Container made of olefin-based polymeric material

Abstract

A container (1) made of olefin-based polymeric material, obtained by blow moulding a parison (2) made by compression moulding a charge of molten polymeric material, comprises a body (11) which extends around a 5 longitudinal axis (X) between a first end (11A) and a second end (11B), and a neck (12) which is joined to the body (11) at the first end (11A); the step of compression moulding has a duration included in an interval between 0.2 and 2.0 seconds; a temperature of the molten polymeric material from which the charge is obtained is less than or equal to 240°C.

Description

[0001] DESCRIPTION

[0002] CONTAINER MADE OF OLEFIN-BASED POLYMERIC MATERIAL

[0003] Technical field

[0004] This invention relates to a container made of olefin-based polymeric material, where the container is obtained by blow moulding a parison made by compression moulding a charge of the molten polymeric material.

[0005] Background art

[0006] A container of this type may be used to contain foods, drinks, medicines or other products. Generally speaking, the container comprises a body which extends around a longitudinal axis between a first end and a second end, and a neck which is joined to the body at the first end.

[0007] An example of a container made of olefin-based polymeric material is described in patent US11578151 B2; in particular, that document describes a container made of HDPE by compressing a charge of the material to obtain a parison and then blow moulding the parison to obtain the container.

[0008] Patent document US2017 / 175260A1 describes a container where the main material is polyamide, mixed with polyolefin.

[0009] In the field of compression and blow moulding, there continues to be a need for a container which is capable of combining good mechanical properties with a particularly low cost.

[0010] Disclosure of the invention

[0011] This invention has for an aim to provide a container made of olefin-based polymeric material to overcome the above mentioned disadvantages of the prior art.

[0012] In particular, the aim of this invention is to provide a high-quality container made of olefin-based polymeric material and which, in particular, has good mechanical properties.A further aim of this invention is to provide a container made of olefin-based polymeric material and which has a low production cost.

[0013] This aim is fully achieved by the container made of olefin-based polymeric material of this disclosure as characterized in the appended claims.

[0014] In particular, the container is obtained by blow moulding a parison made by compression moulding a charge of the molten polymeric material. The container comprises a body which extends around a longitudinal axis between a first end and a second end, and a neck which is joined to the body at the first end.

[0015] Preferably, the container is a pharmaceutical container.

[0016] The step of compression moulding has a duration included in an interval between 0.2 and 2.0 seconds. In particular, the step of compression moulding has a duration of between 0.2 and 1.0 second; more in particular the step of compression moulding may have a duration of between 0.5 and 1.0 second.

[0017] A temperature of the molten polymeric material from which the charge is obtained is less than or equal to 240°C. In particular, the temperature of the molten polymeric material may be less than or equal to 220°C.

[0018] The container may be made using the apparatus described in patent document IT2021000032507 which is in the name of the present Applicant and which is incorporated herein by reference; in such an apparatus, the production of the containers comprises: a step of obtaining the charges of polymeric material by means of an extruder, and a step of distributing the charges into a plurality of cavities of a compression station; a step of compressing the charges by inserting a plurality of punches into the cavities, a step of translating the parisons thus moulded (towards at least one blow moulding module) and blow moulding the parisons to form containers and then extracting the containers from the machine. Patent documents IT102022000011978 and IT102022000011984, in the name of the present applicant, show examples of apparatuses for distributing a plurality of charges simultaneously from the same extruder. The texts ofIT2021000032507, IT102022000011978 and IT102022000011984 are incorporated herein by reference. In the examples illustrated, the process of distributing and compressing the charges and blow moulding the parisons is carried out in batches, which allows simultaneously moulding and compressing a plurality of parisons, and simultaneously blow moulding the same plurality to obtain a plurality of containers at the same time. Moreover, the systems used to distribute the charges guarantee high precision, ensuring that the weight of the charges is constant. Consequently, the containers made vary by less than 1.5% with respect to the nominal weight of the product, thus ensuring uniform product quality. Since the time needed for the compression moulding of the charges is reduced (in particular, between 0.2 and 2 seconds), it is possible to start with a lower melting point for the polymeric material (in particular, less than or equal to 240°) because, after being moulded, the parison is still hot enough to be blow moulded; moreover, the parison need not be reconditioned, for example by heating, before being blow moulded, which means saving time and energy. Thus, the reduced production times and the lower temperature of the polymeric material combine to allow savings in production costs.

[0019] Further, a duration of moulding between 0.2 and 2 seconds allows to complete the preform before the plastic material undergoes a significant cooling, allowing to obtain a preform with reduced thickness and substantially uniform.

[0020] Patent document WO2023 / 237968A1 discloses an apparatus for the compression moulding; however, said document does not provide any indication regarding the duration of the preform moulding. It is also observed that, in case of alternative technologies such as injection moulding, moulding durations less than 2 seconds are not realistically achievable.

[0021] Document US2017 / 175260A1 does not refer to the temperature of the molten material that is used, it merely indicates that the mold temperaturemay be as high as 80°C; it is also noted that the polymeric material primarly used in the containers of US2017 / 175260A1 is a polyamide, which has a melting temperature of approximately 238°C, implying a significantly higher processing temperature for the material, for example, in the order of 270-280°C.

[0022] In particular, the step of compression moulding includes a step of inserting the charge into a mould.

[0023] The mould comprises an upper half mould (or punch) and a lower half mould (or cavity). The upper half mould and the lower half mould are aligned along a main axis. In particular, the main axis coincides with a longitudinal axis of the parison (which coincides with the longitudinal axis of the container after blow moulding the parison). The step of moulding comprises a step of moving the upper half mould and the lower half mould towards each other (preferably along the main axis); the upper half mould and the lower half mould can move towards each other until reaching a limit distance between the upper half mould and the lower half mould. At the limit distance, the upper half mould is operatively inserted in the lower half mould to define a moulding cavity. The step of moulding includes a step of compressing the charge by means of the upper half mould and the lower half mould positioned at the limit distance so as to make the parison. The step of moulding comprises a step of moving the upper half mould and the lower half mould apart, starting from the limit distance, and a step of extracting the moulded parison.

[0024] Preferably, the duration of compression moulding starts at an instant when the upper half mould and the lower half mould reach the limit distance; preferably, the duration of compression moulding ends at an instant when the upper half mould and the lower half mould start moving apart starting from the limit distance. In other words, the duration of compression moulding has a starting point, when the upper half mould and the lower half mould reach the limit distance and an ending point, when the upper half mould and the lower half mould start moving apart starting from thelimit distance. More specifically, the duration of compression moulding is referenced to the step of compressing the charge when the upper half mould and the lower half mould are positioned at the limit distance so as to make the parison.

[0025] In particular, moulding is accomplished by a compression mould including a body portion, configured to form the body of the container, and a neck portion, configured to form the neck of the container. Thus, the upper half mould and the lower half mould cooperate to define the body portion and the neck portion.

[0026] Preferably, a temperature of the neck portion of the mould (configured to form the neck of the container) during moulding is between 15° and 25°, for example, 20°C.

[0027] Generally speaking, the neck portions of the moulds need to be cooled because of the high temperature of the molten material the process starts with. Since the starting temperature of the molten material is reduced, less heat has to be removed from the neck portion, which means that the neck portion needs less cooling and that moulding temperature can be higher, bringing the mould to a temperature higher than that required by prior art moulds, thereby saving energy.

[0028] Furthermore, since the temperature of the molten plastic is lower to start with (lower compared to prior art moulding methods), it is not necessary to cool the neck portion of the parison very much; consequently, the thermal gradient on the body of the parison is reduced in both axial and radial directions.

[0029] The axial thermal gradient of the parison may be measured using a camera, for example, a thermal camera (infrared camera) capable of capturing images or videos representing the temperature using a colour scale.

[0030] This allows using a single temperature regulation for the compression tools, since heat exchange is limited (because contact duration is short) and there is less temperature difference between the different areas of thetool. This simplifies heat control and optimizes the quality of the process on the mould side of the machine.

[0031] In particular, the container has an OTR oxygen permeability of between 0.025 and 0.470 cc / pkg*day, preferably between 0.035 and 0.350 cc / pkg*day. In particular, the container has an MVTR water vapour permeability of between 0.25 and 4.0 mg / day*container, preferably between 0.33 and 3.20 mg / day*container. Thus, these parameters ensure a low rate of transmission of gaseous substances, such as oxygen and water vapour, into the container. The reference standard for the OTR oxygen permeability is the ASTM F1307 standard. The reference standard for the MVTR water vapour permeability is the USP671 standard.

