BOTTLE WITH AN ENHANCED BOTTOM

Abstract

A bottle having good mechanical properties and lightness due to its bottom design includes a bottom, a body, and a neck. The bottom has a dome, a coronal arch, an annular seat, a side wall, six main radial grooves, five secondary radial grooves situated between the main grooves, each having an end Ev in the arch, and a peripheral end Ep in the side wall. The bottom is such that the ratio Mf/Vuf, wherein Mf is the weight of the bottom and Vuf is the useful volume of the bottom, is less than or equal to 0.050 g/mL and the ratio ?.sup.do/H.sup.do, wherein ?.sup.do is the diameter of the dome at its base and H.sup.do is its apex height along an axis Z, is greater than or equal to 4.4. The invention also relates to a manufacturing method and a mold for the bottle.

Claims

1. A bottle made of thermoplastic polymer, obtained by blow molding an injection-molded preform, comprising from bottom to top along a vertical axis Z of the bottle resting upright on a horizontal plane support in a contact plane XY a bottom, a body and a neck, the spatial frame of reference of this bottle being an orthonormal system of axes [XYZ] with origin O, the bottom comprising successively and in a centrifugal direction: a dome with axis Z extending toward the interior of the bottle, a coronal arch extending toward the interior of the bottle, an annular seat intended to be in contact with a plane support in a contact plane XY on which the bottle is able to rest in upright position, a lateral wall extending in a non-horizontal direction as far as the body at a height H of 15 mm with reference to a height h0 situated at the level of the plane of the seat, the junction between the lateral wall and the annular seat constituting an annular edge, at least three, main grooves extending radially from the dome to the lateral wall, defining between them on the arch main arch portions, at least three secondary grooves disposed between the main grooves, each extending radially between an end Ev in an arch portion and a peripheral end Ep in the lateral wall, wherein: the ratio Mf/Vuf in which Mf is the weight of the bottom and Vuf the usable volume of the bottom, is less than or equal to 0.050 g/mL, the ratio ?.sup.do/H.sup.do in which ?.sup.do is the diameter of the dome at its base and H.sup.do its apex height along the axis Z or an axis parallel to Z, is greater than or equal to 4.4.

2. The bottle as claimed in claim 1, wherein the thickness of the bottom decreases continuously in the radial direction along a radial generatrix line G extending, outside zones comprising the main grooves and secondary grooves, from the axis Z to the annular edge.

3. The bottle as claimed in claim 1, wherein the ratio d/D in which d is the radial distance between the axis Z and the end Ev of at least one of the secondary grooves and D is the radial distance between the axis Z and the annular edge is greater than or equal to 0.65.

4. The bottle as claimed in claim 1, wherein at least one of the main grooves has an inverted U general shape in cross section in a plane parallel to the axis Z, and in that the branches of the U form between them an angle ?1 between 30 and 50? inclusive.

5. The bottle as claimed in claim 1, wherein at least one of the secondary grooves has an inverted V general shape in cross section in a plane parallel to the axis Z, and in that the branches of the V form between them an angle ?2 between 45 and 65? inclusive.

6. The bottle as claimed in claim 1, wherein each arch portion has a substantially rectilinear radial profile.

7. The bottle (1) as claimed in claim 1, wherein each arch portion (21) has a profile forming an angle ?3 with the contact plane XY between 5 and 20? inclusive.

8. The bottle as claimed in claim 1, wherein the bottom, the body and/or the neck have a circular shape in cross section in a plane parallel to the contact plane XY.

9. The bottle as claimed in claim 1, wherein its volume capacity in centiliters is 20 to 30 cL, or 30 to 40 cL, or 40 to 60 cL, or 60 to 80 cL, or 80 to 110 cL, or 110 to 130 cL, or 130 to 160 cL, or 160 to 180 cL, or 180 to 220 cL, or 220 to 260 cL.

10. A blow molding mold comprising a part having an imprint enabling the bottom of the bottle as claimed in claim 1 to be obtained.

11. A method of manufacturing the bottle as claimed in claim 1 comprising employing a preform employing a blow molding technology using a blow molding mold comprising a part having an imprint enabling the bottom of the bottle to be obtained.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0094] This description is given with reference to the appended figures depicting non-limiting embodiments in which:

[0095] FIG. 1 is a perspective view of a preform intended for the manufacture of the bottle according to the invention by blow molding.

