing step performed to impart an annealed state to the tubular part (16), at least in the height of a rear band (162) of said tubular part (16) intended to be formed into a rolled flange (7).

Description

DESCRIPTION PROCEDURE FOR MANUFACTURING A METAL CONTAINER IN THE SHAPE OF A BOTTLE Technical field of the invention The present invention relates to the technical field of metal containers in the form of a bottle. The invention relates, in particular, to processes for manufacturing such bottle-shaped metal containers, the neck of which comprises at least one rolled flange, a thread, and a carrying ring. Prior art Certain bottle-shaped containers consist of a threaded neck that is hermetically sealed, after filling, by means of a capsule. The design of such a container must take into account restrictions related to its manufacture, but also to its numerous manipulations in the filler from its reception to the final conditioning operations. However, depending on their constituent material, the containers are obtained through manufacturing techniques that generate structural restrictions that lead to the implementation of dedicated transport facilities. In this respect, the tubular part that forms the neck of containers made of plastic material (such as bottles or jars) generally consists of an annular crown, protruding from the circumference and designated as the transport ring, useful for individual collection. These plastic containers can thus be held, handled and / or transferred by positioning a holding element in the general shape of a fork, which rests under this transport ring. In practice, for such plastic containers, the neck and its ring of 1594119 of 23 transport are formed simultaneously, for example in a preform (semi-finished part obtained by injection) before a finish by injection blow molding or by extrusion blow molding. Containers made of a metallic material, for example steel or aluminum, are, for their part, often devoid of such a transport ring due to technical restrictions linked to the shaping of the metal. The manufacture, handling, and filling of such metal containers thus lead to the implementation of dedicated handling equipment. Therefore, for the filler, the transition from plastic containers to metal containers requires significant investments, specifically for the transformation of handling equipment. To alleviate this problem, there are developments of metal containers whose threaded neck, which consists, specifically, of a terminal rolled flange and a transport ring, would be adapted to handling within a facility usually dedicated to plastic containers. However, in practice, technical constraints related to metal forming create fragility during the shaping of this threaded neck. The threaded neck of the metal bottle must also be able to withstand the capping forces, while simultaneously allowing for a reduction in metal thickness. Given the above, there is a need for a technical solution that would allow the manufacture of metal bottles consisting of a threaded neck adapted to receive a capsule and that would be compatible with plastic bottle filling lines, while allowing a reduction in the thickness of their metal wall. Presentation of the invention In order to remedy the aforementioned drawback of the prior art, the present invention proposes a method for manufacturing such bottle-shaped metal containers, the neck of which comprises at least one rolled flange, a thread, and a carrying ring. 1594119 of 23 More particularly, the invention proposes a method for manufacturing a bottle-shaped metal container, said metal container consisting of a body connected to a threaded neck by means of a shoulder. The procedure according to the invention comprises: - a manufacturing stage of a preform consisting of a tubular part, which defines a longitudinal axis and a free rear edge, a tubular part that is connected to a body by means of a shoulder, and - a shaping stage of said tubular part, to form said threaded neck. The forming stage comprises forming operations adapted to create monoblock structures in said tubular part: - an operation forming a rolled flange within a back band of said tubular part, terminated by said back edge, to form a rolled flange at the level of the back edge of the threaded neck, - an operation forming a thread within an intermediate band of said tubular part, and - an operation of forming a transport ring within a front band of said tubular part, on the shoulder side, intended to cooperate with a holding member (said transport ring advantageously comprising at least one molding that is made in a plane extending perpendicular to said longitudinal axis and on the circumference of the tubular part, at least one molding consisting of a lower and / or upper surface against which a holding member is intended to rest). And according to the invention, the