Pressurised container with deformable shoulder and deformable bottom

Abstract

The present invention relates to a container (1) obtained by blow moulding or stretch blow moulding from a blank made of plastics material, which container comprises a body (2), a shoulder (3) extending from said body (2) at an upper end thereof, a neck (4) extending from the shoulder (3), said shoulder (3) being articulated between at least two stable positions, namely a so-called extended position in which the shoulder (3) projects from the body (2), and a so-called retracted position in which the shoulder (3) extends level with the upper end of the body (2) or is at least partially retracted into the body (2), and a bottom (5) at the lower end of said body (2); said container is characterised in that said bottom (5) is articulated to the lower end of the body (2) between at least two stable positions, namely a so-called extended position in which the bottom (5) extends level with the lower end of the body (2) or projects at least partially from the body (2) and a so-called retracted position in which said bottom (5) is at least partially retracted into the body (2) in such a way that, when the container (1) is filled and closed, the movement of the shoulder (3) from the extended position into the retracted position causes the bottom (5) to move from the retracted position into the extended position and vice-versa. The invention also relates to a mould for the production of such containers.

Description

Description Title of the invention: Pressurized container with deformable shoulder and base Technical field

[0001] The present invention relates to a container, and more particularly to a potentially stackable PET bottle, comprising for this purpose a substantially complementary bottom and neck, so as to allow stable stacking of the containers, as well as a mold for the production of such containers. State of the art

[0002] It is well known to produce so-called stackable containers. This is particularly the case with US patent US 2077 027 which describes a stackable container, which comprises a body and a truncated cone-shaped shoulder attached and fixed to the body by a folded edge. The stacking of this type of container is naturally stable, but this stability depends largely on the (metallic) material from which the container is made.

[0003] However, it is difficult to achieve such stability when the container is obtained by blow molding (or stretch blow molding) from a blank (in particular a preform) made of plastic material such as polyethylene terephthalate, also known as PET. Indeed, in addition to the fact that plastic materials are naturally malleable, market requirements are causing production to tend towards lighter containers, which reduces their rigidity.

[0004] In this regard, document EP 0698 557 describes such a stackable container made of plastic, the bottom of which is shaped in a manner substantially complementary to the neck to allow stacking. For this purpose, the bottom and the shoulder of the container are provided on their periphery with flat support surfaces, and the bottom is further provided with a hollow portion for receiving the neck of an underlying container.

[0005] However, the manufacture of such a container requires, for the production of the base, a substantial quantity of material, necessary to give the base sufficient rigidity, capable of giving the entire container good mechanical strength and good stability when stacked. Similarly, a sufficient quantity of material is necessary for the good blowability of the base (i.e. its ability to be correctly formed). Conversely, inconsiderate lightening of the container, particularly at the base, is detrimental to the mechanical strength of the container and the stability of its stacking.

[0006] In order to overcome these drawbacks, we already have a container comprising means for creating a positive pressure inside the container and, ultimately, reinforce said container. This is particularly the case of document WO2007 / 127337.

[0007] Said document WO2007 / 127337 describes a plastic container comprising an upper portion comprising a neck intended to receive a closure, a lower portion comprising a base and a side wall extending between the upper portion and the lower portion. The upper portion, the lower portion and the side wall define an interior volume intended to store liquid contents. The plastic container further comprises a pressure panel located on the container and movable between an initial position and an activated position. The pressure panel is located in the initial position before filling the container and is placed in the activated position after filling the container. Moving the pressure panel from the initial position to the activated position reduces the internal volume of the container and creates a positive pressure inside the container, said positive pressure reinforcing the side wall.

[0008] Document EP2861499, from the applicant, is also known, which describes a container whose shoulder is articulated between at least one stable position called deployed and one stable position called retracted in which the internal volume of the container is reduced so as to create a positive pressure inside the latter.

