Preform for manufacturing a five-gallon type container

Abstract

The present invention relates to a preform (1) for manufacturing a five-gallon demijohn-type container, which preform (1) comprises a cylindrical preform body (2) which is extended, on one side, by a one-piece bottom element (3), and, on the other side, by a one-piece cylindrical neck (4). According to the invention, the constituent material of this preform (1) comprises: - a first copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid (IPA), containing between 3 and 6% by mass of IPA, and - a second copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid (IPA) containing between 8 and 13% by mass of IPA; Furthermore: - the external diameter (D) of the preform body (2) is between 60 and 80 mm, - the wall thickness (E) of the preform body (2) is between 10 and 15 mm, and - the total length (B) of the preform (1) is between 280 and 350 mm. Figure for the abbreviation: Figure 2

Description

Title of the invention: Preform for the manufacture of a five-gallon carboy-type container Technical field of the invention

[0001] The present invention relates to the technical field of preforms for the manufacture of containers.

[0002] It relates more particularly to preforms for the manufacture of five-gallon bottle-type containers. State of the art

[0003] Certain containers are made from a preform obtained by injection of plastic material (generally Poly(ethylene terephthalate (PET)), at very high temperature, in a suitable preform mold.

[0004] This preform, produced on a first site, comprises a cylindrical body which is extended, at one of its ends, by a single-piece bottom element, and, at its other end, by a single-piece cylindrical neck, provided with external ribs or a screw thread.

[0005] This single-piece cylindrical neck has its definitive shape and dimensions.

[0006] The final container is made on a second site (generally the rem site pleating):

[0007] - by inserting the preform into a container mold, within which it is heated, then

[0008] - by “blowing” it to stick it to the walls of the mold, using a powerful jet air of several dozen bars.

[0009] For their part, large containers of the "five-gallon carboy" type, capable of receiving a volume of five gallons (for water conditioning for example), are conventionally manufactured by molding Polycarbonate, a material which is resistant to temperatures and therefore to the washing cycles to which the containers may be subjected, but which contains bisphenol A (BPA), the presence of which is increasingly undesirable.

[0010] We therefore sought to obtain such “five-gallon bottles” from Poly(ethylene terephthalate) (PET) preforms.

[0011] However, the body diameter and wall thickness of these PET preforms are limited by the nature of the manufacturing material; and these preforms then require significant lengths to enable the manufacture of the desired container.

[0012] However, these significant lengths of current five-gallon PET preforms require the use of large container molds (for example, 400 presses). tons of closing force), which are very expensive.

[0013] In addition, the stretching rules for current five-gallon PET preforms are not optimized and this lack of optimization needs to be compensated for by material additions which increase the cost of the preforms.

[0014] There is therefore a need to provide five-gallon preforms made of Poly(ethylene terephthalate) (PET) of less length and / or weight than those known to date. Presentation of the invention

[0015] In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes a preform for the manufacture of a five-gallon carboy-type container, which preform comprises a cylindrical preform body, which is extended, at one of its ends, by a single-piece bottom element, in the general shape of a spherical cap, and, at its other end, by a single-piece cylindrical neck,

[0016] which preform comprises a cylindrical internal volume of constant diameter which extends over the entire length of said preform body and of said cylindrical neck,

[0017] this preform being characterized by the fact that its constituent material comprises:

[0018] - a first copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic acid (IPA), containing between 3 and 6% (preferably between 4 and 5%) by mass of isophthalic acid (IPA), and

[0019] - a second copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic acid (IPA), containing between 8 and 13% (preferably between 9 and 12%) by mass of isophthalic acid (IPA),

[0020] and by the fact that:

[0021] - the external diameter of its preform body is between 60 and 80mm,

[0022] - the thickness of the wall of its preform body is between 10 and 15mm, and

[0023] - its total length is between 280 and 350mm.

[0024] Such a mixture of copolymers makes it possible to limit or even eliminate crystallization phenomena during the preform molding process. It is then possible to envisage relatively large wall thicknesses for the preform and to limit its length, in order to allow the use of molds for small containers (for example, presses with a closing force of 300 tons).

[0025] Such preform sizing also makes it possible to optimize the stretching ratios of the preform.

[0026] Other non-limiting and advantageous characteristics of the preform according to the invention, taken individually or in all technically possible combinations, are the following:

[0027] - the external diameter of the preform body can be of the order of 70mm to within 10% (and preferably to within 5%); the thickness of the wall of the cylindrical body may be of the order of 12mm to within 10% (and preferably to within 5%); the total length of the preform may be of the order of 315mm to within 10% (and preferably to within 5%);

[0028] - the material constituting the preform may comprise:

[0029] (a) said first copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic acid (IPA), present in a proportion of between 50 and 60% by mass, and

[0030] (b) said second copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic (IPA), present in a proportion of between 40 and 50% by mass;

[0031] - the average thickness of the bottom element of the preform can be between 8 and 9mm;

[0032] - the internal diameter of the internal volume of the preform can be of the order of 46mm, to within 10% (and preferably to within 5%).

[0033] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0034] Furthermore, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate a non-limiting embodiment of the invention and where:

[0035] [Fig. 1] is a front view of a preform according to the invention for the manufacture of a five-gallon carboy type container;

[0036] [Fig.2] is a side view and partial section of the preform, according to section plane 2-2 of [Fig.l].

[0037] The preform 1 illustrated in Figures 1 and 2 is intended for the manufacture of a five-gallon carboy type container.

[0038] This preform 1 is produced by molding a mixture of two particular copolymers of polyethylene terephthalate (PET) and isophthalic acid (IPA); and it includes particular dimensions which allow the manufacture of the five-gallon bottle in a mold for relatively small containers (for example a press with a closing force of 300 tons), and which also allow the rules for drawing the material to be optimized. Material constituting the preform 1

[0039] the constituent material of the preform 1 comprises:

[0040] (1) a first copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic acid (IPA), containing between 3 and 6% (preferably between 4 and 5%) by mass of isophthalic acid (IPA). This first copolymer is preferably present in a proportion between 50 and 60% by mass (it can be present in a proportion of around 55% by mass); and

[0041] (2) a second copolymer of poly(ethylene terephthalate) (PET) and acid isophthalic acid (IPA), containing between 8 and 13% (preferably between 9 and 12%) by mass of isophthalic acid (IPA). This second copolymer is preferably present in a proportion of between 40 and 50% by mass (it may be present in a proportion of the order of 45% by mass).

[0042] Such copolymers of poly(ethylene terephthalate) and isophthalic acid (IPA) are known and commercially available.

[0043] For example, copolymers can be used:

[0044] - reference CUMAPET (Registered trademark) of the company Dufor Resins BV - Zevenaar - The Netherlands;

[0045] - reference RAMAPET PI84 (Registered trademark) of the company Indorama Ventures Europe - Rotterdam, The Netherlands;

[0046] - reference CB606, from the company Far Eastern New Century Corporation (FENC) Taipei, Taiwan, ROC;

[0047] - reference SELENIS INFINITE +300 (Registered trademark) of the company SELENIS EUROPE 33058 San Giorgio di Nogaro (UD) - Italy. Dimensions / proportions of preform 1

[0048] The preform 1 comprises a preform body 2 which is extended and closed, at one of its ends, by a single-piece bottom element 3, and which is extended, at its other end, by a single-piece cylindrical neck 4.

[0049] The preform 1 is centered on a longitudinal axis A.

[0050] The bottom element 3 is of the domed type, in the general shape of a spherical cap.

[0051] The cylindrical neck 4 has its final shape and dimensions.

[0052] It comprises a circular end opening 41, bordered by a single-piece bead 42, projecting outwards.

[0053] Its external surface also comprises conventional, single-piece ribs, adapted to receive a capsule (ribs 43) and to transport the preform during the blowing process (rib 43a).

[0054] The preform 1 comprises an internal volume 5 which is cylindrical and of constant diameter over the entire length of the preform body 2 and the cylindrical neck 4 (except at the level of the domed bottom element 3).

[0055] Between the cylindrical neck 4 and the preform body 2, we notice the presence of an intermediate sloping zone 6, seen from the outside, which makes it possible to compensate for the difference between the external diameter of the preform body 2 and the external diameter of the cylindrical neck 4.

[0056] The total length B of the preform 1 (between the end circular opening 41 and the end of the bottom element 3) is between 280 and 350 mm. More precisely, this length of preform B can be of the order of 315 mm to within 10% (and preferably 315 mm to within 5%).

[0057] The preform body 2 extends between the bottom element 3 and the intermediate zone 6. Its length C can be of the order of 172 mm, to within 10% (and preferably to within 5%).

[0058] Its external diameter D is between 60 and 80 mm; more precisely, this external diameter D of the preform body 2 is of the order of 70 mm to within 10% (and preferably 70 mm to within 5%).