[0096] FIG. 2 is a view in section of FIG. 1 in the median diametral plane of the preform shown in FIG. 1.

[0097] FIG. 3 is a front view of one embodiment of a bottle according to the invention.

[0098] FIG. 4 is a perspective view of another embodiment of a bottle according to the invention.

[0099] FIG. 5 is a view from below and from the front of the bottom of the bottle from FIG. 3.

[0100] FIG. 6 is a perspective view from below of the bottom of the bottle from FIG. 4.

[0101] FIG. 7 is a view from below and from in front of the bottom of the bottle from FIG. 4.

[0102] FIG. 8 is a side view of FIG. 7.

[0103] FIG. 9 is a perspective view of the bottom from FIGS. 7 and 8.

[0104] FIG. 10 is a view in section taken along the line A-A in FIG. 7.

[0105] FIG. 11 is a view in section taken along the line B-B in FIG. 7.

[0106] FIG. 12 is a view in section taken along the line C-C in FIG. 7.

[0107] FIG. 13 is a view of the detail H in FIG. 12.

[0108] FIG. 14 is a view in section taken along the line D-D in FIG. 7.

[0109] FIG. 15 is a view in section taken along the line F-F in FIG. 7.

[0110] FIG. 16 is a view in diametral section of the preform used to manufacture a bottle according to the invention used in example 1.

[0111] FIG. 17 is a lateral view of a bottle according to the invention used in example 1 produced from the FIG. 16 preform.

[0112] FIG. 18 is a view from below showing the bottom of the bottle represented in FIG. 17.

[0113] FIG. 19 is a photograph from below showing the bottom of the bottle represented in FIG. 17.

[0114] FIG. 20 is a partial perspective view from below showing the bottom of the bottle represented in FIG. 17.

[0115] FIG. 21 is a photograph from below showing the bottom of the negative reference bottle used in comparative example 2.

[0116] FIG. 22 is a partial lateral view in diametral section of the preform used to manufacture a bottle according to the invention used in example 3.

[0117] FIG. 23 is a lateral view of a bottle according to the invention used in example 3 produced from the FIG. 22 preform.

[0118] FIG. 24 is a view from below showing the bottom of the bottle represented in FIG. 23.

[0119] FIG. 25 is a photograph from below showing the bottom of the bottle represented in FIG. 23.

[0120] FIG. 26 is a partial perspective view from below showing the bottom of the bottle represented in FIG. 23.

[0121] FIG. 27 is a photograph from below showing the bottom of the negative reference bottle used in comparative example 4.

[0122] The reference numbers used in all the figures designate the same elements.

Definitions

[0123] Conforming to the terminology used in the present text, the following non-limiting definitions are given by way of example and illustration for the interpretation of the present text: [0124] any singular designates a plural and vice versa, [0125] thermoplastic refers to a thermoplastic or moldable copolymer or homopolymer that becomes fluid, viscous, pliable, moldable above a specific temperature (for example the glass transition temperature) and returns to the solid/hardened state after cooling.

DETAILED DESCRIPTION OF THE INVENTION

[0126] The container at the heart of the invention is a bottle 1 made of thermoplastic polymer material, preferably of polyethylene terephthalate (PET).

[0127] This bottle 1 represented in FIGS. 3 and 4 is described hereinafter with reference to a three-dimensional orthonormal system of axes [XYZ] with origin O. The axis Z-Z or Z is the axis of the bottle 1. The axes X-X or X and Y-Y or Y define a plane XY which is the contact plane between the bottom of the bottle and a plane horizontal support on which the bottle rests when upright. The origin O of the orthonormal system of axes XYZ is in this plane XY. FIGS. 3,5, 6 and 9 in particular show this spatial system of axes XYZ.

[0128] The bottle 1 comprises from top to bottom along the axis Z a bottom 2, a body 3 and a neck 4 delimiting the upper opening 5 of the bottle 1 and separated from the body 3 by a flange 6 surmounted by a thread 7 intended to cooperate with a screw cap to close the bottle 1. The body 3 of the bottle 1 comprises groove and rib patterns known in themselves with no references in the figures and intended to contribute to the mechanical strength of the body 3.