manufacturing process comprises, prior at least to said operation of forming the rolled flange, preferably prior to said stage of forming said tubular part, a localized annealing stage which is performed to give an annealed state to the tubular part, at least in the height of the back band of said tubular part. 1594119 of 23 The present invention thus offers a technical solution that would allow the manufacture of metal bottles consisting of a threaded neck adapted to receive a capsule and that would be compatible with plastic bottle filling lines, while allowing a reduction in the thickness of their metal wall. Indeed, the rolled flange is formed above the thread at the end of the tubular portion of the preform. Often, the metal that has been drawn to form the preform is then upset to form the threaded neck; however, the applicant has found that the metal is susceptible to tearing during the forming of the rolled flange. This results in a significant proportion of production being discarded. The applicant has found that annealing this area, improving its conformability, allows for a reduction in the rate of cut necks. Other non-limiting and advantageous features of the procedure according to the invention, taken individually or in all technically possible combinations, are as follows: - the localized annealing stage is performed to confer an annealed state at a height of at least 3 to 7 mm of the back band of said tubular part; - the localized annealing stage is performed to confer an annealed state only at the level of said back band, only at the level of the back band and the front band, to retain at least part of the height of the middle band in an unannealed state, or at the level of the back band, the middle band and the front band; - the localized annealing stage is performed to confer an annealed state at the height of the previous band of said tubular part, advantageously at a height of 5 to 15 mm; - the preform manufacturing stage comprises a phase of deforming a metal part to obtain a primary preform comprising a bottom extended by a tubular wall, for example, selected from deep drawing and / or stretching and / or reverse spinning, for example, by 1594119 of 23 drawing and / or stretching of a metal sheet for, for example, a thickness ranging from 0.2 mm to 0.7 mm, advantageously by a technique selected from drawing / stretching or drawing and redrawing (DWI or Draw and Re Draw process (DRD)) or reverse spinning from a 2 to 15 mm pin, a trimming stage, to form a back edge of said primary preform, and an upsetting stage, to form said tubular part of a secondary preform; and said localized annealing stage is applied to the tubular wall of the primary preform, before said upsetting stage; - the localized annealing stage is implemented by an induction technique, advantageously within a tunnel inductor, advantageously with preform rotation; - the procedure comprises an upsetting operation of the back band of the tubular part prior to the rolled flange forming operation; said rolled flange forming operation is adjusted to form said rolled flange outwards and so that the outside diameter of said rolled flange is less than or equal to the thread root diameter; - The carrier ring forming operation is implemented before the rolled flange forming operation; the carrier ring is advantageously used for clamping the tubular part during said rolled flange forming operation; - the thread forming operation is applied to an intermediate band with a height of 10 to 25 mm; - the tubular part forming stage 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 previous band, which forms a tamper-evident counter-ring groove between said tamper-evident counter-ring and said transport ring; - the procedure also includes a varnishing phase, preferably an exterior varnishing phase and an interior varnishing phase 1594119 of 23 implemented after the localized annealing stage; - the metal container is made of an aluminum alloy from the 3000 or 5000 series, for example an aluminum alloy 3104; - the operation of forming the transport ring is selected from a molding technique, for example by internal pressure exerted by a pressurized fluid or by compression of an elastomer, which causes the wall to conform to the shape of a mold, or a direct mechanical action by means of a movable tool, for example by embossing the metal by rotating a grooved wheel on the inner face of the tubular part during which an external grooved wheel, opposite the first, holds the metal, or an overlying and underlying upsetting technique; - the operation of forming the transport ring comprises 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 transport ring into contact with each other, or of obtaining an upper connection radius and a lower connection radius of the transport ring that are radially displaced from one another, with