[0032] In particular, the body of the container has a wall. The wall of the container has an average thickness, measured transversely to the longitudinal axis, preferably of between 0.3 mm and 2.5 mm, more preferably of between 0.3 mm and 0.8 mm; even more preferably between 0.5 mm and 0.8 mm. The parison has a body and a neck. The body of the parison extends around the longitudinal axis and defines the body of the container (when the parison is blow moulded). The neck of the parison defines the neck of the container (when the parison is blow moulded). The neck of the parison also extends around the longitudinal axis. The body of the parison has a wall. The wall of the parison body has an average thickness, measured transversely to the longitudinal axis, preferably of between 1.2 mm and 4.0 mm, more preferably between 1.5 mm and 3.0 mm.

[0033] The rapidity of moulding makes it possible to blow mould even thin parisons because these remain within a temperature window which is suitable for subsequent blow moulding.

[0034] A variation along the longitudinal axis of the extension of the body of the container around the longitudinal axis is less than 1% with respect to a nominal value. In other words, a radial distance of the container body from the longitudinal axis has a variation along the longitudinal axis of less than 1% with respect to a nominal value. That is to say, the body of thecontainer extends axially in a substantially straight manner. Since the thicknesses are distributed uniformly, both axially and radially, the container is characterized by a low rate of transmission of gaseous substances, such as oxygen and water vapour, into the container.

[0035] The neck of the container has a wall which extends annularly around the longitudinal axis. In an example, the wall of the container neck has a plurality of portions which are withdrawn towards the longitudinal axis relative to the annular extension. Thus, the neck wall is not perfectly cylindrical but is marked by thermal shrinkage of the screw thread. That is because the container production time is reduced.

[0036] In an embodiment, the neck has a screw thread (configured to be coupled to a matching screw thread of a closure for the container).

[0037] The annular extension of the body wall may have a factor of ovalization (called sink) of less than 1% with respect to a nominal value.

[0038] The annular extension of the neck wall may have a factor of ovalization of less than 1% with respect to a nominal value. In particular, the ovalization is measured considering a diameter of the neck wall and / or of the neck thread. The ovalization may be measured as a difference between a diameter of the neck which is circular in shape and a diameter of the neck which is oval in shape. The ovalization of the neck may be less than or equal to 0.33 mm (in absolute terms). The diameter (hence also the factor of ovalization) is measured at an outside surface of the neck wall.

[0039] The annular extension of the neck may be between 15 mm and 63 mm in diameter.

[0040] The annular extension of the container body may be between 15 mm and 90 mm in diameter.

[0041] The container has a bottom which extends transversely to the longitudinal axis and is joined to the body at the second end. Preferably, the bottom has an outside surface which is substantially smooth. In an example, the outside surface is without the dividing centre line between the moulds. Thus, the bottom of the container does not have the typical marks createdby the processing of the plastic. The container does not have cut scars, that is to say, it does not have any scar marks.

[0042] This disclosure also provides a container made of olefin-based polymeric material obtained by blow moulding a parison made by compression moulding a charge of molten polymeric material, wherein the container comprises a body which extends around a longitudinal axis between a first end and a second end, and a neck which is joined to the body at the first end, and wherein the body of the container has a wall having an average thickness, measured transversely to the longitudinal axis, of between 0.3 mm and 2.5 mm.; an OTR oxygen permeability of the container is between 0.025 and 0.470 cc / pkg*day and an MVTR water vapour permeability of the container is between 0.25 and 4.0 mg / day*container. The reference standard for the OTR oxygen permeability is the ASTM F1307 standard. The reference standard for the MVTR water vapour permeability is the USP671 standard.

[0043] In an embodiment, the container has a top load (defined as the load applied parallel to the longitudinal axis) of at least 100N and / or a side load (defined as the load orthogonal to the longitudinal axis) of at least 20N. The reference standard for top load and / or side load is the ASTM D642 standard.

[0044] In an example, a variation along the longitudinal axis of the extension of the body of the container around the longitudinal axis is less than 1% with respect to a nominal value.

[0045] The neck of the container has a wall which extends annularly around the longitudinal axis; in an example, the wall of the container neck has a plurality of portions which are withdrawn towards the longitudinal axis relative to the annular extension.

[0046] An annular extension around the longitudinal axis of the container wall has a factor of ovalization of less than 1% with respect to a nominal value. The container has a bottom which extends transversely to the longitudinal axis and is joined to the body at the second end. Preferably, the bottommay have an outside surface which is substantially smooth.