[0129] In the following description the terms interior, internal toward the interior refer to an element close to or in the direction of the axis Z of the bottle 1 or in the enclosure 8 defined by the bottom 2, the body 3 and the neck 4, forming an envelope delimiting this enclosure 8 of the bottle 1, and the terms exterior, external, toward the exterior relate to an element situated in an opposite direction along the axis Z of the bottle 1 or outside the enclosure 8 of the bottle 1. The terms low, lower, high, upper are to be understood as relative to the bottle 1 placed on a plane horizontal support XY when upright.

[0130] This bottle 1 is produced industrially by the technology of injection blow molding a preform sufficiently heated to be fluid in a mold having the imprint of the bottle. Blow molding may be complemented by stretching by means of an axial rod introduced into the preform (injection stretch blow molding (ISBM)).

[0131] FIGS. 1 and 2 show an example of this preform 100 in the form a tube with axis Z defined by a wall 101, open at its upper end 102 and including the neck 4 of the future bottle 1 and the bottom 103 of which has a hemispherical general shape. When this preform is manufactured by injection molding the lower end of the bottom 103 includes on the exterior face of the wall 101 a protrusion 104 extending outward along the axis Z. This is a mark left by the injection point of the preform 100.

[0132] In a compression molding production variant the preform has no such mark.

[0133] As shown in FIGS. 5, 6, 7, 9, 10 and 11 the bottom 2 of this bottle 1 successively and centrifugally comprises: [0134] a dome 9, [0135] a coronal arch 12 extending toward the interior of the bottle 1 (enclosure 8), [0136] an annular seat 13 intended to be in contact with the plane support in a contact plane XY on which the bottle 1 may rest when upright, [0137] a lateral wall 14 extending in a non-horizontal direction (different from XY) as far as the body, at a height H of 15 mm with a height h0 situated at the level of the plane of the seat 13 that coincides with the contact plane XY of the plane support on which the bottle 1 may rest when upright.

[0138] As appears in particular in FIGS. 10 and 11 the junction between the lateral wall 14 and the annular seat 13 constitute an annular edge 15 that forms a sort of line of demarcation between these two parts of the bottom 2.

[0139] FIGS. 5, 6, 7 and 9 show that the lower face of the bottom 2 is marked by radial mechanical reinforcement grooves of two types: main grooves 16 and secondary grooves 17.

[0140] The bottom 2 is represented in FIGS. 5 to 14 as a cup as if detached from the rest of the bottle 1. This virtual cup, considered in isolation, contributes to the definition of the bottle according to the invention. To this end three generatrices G1, G2, G3 are defined as shown in FIG. 7: [0141] G1: radial direction along the axis X, between the axis Z and the lateral wall of the bottom 2; [0142] G2: radial direction at an angle of 120? relative to G1 in the clockwise rotation direction, between the axis Z and the lateral wall of the bottom 2; [0143] G3: radial direction at an angle of 240? relative to G1 in the clockwise rotation direction, between the axis Z and the lateral wall of the bottom 2.

[0144] Apart from its shape and its height H=15 mm described hereinabove, the bottom 2 may equally be defined by its weight Mf and by a usable volume Vuf. Mf is measured by weighing the bottom when dry and Vuf by filling it with water up to a level such that the meniscus is concave, the edge of that meniscus being contained in the plane perpendicular to Z corresponding to the upper edge of the lateral wall 14 of the bottom 2.

[0145] In accordance with the invention, outside the zones comprising the main grooves 16 and the secondary grooves 17, the thickness of the bottom 2 decreases continuously in the radial direction from the axis Z (dome 9) at least as far as the annular edge 15, to the exclusion of the zones comprising the main and secondary grooves, that is to say for example along the control lines 16 shown in FIG. 7.