said lower connection radius being advantageously supported against the upper surface of the transport ring, in particular to ensure the transfer of axial force to the transport ring during encapsulation, and / or of bringing the outer radius of the transport ring to a minimum radius acceptable by the constituent material;The calibration phase is advantageously carried out by pressing the annular deformation between two calibration rings that are coaxial to the longitudinal axis of the tubular part, or by means of two grooved 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; - During the process of forming the transport ring, an axial load is exerted on the metal container to accompany the metal in its deformation and prevent thinning and breakage; 1594119 of 23 - the procedure also includes a step of placing a metal capsule on the threaded neck. The present invention also relates to the metal container, in the form of a bottle, derived from a process according to the invention. Of course, the different features, variants, and embodiments of the invention can be associated with each other in various combinations, provided they are not incompatible or exclusive of each other. Detailed description of the invention Furthermore, several other features of the invention are apparent from the accompanying description made with reference to the drawings illustrating non-limiting ways of embodying the invention, and in which: Figure 1 is a general and schematic view of a bottle-shaped metal container, derived from the manufacturing process according to the invention; Figure 2 is a schematic and partial view of the metal container according to Figure 1, which illustrates its threaded neck in more detail; Figure 3 is a schematic, cross-sectional view of a stage in placing a metal capsule on the threaded neck; Figure 4 is a schematic view illustrating the main phases / stages of the manufacturing process according to the invention for the manufacture of the metal bottle-shaped container; Figure 5 is a schematic view of the localized annealing stage applied to a preform during the manufacturing process according to the invention; Figure 6 is a schematic view of the operation of forming the transport ring by means of a compression molding technique of an elastomer; Figure 7 is a schematic view of the operation of forming the transport ring by means of a molding technique using an internal pressure exerted by a pressurized fluid; Figure 8 is a schematic view of the forming operation of 1594119 of 23 transport ring by means of a direct mechanical action using expandable segments; Figure 9 is also a schematic view of the operation of forming the transport ring by direct mechanical action by embossing the metal by rotating an internal grooved wheel / external grooved wheel pair; Figure 10 is a schematic view illustrating an axial load exerted on the metal container during the operation of forming the transport ring; Figure 11 is a schematic view illustrating the operation of shaping the transport ring by means of overlying and underlying upsets applied to the tubular part; Figure 12 is a schematic view of a calibration phase of the transport ring, to give a definitive shape to said transport ring, by implementing two calibration rings; Figure 13 is a schematic view of a calibration phase of the transport ring, to give a definitive shape to said transport ring, by implementing two rotating grooved wheels; Figure 14 is a schematic, partial, and cross-sectional view of a threaded neck after the calibration phase, whose upper connection radius and lower connection radius of the carrying ring are in contact with each other; Figure 15 is also a schematic, partial, and cross-sectional view of a threaded neck after the calibration phase, whose upper connection radius and lower connection radius of the transport ring are offset from each other. It should be noted that, in these figures, the structural and / or functional elements common to the different variants may have the same references. Figures 1 to 3 thus represent a metal container, in the form of a bottle, derived from the procedure according to the invention. In general, a metal container of this type is advantageously 1594119 of 23 made of aluminum or steel. For example, metal container 1 is made of an aluminum alloy from the 3000 or 5000 series, for example an aluminum alloy 3104. A metal container 1 of this type advantageously consists of a receptacle or container, intended to receive, for example, a liquid product (specifically beverages), a pasty product, or a solid product (specifically powders or granules). This metal container 1 consists, for example, of a bottle, a jar, or a drum. This metal container 1 is advantageously intended to be hermetically sealed, after filling, by means of a metal capsule C which is advantageously classic in itself (described below in relation to Figure 3). In general, a metal capsule C of this type advantageously consists of: - a bottom C1 provided with a compressible joint C2, - a C3 skirt, intended to cooperate with a thread, and - advantageously a C4 tamper-evident ring. The bottle-shaped metal container 1 advantageously comprises a body 2 (or belly) that is connected to a threaded neck 3 (or spout) by means of a shoulder 4. The threaded neck 3 defines a longitudinal axis 3', here oriented vertically and, advantageously, coaxially to the body 2. This threaded neck 3 consists of a monoblock metal wall, 5 which defines its circumference and delimits an internal channel T, terminated at the level of an anterior opening 6 opposite the shoulder 4 (figures 2 and 3). The general horizontal section of this threaded neck 3, perpendicular to the longitudinal axis 3', is here circular in shape; it could also be oval, rectangular or square, for example. The threaded neck 3 of this metal container 1 consists of a succession of monoblock structures, illustrated in particular in figures 2 and 3, namely: - a rolled flange 7, at the level of the anterior opening 6 of the threaded neck 1594119 of 23 3, advantageously intended to cooperate with the C1 fund of capsule C (see, in particular, Figure 3), - an 8 thread, advantageously intended to cooperate with the C3 skirt of capsule C, - a carrying ring 9, on the shoulder side 4, intended to cooperate with a holding organ (not shown), and - eventually a tamper-evident counter-ring 10, which forms a tamper-evident counter-ring groove 11 with the transport ring 9, advantageously intended to cooperate with the tamper-evident ring C4 of capsule C. The anterior opening 6 of the tubular part 1 is formed here by the coiled rim 7 which is oriented outwards, which delimits this anterior opening 6 from the inner duct T (figures 1 and 2). Thread 8 forms means for receiving a plug or a capsule (Figure 3), in this case in the form of a helical thread. The transport ring 9 advantageously comprises at least one molding 9 that is made in a plane extending perpendicular to the longitudinal axis 3' and on the circumference of the threaded neck 3. Said at least one molding 9 consists of a lower surface 91 and / or upper surface 92 against which a holding organ (not shown) is intended to rest. This holding organ (not shown) advantageously features a fork shape, of the type classically found in the field of holding plastic bottles equipped with a transport ring. Specifically, a molding is understood to be a rib in the monoblock metal wall 5 (commonly referred to in English as a 'bead'), either hollow or in relief, obtained, for example, by stamping or by embossing. Molding 9 is continuous here, extending around the entire circumference of the threaded neck 3. Molding 9 is made here projecting outwards from the threaded neck 3. 1594119 of 23 The vertical section of this molding 9 is advantageously identical or at least approximately identical in its circumference, without geometric break. In general, the lower 91 and upper 92 surfaces of said at least one molding 9 advantageously consist of a crown shape. At least one molding 9 is also defined by different radii: - a lower connection radius of 93, on the shoulder side 4, - a top connection radius of 94, on the thread side 8, - an external radius 95, which connects the two lower surfaces 91 and upper surfaces 92. Advantageous features relating to the shape of this molding 9, as well as its conformation and calibration, will be described in more detail below in relation to Figures 6 and following. In general, the present invention relates to the process for manufacturing a metal container 1 of this type in the form of a bottle. As illustrated in Figure 4, the manufacturing process according to the invention comprises successive steps: - a manufacturing stage of a preform 15 consisting of a tubular part 16 (intended to be further shaped to form the threaded neck 3) which is connected to the body 2 by means of a shoulder 4 (elements A and B in Figure 4), and further - a shaping stage of this tubular part 16, to form the threaded neck 3 (elements C to F of figure 4). In particular, the tubular part 16, intended to form the threaded neck 3 after shaping, defines a longitudinal axis 16' and a free rear edge 161. For the manufacture of the threaded neck 3 in this tubular part 16, the forming stage comprises forming operations of the monoblock metal wall 5 that are adapted to form the different monoblock structures 7, 8, 9 and 10 of the threaded neck 3 within overlapping bands of the tubular part 16. In this specific case, as also illustrated in figure 4, the 1594119 of 23 forming operations comprise: - a forming operation of the rolled flange 7 within a back band 162 of the tubular part 16, terminated by the back edge 161, to form the rolled