[0009] Said document EP2861499 describes a container obtained by blow molding or stretch blow molding from a plastic blank which comprises a body, a shoulder in the extension of the body at an upper end thereof and a neck in the extension of the shoulder, the shoulder being articulated between two stable positions, namely a deployed position in which the shoulder projects from the body and a retracted position in which the shoulder is at least partially retracted into the body, the shoulder being articulated to be able to adopt, in addition to the deployed position and the retracted position, a third stable position, intermediate between the deployed position and the retracted position.

[0010] The retracted position, in which stacking can be carried out, makes it possible to reduce the shoulder height and, consequently, the reception volume provided in the base. In addition, the shoulder being placed in its retracted position after filling and capping the container, the contents of said container are put under pressure and increase the rigidity of the latter. Thus, the stability of the stack of containers is increased while reducing the quantity of material necessary to form the base.

[0011] It is clear that it is difficult to achieve a good compromise between stacking stability and the lightness of a plastic container. Furthermore, there is now a growing demand to reduce the weight of containers for not only economic reasons, given the increasing cost of raw materials, but also ecological reasons.

[0012] Thus, the objective of the invention is to improve the rigidity and stability of the stacking of containers whose quantity of material, and consequently its weight, is as low as possible without adding additional gas under pressure, such as liquid nitrogen for example, inside said containers. Disclosure of the invention

[0013] One of the aims of the invention is therefore to overcome these drawbacks by proposing a container and a mold of simple and inexpensive design, requiring a small quantity of material while providing good rigidity.

[0014] For this purpose, and in accordance with the invention, there is provided a container obtained by blow molding or stretch blow molding from a plastic blank, which comprises a body, a shoulder in the extension of said body at an upper end thereof, a neck in the extension of the shoulder, said shoulder being articulated between at least two stable positions, namely a so-called deployed position in which the shoulder extends at the same level as the upper end of the body or projects from the body, and a so-called retracted position in which the shoulder is at least partially retracted into the body, and a bottom at the lower end of said body;said container is remarkable in that said bottom is hinged at the lower end of the body between at least two stable positions, namely a so-called deployed position in which the bottom extends at the same level as the lower end of the body or projects at least partially from the body and a so-called retracted position in which said bottom is at least partially retracted into the body in such a way that, when the container is filled and closed, the passage from the deployed position to the retracted position of the shoulder causes the passage from the retracted position to the deployed position of the bottom and vice versa.;

[0015] Preferably, the articulations of the shoulder on the body and of the bottom on the body are configured such that, when the container is filled and closed, the transition from the deployed position to the retracted position of the shoulder causes the transition from the retracted position to the deployed position of the bottom while maintaining a pressure level inside the bottle greater than 100 mbar.

[0016] According to a preferred embodiment of the invention, the shoulder comprises a peripheral section, a central section and an under-collar section, a first articulation being defined at a junction between the peripheral section and the central section and a second articulation being defined at a junction between the central section and the under-collar section.

[0017] Additionally, the second shoulder joint defined at the junction between the center section and the under-collar section is configured to remain locked in the retracted position.

[0018] In addition, the bottom includes a peripheral section and a central section, a first joint being defined at a junction between the peripheral section and the central section and a second joint being defined at a junction between the peripheral section and the body.

[0019] Preferably, the central section of the bottom comprises a concave central dome, in the form of a substantially spherical cap with concavity facing the outside of the container in the absence of stress.

[0020] The said central dome is rigid or semi-rigid, and non-deformable.

[0021] For this purpose, said central dome may include one or more stiffeners.

[0022] Preferably, said central dome comprises a plurality of radial grooves extending from the center of said central dome to the first hinge of the bottom.

[0023] Said body has a substantially truncated cone shape, the large base of which corresponds to the lower end of the body and the small base corresponds to the upper end of said body.

[0024] According to a variant of execution, the body has a square cross-section with quarter-round edges.

[0025] According to another variant, the body has a substantially cylindrical shape.

[0026] Furthermore, the body is provided with at least one deformable zone.

[0027] Advantageously, except for the deformable zone(s), the body is stiffened.

