Bottle with reinforced bottom

Abstract

The object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that provides an optimal balance between mechanical properties and lightweight, particularly due to its bottom. To achieve this, the bottle according to the invention comprises a bottom (2), a body (3), and a neck (4). The bottom (2) comprises: - a dome (9), - a crown-shaped arch (12), - an annular base (13), - sidewalls (14), - six radial main grooves (16), - five radial secondary grooves (7) located between the main grooves (16), each radial secondary groove having an end Ev located in the arch (12) and a peripheral end Ep located in the sidewalls (14). The bottom (2) is such that the ratio Mf / Vuf is less than or equal to 0.050 g / ml, where Mf is the weight of the bottom and Vuf is the available volume of the bottom (2), and such that the ratio is greater than or equal to 4.4, where the base of the dome (9) (P) is the weight of the bottom and Vuf is the available volume of the bottom (2), and ... base of the dome (9) (P) is the base of the bottom (P) and V B The diameter of H do (P A According to 1, the present invention also relates to a method for manufacturing the aforementioned bottle and a mold.

Description

Technical Field

[0001] This invention relates to the field of bottles made of thermoplastic materials (e.g., polyethylene terephthalate (PET)), which are manufactured by blow molding or stretch blow molding of preforms obtained by molding thermoplastic materials (e.g., by injection stretch blow molding (ISBM)).

[0002] These bottles are specifically designed for holding beverages, such as water or other drinks. The bottles of this invention can also be specifically used for holding non-carbonated beverages, such as still water.

[0003] Another object of the present invention is to provide a blow molding die capable of producing these bottles. Background Technology

[0004] The manufacture of PET bottles involves blow molding a preform obtained by molding PET (e.g., by injection molding or compression molding). This preform consists of a tube closed at one end, the opening of which is defined by a neck intended to become the bottle neck. The preform is placed in a mold, the mold's imprint corresponding to the bottle body and bottom. The preform is heated to a temperature above the glass transition temperature of PET. Compressed air is blown into the softened preform, causing it to expand and press against the mold wall, thus perfectly supporting the mold-imprinted relief. Blow molding can be supplemented by stretching using a slide bar.

[0005] The rigidity and mechanical strength of a finished bottle depend primarily on its shape, structure, thickness, and the PET hardened to a near-crystalline state. The bottle body, when upright on a flat support, comprises, from top to bottom, its vertical axis Z: neck, body, and bottom. The body and bottom can be distinguished by various grooves / ribs / steps according to a wide range of patterns, intended to impart the desired aesthetic shape and mechanical properties after filling, particularly impact resistance, sufficient rigidity, and satisfactory strength when upright. Plastic drinking water bottles are stored in packages of multiple units shrink-wrapped with plastic film. These packages are stacked, particularly on pallets, for storage and transport. Therefore, it is crucial that the filled bottles can withstand the mechanical loads imposed by such storage and transport methods. Any deformation, breakage, or deterioration of the filled bottles is a defect that limits sales and / or reduces the user experience.

[0006] The mechanical strength properties of water-filled plastic bottles stored on pallets by stacking multiple layers of bottles shrink-wrapped in plastic film are particularly determined by the bottom of the bottle, and more precisely by the raised and recessed patterns it contains and the quality of the thermoplastic material constituting it.

[0007] Another factor considered by designers and manufacturers of plastic bottles for (still) drinking water is the amount of plastic material used. For both economic and ecological reasons, there is a desire to reduce the amount of plastic material used, and therefore a search for reducing the thickness of various parts of the bottle.

[0008] Another factor considered by designers and manufacturers of plastic bottles for (still) drinking water is related to manufacturing conditions. For obvious reasons of energy conservation and therefore good environmental protection, there is a particular desire to use standard injection blow molding technology (i.e., no vents around the injection point) to reduce the blow molding pressure as much as possible; for example, for a 150cL bottle, the blow molding pressure is between 25 bar and 30 bar.

[0009] Patent application WO 2013 / 178905 describes a plastic container having a body and a bottom extending from the lower end of the body. The bottom includes an outer peripheral base defining a placement plane, a concave arch extending from a central region to the base, and a series of reinforcing joints extending radially from the central region at least to the base. The arch has two concentric regions separated by an axial step, namely a central region and an outer peripheral region, which extends circumferentially and continuously around the central region, such that the central region is elevated relative to the outer peripheral region. This step constitutes a means of stabilizing the container, particularly under extreme pressure and / or volume conditions. Such a plastic bottle with a specific bottom requires improvement in terms of mechanical and weight properties.

[0010] Purpose of the invention

[0011] In this context, the present invention is intended to satisfy at least one of the objectives described below.

[0012] One object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that achieves an optimal balance between mechanical properties and lightweight, particularly due to its bottom.

[0013] Another object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) whose mechanical properties, as evaluated in palletized transport tests (particularly in cases involving the bottle's ability to remain upright), are significantly enhanced relative to existing properties, while minimizing the bottle's weight.

[0014] Another object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that achieves an optimal balance between mechanical properties and lightweight, and is suitable for blow molding using standard injection blow molding technology (without vents around the injection point) under normal conditions and blow molding pressures of the heated preform, even at lower blow molding pressures to achieve the same heating temperature as the preform.

[0015] Another object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that resists uncontrolled deformation, particularly against tipping or angular displacement, and especially under high internal pressure. This angular displacement is a phenomenon in which, when the container is placed on a flat surface, its axis pivots relative to the vertical axis (due to the container's light weight), and the container rotates about a theoretical vertical axis, correcting its axis until it lies on the theoretical vertical axis, at which point the container comes to a stop on its own.

[0016] Another object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that has good stability when filled and stored on a pallet.

[0017] Another object of the present invention is to provide a bottle made of a thermoplastic material (e.g., PET) that is particularly economical in terms of manufacturing, does not consume excessive energy, and is as environmentally friendly as possible.

[0018] Another object of the present invention is to provide an injection blow mold capable of producing bottles that meet the above-mentioned objectives.

[0019] Another object of the present invention is to provide a high-performance method for manufacturing bottles that meet the above-mentioned objectives by injection blow molding. Summary of the Invention

[0020] The present invention satisfies at least one of the above-mentioned objectives, and in a first aspect relates to a bottle made of a thermoplastic polymer, preferably polyethylene terephthalate (PET), obtained by injection blow molding of a preform, the bottle comprising, from bottom to top, a bottom, a body, and a neck along a vertical axis Z of the bottle placed upright on a horizontal support within a contact plane XY, the bottle's spatial reference system being an orthogonal coordinate system [XYZ] with an origin at O.

[0021] *The bottom section, in the centrifugal direction, includes:

[0022] - A dome, whose Z-axis extends toward the interior of the bottle, and preferably has injection molding marks for the preform located in the vertex region of the dome.

[0023] - A crown-shaped arch that extends toward the interior of the bottle.

[0024] - A ring-shaped base for contacting a planar support within the XY contact plane on which the bottle can stand upright.

[0025] - The sidewall extends 15mm high (H) into the main body in a non-horizontal direction, with height h0 located at the horizontal plane of the base, i.e., the plane that coincides with the contact plane (XY) of the planar support on which the bottle can be placed upright.

[0026] The joint between the sidewall and the annular base forms an annular edge.

[0027] - At least three, preferably four to eight, and preferably equiangular main grooves, extending radially from the dome to the sidewalls, defining arched portions between the main grooves on the arch.

[0028] - At least three, preferably four to eight, and preferably equiangular secondary grooves are arranged between the main grooves, preferably at equal angles to the main grooves, each secondary groove extending radially between its end Ev in the arched portion and its peripheral end Ep in the sidewall, characterized in that:

[0029] -Ratio Mf / Vuf

[0030] Less than or equal to 0.050 g / mL, preferably less than or equal to 0.045 g / mL, more preferably less than or equal to 0.035 g / mL, where Mf is the weight of the bottom and Vuf is the available volume of the bottom.

[0031] -Ratio d / D

[0032] The value is greater than or equal to 0.65, preferably greater than or equal to 0.70, where d is the radial distance between the Z-axis and the end Ev of at least one secondary groove, and D is the radial distance between the Z-axis and the annular edge.

[0033] -ratio

[0034] Greater than or equal to 4.4, preferably 4.8, wherein H is the diameter of the base of the dome. do It is the height of its vertex along the Z-axis or an axis parallel to the Z-axis.

[0035] These ratios are Mf / Vuf, d / D, It is an expression of the careful design and arrangement of the bottle's bottom shape and slots, which, from a mechanical point of view, achieves the optimal distribution of thermoplastic material at the bottom of the bottle. This arrangement also improves the circulation of molten plastic material in the mold during the manufacturing process.

[0036] This results in a particularly high-performance response of the bottle in pallet testing, as described below, which involves stacking multiple layers of water-filled bottles on a pallet and shrink-wrapping them with plastic film. Therefore, compared to a negative reference in the prior art, the bottle according to the invention has a quality level corresponding to a low proportion of defects caused by pallet constraints.

[0037] Furthermore, the bottle according to the invention is unique in that it has at least one of the features described in paragraphs 22 to 44 below.

[0038] According to one feature, the thickness of the bottom continuously decreases in the radial direction along the radial generatrix G, which extends from the Z-axis to the annular edge outside the region including the main groove and the secondary groove.

[0039] The radial generatrix is, for example, along... Figure 7 The cutting line (CC) shown is G2.

[0040] The thickness e at the horizontal plane of the dome is preferably greater than or equal to 1200 μm.

[0041] The thickness e at the horizontal plane of the annular edge is preferably equal to or less than 150 μm.

[0042] The preferred thickness e is:

[0043] - at the horizontal plane of the dome, greater than or equal to 1200 μm, and

[0044] - Less than or equal to 150 μm at the horizontal plane of the annular edge.

[0045] Preferably, the thickness of the bottle bottom continuously decreases radially along three generatrices G1, G2, and G3, which extend from the center of the dome toward the outer perimeter of the bottom and are distributed at equal angles on the arched portion excluding any grooves. The thickness is measured at different radial distances along each generatrice as it increases from the center to the perimeter.

[0046] Therefore, G1, G2 and G3 are as follows Figure 7 The following definition is used, with reference to the orthogonal coordinate system [XYZ] with origin O:

[0047] *G1: Radial direction along the X-axis between the Z-axis and the bottom sidewall;

[0048] *G2: The radial direction at a 120° angle relative to G1 in the clockwise rotation direction between the Z-axis and the bottom sidewall;

[0049] *G3: The radial direction at a 240° angle relative to G1 in the clockwise rotation direction between the Z-axis and the bottom sidewall.

[0050] Therefore, in one embodiment, for the abscissa G(x) relative to the Z-axis, where G corresponds to G1, G2, or G3 between 5 mm (inclusive) and the distance to the annular edge (inclusive), for example, about 5 mm (inclusive) to about 25 mm (inclusive) for small-volume bottles (e.g., less than or equal to 50 cL), or about 5 mm (inclusive) to about 35 mm (inclusive) for large-volume bottles (e.g., less than or equal to 150 cL), the thickness e of the bottom wall (2) can thus vary:

[0051] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0052] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0053] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0054] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0055] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0056] -x = 30mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0057] -x = 35mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0058] In a variation of this implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to the average of the values ​​of e on G1, G2, and G3 between 5 mm (inclusive) and the distance to the annular edge (inclusive), for example, about 5 mm (inclusive) to about 25 mm (inclusive) for a small-volume bottle (e.g., 50 cL), or about 5 mm (inclusive) to about 35 mm (inclusive) for a large-volume bottle (e.g., 150 cL), the thickness e of the bottom wall (2) can therefore vary:

[0059] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0060] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0061] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0062] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0063] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0064] -x = 30mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0065] -x = 35mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0066] In another embodiment, for the abscissa G(x) relative to the Z-axis, where G corresponds to G1, G2, or G3 between 5 mm (inclusive) and the distance to the annular edge (inclusive) (e.g., 5 mm (inclusive) to about 25 mm (inclusive)), the thickness e of the bottom wall (2) can therefore vary:

[0067] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0068] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0069] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0070] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0071] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0072] In a variation of this implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to the average of the e values ​​of G1, G2, and G3 between 5 mm and the distance to the annular edge (15) (e.g., 5 mm (inclusive) to about 25 mm (inclusive)), the thickness e of the bottom wall (2) can therefore vary:

[0073] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0074] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0075] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0076] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0077] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0078] The bottom portion of the invention advantageously provides a good axial distribution of material. For the same abscissa G(x) along the three generatrices, the standard deviation is small. Therefore, the average standard deviation of the bottom portion extending from the Z-axis to the annular edge is preferably less than or equal to 35 μm.

[0079] According to another feature, the ratio d / D of the bottle (where d is the radial distance between the Z-axis and the end Ev of at least one secondary groove, and D is the radial distance between the Z-axis and the annular edge) is greater than or equal to 0.65, preferably greater than or equal to 0.70.

[0080] According to another feature, at least one main groove has a generally inverted "U" shaped cross-section in a plane parallel to the Z-axis.

[0081] Furthermore, the "U"-shaped branches form an angle α1 of 30° (inclusive) to 50° (inclusive), preferably 45° (inclusive) to 55° (inclusive) between them.

[0082] According to another feature, at least one secondary groove in the bottom of the bottle has a cross-section that is generally inverted "V" shaped in a plane parallel to the Z-axis.

[0083] Furthermore, the "V"-shaped branches form an angle α2 of 45° (inclusive) to 65° (inclusive), preferably 50° (inclusive) to 60° (inclusive) between them.

[0084] According to another feature, each arched portion of the crown-shaped arch at the bottom of the bottle has a radial profile that is essentially straight.

[0085] According to another feature, each arched portion has a profile that forms an angle α3 of 5° (inclusive) to 20° (inclusive), preferably 10° (inclusive) to 15° (inclusive) with the contact plane XY.

[0086] According to a preferred embodiment, the bottle has a circular cross-section in a plane parallel to the contact plane XY in at least one of its bottom, body, and neck portions.

[0087] According to another embodiment, the neck of the bottle has a non-circular (e.g., elliptical or rectangular, especially square) cross-section in a plane parallel to the contact plane XY.

[0088] According to another feature, the volume of the bottle, in centiliters, is: 20 cL to 30 cL, or 30 cL to 40 cL, or 40 cL to 60 cL, or 60 cL to 80 cL, or 80 cL to 110 cL, or 110 cL to 130 cL, or 130 cL to 160 cL, or 160 cL to 180 cL, or 180 cL to 220 cL, or 220 cL to 260 cL, preferably 25 cL, or 33 cL, or 50 cL, or 75 cL, or 100 cL, or 125 cL, or 150 cL, or 175 cL, or 200 cL.

[0089] According to another feature, each main groove has one end Ev in the arch and an outer peripheral end Ep in the sidewall. In addition, some or all of the ends Ev of the main grooves are open and open below the dome, and / or some or all of the ends Ep of the main grooves are open and open toward the outside of the bottle.

[0090] According to another feature, some or all of the ends Ep of the secondary grooves are open and open to the outside of the bottle, and are preferably shorter than the end Ep of at least one adjacent primary groove.

[0091] According to another feature, the ends of some or all of the sub-grooves are open and open below the arch.

[0092] According to another feature, some or all of the ends Ev of the sub-grooves have a pointed profile, which forms an angle α4 of less than or equal to 30°, preferably less than or equal to 20°.

[0093] According to a second aspect, the present invention relates to a blow molding die, a portion of which has an impression capable of obtaining the bottom of a bottle according to the invention.

[0094] According to its third aspect, the present invention relates to a method for manufacturing a bottle according to the invention, the method comprising employing a preform, the preform preferably obtained by injection molding, employing a blow molding technique (possibly stretch blow molding) using a mold according to the invention. Attached Figure Description

[0095] This description is given with reference to the accompanying drawings depicting a non-limiting embodiment, wherein:

[0096] Figure 1

[0097] [ Figure 1 [Illustration] is a perspective view of a preform for manufacturing a bottle according to the present invention by blow molding.

[0098] Figure 2

[0099] [ Figure 2 ]yes Figure 1 On the mid-diameter surface of the precast component shown Figure 1 Cross-sectional view.

[0100] Figure 3

[0101] [ Figure 3 [Illustration 1] is a front view of one embodiment of the bottle according to the present invention.

[0102] Figure 4

[0103] [ Figure 4 [Illustration 1] is a perspective view of another embodiment of the bottle according to the present invention.

[0104] Figure 5

[0105] [ Figure 5 ] is from Figure 3 A view of the bottom of the bottle from below and from the front.

[0106] Figure 6

[0107] [ Figure 6 ] is from Figure 4 A three-dimensional view of the bottom of the bottle.

[0108] Figure 7

[0109] [ Figure 7 ] is from Figure 4 A view of the bottom of the bottle from below and from the front.

[0110] Figure 8

[0111] [ Figure 8 ]yes Figure 7 Side view.

[0112] Figure 9

[0113] [ Figure 9 ]yes Figure 7 and Figure 8 The bottom 3D view.

[0114] Figure 10

[0115] [ Figure 10 ] is along Figure 7 The cross-sectional view taken by line AA in the diagram.

[0116] Figure 11

[0117] [ Figure 11 ] is along Figure 7The cross-sectional view taken from the BB line.

[0118] Figure 12

[0119] [ Figure 12 ] is along Figure 7 The cross-sectional view taken from the CC line.

[0120] Figure 13

[0121] [ Figure 13 ]yes Figure 12 The view of details H in the middle.

[0122] Figure 14

[0123] [ Figure 14 ] is along Figure 7 The cross-sectional view taken from the DD line in the diagram.

[0124] Figure 15

[0125] [ Figure 15 ] is along Figure 7 The cross-sectional view taken from the FF line in the image.

[0126] Figure 16

[0127] [ Figure 16 [I] is a diameter cross-sectional view of the preform according to the invention used in manufacturing Example 1.

[0128] Figure 17

[0129] [ Figure 17 ] is by Figure 16 A side view of the bottle according to the invention used in Example 1 of the prefabrication production.

[0130] Figure 18

[0131] [ Figure 18 [This is a view shown from below] Figure 17 The view shown is of the bottom of the bottle.

[0132] Figure 19

[0133] [ Figure 19 [This is a view shown from below] Figure 17 The photo shown is of the bottom of the bottle.

[0134] Figure 20

[0135] [ Figure 20 [This is a view shown from below] Figure 17A partial 3D view of the bottom of the bottle is shown.

[0136] Figure 21

[0137] [ Figure 21 [A photograph of the bottom of the bottle, shown from below, illustrating the negative reference used in Comparative Example 2.]

[0138] Figure 22

[0139] [ Figure 22 [ ] is a partial side view of the diameter section of the preform of the bottle according to the invention used in Example 3.

[0140] Figure 23

[0141] [ Figure 23 ] is by Figure 22 A side view of the bottle according to the invention used in Example 3 of the prefabrication production.

[0142] Figure 24

[0143] [ Figure 24 [This is a view shown from below] Figure 23 The view shown is of the bottom of the bottle.

[0144] Figure 25

[0145] [ Figure 25 [This is a view shown from below] Figure 23 The photo shown is of the bottom of the bottle.

[0146] Figure 26

[0147] [ Figure 26 [This is a view shown from below] Figure 23 A partial 3D view of the bottom of the bottle is shown.

[0148] Figure 27

[0149] [ Figure 27 [This is a photograph of the bottom of the bottle used as a negative reference in Comparative Example 4, viewed from below.]

[0150] The reference numerals used in all the accompanying drawings denote the same elements.

[0151] definition

[0152] Based on the terminology used herein, the following non-restrictive definitions are given by way of example and illustration to explain this document:

[0153] -Any singular form represents a plural form, and vice versa.

[0154] - "Thermoplastic" refers to thermoplastic or moldable copolymers or homopolymers that become fluid, viscous, flexible, and moldable above a certain temperature (e.g., glass transition temperature) and return to a solid / hardened state upon cooling. Detailed Implementation

[0155] The core container of this invention is a bottle 1 made of thermoplastic polymer material, preferably polyethylene terephthalate (PET).

[0156] The following describes a three-dimensional orthogonal coordinate system [XYZ] with origin O. Figure 3 and Figure 4 Bottle 1 is shown. The ZZ or Z-axis is the axis of bottle 1. The XX or X-axis and the YY or Y-axis define the plane XY, which is the contact plane between the bottom of the bottle and the horizontal support on which the bottle is placed upright. The origin O of the XYZ orthogonal coordinate system lies in the plane XY. Figure 3 , 5 6 and 9 specifically illustrate the XYZ spatial coordinate system.

[0157] Bottle 1 includes a bottom 2, a body 3, and a neck 4 along the Z-axis from top to bottom. The neck 4 defines the upper opening 5 of bottle 1 and is separated from the body 3 by a flange 6. A thread 7 is provided above the flange 6 for engaging with a screw cap to close bottle 1. The body 3 of bottle 1 includes grooves and rib patterns known per se (not referenced in the figure), which are intended to increase the mechanical strength of the body 3.

[0158] In the following description, the terms "inner," "internal," and "facing inward" refer to elements near the Z-axis of bottle 1 or in the direction of the Z-axis of bottle 1, or elements within the outer casing 8 defined by the bottom 2, body 3, and neck 4, which forms an envelope defining bottle 1. The terms "outer," "external," and "facing outward" refer to elements located in the opposite direction along the Z-axis of bottle 1 or elements outside the outer casing 8 of bottle 1. The terms "low," "below," "high," and "above" should be understood relative to bottle 1 when it is placed upright on a planar horizontal support XY.

[0159] Bottle 1 is industrially produced using injection blow molding technology on a preform that has been fully heated into a fluid state in a mold with a bottle imprint. Blow molding can be supplemented by stretching using an axial rod introduced into the preform (injection stretch blow molding (ISBM)).

[0160] Figure 1 and Figure 2An example of the preform 100 is shown, which is in the form of a tube having a Z-axis defined by a wall 101, opening at its upper end 102, and including the neck 4 of the future bottle 1, with its bottom 103 generally hemispherical in shape. When the preform is manufactured by injection molding, the lower end of the bottom 103 includes a protrusion 104 extending outward along the Z-axis on the outer surface of the wall 101. This is a mark left by the injection point of the preform 100.

[0161] In the variations produced by compression molding, the preforms do not have such markings.

[0162] like Figure 5 , 6 As shown in figures 7, 9, 10, and 11, the bottom 2 of bottle 1 centrifugally comprises, in sequence:

[0163] -Dome 9,

[0164] - The crown-shaped arch 12 extends toward the interior of the bottle 1 (outer shell 8),

[0165] - Annular base 13, for contacting a planar support within the contact plane XY when the bottle 1 can be placed upright on it.

[0166] - Sidewall 14, which extends to the body in a non-horizontal direction (different from XY), with a height H of 15mm and a height h0 located at the horizontal plane of the base 13, the horizontal plane coinciding with the contact plane XY of the planar support when the bottle 1 can be placed upright on it.

[0167] Especially Figure 10 and Figure 11 As shown, the joint between the sidewall 14 and the annular base 13 forms an annular edge 15, which forms a dividing line between the two parts of the bottom 2.

[0168] Figure 5 , 6 Figures 1, 7, and 9 show that the lower surface of the bottom 2 is marked with two types of radially mechanically reinforced grooves: the primary groove 16 and the secondary groove 17.

[0169] Bottom 2 Figures 5 to 14 The middle part is represented as a cup-shaped object, as if separated from the rest of the bottle 1. This separately considered virtual cup-shaped object helps to define the bottle according to the invention. For this purpose, three generatrices G1, G2, and G3 are defined, as follows: Figure 7 As shown:

[0170] G1: Between the Z-axis and the sidewall of bottom 2, in the radial direction along the X-axis;

[0171] G2: The radial direction at a 120° angle relative to G1 in the clockwise rotation direction between the Z-axis and the side wall of the bottom 2;

[0172] G3: The radial direction at a 240° angle relative to G1 in the clockwise rotation direction between the Z-axis and the side wall of the bottom 2;

[0173] In addition to its shape and height H = 15 mm as described above, the bottom 2 can also be defined by its weight Mf and available volume Vuf. Mf is measured by weighing the bottom while it is dry, and Vuf is measured by filling it with water to a level that makes the meniscus concave, the edge of which is contained in a plane perpendicular to Z, which corresponds to the upper edge of the sidewall 14 of the bottom 2.

[0174] According to the invention, outside the region including the main groove 16 and the secondary groove 17, the thickness of the bottom 2 decreases continuously in the radial direction from the Z-axis (dome 9) to at least the annular edge 15, until the region excluding the main groove and the secondary groove, i.e., for example along... Figure 7 Control line 16 is shown.

[0175] In one implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to G1, G2, or G3 between 5 mm (inclusive) and 35 mm (inclusive), the thickness e of the wall of the bottom 2 can therefore vary:

[0176] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0177] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0178] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0179] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0180] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0181] -x = 30mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0182] -x = 35mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0183] In a variation of this implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to the average value of e on G1, G2, and G3 between 5 mm (inclusive) and 35 mm (inclusive), the thickness e of the wall at the bottom 2 can vary:

[0184] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0185] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0186] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0187] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0188] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0189] -x = 30mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm;

[0190] -x = 35mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0191] In another implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to G1, G2, or G3 between 5 mm (inclusive) and 35 mm (inclusive), the thickness e of the wall of the bottom 2 can vary:

[0192] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0193] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0194] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0195] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0196] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0197] In a variation of this implementation, for the abscissa G(x) relative to the Z-axis, where G corresponds to the average value of e on G1, G2, and G3 between 5 mm (inclusive) and 35 mm (inclusive), the thickness e of the wall at the bottom 2 can vary:

[0198] -x = 5mm; 1200μm ≤ e ≤ 1600μm, preferably 1300μm ≤ e ≤ 1500μm;

[0199] -x=10mm; 200μm≤e≤600μm, preferably 300μm≤e≤500μm;

[0200] -x = 15mm; 100μm ≤ e ≤ 300μm, preferably 150μm ≤ e ≤ 250μm;

[0201] -x = 20mm; 80μm ≤ e ≤ 280μm, preferably 100μm ≤ e ≤ 220μm;

[0202] -x = 25mm; 30μm ≤ e ≤ 150μm, preferably 60μm ≤ e ≤ 120μm.

[0203] A dome 9 with a Z-axis extends toward the interior of the bottle 1 (outer shell 8). The area of ​​the apex 11 of the dome 9 includes a raised well 111 with a Z-axis. An injection mark 104 on the preform 100 corresponds to the well 111 as seen from the outside of the bottom 2. The well 111 may correspond to the injection point of the preform.

[0204] The region of vertex 11 is defined by plane P perpendicular to Z. A The well 111 is defined by its outer edge. According to a variation, the region of vertex 11 of dome 9 is not well 111 but vertex 11. A plane P orthogonal to Z... A Only vertex 11 is included.

[0205] According to the present invention, the dome 9 is preferably located on plane P. A It extends between itself and its base, which is internally tangent to a point parallel to P. A plane P B In the middle, the plane P B This includes the circle corresponding to the inflection point (i.e., the curvature break) between the crown arch 12 and the dome 9. Viewed from a cross-section on a vertical plane containing the Z-axis, the crown arch 12 is advantageously straight over its entire thickness.

[0206] Plane P A and plane P B The distance between them corresponds to the height H of dome 9. do ( Figure 14 ).

[0207] The diameter of the circle defining the base of dome 9 is determined by reference number 9. express.

[0208] The ratio is one of the noteworthy features of this invention. Preferably, it is greater than or equal to 4.5, for example, between 4.6 (inclusive) and 10 (inclusive), or more preferably between 4.6 (inclusive) and 8 (inclusive).

[0209] A crown-shaped arch (crown meaning it forms a ring between the dome and the base) 12 connects the base of the dome 9 to the annular edge 18 of the annular base 13. Similar to the dome 9, this crown-shaped arch 10 is a thin section of the bottom 2 that protrudes in the centripetal direction toward the interior of the bottle 1 (outer shell 8). The thickness of the arch 12 increases slightly, for example, from the dome 9 toward the annular base. (From a vertical section on the Z-axis...) Figure 13 The one shown Figure 7 Viewed in the CC section, its inner surface 12i is preferably straight, but alternatively may be curved or actually corrugated. In a preferred embodiment having a straight radial profile, the inner surface 12i of the arch 12 forms an angle 3 with the contact plane XY, which may be, for example, 12°.

[0210] The annular base 13, defined by annular edge 18 and outer annular edge 15, is intended to be the area that contacts a planar support when the bottle 1 can be placed upright on it. It is part of the plane XY. Its thickness advantageously decreases from edge 18 to edge 15, or is even constant.

[0211] The annular edge 15 forms an inflection point limit, from which the sidewall 14 rises from h0 in the XY plane to a value equal to 15 mm, where H is located on a horizontal plane perpendicular to the Z plane corresponding to the upper edge of the sidewall 14 at the bottom 2. According to a significant feature of the invention, the thickness of the sidewall 14 continuously decreases from the annular edge 15 until the upper edge at H = 15 mm. According to a variation, this thickness can be substantially constant.

[0212] exist Figure 5 The implementation scheme has five main grooves 16, in Figures 6 to 14 The embodiment has six main grooves 16. These main grooves 16 extend radially from the dome 9 to the sidewall 14. For Figure 5 In the implementation scheme, these main grooves are separated from each other by the same 72° angular offset, for Figures 6 to 14 In the implementation scheme, these main grooves are separated from each other by the same 60° angular offset.

[0213] from Figure 5 , 6 More specifically as seen in 7 and 9, each radial main rib 16 has a central open end 19 recessed in the dome 9 and a peripheral open end 20 located on the sidewall 14.

[0214] Figure 15 The cross-section of each main groove 16 is shown to have a generally inverted "U" shape, and an angle α1 defined by the sides (branches of the "U") of the grooves 16 on the opposite sides of the central radial plane PD. Angle α1 is, for example, equal to 40° ± 5°.

[0215] The radial main groove 16 passes through the entire crown arch 12 and thus defines a similar arched portion 21.

[0216] Radial secondary grooves 17 are disposed between radial primary grooves 16. In the example shown in the figure, the radial secondary grooves 17 have the same angle between them, and each radial secondary groove 17 is separated from the two adjacent radial primary grooves 16 by the same angle. Figure 5 The illustrated embodiment has five radial sub-grooves 17, in Figure 6 , Figure 7 , Figure 9 The illustrated embodiment has six radial sub-grooves 17.

[0217] Each radial sub-groove 17 has an open end Ev located in the arched portion 21 and a peripheral open end Ep embossed in the sidewall 14.

[0218] like Figure 7 As shown, each end Ev is separated from the Z-axis by a distance d, which is another noteworthy parameter of the invention. Therefore, each radial sub-groove 17 can contribute to the hardening and mechanical reinforcement of the bottom 2 of the bottle 1 without hindering the circulation of molten plastic material during injection blow molding. According to the invention, this distance d between Ev and Z is defined in a relative manner to a distance D, which is the radial distance between the Z-axis and the annular edge 15 (…). Figure 7 ).

[0219] Therefore, the ratio d / D is advantageously greater than or equal to 0.65, preferably 0.65, for example between 0.70 (inclusive) and 1.0 (inclusive), and more preferably between 0.71 (inclusive) and 0.80 (inclusive).

[0220] Figure 8 , Figure 10 and Figure 11 It is shown that the height of the outer open end Ev of the radial secondary groove 17 is lower than the height of the outer open end 20 of the radial main groove 16.

[0221] Figure 15 The cross-section of each sub-groove 17 is shown to have a generally inverted "V" shape, and is formed by the central radial plane P. F The angle α2 is defined by the sides (branches of the “U”) of the grooves 17 on both sides. The angle α2 is, for example, equal to 55° ± 5°.

[0222] According to a particular feature of the invention, each radial sub-groove 17 has an irregular shape, the tip of which is the end Ev at a distance d from the Z-axis. The angle α4 defined by this irregular shape is advantageously between 20° (inclusive) and 60° (inclusive), preferably between 30° (inclusive) and 20° (inclusive). This value is consistent with the pursuit of optimal circulation of molten plastic material during the bottle molding process by injection blow molding to obtain a good distribution of thermoplastic material that matches the goals of lightweight form and mechanical strength.

[0223] The embodiment shown in the figure corresponds to a circular shape of the bottle's cross-section on a plane parallel to the contact plane XY. The invention also includes any non-circular bottle shape. Therefore, modifiers related to circular shapes such as "radial," "annular," and "diameter" will be converted to a description of a bottle with a non-circular cross-section according to the invention.

[0224] Example

[0225] The following examples illustrate the performance of bottles according to the present invention in terms of mechanical properties / lightweight balance during palletized transport testing.

[0226] The bottles used in these examples are as shown in the attached image. Figures 16 to 27 As shown.

[0227] Example 1 and 2 (comparison) – 150cL bottle

[0228] 150cL PET bottles are manufactured by injection molding a preform followed by blow molding. Blow molding is achieved by heating the preform with lamps distributed along it, then introducing it into a mold, where it is subsequently stretched and blow-molded.

[0229] The mold consists of two half-molds for the bottle body and a bottom mold for the bottle bottom.

[0230] The weight of PET at the bottom can be adjusted by using different lamps to change the heating intensity: increasing the heating at the bottom level of the preform reduces the amount of PET at the bottom level of the bottle.

[0231] The bottles were analyzed by measurements (weight and volume at the bottom, distance, and thickness), and the obtained bottles were evaluated through palletized transport tests.

[0232] They also analyzed and evaluated a 150cL bottle purchased in France in early 2021, which was said to be the lightest bottle on the French market.

[0233] Table 1 lists the main characteristics of the manufactured or purchased bottles, along with the results of analysis and testing.

[0234] analyze

[0235] Weight and volume at the bottom: Cut off the bottom of the bottle at a height of 15mm. Measure the weight and usable volume.

[0236] Thickness profile:

[0237] The thickness of the bottle was measured along three generatrices G1, G2, and G3, which are equiangularly distributed and extend from the center of the dome to the outer perimeter of the bottom on the arched portion excluding any grooves (see paragraph

[0027] above). The thickness was measured at different radial distances increasing from the center towards the perimeter on each generatrice. For each radial distance, the average thickness on the three generatrices and the standard deviation of the thickness on the three generatrices were recorded. Table 2 lists the thickness profile.

[0238] All analyses were performed on samples from three bottles. The average values ​​were recorded.

[0239] Palletized transport test

[0240] Divide the filled and capped bottles into six-bottle shrink-wrapped packages. Place these packages on an 800mm x 1200mm pallet, stacking 21 packages per layer, with each layer separated by a layer of cardboard. Wrap the pallet with plastic film.

[0241] The pallet was placed on a vibration table for four hours and then stored at 40°C and 40% relative humidity for ten days to simulate transportation.

[0242] Then examine the 216 bottles (43%) on each tray. Record the following results:

[0243] -Severe instability defect: The number of bottles that do not remain upright (e.g., bottom inverted).

[0244] - Severe verticality defect: The radial distance between the center of the cap and the center of the bottom of the bottle is greater than 8 mm, based on the number of bottles that are tilted while upright.

[0245] - Quality Index: The proportion of bottles that are free of defects or have minor defects in all of the following criteria: instability, shoulder collapse, bottle deformation (bending), verticality, flattening, and bottle side flattening.

[0246] [Table 1]

[0247]

[0248] Obviously, the bottom of the present invention, due to its lighter weight, can limit defects and improve the quality after palletizing.