flange 7 at the level of this back edge 161 of the threaded neck 3 (elements E and F of figure 4), - a thread forming operation 8 within an intermediate band 163 of the tubular part 16 (elements D and E of figure 4), and - a forming operation of the transport ring 9 within a previous band 164 of the tubular part 16, on the shoulder side 4, by means of a metal fold forming an annular deformation (elements B to D of figure 4), and eventually - a shaping operation of the tamper-evident counter-ring 10 within an additional band 165 of the tubular part 16, located between the intermediate band 163 and the previous band 164. According to a particular embodiment, the shaping step of the tubular part 16 comprises an upsetting operation of the back band 162 of the tubular part 16, prior to the shaping operation of the rolled flange 7 (see element B of figure 4). The rolling flange forming operation 7 is then advantageously adjusted to form the rolling flange 7 outwards and so that the outside diameter of this rolling flange 7 is less than or equal to the thread root diameter 8 (see specifically Figure 3). According to the embodiment illustrated in Figure 4, the shaping operation of the transport ring 9 (elements C and D) is implemented before the shaping operation of the rolled flange 7 (element F). This arrangement of operations allows the transport ring 9 to be used for securing the tubular part 16 during the rolled flange forming operation 7, and also during the subsequent thread forming operation 8. Without being exhaustive, and independently of each other, the shaping operations are applied at the following respective heights: 1594119 of 23 - a back band 162 of 3 to 7 mm, - an intermediate band 163 of 10 to 25 mm, and - a previous band 164 of 5 to 15 mm. Preferably, the manufacturing process may also include a step of placing a metal capsule C in the threaded neck 3 (Figure 3). This operation is implemented using a classic technique per se. The capsule C is made integral with this threaded neck 3 by means of a rotary capping head R. For example, the rotary capping head R performs three simultaneous operations: - the central end piece of the rotary capping head R, applying an axial load to the capsule C, compresses the seal C2 onto the top of the rolled flange 7 of the metal container 1 and re-embosses the upper corner of the capsule C to apply the seal C2 onto the outer face of the rolled flange 7, - Splined wheels rotating around the C3 skirt of the C capsule apply an axial force that pushes the metal of the C3 skirt into the holes of the thread 8, thus creating the C3 skirt thread, and - grooved wheels rotating around the tamper-evident ring C4 engage it under the projection of the tamper-evident counter-ring 10. At the end of the manufacturing process, a metal container 1 in the shape of a bottle is obtained, as illustrated in figures 1 to 3. Localized annealing stage The manufacturing process according to the invention comprises, prior at least to the operation of forming the rolled flange 7, a localized annealing stage (also called annealing) which is performed to give an annealed state to the tubular part 16 at least in the height of the back band 162 of the tubular part 16 (illustrated very schematically by element B in figure 4). In other words, the localized annealing stage is advantageously performed so that the tubular part 16 is in an annealed state 1594119 of 23 which is variable in its height. In other words, the tubular part 16 advantageously presents, in its height, an annealing gradient. Also preferably, the localized annealing step is performed to 5 confer an annealed state only to the tubular part 16, at least in the height of the back band 162 of the tubular part 16. In other words, only the tubular part 16 is in an annealed state, at least to the height of the back band 162 of the tubular part 16. The body 2 and / or the shoulder 4 are advantageously in a non-annealed state. In general, the localized annealing stage is advantageously performed to confer an annealed state: - only at the level of the back band 162 (intended to form the rolled rim 7), - only at the level of the rear band 162 and the front band 164 15 (intended to form respectively the rolled flange 7 and the transport ring 9), to retain at least part of the height of the intermediate band 163 in an unannealed state to give the thread 8 optimal mechanical strength qualities, or - at the level of the rear band 162, the intermediate band 163 and the front band 164, including the entire height of the tubular part 16 intended to form the threaded neck. A localized annealing stage of this type has the interest of modifying the material property, the elastic limit, the ductility and the elongation at break, giving malleability to the material constituting the tubular part 25 16. The annealing stage thus allows the shaping