[0146] In one embodiment, for abscissae G(x) relative to the axis Z, with G corresponding to G1, G2 or G3, between 5 and 35 millimeters inclusive, the thickness e of the wall of the bottom 2 may therefore vary: [0147] for x=5 mm; 1200 ?m?e?1600 ?m, preferably 1300 ?m?e?1500 ?m; [0148] for x=10 mm; 200 ?m?e?600 ?m, preferably 300 ?m?e?500 ?m; [0149] for x=15 mm; 100 ?m?e?300 ?m, preferably 150 ?m?e?250 ?m; [0150] for x=20 mm; 80 ?m?e?280 ?m, preferably 100 ?m?e?220 ?m; [0151] for x=25 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m; [0152] for x=30 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m; [0153] for x=35 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m.

[0154] In a variant of this embodiment, for abscissae G(x) relative to the axis Z, with G corresponding to a mean of the values of e over G1, G2 and G3, between 5 and 35 millimeters inclusive, the thickness e of the wall of the bottom 2 may vary: [0155] for x=5 mm; 1200 ?m?e?1600 ?m, preferably 1300 ?m?e?1500 ?m; [0156] for x=10 mm; 200 ?m?e?600 ?m, preferably 300 ?m?e?500 ?m; [0157] for x=15 mm; 100 ?m?e?300 ?m, preferably 150 ?m?e?250 ?m; [0158] for x=20 mm; 80 ?m?e?280 ?m, preferably 100 ?m?e?220 ?m; [0159] for x=25 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m; [0160] for x=30 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m; [0161] for x=35 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m. In another embodiment for abscissae G(x) relative to the axis Z, with G corresponding to G1, G2 or G3, between 5 and 35 millimeters inclusive, the thickness e of the wall of the bottom 2 may vary: [0162] for x=5 mm; 1200 ?m?e?1600 ?m, preferably 1300 ?m?e?1500 ?m; [0163] for x=10 mm; 200 ?m?e?600 ?m, preferably 300 ?m?e?500 ?m; [0164] for x=15 mm; 100 ?m?e?300 ?m, preferably 150 ?m?e?250 ?m; [0165] for x=20 mm; 80 ?m?e?280 ?m, preferably 100 ?m?e?220 ?m; [0166] for x=25 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m. In a variant of this embodiment, for abscissae G(x) relative to the axis Z, with G corresponding to a mean of the values of e over G1, G2 and G3, between 5 and 35 millimeters inclusive, the thickness e of the wall of the bottom 2 may vary: [0167] for x=5 mm; 1200 ?m?e?1600 ?m, preferably 1300 ?m?e?1500 ?m; [0168] for x=10 mm; 200 ?m?e?600 ?m, preferably 300 ?m?e?500 ?m; [0169] for x=15 mm; 100 ?m?e?300 ?m, preferably 150 ?m?e?250 ?m; [0170] for x=20 mm; 80 ?m?e?280 ?m, preferably 100 ?m?e?220 ?m; [0171] for x=25 mm; 30 ?m?e?150 ?m, preferably 60 ?m?e?120 ?m.

[0172] The dome 9 with axis Z extends toward the interior (enclosure 8) of the bottle 1. The region of the apex 11 of the dome 9 includes a convex well 111 with axis Z. The injection mark 104 on the preform 100 corresponds to the well 111 as seen from outside the bottom 2. The well 111 may correspond to a point of injection of the preform.

[0173] The region of the apex 11 is defined by the peripheral edge of the well 111 in the plane P.sup.A perpendicular to Z. In accordance with a variant in which the region of the apex 11 of the dome 9 is not a well 111 but an apex point 11. The plane P.sup.A orthogonal to Z comprises only the apex point 11.

[0174] In accordance with the invention the dome 9 preferably extends between the plane P.sup.A and its base which is inscribed in a plane P.sup.B parallel to P.sup.A comprising the circle corresponding to an inflexion (that is to say a break of curvature) between the coronal arch 12 and the dome 9. Throughout its thickness the coronal arch 12 is advantageously rectilinear as seen in section on the vertical plane containing the axis Z.

[0175] The distance between the plane P.sup.A and the plane P.sup.B corresponds to the height H.sup.do of the dome 9 (FIG. 14).

[0176] The diameter of the circle defining the base of the dome 9 is designated by the reference ?.sup.do.

[0177] The ratio ?.sup.do/H.sup.do is one of the noteworthy features of the invention. Preferably greater than or equal to 4.5, it is for example between 4.6 and 10 inclusive, or better still between 4.6 and 8 inclusive.

[0178] The coronal arch (coronal in the sense that it forms a ring between the dome and the seat) 12 connects the base of the dome 9 to the annular edge 18 of the annular seat 13. Like the dome 9, this coronal arch 10 is a thin part of the bottom 2 that projects in the centripetal direction toward the interior of the bottle 1 (enclosure 8). The thickness of this arch 12 for example increases slightly from the dome 9 toward the annular seat. Its interior face 12i as seen in vertical section on the axis Z (section CC of FIG. 7 shown in FIG. 13) is preferably rectilinear but could alternatively be curvilinear or indeed corrugated. In a preferred embodiment with a rectilinear radial profile this interior face 12i of the arch 12 forms an angle ?3 with the contact plane XY that may for example be of the order of 12?.

[0179] The annular seat 13 delimited by the annular edge 18 and the peripheral annular edge 15 is intended to be the zone of contact with the plane support on which the bottle 1 may rest when upright. It is part of the plane XY. Its thickness from the edge 18 to the edge 15 advantageously decreases, or is even constant.

[0180] The annular edge 15 forms an inflexion limit from which the lateral wall 14 rises from h0 in the plane XY to H equal to 15 mm at the level of the plane perpendicular to Z corresponding to the upper edge of this lateral wall 14 of the bottom 2. In accordance with a remarkable feature of the invention the thickness of this lateral wall 14 continues to decrease from the annular edge 15 as far as the upper edge at H=15 mm. In accordance with a variant, this thickness may be substantially constant.

[0181] There are five main grooves 16 in the embodiment from FIG. 5 and six in the embodiment from FIGS. 6 to 14. These main grooves 16 extend radially from the dome 9 as far as the lateral wall 14. They are separated from one another by the same angular offset of 72? for the FIG. 5 embodiment and 60? for the embodiment from FIGS. 6 to 14. As can be seen more particularly in FIGS. 5, 6, 7 and 9, the radial main ribs 16 each have a central open end 19 recessed in the dome 9 and a peripheral open end 20 located on the lateral wall 14.

[0182] FIG. 15 shows the inverted U general shape of the cross section of each main groove 16 and the angle ?1 defined by the lateral faces of the groove 16 on respective opposite sides of the median diametral plane PD (branches of the U). The angle ?1 is for example equal to 40? plus or minus 5?.

[0183] The radial main grooves 16 cross all of the coronal arch 12 and therefore delimit similar arch portions 21.

[0184] The secondary radial grooves 17 are disposed between the main radial grooves 16. In the example shown in the figures the secondary radial grooves 17 have the same angles between them and each is separated from the two adjacent radial main grooves 16 by the same angle. There are five secondary radial grooves 17 in the embodiment shown in FIG. 5 and six in the embodiment appearing in FIGS. 6, 7, 9.

[0185] Each secondary radial grooves 17 has an open end Ev situated in an arch portion 21 and a peripheral open end Ep imprinted in the lateral wall 14.

[0186] As shown in FIG. 7 each end Ev is separated from the axis Z by a distance d that is another of the noteworthy parameters of the invention. Each secondary radial groove 17 is therefore able to contribute to the stiffening and to the mechanical reinforcement of the bottom 2 of the bottle 1 without impeding the circulation of the molten plastic material during injection blow molding. In accordance with the invention this distance d between Ev and Z is defined in a relative manner relative to the distance D that is the radial distance between the axis Z and the annular edge 15 (FIG. 7).

[0187] The ratio d/D is therefore advantageously greater than or equal to 0.65, preferably 0.65, for example between 0.70 and 1.0 inclusive, and better still between 0.71 and 0.80 inclusive. FIGS. 8, 10 and 11 show that the peripheral open ends Ev of the secondary radial grooves 17 are located at a height lower than that of the open peripheral ends 20 of the main radial grooves 16.

[0188] FIG. 15 shows the V general shape of the cross section of each secondary groove 17 and the angle ?2 defined by the lateral faces of the groove 17 on respective opposite sides of the median diametral plane P.sup.F (branches of the V). The angle ?2 is for example equal to 55? plus or minus 5?.

[0189] In accordance with one particular feature of the invention each secondary radial groove 17 has a profiled shape the point of which is the end Ev at a distance d from the axis Z. The angle ?4 defined by this profiled shape is advantageously between 20? and 60? inclusive, preferably between 30? and 20? inclusive. This value is consistent with seeking optimum circulation of molten plastic material during shaping of the bottle by injection blow molding, to obtain in fine a distribution of thermoplastic material matched to the target objectives of lightness and mechanical strength.

[0190] The embodiments shown in the figures correspond to a circular shape of the bottle in cross section on a plane parallel to the contact plane XY. The invention also encompasses any non-circular bottle shape. Consequently, the qualifiers relating to the circular shape: radial, annular, diameter, etc. would be transposed to the description of a bottle in accordance with the invention of non-circular shape in cross section.

EXAMPLES

[0191] The following examples illustrate the performance of bottles in accordance with the invention in terms of a mechanical properties/lightness trade-off in a palletization test.

[0192] The bottles used in these examples are shown in the appended FIGS. 16 to 27.

Examples 1 and 2 (Comparative)150 cL Bottles

[0193] 150 cL PET bottles are manufactured by injection moulding a preform and then blow moulding. The blow moulding is effected by heating preforms using lamps distributed along the preforms and then by introduction into moulds, followed by stretching and blow moulding in the moulds.

[0194] The molds consist of two half-molds for the body of the bottles and a mold bottom for the bottoms of the bottles.

[0195] The weight of PET in the bottom is adjusted by varying the intensity of heating by the different lamps: an increase of heating at the level of the bottom of the preform enables the quantity of PET to be reduced at the level of the bottom of the bottle.

[0196] The bottles are analyzed by measurement (weight and volume of the bottom, distances, thickness measurements) and the bottles obtained are evaluated by a palletization test.

[0197] Also analyzed and evaluated are 150 cL bottles purchased commercially in France in early 2021, described as being the lightest on the French market.

[0198] The main characteristics of the manufactured or purchased bottles and the results of the analyses and tests are set out in table 1.

Analyses

[0199] Weight and volume of the bottom: the bottom of a bottle is cut off at a height of 15 mm. The weight and the usable volume are measured.

Profile of Thicknesses:

[0200] The thicknesses of the bottle are measured along three generatrices G1, G2 and G3 distributed equiangularly and extending from the center of the dome to the periphery of the bottom on arch portions excluding any groove (cf. ? [0027] supra). The thicknesses are measured at different radial distances, increasing on each generatrix from the center toward the periphery. For each radial distance the mean thickness for the three generatrices and the standard deviation of the thicknesses for the three generatrices are noted. The thickness profiles are set out in table 2.

[0201] All the analyses are carried out on a sample of three bottles. The mean values are noted.

Palletization Test

[0202] The filled and capped bottles are grouped into shrink-wrapped packs of six bottles. The packs are disposed on 800 mm?1200 mm pallets in four superposed layers of 21 packs separated by a layer of cardboard. The pallets of bottles are wrapped in plastic film.

[0203] The pallets are subjected to simulation of transport by placing them on a vibrating table for four hours, before storage for ten days at 40? C. at 40% relative humidity.

[0204] 216 bottles (43%) from each pallet are then examined. The following results are noted: [0205] Critical instability defects: number of bottles that do not remain upright (for example with an inverted bottom). [0206] Critical verticality defects: number of bottles that lean when upright, with a radial distance greater than 8 mm between the center of the cap and the center of the bottom. [0207] Quality index: proportion of bottles having no defects or minor defects in respect of all of the following criteria: instability, collapsed shoulder, deformed body (buckling), verticality, ovalization, lateral flattenings of the body.

TABLE-US-00001 TABLE 1 Example 1 Example 2 (comparative) Source of the bottle Manufactured Purchased Capacity of the bottle 150 cL 150 cL Preform FIG.16 NA Weight of preform and bottle 22 g 20 g Bottle and bottom FIG. 17 Details of bottom FIG. 18 FIG. 19 Weight of bottom 2.30 g 2.91 g Measured weight of bottom 67 mL 66.5 mL Mf/Vuf 0.034 g/mL 0.044 g/mL d/D 0.72 0.64 ?.sup.do/H.sup.do 6.9 2.55 Critical instability defects 3 45 (number of bottles) Critical verticality defects 3 45 (number of bottles) Quality index (%) 41.7 21.9

[0208] It is apparent that the bottom of the invention, for a lower weight, makes it possible to limit defects and to enhance quality after palletization.

TABLE-US-00002 TABLE 2 Example 1 Example 2 (Comparative) Source of the bottle Manufactured Purchased Capacity of the bottle 150 cL 150 cL Distance from Mean Standard Mean Standard center thickness deviation thickness deviation 5 mm 1419.00 100.434672 673.11 86.7193213 10 mm 457.44 72.6128924 497.33 72.9257933 15 mm 283.78 14.3982487 363.22 39.9279947 20 mm 215.11 8.25917828 439.44 47.1170946 25 mm 174.11 8.14817745 312.78 32.0689345 30 mm 137.56 7.00034502 214.44 12.4185974 35 mm 109.89 3.72537003 175.00 9.09806003 Mean value from 0 509.89 40.7706338 457.18 55.7518277 to 25 mm Mean value from 0 253.60 30.6541263 382.19 42.8965423 to 35 mm Commentary The bottom offers and features a The bottom offers and features an regular distribution of the material irregular distribution of the material well distributed over the perimeter badly distributed over the perimeter of the bottle (low standard of the bottle (high standard devi- deviations) and with a decreasing ations) and with an irregular profile only profile. (overthickness at 20 mm). The bottom offers and features The bottom offers and features reduced thicknesses at the large thicknesses at the periphery, conferring an increased periphery, conferring a reduced capacity to return to shape after capacity to return to shape after loading. loading.

Examples 3 and 4 (Comparative)50 cL Bottles

[0209] 50 cL PET bottles are manufactured in a similar manner.

[0210] The bottles are analyzed in a similar manner and the bottles obtained are evaluated by a palletization test of the same kind, adapted to suit the format of the bottles.

[0211] Also analyzed and evaluated are 50 cL bottles purchased commercially in France in 2021. The mark is identical for the 150 cL bottles and for the 50 cL bottles.

[0212] The main features of the bottles manufactured or purchased and the results of analyses and tests are set out in table 3. The thickness analyses are set out in table 4.

TABLE-US-00003 TABLE 3 Example 3 Example 4 (Comparative) Source of the bottle Manufactured Purchased Capacity of the 50 cL 50 cL bottle Preform FIG. 20 NA Weight of preform 9 g 9.2 g and bottle Bottle and bottom FIG. 21 Details of bottom FIG. 22 FIG. 23 Weight of bottom 1.10 g 1.20 g Measured weight of 37 mL 39.5 mL bottom Mf/Vuf 0.030 g/mL 0.030 g/mL d/D 0.75 0.76 ?.sup.do/H.sup.do 4.85 4 Critical instability 0 42 defects (number of bottles) Critical verticality 9 15 defects (number of bottles) Quality index (%) 46.3 21.7

[0213] 6) It is apparent that the bottom of the invention, for a lower weight, makes it possible to limit defects and to enhance quality after palletization.

TABLE-US-00004 TABLE 4 Example 3 Example 4 (Comparative) Source of the bottle Manufactured Purchased Capacity of the bottle 50 cL 50 cL Distance from Mean Standard Mean Standard center thickness deviation thickness deviation 5 mm 1385.78 72.0472671 455.00 197.463993 10 mm 330.78 52.7609633 193.33 44.3148296 15 mm 171.44 11.8804609 153.00 15.123696 20 mm 110.33 4.48503793 153.00 15.3346189 25 mm 72.22 5.39532657 122.78 8.66658654 Mean value from 0 414.11 29.3138112 215.42 56.1807449 to 25 mm Commentary The bottom offers and features a The bottom offers and features an regular distribution of the material irregular distribution of the material well distributed over the perimeter badly distributed over the perimeter of the bottle (low standard of the bottle (high standard devi- deviations) and with a decreasing ations) and with a partially flat profile only profile. (same thicknesses at 15 and 20 mm. The bottom offers and features The bottom offers and features reduced thicknesses at the large thicknesses at the periphery, conferring an periphery, conferring a increased capacity to return to reduced capacity to return to shape after loading. shape after loading.