[0028] Preferably, the body has over all or part of its height a superposition of annular stiffeners.

[0029] Another subject of the invention relates to a mold for the manufacture of a container according to the invention by blow molding or stretch blow molding of a plastic blank.Said mold comprises at least one mold base capable of being movably mounted in a side wall which defines a cavity in the impression of a part of the container, said side wall comprising two half-molds each defining a half-impression of the body of the container and mounted in rotation relative to each other, between a so-called open position, in which the half-molds are angularly spaced from each other and the mold base is lowered relative to the half-molds to allow the introduction of the blank and the evacuation of the formed container, and a so-called closed position, in which the half-molds are applied against each other and trap the mold base between them to thus form the cavity and define the total impression of the container to be formed; said mold is remarkable in that the half-impressions of the side walls and / or the mold base are shaped to produce a container according to the invention. Brief description of the drawings

[0030] Other advantages and characteristics will emerge more clearly from the following description of several variant embodiments, given as non-limiting examples, of the container and the mold for the production of said container in accordance with the invention, with reference to the appended drawings in which:

[0031] [Fig.1] is a perspective view illustrating a container according to the invention in a so-called retracted shoulder position,

[0032] [Fig.2] is a side view of a container according to the invention in a so-called shoulder-deployed position,

[0033] [Fig.3] is an elevational view of the upper portion of the container in a shoulder-deployed position,

[0034] [Fig. ] is an elevational view of the upper portion of the container in a retracted shoulder position,

[0035] [Fig.5] is an elevational view of the lower portion of the container in a retracted position from the bottom,

[0036] [Fig.6] is an elevational view of the lower portion of the container in a bottom-deployed position,

[0037] [Fig.7] is a side view of the upper portion of the container in the shoulder-deployed position,

[0038] [Fig.8] is a side view of the lower part of the container in the retracted position of the bottom,

[0039] [Fig.9] is an exploded perspective view of a mold for the production of a container according to the invention. Method of carrying out the invention

[0040] In the following description of the container according to the invention, the same numerical references designate the same elements. The different views are not necessarily drawn to scale.

[0041] The figures show a container 1 obtained by blow molding, or by stretch blow molding, from a plastic blank not shown in the figures. Said blank is, for example, a preform but it can also be an intermediate container having undergone a first transitional blow molding operation.

[0042] With reference to Figures 1 and 2, said container 1 comprises a body 2 of substantially truncated cone shape which extends along the main axis X, said main axis X being vertical, the container 1 usually being represented in a vertical position. It will be observed that the body 2 is not necessarily symmetrical in revolution around its main axis X. Indeed, it could have a circular cross-section, such as cylindrical, or a square cross-section with quarter-round edges, i.e. rounded at the corners, or not without departing from the scope of the invention.

[0043] Said container 1 also comprises a shoulder 3 in the extension of the body 2 at an upper end thereof, a neck 4 in the extension of the shoulder 3, and a bottom 5 in the extension of the body 2 at a lower end. Said neck 4 has, in the vicinity of its junction with the shoulder 3, a collar 6 which is already present at the open end of the blank and allowing the suspension of said blank at various stages of manufacture of the container 1. Furthermore, between the collar 6 and the shoulder 3, the container 1 has a section 7 under the neck, cylindrical of revolution around the main axis X, providing sufficient space to accommodate a member for gripping the container 1, such as pliers for example.

[0044] Said shoulder 3 comprises a peripheral section 8, in the form of a relatively narrow strip of material, i.e. a strip with a width of between 0.5 and 25 mm, the width depending in particular on the dimensions of the container 1, which extends from an external edge and which defines a first so-called external articulation 9 of the shoulder 3 relative to the body 2, at a junction between the body 2 at the upper end thereof up to a concentric internal edge of the external edge, said internal edge defining a second so-called internal articulation 10, of a central section 11 of the shoulder 3 relative to the peripheral section 8. The central section 11 of the shoulder 3 is substantially frustoconical and extends from the internal articulation 10 of the peripheral section 8 up to the under-neck section 7.