of the threaded neck 3, allowing a reduction in the thickness of the metal container body 1 while maintaining resistance to capping forces. For example, the monoblock metal wall 5 has a thickness ranging from 0.2 to 0.5 mm. Preferably, the annealing stage is also applied before the stage 1594119 of 23 of forming the tubular part 16 (i.e., before forming the different monoblock structures 7, 8, 9 and 10 of the threaded neck 3 within the overlapping bands 162, 163, 164, 165 of the tubular part 16). Preferably, the localized annealing step is performed to 5 confer an annealed state to a height of at least 3 to 7 mm on the back band 162 of the tubular part 16, starting from the back edge 161. Furthermore, the localized annealing stage is advantageously performed to confer an annealed state on the height of the previous band 164 of said tubular part 16, advantageously at a height of 5 to 15 mm. As described below, the localized annealing stage is advantageously implemented in a primary preform 15a consisting of a tubular wall 18, a front section 181 of which is intended to undergo upsetting to form the tubular part 16 of the preform 15. The implementation of this localized annealing stage in this previous section 181, in addition to upsetting this previous section 181, has the interest of conferring interesting mechanical properties for the forming operations of the tubular part 16 (advantageously, the mechanical work in upsetting restores a part of the cold beating). In general, the localized annealing stage can be implemented 20 to bring other parts of the preform 15, 15a to an annealed state, for example the body 2 or the shoulder 3 to facilitate its shaping. Also in general, in this localized annealing stage, 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 25 more preferably from 200 to 350 °C. Annealing is carried out at an appropriate temperature for an appropriate period of time to obtain the desired reduction of the yield strength and the improvement of ductility and elongation at break. Generally, for aluminum, the temperature is between 30,200 °C and 400 °C. For high-temperature annealing, the annealing temperature is higher 1594119 of 23 high, for example 350 °C to 454 °C for a period of 1 ps (microsecond) to 1 h (hour), for example 0.1 s (second) to 30 min (minutes), 1 sa 5 min or 10 sa 1 min. For steel, the annealing temperature range is normally much higher and can be, for example, from 500 °C to 950 °C, and the time period can be, for example, from 1 ps to 1 h, such as 0.1 sa 30 min, 1 sa 5 min, or 10 sa 1 min. Annealing treatment results in a reduction of hardness, a reduction of the yield strength, and an increase in ductility. In general, as illustrated in Figure 5, the localized annealing stage is implemented using an induction technique. This induction technique is advantageously performed within a tunnel inductor D, advantageously with rotation of preforms 15, 15a. This rotation is, for example, guaranteed by means of putting each preform 15, 15a into rotation around an axis of rotation parallel to its longitudinal axis (for example the longitudinal axis 18' of the tubular wall 18 described below). The means of setting up rotation M consist, for example, of a pair of lateral conveyor belts consisting of facing strands that interleave the preforms 15, 15a and run at a relative speed appropriate to generate the rotation of the preforms 15, 15a during the localized annealing stage. Induction annealing is thus carried out by displacement of 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. This approach advantageously reduces the axial strength loss of thread 8, while improving the conformability of the rolled flange 7. Preform manufacturing stage Prior to forming the tubular part 16 into a threaded neck 3, the preform manufacturing stage advantageously comprises: 1594119 of 23 - a deformation phase of a metal piece (not shown) to obtain a primary preform 15a comprising a bottom 17 extended by a tubular wall 18 advantageously having a constant diameter in its height (see element A of figure 4), - a trimming phase, to form the rear edge 161 of the primary preform 15a (element A in figure 4), and - an upsetting stage, here of a previous section 181 of the tubular wall 18, to form the tubular part 16 of a secondary preform 15, whose tubular part 16 is connected to the body 2 by means of a shoulder 4 (elements A and B of figure 4). The deformation phase is advantageously selected from the classic techniques per se, for example from deep drawing and / or stretching and / or reverse spinning. In particular, deep drawing and / or stretching is preferably applied to a metal part consisting of a metal sheet that has, for example, a thickness ranging from 0.2 mm to 0.7 mm. Drawing and / or stretching consist, for example, of a technique selected from drawing / stretching (also