[0047] In particular, the container is made of HDPE material. HDPE material is characterized by a t / 2 crystallization time of less than 2 min if measured at 124°C. HDPE material is characterized by a minimum density of 0.940 g / cc. HDPE material is characterized by post extrusion swelling (die swell) of less than 1.5.

[0048] HDPE material may have one or more of the following properties: density (g / cc) of between 0.941 and 0.960; melt flow index MFI (g / 10min), with 2.16 kg applied load, of between 0.2 and 57.0; melting point (°C) of between 130 and 138; tensile modulus (MPa) of between 180 and 1800; tensile strength (MPa) of between 10 and 43; elongation at break (%) of between 6 and 45.

[0049] Brief description of drawings

[0050] These and other features will become more apparent from the following description of a preferred embodiment, illustrated by way of non-limiting example in the accompanying drawings, in which:

[0051] - Figures 1A and 1B illustrate a container according to one or more features set out in this disclosure;

[0052] - Figures 2A and 2B illustrate a parison according to one or more features set out in this disclosure;

[0053] - Figure 3 illustrates a mould according to one or more features set out in this disclosure.

[0054] Detailed description of preferred embodiments of the invention The numeral 1 in the drawings denotes a container made of olefin-based polymeric material. The container 1 comprises a body 11 and a neck 12. The body 11 extends around a longitudinal axis X between a first end 11 A and a second end 11 B. The neck 12 is joined to the body 11 at the first end 11 A. The container 1 has a bottom 13. The bottom wall 13 extends transversely to the longitudinal axis X and is joined to the body 11 at thesecond end 11 B.

[0055] The body 11 of the container 1 has a wall. The wall of the body 11 extends annularly around the longitudinal axis X; however, the wall of the body 11 might also have other shapes extending around the longitudinal axis X. The neck 12 of the container 1 has a wall which extends annularly around the longitudinal axis X. The neck 12 is provided with a screw thread to couple the container 1 to a corresponding screw thread of a closure or cap.

[0056] The container 1 is made by blow moulding a parison 2 obtained from a charge of polymeric material. The parison 2 comprises a body 21 and a neck 22. The body 21 of the parison 2 extends around the longitudinal axis X and defines the body 11 of the container 1 when the parison 2 is blow moulded. The body 22 of the parison 2 extends around the longitudinal axis X and defines the body 12 of the container 1 when the parison 2 is blow moulded.

[0057] The wall of the body 11 of the container 1 has an average thickness S1 , preferably of between 0.3 mm and 2.5 mm, preferably 0.7 mm, where the average thickness S1 is measured transversely (that is, radially) to the longitudinal axis X.

[0058] The wall of the body 22 of the parison 2 has an average thickness S2 of between 1.2 mm and 4.0 mm, preferably between 1.5 mm and 3.0 mm, where the average thickness S2 is measured transversely (that is, radially) to the longitudinal axis X.

[0059] A radial distance of the body 11 of the container 1 from the longitudinal axis X has a variation along the longitudinal axis X of less than 1% with respect to a nominal value. Furthermore, the annular extension of the wall of the body 11 of the container 1 has a factor of ovalization of less than 1% with respect to a nominal value; the annular extension of the wall of the neck 12 of the container 1 has a factor of ovalization of less than 1% with respect to a nominal value. The ovalization of the neck 12 of the container 1 is less than or equal to 0.33 mm in absolute terms. Theannular extension of the neck 12 is between 15 mm and 63 mm in diameter; the annular extension of the container body is between 15 mm and 90 mm in diameter.

[0060] The wall of the neck 12 of the container 1 has a plurality of portions which are withdrawn towards the longitudinal axis X; the withdrawn portions represent thermal shrinkage of the neck 12 of the container 1.

[0061] The container 1 has an OTR oxygen permeability of between 0.025 and 0.470 cc / pkg*day, preferably between 0.035 and 0.350 cc / pkg*day. In particular, the container has an MVTR water vapour permeability of between 0.25 and 4.0 mg / day*container, preferably between 0.33 and 3.20 mg / day*container.

[0062] The container 1 has an outside surface which is substantially smooth, in particular without any scar marks.

