WO2017103467A1

WO2017103467A1 - Container having a petaloid base with rib feet

Info

Publication number: WO2017103467A1
Application number: PCT/FR2016/053414
Authority: WO
Inventors: Ivan Pierre; Laurent NAVEAU
Original assignee: Sidel Participations
Priority date: 2015-12-16
Filing date: 2016-12-14
Publication date: 2017-06-22
Also published as: FR3045571A1; EP3390237A1; CN108367833A; EP3390237B1; US20180362205A1; FR3045571B1; MX2018006696A

Abstract

The invention relates to a plastics container obtained by blow moulding or stretch blow moulding from a blank, this container comprising a body, a neck which extends at an upper end of the body and a petaloid base (4) which extends at a lower end of the body, this petaloid base (4) being provided with protruding feet (5) that are separated by recessed valleys (6) that extend radially from a central region (7) of the base (4), each foot (5) having an external wall (10) which extends in continuation of the body (2) and two side walls (11) that each border a valley (6) and are each connected to the external wall (10) by a fillet (12), each foot (5) being provided with at least one rib (14), a lateral portion (15) of which overlaps said fillet (12).

Description

Container with petaloid bottom with ribbed feet

The invention relates to the manufacture of containers, especially bottles, by blow molding or stretch blow molding from blanks (preforms or unfinished intermediate containers) in a thermoplastic material such as PET (polyethylene terephthalate).

A container usually comprises a body, which gives the container its volume, an open neck, which projects from an upper end of the body and which fills the container (usually by means of a liquid or a paste), and a bottom, which closes the body opposite the neck and forms a base by which the container must be able to rest stably on a flat surface such as a table.

In general, it is sought to give the bottom a good mechanical rigidity because, in addition to the bottom must form a stable base for the container (not only during conveying operations subsequent to its filling, but also during its storage and its daily use by consumers), it must also withstand the hydrostatic pressure exerted by the contents, any thermal stresses induced by a high temperature of the contents when it is introduced hot into the container, or a possible gas pressure dissolved in the liquid (typical case of carbonated drinks).

If it allowed the container to stand upright, the ideal shape of the bottom would be the sphere, because it would evenly distribute the stresses that are applied to it. There was a time when PET containers were manufactured with a spherical base on which was inserted a pedestal-shaped base, made of a softer material (especially polypropylene, to allow its snapping on the bottom). But this design made it difficult to recycle, the two materials to follow different channels, forcing the operators responsible for sorting to proceed themselves to separate the base of the container.

The advent of the petaloid bottom has made it possible to overcome these problems: such a bottom comprises an alternation of projecting feet, intended to ensure the vertical maintenance of the container placed on a flat horizontal surface, and convex valleys (generally under shape of portions of sphere) which absorb some of the efforts (thermal, mechanical) exerted by the content.

It is in containers with petaloid bottoms that are usually contained carbonated drinks. The capacities of these containers are variable: for example 0.2 I, 0.5 I, 1 I, 1.5 I, 2 I or more.

Environmental standards (ever more stringent) and the random nature of the prices of raw materials force manufacturers to reduce the amount of material used, which results in a reduction in the weight (and therefore the thickness) of the containers.

We observe, on lightened petaloid bottoms, undesirable deformations. In particular, we note on the feet the appearance of creases. In addition to being unsightly, creases can form fracture primers, especially when the containers are palletized: the stresses due to the internal pressure are in fact added compressive stresses due to the weight of the superimposed containers.

Even the recent improvements to the petaloid bottoms (see in particular the European patent application EP 2560887 in the name of the applicant) do not allow to overcome these creases.

One objective is therefore to propose a petaloid background which, although alleviated, is however less subject to uncontrolled deformations than known petaloid bottoms.

For this purpose, there is provided a plastic container obtained by blowing or stretching blow from a blank, this container comprising a body, a neck which extends to an upper end of the body and a petaloid bottom which extends to a lower end of the body, this petaloid bottom being provided with projecting feet, separated by recessed valleys which extend radially from a central zone of the bottom, each foot having an outer wall which extends into the extension of the body and two flanks each bordering a valley and which each connect to the outer wall by a fillet, each foot being provided with at least one rib, a lateral portion overlaps said fillet.

By deploying under the pressure of the contents of the container, this (or these) ribs (s) absorb (s) a part of the deformations induced in the foot which are thus channeled, which avoids the formation of unwanted creases.