called Drawing and Wall Ironing or DWI) or drawing and redrawing (also called Draw and Re Draw process or DRD). Reverse spinning is preferably applied starting from a pin of 2 to 15 mm. On the other hand, according to the invention and as mentioned above, the localized annealing stage is advantageously applied prior to the forming stage of the tubular part 16. In this specific case, this annealing stage is applied prior to the upsetting stage, preferably between the trimming stage and the upsetting stage. This annealing stage is thus advantageously applied to the tubular wall 18 of the primary preform 15a (element A in Figure 4), before the upsetting stage (element B in Figure 4). The localized annealing stage is preferably applied in at least 1594119 of 23 a part of the height (including the entire height) of the previous section 181 of the tubular wall 18 (intended to form the tubular part 16), depending on the annealed / unannealed state that thickens at the level of the bands of the tubular part 16. In particular, the localized annealing stage is advantageously located at the level of: - only at the level of a posterior portion 182 corresponds, after upsetting, to the posterior band 162 (intended to form the rolled rim 7), - only at the level of a posterior portion 182 and an anterior portion 184 corresponds, after the stress, respectively to the back band 162 and the previous band 164 (intended to form, respectively, the rolled flange 7 and the transport ring 9), or - at the level of the rear portion 182, of an intermediate portion 183 and of the front portion 184 which correspond, after upsetting, respectively to the rear band 162, to the intermediate band 163 and to the front band 164, including the entire height of the front section 181 intended to be upset to form the tubular part 16. In general, the procedure also advantageously includes a varnishing phase of the preform 15, 15a, preferably an exterior varnishing phase and an interior varnishing phase. This varnishing phase is preferably implemented after the localized annealing stage, and even before the upsetting stage (between elements A and B in Figure 4). The varnishing phase, following the localized annealing stage, allows the varnish to be protected against thermal degradation. Conveyor ring shaping / calibration operation The present invention also relates to the shaping operation, including calibration, of the transport ring 9. The shaping operation consists, for example, of a molding technique (Figures 6 and 7). In this sense, the molding technique consists, for example, of applying 1594119 of 23 an internal pressure that causes the monoblock metal wall 5 to conform to the shape of a mold 20. This internal pressure is exerted, for example, by: - the compression of an elastomer 21 (Figure 6), or - a pressurized fluid that is injected by means of an injection head 22 (figure 7). The molding technique can also consist of using extensible segments 23 (figure 8). The forming operation can also consist of a direct mechanical action by rotating an internal splined wheel 24 on the inner face of the tubular part 16 while an external splined wheel 25, opposite the first, clamps the metal of the monoblock metal wall 5. In this particular case, the internal splined wheel 24 preferably consists of a single rib 241; and the external splined wheel 25 consists of a pair of ribs 251, located on either side of the single rib 241. In general, during the operation of forming the transport ring 9, an axial load F is advantageously exerted on the metal container 1, advantageously parallel to the longitudinal axis 16' of the tubular wall 16 (Figure 10). This approach is useful for supporting the metal during its deformation and preventing thinning and breakage. This axial load is exerted, for example, 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. Said at least one tool 28 can exert an axial load, for example, at the level of the rear edge 161 of the tubular part 16 and / or at the level of the bottom of the body 2 (on the other side of the tubular part 16, at the level of the bottom 17). Said at least one tool 28 can exert an axial load that is, for example, uniform over the entire circumference of the trailing edge 161 or localized in an area located on a generatrix passing through the area in progress 1594119 of 23 of the transport ring formation 9. This axial load is exerted, for example, by means of a support tool 28, for example in the form of a crown, which exerts an axial load on the rear edge 161 (in the direction of the bottom 17 of body 2). According to an embodiment illustrated in Figure 11, the operation of forming the transport ring 9 can consist of an overlying and underlying upsetting technique of the tubular part 16. To achieve this, for example, the following successive phases are implemented: - an overlying upsetting phase of the tubular part 16, to form the upper surface 92 of the transport ring 9 (elements A and B of figure 11), and then - an underlying upsetting phase, to form the lower surface 91 of the transport ring 9, for example by means of a pair of grooved wheels 29 (elements C and D of figure 11). Preferably, the operation of forming the transport ring 9 also includes a calibration phase to give a final shape to the transport ring 9. This calibration operation is specifically intended to deform the lower 91 and upper 92 surfaces of the transport ring 9 to give it its final shape. The calibration phase is carried out, for example: - pressing the annular deformation between two calibration rings 30, which are coaxial to the longitudinal axis 16' of the tubular part 16 and which are maneuvered according to an axial translation towards each other (figure 12), or - by means of two grooved wheels 31 rotating around the tubular part 16 (figure 13). In particular, these calibration rings 30 and grooved 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. Preferably, a centering mandrel 32 (illustrated in figure 12) is 1594119 of 23 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). In practice, as illustrated in Figure 14, the calibration phase consists, for example: - in bringing the upper connection radius 94 and the lower connection radius 93 of the carrier ring 9 into contact with each other, to ensure optimal transfer of axial force to the carrier ring 9 during capping (Figure 14), and / or - in bringing the external radius 95 of the transport ring 9 to a minimum radius acceptable by the constituent material. Alternatively, as illustrated in Figure 15, the upper connection radius 94 and the lower connection radius 93 of the transport ring 9 are radially offset from each other (while advantageously extending coaxially). In this case, the diameter of the upper connection radius 94 (in a plane perpendicular to the longitudinal axis 16') is advantageously smaller than the diameter of the lower connection radius 93 (in a plane perpendicular to the longitudinal axis 16') of the transport ring 9. The lower connecting radius 93 is advantageously supported against the upper surface 92 of the carrying ring 9. One embodiment of this type offers a transport ring 9 whose upper surface 92 and lower surface 91 consist of different widths (the upper surface 92 is here wider than the lower surface 91). This embodiment is obtained, for example, by means of a set of grooved wheels 29 adapted, similar to figure 11, for an overlying and underlying upsetting technique of the tubular part 16 which is differential in diameter (whose overlying and underlying diameters of the tubular part 16 are different from each other; the overlying diameter here is less than the underlying diameter). 1594119 of 23 Of course, various other modifications to the invention can be provided within the framework of the attached claims. 1594119 of 23 ARIEL JUAN IBAÑEZ - 20232572532 Digitally signed by PORTALTRAM ITES - INPI Date: 2021.11.25 14:38:18-03:00 Reason: Digitally Signed by the INPI Location: Buenos Aires, Argentina 1594119

Claims

1. A method for manufacturing a bottle-shaped metal container, said metal container (1) comprising a body (2) connected to a threaded neck (3) by means of a shoulder (4), the method comprising: - a step of manufacturing a preform (15) comprising a tubular part (16) defining a longitudinal axis (16') and a free rear edge (161), the tubular part (16) being connected to a body (2) by means of a shoulder (4), and - a step of forming said tubular part (16) to form said threaded neck (3), the forming step comprising forming operations adapted to form monoblock structures in said tubular part (16): - an operation of forming a rolled flange (7) within a rear band (162) of said tubular part (16), terminated by said rear edge (161), to form a rolled flange (7) at the level of the rear edge (161) of the threaded neck (3),- a thread forming operation (8) within an intermediate band (163) of said tubular part (16), and - a carrying ring forming operation (9) within a front band (164) of said tubular part (16), on the shoulder side (4), intended to cooperate with a holding member, and comprising, prior at least to said rolled flange forming operation (7), preferably prior to said forming step of said tubular part (16), a localized annealing step that is performed to confer an annealed state to the tubular part (16), at least at the height of the rear band (162) of said tubular part (16); characterized in that the localized annealing step is performed to confer an annealed state: - only at the level of said rear band (162), or - only at the level of the rear band (162) and the front band (164),to retain at least a portion of the height of the intermediate band (163) in an unannealed state. Two claims follow,