Bottle-forming preform with a multilayered wall, and gaseous beverage bottle obtained with such a preform

Abstract

The invention concerns a preform (10) for forming a bottle for gaseous beverage, the preform comprising a multilayered wall obtained by injection in a mould from an injecting point (22) located at a central bottom end of the preform, the multilayered wall including an inner layer (24), an outer layer (26) and a gasbarrier layer (28) sandwiched between the inner and outer layer. The gas barrier layer (26) advantageously extends along the entire preform multilayered wall except for a bottom ending portion (30), this bottom ending portion free of barrier layer (30) being a central part of a base-forming portion (20) delimited by a solid angle () comprised between 5 to 80, the apex (C) of this solid angle being the centre of a semi-spherical lower segment of the base-forming portion (20). A bottle obtained by blow-moulding such a preform has a bottom ending portion free of barrier layer within a solid angle comprised between 5 and 50.

Claims

1. Preform for forming a bottle for gaseous beverage, the preform comprising a preform multilayered wall obtained by injection in a mould from an injecting point located at a bottom end of the preform, the multilayered wall defining, from an open top end to a closed bottom end of the preform along a main axis of the preform: a neck finish portion, a body-forming portion configured to form a body portion of the bottle, a base-forming portion configured to form a base portion of the bottle, the base forming-portion having a lower segment which is globally semi-spherical, wherein the preform multilayered wall includes: an inner layer having an inner face intended to form the gaseous beverage side of the bottle, an outer layer having an outer face intended to form the outside of the bottle, a gas barrier layer sandwiched between the inner layer and the outer layer, the gas barrier layer extends along the entire preform multilayered wall except for a bottom ending portion which is free of barrier layer, this bottom ending portion free of barrier layer being a central part of the base-forming portion extending around the injecting point in a solid angle () comprised between 5 to 80, the apex of this solid angle being the centre of the globally semi-spherical lower segment of the base-forming portion.

2. Preform according to claim 1, wherein the inner layer is made of a material selected from the group consisting of PET-based polymers and copolymers, where PET means polyethylene terephthalate, the outer layer is made of a material selected from the group consisting of PET-based polymers and copolymers, and the gas barrier layer is made of a material selected from the group consisting of polymers or copolymers based on polyglycolic acid (PGA), 2,5-furandicarbonate polyester including polyethylene 2,5-furandicarboxylate (PEF), poly (trimethylene furan-2,5-Dicarboxylate) (PTF), Poly (Neopentyl Glycol 2,5-Furanoate) (PNF), Polyethylene Naphthalate (PEN), PEN/PET Co-Polymer, Polytrimethylene Naphthalate (PTN), polybutylene naphthalate (PBN); polyacrylonitrile (PAN), nanoclay, MXD6 (Nylon); nano nylon-MXD6 and Polybutadiene mixtures.

3. Preform according to claim 1, wherein the preform is configured to form a gaseous beverage bottle having a volume less than 50 cl and the solid angle () delimiting the bottom ending portion free of barrier layer is comprised between 5 to 80.

4. Preform according to claim 1, wherein the preform is configured to form a gaseous beverage bottle having a volume comprised between 50 cl and 100 cl and the solid angle () delimiting the bottom ending portion free of barrier layer is comprised between 5 to 70.

5. Preform according to claim 1, wherein the preform is configured to form a gaseous beverage bottle having a volume more than 100 cl and the solid angle () delimiting the bottom ending portion free of barrier layer is comprised between 5 to 60.