Various additional features may be provided, alone or in combination:

- At least one rib has an inner end portion which extends at least partly on a sidewall, in the extension of the lateral portion;

at least one rib has an external portion which extends at least partly on the outer wall of the foot, in the extension of the lateral portion;

the rib is interrupted, outwards, on the outer wall of the foot;

the container comprises at least one rib having two lateral portions which are connected by the outer portion;

- the outer portion is arched;

the (or each) lateral portion is arched in the opposite direction of the outer portion;

the rib follows the contour of an intersection of the foot with a cylinder of revolution about a radial axis;

- the lateral portion is straight;

the rib follows the outline of an intersection of the foot with a plane; the feet having ends which define for the container a laying plane, the aforementioned intersection plane is parallel (or, alternatively, inclined relative to) the laying plane;

the container comprises at least two superposed ribs;

the container comprises three superimposed ribs;

the ribs are equidistant;

examined ascending towards the neck from one end of the foot, the ribs are of increasing length;

the ribs follow the contour of an intersection of the foot with cylinders of coaxial revolution, of radial axis and of different radii;

at least one rib is interrupted, inwardly, on the connection fillet between the outer wall and the sidewall;

the (or each) rib has a width of between 0.4 mm and 1.5 mm. Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given hereinafter with reference to the accompanying drawings, in which:

Figure 1 is a perspective view, from below, of a petaloid bottom container whose feet are ribbed;

Figure 2 is a detail view, on an enlarged scale, of the bottom of the container of Figure 1;

Figure 3 is a detail view from below, on an enlarged scale, of a ribbed foot;

- Figure 4 is a side view of the bottom of the container;

Figure 5 is a detail view, on an enlarged scale, of a foot of the container of Figure 4, according to the box V;

Figure 6 is a detail view in section of the bottom, on an enlarged scale, along the section plane VI-VI of Figure 5;

- Figure 7 is a view similar to Figure 4, illustrating an alternative embodiment;

Figure 8 is a detail view, from the side, of a bottom foot of Figure 7;

FIG. 9 is a detail view from below, on an enlarged scale, of a ribbed foot of the bottom illustrated in FIG. 7.

In FIG. 1 is shown a container 1, obtained by blow-molding or stretch-blow molding from a blank (term designating a raw injection preform or an intermediate receptacle intended to undergo one or more finishing operations) made of plastic, by ex. PET (polyethylene terephthalate).

The container 1 comprises a body 2, which extends along an axis X which can constitute an axis of revolution of the body 2, a neck 3 which extends to an upper end of the body 2, and a bottom 4 petaloid which extends to a lower end of the body 2, opposite to the neck 3.

The bottom 4 is provided with projecting feet 5 separated in pairs by hollow valleys 6 which extend radially from a central zone 7 of the bottom 4.

Each foot 5 extends in axial projection to one end 8. The ends 8 of the feet 5 are coplanar and jointly define a laying plane 9 by which the container 1 can rest stably on a horizontal flat surface (typically a table).

Each foot 5 has an outer wall 10, which extends in the extension of the body 2, and two flanks 11 each bordering a valley 6 and which are each connected to the outer wall 10 by a fillet 12.

According to an embodiment illustrated in the figures, and in particular in Figures 3 and 4, each fillet 12 widens from an upper end 13 of the valley 6 towards the end 8 of the foot. In the same direction, the fillet radius 12 may be constant, or increase.

As is also seen in Figures 3 and 4, each sidewall 11 has a crescent shape (but this form is not limiting). It should be noted that the boundaries between the different zones of the foot 5 are not sharp edges but are soft (otherwise these limits would accumulate the stresses and form, under load, as many breaking primers). For the sake of clarity, however, these limits have been embodied in the drawings (in the form of double dashed lines).

Each foot 5 has plane symmetry with respect to a radial plane R (containing the axis X of the container 1) passing through its end 8. Each foot 5 thus comprises a single external wall 10, symmetrical with respect to this plane R, two leaves 12 which are the mirror image of each other with respect to this plane R, and two flanks 11 which are also the mirror image of each other with respect to this plane R.

As can be seen in the figures, each foot 5 is provided with at least one rib 14. As seen in section, this rib 14 projects (that is to say, forms a relief) towards the inside of the container 1 (Figure 6). Alternatively, this rib 14 projects outwardly of the container.

Whatever its shape (several of which are described hereinafter), the rib 14 includes a lateral portion which overlaps the fillet 12, i.e. this side portion extends over at least a portion of the width of the holiday 12.

The number of ribs 14 present on each leg 5 can be a function of the volume capacity of the container 1. Thus, in a container 1 of large capacity (1.5 l, 2 I or 3 I), each foot 5 can be provided of three ribs 14 (or three pairs of ribs 14 symmetrical with respect to the radial plane R symmetry of the foot) superimposed (see the first bottom 4 shown in Figures 1 to 5, which comprises, for each foot 5, an upper rib 14.1, an intermediate rib 14.2 and a rib 14.3 lower ). In a container 1 of average capacity (0.5 I or 1 I), each foot 5 may be provided with two (or two pairs of) ribs 14 superimposed (see the second bottom 4 illustrated in Figures 7, 8 and 9 which comprises, for each foot 5, a pair of symmetrical upper ribs 14.4 and a pair of symmetrical lower ribs 14.5). In a container 1 of small capacity (less than 0.5 I, for example 0.2 I), each foot 5 may be provided with a single rib 14 (or a single pair of ribs 14 symmetrical relative to at the plane R of symmetry of the foot 5).

At least one of the ribs 14 may have one or more of the following features:

the lateral portion extends over the entire width of the fillet 12, thus joining the outer wall 10 to one of the flanks 11 of the foot 5; this is the case of the upper rib 14.1 of the first bottom 4

(Figures 3 and 4) and ribs 14.4, 14.5 of the second bottom 4

(Figures 7, 8, 9);

- The rib 14 extends on the sidewall 11, beyond the leave 12; the rib 14 then has an internal end portion 16 which extends at least partly on the sidewall 11, in the extension of the lateral portion 15: this is the case of the upper rib 14.1 of the first bottom 4 ( Figures 3 and 4) and two ribs 14.4, 14.5 of the second bottom 4 (Figures 7, 8, 9);

the lateral portion extends over only a part of the fillet 12, starting from the outer wall 10 and interrupting in the vicinity of the boundary between the fillet 12 and the sidewall 11: this is the case of the intermediate rib 14.2 first bottom 4 (Figures 3 and 4); the lateral portion extends over only part of the holiday

12, starting from the outer wall 10 and interrupting substantially midway between the outer wall 10 and the sidewall 11: this is the case of the lower rib 14.3 of the first bottom 4 (Figures 3 and 4);

the rib 14 has an outer portion 17 which extends at least partly on the outer wall 10 of the foot 5, in the extension of the lateral portion 15: this is the case of the rib 14.1 upper first bottom 4 (Figures 3 and 4) and two ribs 14.4, 14.5 of the second bottom 4 (Figures 7, 8, 9);

the rib 14 stops, on the outside, on the outer wall of the foot 5: the rib 14 then has an outer end portion 18, which extends in part on the outer wall: this is the case of the ribs 14.4, 14.5 of the second bottom 4 of Figures 7, 8, 9; the foot 5 illustrated in these figures comprises two superposed pairs of ribs 14 symmetrical with respect to the plane R of symmetry of the foot 5. The ribs 14.4, 14.5 of each pair are spaced apart from each other, their end portions 18 external interrupting at a distance from each other of a few millimeters;

the outer portion 17 extends the full width of the outer wall; the rib 14 then comprises two lateral portions 15 which are connected by the outer portion 17: this is the case of the ribs 14.1, 14.2, 14.3 of the first bottom 4 of FIGS. 3 and 4; the outer portion 17 is arcuate: this is the case of the ribs 14.1, 14.2, 14.3 of the first bottom 4 of Figures 3 and 4, the outer portions 17 extend in a concave arc facing the laying plane 9;

the (or each) lateral portion is furthermore arcuate in the opposite direction of the outer portion 17: this is the case of the ribs 14.1, 14.2, 14.3 of the first bottom of FIGS. 3 and 4, the lateral portions of which extend following a concave arc facing the neck 3;

the rib 14 follows the contour of an intersection of the foot 5 with a cylinder C of revolution about a radial axis: this is the case of the ribs of the first bottom 4 of Figures 3, 4 and 5; in this first bottom 4, and as is clearly visible in FIG. 5, the ribs 14.1, 14.2, 14.3 follow the contour of an intersection of the foot 5 with cylinders C1, C2, C3 of respective revolution, of the same axis A radial and of different radii;

alternatively, the rib 14 follows the contour of an intersection of the foot 5 with a plane P inclined relative to the laying plane 9: this is the case of the ribs 14.4, 14.5 of the second base 4 of FIGS. 7, 8,

9; alternatively, the plane P could be parallel to the laying plane; in either case, the (or each) side portion appears straight instead of being arcuate;

the rib 14 has a width L between 0.4 mm and 1.5 mm.

It is conceivable to combine some of the above characteristics. At least one (or each) rib 14 could thus have an arcuate outer portion 17 and one (or each) right side portion.

Given the rather tortuous relief of the foot 5, the general shape of each rib 14 depends on the angle at which the bottom 4 is observed.

Thus, when the first bottom 4 of Figures 1 to 5 is observed from below (Figure 3), each rib 14.1, 14.2, 14.3 has an open U-shape. When a foot 5 of the same bottom 4 is observed radially from the outside (see foot 5 in the center of Figure 4), each rib 14.1, 14.2, 14.3 has a circular shape. When a foot 5 of this first bottom 4 is observed laterally (see the feet 5 located on the sides of Figure 4), each rib 14.1, 14.2, 14.3 has a Gaussian shape.

When a foot 5 of the second bottom 4 of Figures 7 to 9 is observed from below (Figure 9), each rib 14.4, 14.5 also has an open U-shape. When a foot of the same bottom is observed laterally (Figure 8), each rib 14.4, 14.5 extends in a straight line.

When each foot 5 comprises several ribs 14 superimposed, the ribs 14 can, when examined going up towards the neck from the end 8 of the foot 5, be of different lengths (eg increasing, see the first bottom 4 illustrated). in Figures 2, 3 and 4) or the same length (see the second bottom 4 shown in Figures 7, 8 and 9).

When each foot 5 comprises a number of ribs 14 greater than or equal to three, these can be equidistant, as in the first bottom 4 illustrated in Figures 1 to 5.

The container 1 is intended to be filled with a content under pressure, typically a carbonated beverage, which generates in the container 1 a pressure which can reach 6 bars. Its petaloid form allows the bottom 4 to maintain overall shape without collapsing, the valleys 6 ensuring, thanks to their spherical shape, a relatively homogeneous distribution of the constraints they suffer because of the pressure of the content. Feet 5, meanwhile, are subject to significant stress variations because of their tortuous shape. It has been found that the stresses accumulate in the fillets 12, between the outer wall and the flanks 11. Each rib 14 contributes, by unfolding towards the outside of the container 1 (as shown in dashed lines in FIG. 6) to channel the deformations generated by these constraints. In other words, the deformations are located on the (or) ribs 14. As a result, the uncontrolled (undesired) deformations of the feet 5 are minimized or even eliminated, even when the container 1 is lightened. The aesthetics of the container 1 is preserved, and its strength under load (including palletization) increased, equal mass or less.

Claims

Plastic container (1) obtained by blowing or stretching from a blank, which container (1) comprises a body (2), a neck (3) which extends to an upper end of the body ( 2) and a bottom (4) petaloid which extends to a lower end of the body (2), the bottom (4) petaloid being provided with feet (5) projecting, separated by recessed valleys (6) which extend radially from a central zone (7) of the bottom (4), each foot (5) having an external wall (10) extending in the extension of the body (2) and two sidewalls (11) bordering each a valley (6) and which are each connected to the outer wall (10) by a fillet (12), characterized in that each foot (5) is provided with at least one rib (14), a portion (15) of which ) overlaps said leave (12).

2. Container (1) according to claim 1, characterized in that at least one rib (14) has an inner end portion (16) which extends at least partly on a sidewall (11), in which the extension of the portion (15) side.

Container (1) according to claim 1 or claim 2, characterized in that at least one rib (14) has a portion

(17) which extends at least in part on the wall (10) external foot (5), in the extension of the portion (15) side.

4. Container (1) according to claim 3, characterized in that the rib (14) is interrupted, outwardly, on the wall (10) external foot (5).

5. Container (1) according to claim 3, characterized in that it comprises at least one rib (14) having two portions (15) side which are connected by the portion (17) external.

6. Container (1) according to one of claims 3 to 5, characterized in that the portion (17) outer is arcuate.

7. Container (1) according to claim 6, characterized in that the (or each) portion (15) side is arcuate in the opposite direction of the portion (17) external.

8. Container (1) according to one of the preceding claims, characterized in that the rib (14) follows the contour of an intersection of the foot (5) with a cylinder (C) of revolution about an axis (A). ) radial.

9. Container (1) according to one of claims 1 to 5, characterized in that the portion (15) side is right.

10. Container (1) according to one of claims 1 to 4, characterized in that the rib (14) follows the contour of an intersection of the foot (5) with a plane (P).

Container according to claim 10, characterized in that, the feet (5) having ends (8) which define for the container (1) a laying plane (9), the plane (P) of intersection is inclined relative to the laying plane (9).

12. Container according to claim 10, characterized in that, the feet (5) having ends (8) which define for the container (1) a laying plane (9), the plane (P) of intersection is parallel to the laying plane (9).

13. Container (1) according to one of the preceding claims, characterized in that it comprises at least two ribs (14) superimposed.

14. Container (1) according to claim 13, characterized in that it comprises three ribs (14) superimposed.

15. Container (1) according to claim 14, characterized in that the ribs (14) are equidistant.

16. Container (1) according to one of claims 13 to 15, characterized in that, examined in ascending direction to the neck (3) from one end (8) of the foot (5), the ribs (14) are of increasing lengths.

Container (1) according to one of claims 13 to 16, characterized in that the ribs (14) follow the contour of an intersection of the foot with cylinders (C1, C2, C3) of coaxial revolution, of axis (A) radial and of different radii.

18. Container (1) according to one of the preceding claims, characterized in that at least one rib (14) is interrupted, inwardly, on the fillet (12) connection between the wall (10) external and the flank (11).

19. Container (1) according to one of the preceding claims, characterized in that the (or each) rib (14) has a width (L) between 0.4 mm and 1.5 mm.