[0045] The external 9 and internal 10 articulations give the shoulder 3 the ability to adopt two stable positions, namely a so-called retracted position, shown in Figures 1 and 4, in which the shoulder 3 is at least partially retracted into the body 2, the retraction of the shoulder being towards the bottom 5, along the main axis X, and the peripheral section 8 and the central section 11 both extending in an inclination, that is to say that their conicity points in the direction of the neck 4, i.e. upwards, and towards the main axis X; and a so-called deployed position, shown in Figures 2, 3 and 7, in which the shoulder 3 projects from the body 2, the peripheral section 8 and the central section 11 both extending in an inclination, that is to say that their conicity points in the direction of the neck 4, i.e. upwards, towards the main axis X.

[0046] According to an alternative embodiment, not shown in the figures, said shoulder 3 could, in its so-called deployed position, extend at the same level as the upper end of the body 2, i.e. extend perpendicular to the main axis X of the container 1, without however departing from the scope of the invention.

[0047] It will be observed that the deployed position (figures 2, 3 and 7) came from forming, that is to say that it is in this deployed position that the container 1 is formed. It is also in this deployed position that the container 1 is filled and capped.

[0048] Furthermore, with reference to figures 5, 6 and 8, the bottom 5 of the container 1 comprises a peripheral heel 12 in the form of an annular bead which extends substantially axially in the extension of the body 2. The peripheral heel 12 ends with a laying plane 13, also called a base, perpendicular to the main axis X of the container 1, said laying plane 13 defining the lower end of the container 1 and allowing the container 1 to be laid, vertically, on a flat surface.

[0049] Towards the interior of the container 1, the peripheral heel 12 comprises a truncated annular cheek 14 which extends towards the interior of the container 1 in the extension of the laying plane 13, the truncated cone formed by the annular cheek 14 opening downwards. Furthermore, the bottom 5 also comprises a concave central dome 15, in the form of a substantially spherical cap with a concavity facing towards the outside of the container 1 in the absence of stress, that is to say in the absence of contents in the container 1. The central dome 15 extends from the peripheral heel 12, in the extension of the annular cheek 14, to a central zone 16 of the bottom 5 forming a pin projecting towards the outside of the container 1, with in its center a generally amorphous pellet 17 which corresponds to the injection zone of the material constituting the preform used to produce the container 1 and can fulfill a centering function during the forming, by blow molding, of the container 1.

[0050] In addition, said bottom 5 comprises a peripheral section 18 extending substantially from the peripheral heel 12 to the central dome 15 and a central section 19 which corresponds substantially to the central dome 15, a first articulation 20 being defined at a junction between the peripheral section 18 and the central section 19 and a second articulation 21 being defined at a junction between the peripheral section 18 and the body 2 of the container 1. Unlike the internal articulation 10 of the shoulder 3 which is configured to remain locked in the retracted position, the first 20 and the second 21 articulation are not configured to remain locked.

[0051] The transition of the shoulder 3 from the deployed position, position in which the container is filled and then closed with a stopper, to the retracted position is carried out by turning the central section 11 around the internal articulation 10 of the shoulder 3 by exerting downward pressure on the stopper closing the neck 4. The orientation of the peripheral section 8 remains substantially unchanged and the neck 4 is animated by a translational movement along the main axis X of the piston directed downwards permitted by a pivoting of the central section 11 relative to the neck 4 around the external articulation 9. Furthermore, in this particular embodiment, in the retracted position of the shoulder 3, the height of the container 1 is less than the height of said container 1 when the shoulder 3 is in the deployed position, despite the deformation of the bottom 5. In this respect, it will be noted that the central dome 15 of the bottom 5 is rigid or semi-rigid, and not deformable.Preferably, said central dome 15 comprises one or more stiffeners, not shown in the figures, such as radial grooves extending substantially from the pad 17 to the first articulation 20.