6. Preform according to any one of claim 1, wherein a cumulated thickness of the inner layer and the outer layer at any point of the bottom ending portion free of barrier layer is higher than a cumulated thickness of the inner layer and the outer layer at any point of a junction between the lower hemispherical segment of the base-forming portion and an upper cylindrical segment of said base-forming portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which:

(2) FIG. 1 represents a schematic longitudinal section of a preform according to the invention;

(3) FIG. 2 represents a schematic longitudinal section of a bottom part of the preform of FIG. 1;

(4) FIG. 3 is a schematic cross-section of a bottle according to the invention, the left part of the figure showing a foot of the bottle whereas the right part of the figure shows a valley;

(5) FIG. 4 represents a profile of a bottom part of a preform according to the invention;

(6) FIG. 5 represents a very schematic cross-section of a bottom part of the bottle obtained from the preform of FIG. 4, the left side of the figure showing a valley of the bottle whereas the right part of the figure shows a foot of the bottle;

(7) FIG. 6 is a table listing the thicknesses of the various layers of the bottle multilayered wall of the bottle of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIGS. 1 and 2 show an embodiment of a preform for forming a gaseous beverage bottle according to the invention.

(9) In a usual way, this preform 10 is essentially composed of a multilayered wall 8, having an inner face 80 intended to form the beverage side of a bottle and an outer face 81 intended to form the outside of the bottle. The preform 10 is rotationally symmetrical around a main axis X and comprises, from top to bottom: an open end 12, a neck finish portion 14, having a threaded peripheral outer face, a flange 16, a body-forming portion 18, where the inner face 80 of the multilayered wall 8 is cylindrical, a base-forming portion 20, which includes an upper segment where the inner face 80 is still cylindrical and a lower segment where the inner face 80 is semi-spherical, a bottom end 22 corresponding to the injecting point where the various layers of the multilayered wall 8 are injected in a mould (not shown) to obtain the preform.

(10) The multilayered wall 8 of the preform comprises (see FIG. 2) along a centrifugal direction, an inner layer 24 preferably in PET, a gas barrier layer 28 preferably in PEF, and an outer layer 26 preferably in PET.

(11) According to the invention, the gas barrier layer 28 is present in the whole multilayered wall 8 (in particular, the gas barrier layer 28 extends along the whole body-forming portion 18) excepted for a bottom ending portion free of gas barrier layer 30. This bottom ending portion free of gas barrier layer 30 is a central part of the base-forming portion 20 extending inside a cone (or solid angle) 32 whose top C is the centre of the lower hemispherical segment of the base-forming portion 20. This cone 32 has an angle comprised between 5 and 80, depending on the volume of the bottle to be formed. For a bottle having a volume less than 50 cl, for example equal to 33 cl or 25 cl, the angle is preferably comprised between 5 and 80. For a bottle having a volume between 50 cl and 100 cl, for example equal to 50 cl or 75 cl or 100 cl, the angle is preferably comprised between 5 and 70. For a bottle having a volume more than 100 cl, for example equal to 1.51 or 21, the angle is preferably comprised between 5 and 60.

(12) As better shown at FIG. 2, the injection point 22 of the preform multilayered wall 8 is located at the bottom of the preform, on the central axis of the preform. The preform of FIGS. 1 and 2 is used to form a bottle such as the one illustrated at FIGS. 3 and 5, by blow moulding the preform, that is to say by expanding the preform in the axial direction and in a hoop direction by blowing the preform in an appropriate mould.

(13) In a usual way, this bottle illustrated at FIGS. 3 and 5 comprises, from top to bottom along its main axis X: an open end 112, a neck portion 114 intended to receive a threaded cap, the neck portion having a threaded peripheral external face corresponding to the threaded cap, a flange 116, intended to abut and close the open bottom end of the threaded cap; it can be noted that the open end 112, the neck portion 114 and the flange 116 of the bottle 100 have the same shape and dimensions as the open end 12, the neck finish portion 14 and the flange 16 of the preform since these parts are not expected to expand during the blow moulding, a body portion 118, which is derived from the expansion of the body-forming portion 18 of the preform 10; in the illustrated embodiment, the body portion 118 includes a conical shoulder portion 117; a base portion 120 derived from the expansion of the base-forming portion 20 of the preform 10; in the illustrated embodiment, the base portion 120 alternately comprises valleys 140 and feet 142 around the main axis X, the central point 122 of the bottom end of the bottle corresponds to the injecting point 22 of the preform.