[0063] The parison 2 is made by compression moulding a charge of molten polymeric material. Moulding is accomplished by a mould 3. The mould 3 includes an upper half mould 31 and a lower half mould 32 (also called punch and cavity, respectively) aligned with each other along a main axis A. The upper half mould 31 and the lower half mould 32 cooperate to define a body portion 32A and a neck portion 31 A. The body portion 32A is configured to form the body 11 of the container 1. The neck portion 31 A is configured to form the neck 12 of the container 1. Preferably, the neck portion 31 A belongs to the upper half mould 31 and the body portion 32A belongs to the lower half mould 32 (and / or to the upper half mould 31). In particular, the upper half mould 31 includes a punch 31 B configured to form the body 11 of the container 1.

[0064] A temperature of the molten polymeric material from which the charge is obtained is less than or equal to 240°C, preferably less than or equal to 220°C. A temperature of the neck portion 31 A of the mould (configured to form the neck 12) during moulding is between 15° and 25°.

[0065] Compression moulding includes a step of inserting the charge into the mould 3; a step of moving the upper half mould 31 and the lower halfmould 32 towards each other until reaching a limit distance L between the upper half mould 31 and the lower half mould 32; a step of compressing the charge by means of the upper half mould 31 and the lower half mould 32 positioned at the limit distance L so as to mould the parison 2; a step of moving the upper half mould 31 and the lower half mould 32 apart, starting from the limit distance L; a step of extracting the moulded parison 2.

[0066] In particular, a duration of the compression moulding, which starts when the upper half mould 31 and the lower half mould 32 reach the limit distance L and ends when the upper half mould 31 and the lower half mould 32 start moving apart starting from the limit distance L, is included in an interval between 0.2 and 2.0 seconds, preferably between 0.5 and 1.0 second.

[0067] The containers 1 are preferably made of HDPE material characterized by: - a t / 2 crystallization time of less than 2 min if measured at 124°C.

[0068] - a minimum density of 0.940 g / cc.

[0069] - post extrusion swelling (die swell) of less than 1.5.

[0070] However, the containers 1 might also be made of other materials. Shown below are the properties of some of these materials.

[0071] Table 1

[0072] PP PP LDPE MDPE HDPE COC

[0073] homopolymer copolymer

[0074] Density 0.926- 0.928- 0.941- 1.02- 0.90-0.91 0.90-0.91

[0075] (g / cc) 0.940 0.950 0.960 1.04

[0076] MFI 10 min,

[0077] 0.2- 0.3- 0.2- 5.5- 2.16 kg 1-40 0.45-100

[0078] 20.0 21.0 57.0 29.4 (g / 10min)

[0079] Melting point 105- 115- 130- ISO- 160-165 135-160

[0080] (°C) 115 130 138 145

[0081]

[0082] Tensile

[0083] 11Q- 150- 180- 2200- modulus 1200-2000 1000-1500

[0084] 1200 1500 1800 3000 (MPa)

[0085] Tensile

[0086] strength 3-56 7-48 10-43 35-40 20-35 50-63 (MPa)

[0087] Elongation at 13- 16- 6-45 15-600 200-600 3-100 break (%) 400 1100

[0088]

Claims

CLAIMS1. A container (1) made of olefin-based polymeric material, obtained by blow moulding a parison (2) made by compression moulding a charge of molten polymeric material, wherein the container (1) comprises a body (11 ) which extends around a longitudinal axis (X) between a first end (11 A) and a second end (11 B), and a neck (12) which is joined to the body (11 ) at the first end (11 A), and wherein:- the step of compression moulding has a duration included in an interval between 0.2 and 2.0 seconds;- a temperature of the molten polymeric material from which the charge is obtained is less than or equal to 240°C.

2. The container (1) according to claim 1 , wherein the step of compression moulding has a duration included in an interval between 0.2 and 1 second.

3. The container (1) according to claim 2, wherein the step of compression moulding has a duration included in an interval between 0.5 and 1 second.

4. The container (1) according to any of the previous claims, wherein the body (11) of the container (1) has a wall having an average thickness (S1) of between 0.3 mm and 2.5 mm, measured transversely to the longitudinal axis (X).

5. The container (1) according to claim 4, wherein the average thickness (S1) is between 0.3 mm and 0.8 mm, measured transversely to the longitudinal axis (X).

6. The container (1) according to claim 5, wherein the average thickness (S1) is between 0.5 mm and 0.8 mm, measured transversely to the longitudinal axis (X).

7. The container (1) according to any of the previous claims, having a load applied parallel to the longitudinal axis (X) top load of at least 100N.

8. The container (1) according to any of the previous claims, having a load applied transverse to the longitudinal axis (X) side load of at least 20N.

9. The container (1) according to any of the previous claims, wherein:- the step of compression moulding has a duration included in an interval between 0.2 and 1 second;- the body (11) of the container (1) has a wall having an average thickness (S1) of between 0.3 mm and 0.8 mm, measured transversely to the longitudinal axis (X), and- the container (1) has a load applied parallel to the longitudinal axis (X) top load of at least 100N.

10. The container (1) according any of the previous claims, wherein the step of compression moulding includes the following steps:- inserting the charge into a mould (3) comprising an upper half mould (31) and a lower half mould (32);- moving the upper half mould (31) and the lower half mould (32) towards each other until reaching a limit distance (L) between the upper half mould (31) and the lower half mould (32);- compressing the charge by means of the upper half mould (31) and the lower half mould (32) positioned at the limit distance (L) so as to mould the parison (2);- moving the upper half mould (31) and the lower half mould (32) apart, starting from the limit distance (L);- extracting the moulded parison (2),wherein a duration of the compression moulding starts at the instant when the upper half mould (31) and the lower half mould (32) reach the limit distance (L) and ends at the instant when the upper half mould (31) and the lower half mould (32) start moving apart starting from the limit distance (L).

11. The container (1) according to any of the previous claims, wherein moulding is accomplished by a compression mould which includes:- a body portion (31 B, 32A), configured to form the body (11) of the container (1), and- a neck portion (31 A), configured to form the neck (12) of the containerwherein a temperature of the neck portion (31 A) of the mould during moulding is between 15°C and 25°C.

12. The container (1) according to any one of the preceding claims, wherein the temperature of the molten polymeric material is less than or equal to 220°C.

13. The container (1) according to any one of the preceding claims, wherein an OTR oxygen permeability of the container (1) is between 0.025 and 0.470 cc / pkg*day and an MVTR water vapour permeability of the container (1) is between 0.25 and 4.0 mg / day*container.

14. The container (1) according to any one of the preceding claims, wherein a variation along the longitudinal axis (X) of the extension of the body (11) of the container (1) around the longitudinal axis (X) is less than 1% with respect to a nominal value.

15. The container (1) according to any one of the preceding claims, wherein the neck (12) of the container (1) has a wall extending annularly around the longitudinal axis (X) and having a plurality of portions withdrawn towards the longitudinal axis (X).

16. The container (1) according to any one of the preceding claims, wherein the neck (12) of the container (1) has a wall extending annularly around the longitudinal axis (X), wherein the annular extension of the wall has a factor of ovalization of less than 1% with respect to a nominal value.

17. The container (1) according to any one of the preceding claims, wherein the container (1) has a bottom (13) which extends transversely to the longitudinal axis (X) and is joined to the body (11) at the second end (11 B), the bottom (13) having a substantially smooth outside surface without the dividing centre line between the moulds.

18. A container (1) made of olefin-based polymeric material, obtained by blow moulding a parison (2) made by compression moulding a charge of molten polymeric material, wherein the container (1) comprises a body (11 ) which extends around a longitudinal axis (X) between a first end (11 A) and a second end (11 B), and a neck (12) which is joined to the body (11 )at the first end (11 A), and wherein- the body (11) of the container (1) has a wall having an average thickness (S1) of between 0.3 mm and 2.5 mm, measured transversely to the longitudinal axis (X);- an OTR oxygen permeability of the container (1) is between 0.025 and 0.470 cc / pkg*day and an MVTR water vapour permeability of the container (1) is between 0.25 and 4.0 mg / day*container.

19. The container (1) according to claim 18, wherein a variation along the longitudinal axis (X) of the extension of the body of the container (1) around the longitudinal axis (X) is less than 1% with respect to a nominal value.

20. The container (1) according to claim 18 or 19, wherein the neck (12) of the container (1) has a wall extending annularly around the longitudinal axis (X) and having a plurality of portions withdrawn towards the longitudinal axis (X).

21. The container (1) according to any one of claims 18 to 20, wherein the extension of the wall around the longitudinal axis (X) has a factor of ovalization of less than 1% with respect to a nominal value.

22. The container (1) according to any one of claims 18 to 21, wherein the container (1) has a bottom (13) which extends transversely to the longitudinal axis (X) and is joined to the body (11) at the second end (11 B), the bottom (13) having a substantially smooth outside surface without the dividing centre line between the moulds.

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