[0249] [Table 2]

[0250]

[0251]

[0252] Examples 3 and 4 (comparison) – 50cL bottles

[0253] 50cL PET bottles are manufactured in a similar manner.

[0254] The bottles were analyzed in a similar manner, and the obtained bottles were evaluated through the same type of palletized transport test applicable to the bottle format.

[0255] The study also analyzed and evaluated 50cL bottles purchased in France in 2021. The 150cL bottles had the same markings as the 50cL bottles.

[0256] Table 3 lists the main characteristics of the manufactured or purchased bottles, along with the results of the analysis and testing. Table 4 lists the thickness analysis.

[0257] [Table 3]

[0258]

[0259]

[0260] Obviously, the bottom of the present invention, due to its lighter weight, can limit defects and improve the quality after palletizing.

[0261] [Table 4]

[0262]

[0263]

Claims

1. A bottle (1) made of a thermoplastic polymer, obtained by blow molding of a preform (100), the bottle (1) comprising, from bottom to top, a bottom (2), a body (3), and a neck (4) along the vertical axis Z of the bottle (1) placed upright on a horizontal support in a contact plane XY, the spatial reference system of the bottle (1) being an orthogonal coordinate system [XYZ] with origin O, the bottom (2) comprising, in the centrifugal direction: - The dome (9) extends along its Z-axis toward the interior of the bottle (1). - The crown-shaped arch (12) extends toward the interior of the bottle (1), - An annular base (13) for contacting a planar support within the contact plane XY on which the bottle (1) can be placed upright. - Sidewall (14), which extends in a non-horizontal direction with a height H to the body (3), the height H being 15 mm relative to the height h0 of the horizontal plane located on the base (13). The joint between the sidewall (14) and the annular base (13) forms an annular edge (15). - At least three main grooves (16) extend radially from the dome (9) to the sidewall (14) and define an arched portion (21) between the main grooves (16) on the arch (12). - At least three secondary grooves (17) are disposed between the main grooves (16), each secondary groove (17) extending radially between its end Ev in the arched portion (21) and its peripheral end Ep in the sidewall (14). Its features are: Among them, the dome (9) lies in the plane (P) orthogonal to the vertical axis Z. A Extending between ) and its base, wherein the plane (P) A It includes only the vertex (11), whose base is inscribed in a plane parallel to (P). A The plane (P) B ), the plane (P B This includes the circle corresponding to the inflection point between the coronal arch (12) and the dome (9). - The ratio Mf / Vuf is less than or equal to 0.050 g / mL, where Mf is the weight of the bottom (2) and Vuf is the available volume of the bottom (2). - Ratio do / H do Greater than or equal to 4.4, where do It is the base of the dome (9) (P) B The diameter of H do It is the height of its vertex along the Z-axis or an axis parallel to the Z-axis (P). A ).

2. The bottle (1) according to claim 1, characterized in that, The thickness of the bottom (2) decreases continuously along the radial generatrix G in the radial direction, the radial generatrix G extending from the Z-axis to the annular edge (15) outside the region including the main groove (16) and the secondary groove (17).

3. The bottle (1) according to claim 1 or 2, characterized in that, The ratio d / D is greater than or equal to 0.65, where d is the radial distance between the Z-axis and the end Ev of the at least one secondary groove (17), and D is the radial distance between the Z-axis and the annular edge (15).

4. The bottle (1) according to claim 1 or 2, characterized in that, At least one of the main grooves (16) has a cross-section in a plane parallel to the Z-axis that is generally inverted "U" shaped, and the branches of the "U" form an angle α1 of 30° to 50° between them.

5. The bottle (1) according to claim 1 or 2, characterized in that, At least one of the secondary grooves (17) has a cross-section in a plane parallel to the Z-axis that is generally inverted "V" shaped, and the branches of the "V" form an angle α2 of 45° to 60° between them.

6. The bottle (1) according to claim 1 or 2, characterized in that, Each arched section (21) has a radial profile that is essentially straight.

7. The bottle (1) according to claim 1 or 2, characterized in that, Each arched section (21) has a profile that forms an angle α3 of 5° to 20° with the contact plane XY.

8. The bottle (1) according to claim 1 or 2, characterized in that, The bottom (2), body (3) and / or neck (4) have a circular cross-section in a plane parallel to the contact plane XY.

9. The bottle (1) according to claim 1 or 2, characterized in that, The volume of the bottle, in centiliters, is: 20 cL to 30 cL, or 30 cL to 40 cL, or 40 cL to 60 cL, or 60 cL to 80 cL, or 80 cL to 110 cL, or 110 cL to 130 cL, or 130 cL to 160 cL, or 160 cL to 180 cL, or 180 cL to 220 cL, or 220 cL to 260 cL.

10. The bottle (1) according to claim 1 or 2, characterized in that, The ratio Mf / Vuf is less than or equal to 0.045 g / mL.

11. A blow molding die, characterized in that, The blow molding die includes a component with an embossing that is capable of obtaining the bottom (2) of the bottle (1) as described in claim 1 or 2.

12. A method for manufacturing the bottle (1) according to claim 1 or 2, characterized in that, The method involves using a preform (100) and employing blow molding technology using the mold according to claim 11.

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