[0052] Container 1 being filled, the retraction of shoulder 3 causes a pressure pressure of the contents of the container 1 as well as the passage from the retracted position to the deployed position of the bottom 5, the passage from the retracted position to the deployed position of the bottom 5 partially compensating for said pressurization. It will be noted that the articulations of the shoulder on the body 2 and of the bottom 5 on the body 2 are configured such that, when the container 1 is filled and closed, the passage from the deployed position to the retracted position of the shoulder 3 causes the passage from the retracted position to the deployed position of the bottom 5 while maintaining a pressure level inside the bottle greater than 100 mbar. Thus, the container 1 is slightly deformed with an internal pressure which makes it possible to stiffen said container so that the thickness of the walls of the container can be reduced, thus allowing a reduction in the material used for its manufacture, in particular the material necessary for the bottom 5.

[0053] According to an alternative embodiment, not shown in the figures, the base 5 could, in its so-called deployed position, extend at the same level as the lower end of the body 2 so that the annular cheek 14 then forms, in this deployed position, the base of the container.

[0054] Incidentally, the body 2 is provided in its upper part, just below the shoulder 3, with two annular stiffeners 22 in order to stiffen said body 2.

[0055] It goes without saying that the body 2 may comprise several annular stiffeners over all or part of its height depending in particular on the shape and dimensions of the body 2 of the container without departing from the scope of the invention.

[0056] According to an alternative embodiment, not shown in the figures, the body 2 could be provided with at least one deformable zone, such as a deformable panel, not shown in the figures, without departing from the scope of the invention. In addition, with the exception of the deformable zone(s), the body is stiffened. In this respect, the body 2 may have over all or part of its height a superposition of annular stiffeners.

[0057] With reference to [Fig. 9], a molding unit 23 according to the invention is described for forming, from a blank, usually a preform, a container, such as a bottle or a can, according to the invention.

[0058] Said molding unit 23, with reference to [Fig. 9], comprises a mold 24 provided with a side wall 25 which defines a cavity 26 in the impression of a part of the container. Said mold 24 further comprises a bottom 27 in the impression of the bottom of the container, said mold 24 being made of metal, for example steel or aluminum (this term also covering aluminum alloys). The cavity 26, and ultimately the container 1, extends along a main axis X which defines a vertical direction. Any plane perpendicular to the main axis X is said to be horizontal. According to an embodiment illustrated in the drawings, the side wall 25 comprises two half-molds 24A, 24B each defining a half-impression 28A, 28B of the body of the container and mounted in rotation with one another. relative to each other around a common axis formed by a hinge, not shown in the figures, between an open position, in which the half-molds 24A, 24B are angularly spaced from each other and the mold base 27 is lowered relative to the half-molds 24A, 24B to allow the introduction of the blank and the evacuation of the formed container, and a closed position, in which the half-molds 24A, 24B are applied against each other and trap between them the mold base 27 to thus form the cavity 26 and define the imprint of the container to be formed. Thus, said mold base 27 is capable of being mounted movably in the mold 24 comprising two walls movable relative to each other and intended to form the body of the container, said movable mold base 27 pushing the plastic material constituting the container towards its opening.The half-cavities 28A, 28B of the side walls 25 and / or the mold base 27 are shaped to produce a container 1 according to the invention as described previously.

[0059] Finally, it is quite obvious that the examples which have just been given are only specific illustrations and in no way limitative as to the fields of application of the invention.

Claims

Claims

1. Container (1) obtained by blow molding or stretch blow molding from a plastic blank, which comprises a body (2), a shoulder (3) in the extension of said body (2) at an upper end thereof, a neck (4) in the extension of the shoulder (3), said shoulder (3) being articulated between at least two stable positions, namely a so-called deployed position in which the shoulder (3) projects from the body (2), and a so-called retracted position in which the shoulder (3) extends at the same level as the upper end of the body (2) or is at least partially retracted into the body (2), and a bottom (5) at the lower end of said body (2), characterized in that said bottom (5) is articulated at the lower end of the body (2) between at least two stable positions,namely a so-called deployed position in which the bottom (5) extends at the same level as the lower end of the body (2) or projects at least partially from the body (2) and a so-called retracted position in which said bottom (5) is at least partially retracted into the body (2) in such a way that, when the container (1) is filled and closed, the passage from the deployed position to the retracted position of the shoulder (3) causes the passage from the retracted position to the deployed position of the bottom (5) and vice versa.,