(14) The bottle multilayered wall is composed of at least three layers (not shown in the figures), namely an inner layer, an outer layer and a gas barrier layer, corresponding to the inner layer 24, the outer layer 26 and the gas barrier layer 28 of the preform. The inner layer has an internal face which is intended to be in contact with the gaseous beverage; the outer layer has an external face forming the outside of the bottle; the gas barrier layer is sandwiched between the inner layer and the outer layer.

(15) According to the invention, the base-portion 120 includes a bottom ending portion free of barrier layer 130, which extends in a solid angle which is comprised between 5 and 50, depending on the volume of the bottle. For a bottle having a volume less than 50 cl, for example equal to 33 cl, the angle is preferably comprised between 5 and 50 For a bottle having a volume between 50 cl and 100 cl, for example equal to 50 cl or 75 cl or 100 cl, the angle is preferably comprised between 5 and 40. For a bottle having a volume more than 100 cl, for example equal to 1.5 l or 2 l, the angle is preferably comprised between 5 and 30.

(16) FIG. 4 and FIG. 5 respectively show a bottom part of the preform 10 and the corresponding bottom part of the bottle 100 (being specified that the considered bottle has a volume of 50 cl). Of course, these two figures are not presented at scale, the preform being blown to form the bottle.

(17) These two figures illustrate various points 201-205 on the preform 10 and their corresponding points 201-205 on a foot 142 of the bottle 100. By way of example, the thickness in m of the various layers of the bottle multilayered wall are reported in the table of FIG. 6. The points 201-205 are schematically indicated for general understanding but their position may vary (especially in the bottle) due to the stretching and blowing occurred to form the bottle from the preform.

(18) It can easily be understood and observed from FIG. 4, 5 and from the table of FIG. 6 that the preform multilayered wall is more stretched by the blow-moulding in the area between points 203 and 205 than in the area between points 122 and 202, whereby the bottle multilayered wall is thinner in the area 203-205 than in the area 122-202.

(19) According to the invention, any point between the points 122 and 202 is in the bottom ending portion free of gas barrier 130. In this portion, the thickness of the outer and inner layers is more than that of the outer and inner layers at point 202 (that is to say more than 281 m and 61 m respectively). In other words, the thickness of the outer layer and the inner layer keeps on increasing from point 202 until point 122, in this area where there is no gas barrier layer.

(20) The inventors have surprisingly observed that no significant gas leakage occurs in the bottom ending portion free of gas barrier 130 in a bottle obtained according to the invention. Despite the absence of gas barrier in that portion, the shelf-life of the bottle according to the invention is not degraded compared with a bottle obtained with a preform having the same specifications in terms of thickness and composition of the inner and outer layer but having a gas barrier layer which extends in the whole preform multilayered wall.

(21) The absence of gas barrier in the bottom ending portion free of gas barrier 30 or 130 saves a quantity of PEF or nylon (or other material used for making such a gas barrier) which may seem low at the level of a single bottle but which becomes significant even important with respect to the number of bottles produced every year.

(22) The cumulated thickness of the outer and inner layers at any point in the bottom ending portion free of gas barrier 130 of the bottle is more than the cumulated thickness of the outer and inner layers at point 202 (that is to say more than 281+61=342 m). The junction between the body portion and the base portion of the bottle is between points 204 and 205. At any point of this junction, the thickness of the bottle multilayered wall is between the thickness of point 204 (which is 195+19+46=260 m) and the thickness of point 205 (which is 219+21+58=298 m). Therefore, the thickness of the bottle multilayered wall at any point of the bottom ending portion free of barrier layer 130 is much higher than the thickness of the bottle multilayered wall at any point of the junction between the base portion 120 and the body portion 118 of the bottle. In the illustrated example, the difference between the thickness of the bottle multilayered wall at the bottom ending portion free of barrier layer and the thickness of the bottle multilayered wall at the junction between the base portion and the body portion of the bottle is thus more than 44 m (=342298).

(23) The inventors demonstrated that the higher thickness of the bottle multilayered wall at the bottom ending portion free of gas barrier 130 is sufficient to compensate the absence of gas barrier in the bottom ending portion free of gas barrier.

(24) It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims.