EP3523208A1

EP3523208A1 - Petaloid base with broken valley

Info

Publication number: EP3523208A1
Application number: EP17783929.7A
Authority: EP
Inventors: Ivan Pierre; Laurent NAVEAU
Original assignee: Sidel Participations SAS
Current assignee: Sidel Participations SAS
Priority date: 2016-10-06
Filing date: 2017-09-21
Publication date: 2019-08-14
Anticipated expiration: 2037-09-21
Also published as: FR3057246A1; CN109789944A; MX2019003138A; EP3523208B1; CN114313530A; WO2018065691A1; US11008129B2; US20190308764A1; FR3057246B1

Abstract

A container (1) provided with a petaloid base (3) having feet (8) that form protrusions towards the outside of the container (1), separated two by two by recessed valleys (10) that extend radially from a central dome (5) of the base (3) to a periphery (9) of same, each foot (8) having a median face (12) with concavity facing outwards and extending via an end face (13) forming a discontinuous seat ring (14), with a planar cross section, each valley (10) having an inner portion (15) extending from the central dome (5) and an outer portion (16) that meets the periphery (9), the inner portion (15) and the outer portion (16) being, in cross section in a central radial plane at the valley (10), straight and together forming an obtuse angle (P) protruding towards the outside of the container (1) and meeting at a vertex (17) situated in line with or very nearly in line with the seat ring (14).

Description

Petaloid background with broken valley

The invention relates to the field of containers, especially bottles or jars, manufactured by blow molding or stretch blow molding from preforms or intermediate containers of plastics material such as polyethylene terephthalate (PET).

A container generally comprises an open neck, through which the contents (usually a liquid), a body, which gives the container its volume, and a bottom, which closes the body opposite the neck and forms a base for maintain and hold the container when it is resting on a surface.

The containers for carbonated beverages, in which the pressure of the gas dissolved in the liquid induces significant mechanical stresses, are mainly provided with high petaloid shaped bottoms, known under the name of "petaloid bottoms". Such bottoms include projecting, petal-shaped feet separated by convex wall portions, called valleys or valleys, which extend radially from a central zone of the bottom. The feet, high (that is to say in a ratio of about 1/2 with the diameter of the container), are intended to ensure the maintenance of the container placed on a surface; the valleys are intended to absorb the efforts (thermal, mechanical) exerted by the contents. An illustrative example of this type of background is found in International Application WO 2012/069759 (Sidel Participations).

The petaloid bottoms appear as a relatively successful solution allowing a good resistance to the strong internal pressures of the containers (in particular thanks to the hemispheric shape of the valleys) which are provided with it.

However, a petaloid bottom requires a large amount of material (a 0.5 liter container with a classic petaloid base, having a weight greater than or equal to about 18 g), as well as a relatively high blowing pressure (from order of 22 to 30 bars), to ensure a correct impression of the feet and valleys in the manufacturing mold.

These constraints tend to disqualify petaloid bottoms for "flat liquid" type applications (typically table water or non-carbonated beverages), for which the pressure is minimized. the amount of material used (today of the order of 10 g at the most for a container of 0.5 I).

It is becoming common for certain applications of flat liquids sensitive to oxidation (in particular fruit juices), but also some flat waters, to replace the air surmounting such flat liquids with an inert gas (typically carbon dioxide). 'nitrogen). In practice, this operation is performed by pouring a drop of liquefied inert gas onto the surface of the flat liquids, immediately preceding the clogging of the container. This operation induces an overpressure in the containers to which this treatment is applied. Even slight in appearance (of the order of 0.5 to 1.3 bar), this overpressure is enough to significantly increase the constraints on the funds, without these constraints however justify the use of petaloid funds classic (that is, high).

Now a bottom provided with a simple concave arch, if it responds a priori to the requirements of saving material and allows easy manufacture of containers by blowing (we speak of containers with a "labil lity" easy), n ' However, it is not able to withstand without significant deformation the stresses due to the hydrostatic pressure doubled by the pressure of the added inert gas.

There is therefore a need for a container whose bottom provides increased resistance to internal stresses compared to ordinary arched bottoms, while not requiring as much material, or a blowing pressure as high as an ordinary petaloid bottom.

It has therefore been proposed, cf. the international application WO2014207331

(Sidel Participations), a petaloid bottom of low height, whose h / d ratio between the height (h) of the feet and the diameter (d) overall of the bottom is less than or equal to 1/5, this bottom being furthermore provided with a central dome and grooves straddling the valleys and the dome.

This bottom has interesting mechanical performance, which make it suitable for the addition of an inert gas under pressure, provided however that the amount of material used for the manufacture of the container is sufficient.

However the operators are always more demanding on the savings of material, and the need is reborn to propose a new container whose bottom can, with quantity of matter still reduced, to offer under pressure a sufficient mechanical resistance while presenting a lability easy.

For this purpose, there is provided a plastic container comprising a body, which extends along a main axis, and a petaloid bottom, which extends the body, this bottom comprising:

a generally convex bottom wall convex towards the outside of the container,

a central dome formed recessed inwardly of the container and extending from a central vertex to a peripheral edge through which the dome connects to the bottom wall, and

at least four feet which form protrusions from the bottom wall towards the outside of the container, separated in pairs by portions of the bottom wall forming at least four recessed valleys which extend radially from a central dome from the bottom to a periphery of it,

each foot having two flanks, each bordering a valley, and a medial face which, in a radial plane, has a concavely curved profile facing outwardly of the container and is extended by an end face, the end faces jointly forming a laying ring, of flat section, interrupted to the right of each valley,

container in which:

each valley has an internal portion that extends from the central dome and an outer portion that joins the periphery in the extension of the inner portion, the inner portion and the outer portion being in section in a radial plane median to the valley, straight and together forming an obtuse angle protruding outwardly of the container and meeting at a vertex located plumb or in the immediate vicinity of the plumb with the laying ring;

the bottom comprises two groups of valleys arranged alternately: o primary valleys whose inner portion connects to the dome at the peripheral edge thereof;

o secondary valleys whose inner portion connects to the dome between the peripheral edge and the central dome, away from the peripheral edge. This architecture provides the bottom a good mechanical rigidity including when the container is pressurized, while having a good breathability.

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

The dome has a height, measured axially between its peripheral edge and its top and, in the secondary valleys, the inner portion is advantageously connected to the dome at a distance from the peripheral edge of between 20% and 70% of said height of the dome;

In the secondary valleys, the inner portion is preferably inclined relative to any plane parallel to the plane of the laying ring, towards the inside of the container, at an angle advantageously between 5 ° and 30 °;

In the primary valleys, the inner portion is preferably inclined relative to any plane parallel to the plane of the laying ring, towards the outside of the container, at an angle advantageously between 2 ° and 10 °;

Alternatively, in the primary valleys, the inner portion is inclined, relative to any plane parallel to the plane of the laying ring, towards the interior of the container by an angle less than or equal to 4 °.

In the median radial plane at each valley, the valley top may be offset relative to the laying ring, for example between 1.5 mm and 3 mm.

The obtuse angle formed, in the radial plane median to a primary valley, between the inner portion and the outer portion, is, for its part, a value preferably between 130 ° and 175 °, and for example of a value of about 160 °.

The obtuse angle formed, in the median radial plane to a secondary valley, between the inner portion and the outer portion, is of a value between 130 ° and 165 °, and preferably from 140 ° to 145 °.

The top of each valley is advantageously distant from the plane of the laying ring by a value of between 10% and 15% - and e.g. about 12% - the overall diameter of the bottom of the container.

The present an overall diameter, all the outer portions join the periphery on the same junction plane, and the feet have a height, measured axially between the plane of the ring of laying and said joining plane, whose value is between 15% and 25%, and preferably about 20%, of the overall diameter of the bottom.

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:

FIG.1 is a perspective bottom view of a container with a low petaloid bottom;

FIG. 2 is a perspective bottom view of the bottom of FIG. 1, on a larger scale;

FIG. 3 is a plan view from below of the bottom of the container of FIG. 2;

FIG.4 is a bottom plan view of detail, on a larger scale, of the bottom of FIG.3 taken in the medallion IV;

FIG. 5 is a section of the bottom of FIG. 3 along the V-V section plane;

FIG.6 is a section of the bottom of FIG.3, according to the section plane VI-VI;

FIG.7 is a partial section of the bottom of FIG.3, according to the section plane VII-VII;

- FIG.8 is a partial section of the bottom of FIG.3, according to the VIN-VIN cutting plane;

FIG.9 is a partial section of the bottom of FIG.3, according to the section plane IX-IX;

FIG.10 is a partial section of the bottom of FIG.3, according to the section plane X-X.

In FIG. 1 is shown, in perspective from below, a container 1 - in this case a bottle - obtained by blowing or stretching from a blank, such as a preform made of thermoplastic material, for example polyethylene terephthalate (PET), previously heated.

The container 1 extends along a main axis X and comprises a side wall called body 2, and a bottom 3 which extends and closes the body 2 at a lower end thereof.

The bottom 3 is petaloid, and comprises a bottom wall 4 of generally convex shape towards the outside of the container 1 (that is to say down when the container 1 is laid flat). Bottom 3 has a central dome 5 which extends recess inwardly of container 1 (i.e., dome 5 has a concavity facing outwardly of container 1). At its center, the dome 5 has an apex 6. In the example illustrated, the apex 6 carries, in axial projection, an injection pellet, the material of which remained substantially amorphous during the forming of the container 1. The dome 5 has the particular function of stretching the material in the center of the bottom, so as to increase the crystallinity and therefore the mechanical strength.

The dome 5 extends to a peripheral edge 7 (here of substantially circular contour when viewed from below) by which it is connected to the bottom wall 4. More specifically, the peripheral edge 7 forms a fillet of connection of the dome 5 to the bottom wall 4.

The bottom 3 also comprises a series of feet 8 which form protrusions projecting axially from the bottom wall 4 towards the outside of the container 1.

The feet 8 extend radially from the central dome 5 (and more precisely from its peripheral edge 7) to a periphery 9 of the base 3 where the latter connects to the body 2.

As can be seen in FIG. 2 and FIG. 3, the legs 8 are separated in pairs by portions of the bottom wall 4 forming valleys 10 which extend radially in a star shape from the dome 5 to the periphery 9.

The valleys 10 extend hollow between the feet 8 that separate two by two. The valleys 10 are substantially straight when viewed in a plane perpendicular to the main X axis (i.e., in the plane of FIG. 3).

Moreover, as is also visible in FIG. 3, the valleys 10 are advantageously slightly curved and have a width (measured perpendicular to the radius) which, from the dome 5 to the periphery 9, first decreases and then increases.

As can be seen in FIG. 2 and FIG. 3, the feet 8 are equal in number to the valleys 10. In the example illustrated, the bottom 3 comprises six feet 8 and six valleys 10, regularly alternated and distributed in a star shape. . This number is a good compromise; it could, however, be less (but greater than or equal to four), or greater (but preferably less than or equal to ten). Each foot 8 has two substantially planar flanks 11 each bordering a valley 10. As can be seen in FIG. 7 to FIG. 10, the flanks 11 are not vertical (because the bottom 3 would then be difficult or impossible to blow), but inclined by opening from the valley 10 to the outside.

Each foot 8 further has a medial face 12 which joins the flanks 11. As illustrated in FIG. 3, seen in a plane perpendicular to the main axis X, the medial face 12 extends substantially radially.

Moreover, as illustrated in FIG. 5, in a radial plane, the face

12 median has a curved profile with concavity turned towards the outside of the container 1.

The most protruding portion of each leg 8, extending the medial face 12, forms an end face 13 of the foot 8. The end faces 13 of the legs 8 are coplanar and together form a ring 14 for laying, interrupted and flat section, through which the container

1 can rest on a flat surface (for example a table).

The fitting ring 14 is connected to the body 2 via a structure having a connection fillet comprising two parts 8A and 8B, connected at a junction 8C. Said structure will be described in more detail later.

As can be seen in FIG. 3, the fitting ring 14

(shown in this figure by a dashed circle), is located radially set back from the periphery 9.

As can be seen in FIG. 2 and FIG. 3, the feet 8 are tapering from the inside to the outside of the container 1 (that is to say downwards), and in that widening from the central dome 5 to the periphery 9.

Each valley 10 has an inner portion extending from the central dome 5, and an outer portion 16 which joins the periphery 9.

All the outer portions 16 join the periphery 9 at the same level, so on the same section or the same plane called joining plan. The overall height of the bottom 3 is defined as the distance, measured axially, between the plane of the laying ring 14 (in other words the end face 13) and the junction plane between the outer portions 16 and the periphery 9. As will be indicated later, this height is referenced Q. As illustrated in FIGS. 5 and 6, the inner portion and the outer portion 16 are, in section in a radial plane median to the valley 10, straight and together form an obtuse angle projecting outwardly of the container 1 .

The inner portion and the outer portion 16 meet at a vertex 17 located at right angles or in the immediate vicinity of the plumb with the setting ring 14, that is to say that the vertex can be offset from the Laying plane determined by the ring 14. According to a preferred embodiment, the top 17 is curved in any radial plane, and has a concavity turned towards the inside of the container 1.

It has been found that this form increases the mechanical strength of the bottom 3, in particular when the container 1 is pressurized.

Moreover, as illustrated in the drawings (and more particularly in FIG. 5 and FIG. 6), the valleys 10 are subdivided into two groups of valleys 10 arranged alternately, namely:

o Primary valleys 10A whose internal portion, denoted 15A, connects to the dome 5 at height of the peripheral edge 7 thereof; o 10B secondary valleys whose internal portion, denoted 15B, connects to the dome 5 at a distance from its peripheral edge 7.

In other words, the internal portion 15B of the secondary valleys 10B is deeper, when measured axially, than the internal portion 15A of the primary valleys 10A. This difference in depth appears clearly in FIG. 2 and on the left of FIG. 6, where the primary valleys 10A are plotted in mixed fine lines while the secondary valleys 10B are plotted in solid bold lines.

We now provide additional details on the sizing of the bottom 3. For this purpose, we note:

At the angle, measured in a median radial plane at valley 10, between the outer portion 16 of the valley and any plane perpendicular to the main X axis

B the width, measured radially, of the fitting ring 14

C the radius of curvature, measured in a radial plane, of a connection fillet between the median face 12 of the foot 8 and the ring

14 laying

D the overall diameter of the bottom 3, measured at the periphery 9 E the radius of curvature, measured in a radial plane, of a first part 8A of the connection fillet between the fitting ring 14 and the body 2, said first part 8A being between the fitting ring 14 and the joint 8C between connecting connection parts 8A and 8b

E 'the radius of curvature of the top 17

F the height of the dome 5, measured axially between the peripheral edge 7 and the vertex 6

F 'the distance, measured axially, between the peripheral edge 7 of the dome 5 and the inner edge of the internal portion 15B of each secondary valley 10B, at its junction with the dome 5 G the angle, considered in a radial plane, between the axis X of the body 2 and the tangent to the first part 8A of the fillet, at the junction 8C between the parts 8A and 8b of this fillet of connection

H the distance, measured axially, between, on the one hand, an outer limit of the peripheral edge 7 of the dome 5 and the plane of the ring

14 laying

J the diameter of the laying ring 14, measured on an internal edge thereof

L the distance, measured axially, between an inner limit of the peripheral edge 7 of the dome 5 and the plane of the fitting ring 14

M is the distance, measured axially, between the top 17 of each valley 10 and the plane of the fitting ring 14

O the offset, measured radially, between the top 17 of each valley 10 and the fitting ring 14

P the obtuse angle formed in the median radial plane at each valley

10A primary, between the internal portion 15A and the outer portion 16

P 'the obtuse angle formed in the median radial plane at each valley

10B secondary, between the internal portion 15B and the outer portion 16

Q the overall height of the bottom 3, that is to say the distance, measured axially, between the plane of the insertion ring 14 and the junction between an outer portion 16 and the periphery 9 R the angular aperture between the flanks 11, measured in a transverse plane relatively more distant from the dome 5, coinciding with the cutting plane VIII-VIII, as illustrated in FIG.

S the angular opening between the flanks 11, measured in a transverse plane (that is to say perpendicular to the median radius of the foot 8) adjacent to the dome 5, coinciding with the sectional plane VII-VII, as illustrated in FIG.

T the radius, measured radially, of the dome 5

U the angular aperture between the flanks 11, measured in a transverse plane close to the periphery, coinciding with the X-X cutting plane, as illustrated in FIG.

V the angular aperture between the flanks 11, measured in a transverse plane even further from the dome 5, coinciding with the IX-IX cutting plane, as illustrated in FIG.

W the radius of curvature, measured in a radial plane, of the face

12 median foot 8

The bottom 3 may be called "petaloid bottom" because of its structure made of alternating projecting feet 8 and valleys 10 recessed. However, its low Q / D diameter ratio disqualifies it for carbonated applications (typically for soft drinks). This ratio is indeed less than or equal to 1/4.

A classic petaloid background would have such a ratio of about 1/2. The present bottom 3, which may be called "petaloid mini" because of its low Q / diameter D ratio, is intended rather for flat liquid type applications associated with the addition, immediately after filling and before capping. , a drop of liquid nitrogen whose vaporization puts the contents of the container 1 under pressure, this overpressure being less than or equal to 1.3 bar.

In this case, the ratio Q height / diameter D is preferably between 0.15 and 0.25, and preferably of the order of 0.2.

According to an embodiment illustrated in FIG. 5, in the primary valleys 10A, the internal portion 15A is inclined, with respect to any plane parallel to the plane of the fitting ring 14, toward the outside of the container 1. this sloping negative slope of the internal portion 15A, advantageously between 2 ° and 10 °. According to an embodiment illustrated in FIG. 6, in the secondary valleys 10B, the internal portion 15B is on the contrary inclined with respect to any plane parallel to the plane of the laying ring 14 towards the interior of the container 1 This positive inclination of the internal portion 15B is advantageously called "proclive", advantageously between 5 ° and 30 °.

As a variant, however, the internal portion 15A of the primary valleys 10A could, like the internal portion 15B of the secondary valleys 10B, be inclined, with respect to any plane parallel to the plane of the fitting ring 14, towards the interior of the container 1 that is to say in proclive, of an angle however less than or equal to 4 °.

Thus, and as is apparent from the joint reading of FIG.3, FIG.5 and FIG.6, the bottom 3 has, in the illustrated example, valleys 10A and 10B whose internal portions 15A, 15B are alternately sloping (FIG. 5) and in proclive (FIG. As already mentioned, the internal portions 15A of the primary valleys 10A debouch internally on the peripheral edge 7 of the central dome 5, while the internal portions 15B of the secondary valleys 10B open internally at a distance from the peripheral edge 7. This configuration increases the mechanical strength of the bottom 3 when under pressure.

More specifically, and as mentioned in the table above, the internal portions 15B of the secondary valleys 10B open on the dome 5 at a distance F 'from the peripheral edge 7 thereof, between this peripheral edge 7 and the vertex 6 of the dome. Depending on the depth (that is to say the inclination) of the internal portions 15B of the secondary valleys 10B, this distance F 'is advantageously between 20% and 70% of the total height F of the dome 5:

0.2 ^■ F≤ F'≤ 0.7 ^■ F

In the illustrated example, the distance F 'is approximately 60% of the total height F of the dome 5:

F '= 0.6 ^■ F

This configuration makes it possible to obtain a compromise between the structural rigidity of the bottom 3, particularly because of the depth of the internal portions 15B of the secondary valleys 10B, especially in the vicinity of the center of the bottom 3, and the good capacity of the latter (c that is to say its capacity to be correctly formed during the blowing of the container 1), particularly because of the relatively shallow depth of the internal portions 15A near the center of the bottom 3. Furthermore, as can also be seen in FIGS. 5 and 6, in at least one of the valleys 10 (and preferably in all the valleys 10), the outer portion 16 is advantageously inclined, with respect to all plane parallel to the plane of the ring 14 for laying, towards the inside of the container 1, by an angle A. In other words, the outer portion 16 is sloped. The angle A of inclination of the outer portion 16 is preferably between 20 ° and 30 °.

The angles P and P 'are obtuse; they are therefore strictly greater than 90 ° and strictly less than 180 °.

More specifically, as illustrated in FIG. 5, the angle P is advantageously between 130 ° and 175 °, and preferably about 160 °.

As for the angle P ', illustrated in FIG. 6, it is advantageously between 130.degree. And 165.degree., And preferably from about 140.degree. To 145.degree.

The width B of the laying ring 14 is advantageously between 0.4 mm and 1 mm, and preferably of the order of 0.5 mm.

The radius C of curvature is advantageously equal to about half the radius E.

The radius E is advantageously between 5 mm and 11 mm. In this case, it follows that the radius C is between 2.5 mm and 5 mm. The center of curvature of the radius E is located vertically to the ring 14 laying.

As previously indicated, the fitting ring 14 is connected to the body 2 via a structure having a connection fillet comprising two parts 8A and 8B. The radius E is that of the first portion 8A, which is between the fitting ring 14 and the junction 8C between the portions 8A and 8b of the fillet. This radius is constant or may vary in a small way.

The second portion 8B of the fillet is between the junction 8C and the periphery 9 of the bottom 3 where it connects to the body 2. This second portion 8B has an evolutionary radius of curvature between the junction 8C and the peripheral edge 9 of the bottom 3.

The overall diameter D of the bottom 3 is a function of the capacity of the container 1. For a container 1 with a capacity of 0.5 I, the diameter D may be about 65 mm (in this case, the radius E is advantageously about 6 mm). For a container 1 with a capacity of 1.5 I, the diameter D may be about 90 mm (in this case, the radius E is preferably about 9 mm).

The radius E 'of the crown is advantageously between 5 mm and 11 mm. It may be equal to the radius E. In practice, like the radius E, the radius E 'is a function of the capacity of the container 1. For a container 1 with a capacity of 0.5 I, the radius E' may be About 6 mm. For a container 1 with a capacity of 1, 5 I, the radius E 'can be about 9 mm.

The height F of the dome 5 is advantageously between 1 mm and 8 mm. In practice, this height F is a function of the capacity of the container 1. For a container 1 with a capacity of 0.5 I, the height F may be about 2 mm. For a container 1 with a capacity of 1.5 I, the height can be about 7.5 mm. In this case, the distance F 'is advantageously approximately 4.5 mm.

The angle G is advantageously between 20 ° and 40 °. It is recalled that this is the angle considered in a radial plane, between the axis X of the body 2 and the tangent to the first portion 8A of the fillet, at the junction 8C between the parts 8A and 8b of this connection holiday. In practice, the angle G is a function of the capacity of the container 1 and, in particular, its diameter D. The value of the angle G, according to the diameter D of the container and the radius E of curvature of the first portion 8A of the leave, determines the position of the junction 8C between the two parts 8A and 8B of the fillet of connection of the ring 14 to the body 2. For a container 1 with a capacity of 0.5 I, the angle G may be 25 ° approx. For a container 1 with a capacity of 1.5 I, the angle G may be about 35 °.

The distance H is advantageously related to the overall diameter D of the bottom 3. More specifically, the distance H is preferably between 10% and 15% (and, for example, approximately 12%) of the diameter D.

The diameter J is advantageously between 65% and 75% (and for example about 70%) of the diameter D.

The distance L is advantageously between 50% and 85% (and eg about 70%) of the overall height Q of the bottom 3.

The distance M is advantageously a function of the overall diameter D of the bottom 3. More specifically, the distance M is advantageously between 10% and 15% (and for example about 12%) of the diameter D.

The offset O may be zero and, in this case, the top 17 is located vertically above the fitting ring 14; it can also be positive (ie that is to say that the top 17 is radially offset, with respect to the laying ring 14, towards the outside of the container 1), or on the contrary negative (that is to say that the top 17 is shifted radially, relative to the insertion ring 14, towards the inside of the container 1). In both cases, the value of the offset O is small compared to the diameter D.

The offset O can be indexed on the radius E, e.g. in a ratio of 1 to 3, that is to say that the ratio O / E is about 1/3.

Given the values already provided for E, it is understood that the offset O is between 1.5 mm and 3 mm.

In addition, the overall radius T of the dome 5 is advantageously between 5 mm and 15 mm. In practice, this radius T is a function of the capacity of the container 1. For a container 1 with a capacity of 0.5 I, the radius T is thus, for example, about 7 mm. For a container 1 with a capacity of 1.5 I, the radius T is e.g. about 13 mm.

Finally, as can be seen in FIGS. 7 to 10, the angular aperture of the flanks 11 is variable. More precisely, the angular aperture of the flanks 11 decreases from the inside to the outside of the bottom 3 (that is from the X axis to the periphery 9), the angular aperture S being greater than the angular aperture R, which in turn is greater than the angular aperture V, itself greater than the angular aperture U, which means that the flanks 11 are closing off from the dome 5 towards the periphery 9.

This variation of angular opening widens the feet 8 towards the periphery 9, to the benefit of the stability of the container 1, and the resistance of the legs 8, in particular during the palletizing of the container 1.

Under the effect of a pressure in the container 1, the angle P tends to deform by closing. As the top 17 is plumb or in the immediate vicinity of the plumb of the laying ring 14, the flanks 11, which present at this point their greatest height (measured axially, coincides with the distance M), absorb this deformation without being too deformed in turn, so that the general deformation of the bottom 3 is of small magnitude, and therefore resists the pressure. The concave shape of the medial face 12, as well as the alternation of relatively shallow primary valleys 10A and of deeper secondary valleys 10B seem to contribute to this rigidity.

Tests carried out on the container 1 show that the most important deformations are located on the dome 5, whose curved shape It is particularly resistant to pressure, while the peripheral areas of the dome 5 (valleys 10, 8) are only slightly deformed.

Claims

A plastic container (1) comprising a body (2) extending along a main axis (X) and a petaloid bottom (3) which extends the body (2), said bottom (3) comprising:

a bottom wall (4) of generally convex shape towards the outside of the container (1),

a central dome (5) formed recessed inwardly of the container (1) and extending from a central vertex (6) to a peripheral edge (7) through which the dome (5) connects to the bottom wall (4), and

at least four feet (8) which form protrusions from the bottom wall (4) towards the outside of the container (1), separated in pairs by portions of the bottom wall (4) forming at least four hollow valleys (10) extending radially from a central dome (5) of the bottom (3) to a periphery (9) thereof,

each foot (8) having two sidewalls (11) each bordering a valley (10) and a medial face (12) which, in a radial plane, has a concavely curved profile facing the outside of the container (1) and extended by an end face (13), the end faces jointly forming a laying ring (14), of flat section, interrupted to the right of each valley (10),

this container being characterized in that:

- Each valley (10) has an inner portion (15, 15A, 15B) extending from the central dome (5) and an outer portion (16) which joins the periphery (9) in the extension of the portion (5). 15, 15A, 15B), the inner portion (15, 15A, 15B) and the outer portion (16) being, in section in a median radial plane to the valley (10), straight and together forming an angle (P) obtuse protruding outwardly of the container (1) and meeting at a vertex (17) located plumb or in the immediate vicinity of the plumb with the ring (14) of installation;

the bottom (3) comprises two groups of valleys (10) arranged alternately: primary valleys (10A) whose internal portion (15A) connects to the dome (5) at the peripheral edge (7) thereof;

o Secondary valleys (10B) whose internal portion (15B) connects to the dome (5) between the peripheral edge (7) and the vertex

(6) central dome at a distance (F ') from the peripheral edge (7).

2. Container (1) according to claim 1, characterized in that the dome has a height (F), measured axially between its peripheral edge (7) and its apex (6) and, in the valleys (10B) secondary, the portion (15B) internally connects to the dome (5) at a distance (F ') from the peripheral edge (7) of between 20% and 70% of said dome height (F).

Container (1) according to claim 1 or claim 2, characterized in that, in the secondary valleys (10B), the internal portion (15B) is inclined with respect to any plane parallel to the plane of the ring ( 14), inwardly of the container (1).

4. Container (1) according to claim 3, characterized in that the angle of inclination of the portion (15B) internal secondary valleys (10B) is between 5 ° and 30 °.

Container (1) according to one of the preceding claims, characterized in that, in the primary valleys (10A), the inner portion (15A) is inclined with respect to any plane parallel to the plane of the ring (14). ) of laying, towards the outside of the container (1).

6. Container (1) according to claim 5, characterized in that the angle of inclination of the portion (15A) internal primary valleys (10A) is between 2 ° and 10 °.

Container (1) according to one of claims 1 to 4, characterized in that, in the primary valleys (10A), the internal portion (15A) is inclined with respect to any plane parallel to the plane of the ring. (14) of installation, inwardly of the container (1) by an angle less than or equal to 4 °.

8. Container (1) according to one of the preceding claims, characterized in that, in the median radial plane to each valley (10), the top (17) of the valley (10) is offset relative to the ring (14) laying.

9. Container (1) according to claim 8, characterized in that the apex (17) is offset with respect to the ring (14) of laying a value (O) between 1.5 mm and 3 mm.

Container (1) according to one of the preceding claims, characterized in that the obtuse angle (P) formed, in the median radial plane to a primary valley (10A), between its internal portion (15A) and its portion. (16) is between 130 ° and 175 °.

Container (1) according to claim 10, characterized in that the obtuse angle (P) formed in the median radial plane at each valley (10A), primary between the internal portion (15) and the portion (16). external, is of a value (P) of about 160 °.

Container (1) according to one of the preceding claims, characterized in that the obtuse angle (Ρ ') formed, in the median radial plane to a secondary valley (10B), between its internal portion (15B) and its outer portion (16) is between 130 ° and 165 °.

Container (1) according to one of the preceding claims, characterized in that the obtuse angle (Ρ ') formed, in the median radial plane to a secondary valley (10B), between its internal portion (15B) and its portion (16) external, is of a value of 140 ° to 145 ° approximately

14. Container (1) according to one of the preceding claims, characterized in that, the bottom (3) of the container having an overall diameter (D), the top (17) of the valley (10) is distant from the plane the ring (14) for laying a value (M) of between 10% and 15% of said diameter.

Container (1) according to claim 14, characterized in that the distance (M) from the top (17) of the valley (10) to the plane of the fitting ring (14) is approximately 12% of the diameter ( D) off the bottom (3).

16. Container (1) according to one of the preceding claims, characterized in that the bottom (3) has a diameter (D) overall, all the portions (16) external join the periphery (9) on the same plane of junction, and the feet have a height (Q), measured axially between the plane of the laying ring (14) and said junction plane, whose value is between 15% and 25% of said diameter (D).

Container (1) according to claim 16, characterized in that the height (Q) of the feet (8) is approximately 20% of the diameter (D) overall of the bottom (3).