2. Container (1) according to claim 1 characterized in that the articulations (9,10;20,21) of the shoulder (3) on the body (2) and of the bottom (5) on the body (2) are configured in such a way that, when the container (1) is filled and closed, the passage from the deployed position to the retracted position of the shoulder (3) causes the passage from the retracted position to the deployed position of the bottom (5) while maintaining a pressure level inside the container (1) greater than 100 mbar.

3. Container (1) according to any one of claims 1 or 2 characterized in that the shoulder (3) comprises a peripheral section (8), a central section (11) and a section under the neck (7), a first so-called external articulation (9) being defined at a junction between the peripheral section (8) and the central section (11) and a second so-called internal articulation (10) being defined at a junction between the central section (11) and the section under the neck (7).

4. Container (1) according to claim 3 characterized in that the internal articulation (10) of the shoulder (3) defined at the junction between the central section (11) and the under-neck section (7) is configured to remain locked in the retracted position.

5. Container (1) according to any one of claims 1 to 4 characterized in that the base (5) comprises a peripheral section (18) and a central section (19), a first articulation (20) being defined at a junction between the peripheral section (18) and the central section (19) and a second joint (21) being defined at a junction between the peripheral section (18) and the body (2).

6. Container (1) according to claim 5 characterized in that the central section (19) of the bottom (5) comprises a concave central dome (15), in the form of a substantially spherical cap with concavity facing the outside of the container (1) in the absence of stress.

7. Container (1) according to claim 6 characterized in that said central dome (15) is rigid or semi-rigid.

8. Container (1) according to claim 7 characterized in that said central dome (15) comprises one or more stiffeners.

9. Container (1) according to claim 8 characterized in that said central dome (15) comprises a plurality of radial grooves extending from the center of said central dome (15) to the first articulation (20) from the bottom (5).

10. Container (1) according to any one of the preceding claims, characterized in that the body (2) has a substantially frustoconical shape, the large base of which corresponds to the lower end of the body (2) and the small base corresponds to the upper end of said body (2).

11. Container (1) according to any one of claims 1 to 10, characterized in that the body (2) has a square-shaped cross-section with quarter-round edges.

12. Container (1) according to any one of claims 1 to 10 characterized in that the body (2) has a substantially circular cross section.

13. Container (1) according to any one of the preceding claims, characterized in that the body (2) is provided with at least one deformable zone.

14. Container (1) according to claim 13 characterized in that, with the exception of the deformable zone(s), the body (2) is stiffened.

15. Container (1) according to claim 14 characterized in that the body (2) has over all or part of its height a superposition of annular stiffeners (22).

16. Mold (24) for manufacturing a container (1) by blow molding or stretch blow molding of a plastic blank, said mold (24) comprising at least one mold base (27) capable of being movably mounted in a side wall (25) which defines a cavity (26) in the impression of a part of the container (1), said side wall comprising two half-molds (24A, 24B) each defining a half-impression (28A, 28B) of the body (2) of the container (1) and mounted in rotation relative to each other, between a so-called open position, in which the half-molds (24A, 24B) are angularly spaced from each other and the mold base (27) is lowered relative to the half-molds (24A, 24B) to allow the introduction of the blank and the evacuation of the container (1) formed, and a position called closed, in which the half-molds (24A,24B) are applied against each other and trap between them the mold base (27) to thus form the cavity (26) and define the total imprint of the container (1) to be formed, characterized in that the half-imprints (28A, 28B) of the side walls and / or the mold base (27) are shaped to produce a container (1) according to any one of claims 1 to 15.,

Images