[0059] The thickness E of the wall of the preform body 2 is between 10 and 15 mm. More precisely, this thickness E of the wall of the preform body 2 is of the order of 12mm to within 10% (and preferably of the order of 12mm to within 5%).

[0060] The length F of the bottom element 3 may be of the order of 33mm to within 10% (and preferably 33mm to within 5%). The average thickness G of this bottom element 3 is between 8 and 9mm.

[0061] The length H of the cylindrical neck 4 may be of the order of 69mm to within 10% (and preferably 69mm to within 5%). The thickness I of this cylindrical neck 4, excluding the bead 42 and ribs 43, 43a, may be of the order of 2.5mm. The external diameter J of this cylindrical neck 4, still excluding the bead 42 and ribs 43, 43a, may be of the order of 51mm.

[0062] The internal diameter K of the cylindrical neck 4, which corresponds to the internal diameter of the preform body 2 and more generally to the internal diameter of the internal volume 5, is of the order of 46mm, to within 10% (and preferably 46mm, to within 5%).

[0063] The length L of the intermediate part 6 may be of the order of 25mm to within 10% (and preferably 25mm to within 5%).

[0064] Conventionally, the preform 1 according to the invention is placed in a container mold of suitable shape; and it is heated there, then “blown” to obtain a desired 5-gallon bottle.

[0065] Such a preform structure 1 has in particular the following advantages:

[0066] - it is compatible with standard presses of 300 tons of closing force; the shaping of the bottles can be transferred to all presses, which secures production;

[0067] - the significant thickness of the preform body allows for optimization of the ratios stretching;

[0068] - limitation or even absence of crystallization due to the copolymers used;

[0069] - possibility of inserting recycled PET.

[0070] - with equal cylinder performance, the preform is lightened due to optimization stretch rates;

[0071] - very good resistance to washing of the bobbins (reduced shrinkage) due to the rates optimized stretching;

[0072] - reduced logistics costs due to the reduced size of the preform;

Claims

Claims

1. Preform (1) for the manufacture of a five-gallon carboy-type container, which preform (1) comprises a cylindrical preform body (2), which is extended, at one of its ends, by a one-piece bottom element (3), in the general shape of a spherical cap, and, at its other end, by a one-piece cylindrical neck (4), which preform (1) comprises a cylindrical internal volume (5) of constant diameter which extends over the entire length of said preform body (2) and of said cylindrical neck (4), characterized in that the constituent material of said preform (1) comprises: - a first copolymer of polyethylene terephthalate (PET) and isophthalic acid (IPA), containing between 3 and 6% by mass of isophthalic acid (IPA), - a second copolymer of polyethylene terephthalate (PET) and isophthalic acid (IPA) containing between 8 and 13% by mass of isophthalic acid (IPA),and in that: - the external diameter (D) of the preform body (2) is between 60 and 80mm, - the thickness (E) of the wall of the preform body (2) is between 10 and 15mm, - the total length (B) of the preform (1) is between 280 and 350mm.,

2. Preform (1) according to claim 1, characterized in that: - said first copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid (IPA) contains between 4 and 5% by mass of isophthalic acid (IPA), and - said second copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid (IPA) contains between 9 and 12% by mass of isophthalic acid (IPA).

3. Preform (1) according to any one of claims 1 or 2, characterized in that: - the external diameter (D) of the preform body (2) is of the order of 70mm to within 10% - the thickness (E) of the wall of the preform body (2) is of the order of 12mm to within 10% - the total length (B) of the preform (1) is of the order of 315mm to within 10%

4. Preform (1) according to claim 3, characterized in that: - the external diameter (D) of the preform body (2) is of the order of 70mm to within 5%, - the thickness (E) of the wall of the preform body (2) is of the order of 12mm to within 5%, - the total length (B) of the preform (1) is of the order of 315mm to within 5%.

5. Preform (1) according to any one of claims 1 to 4, characterized in that the material constituting said preform (1) comprises: - said first copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid (IPA), present in a proportion of between 50 and 60% by mass, and - said second copolymer of poly(ethylene terephthalate) (PET) and isophthalic acid, present in a proportion of between 40 and 50% by mass.

6. Preform (1) according to any one of claims 1 to 5, characterized in that the average thickness (G) of the bottom element (3) is between 8 and 9 mm.

7. Preform (1) according to any one of claims 1 to 6, characterized in that the internal diameter (K) of said internal volume (5) is of the order of 46mm, to within 10%.

8. Preform (1) according to claim 7, characterized in that the internal diameter (K) of said internal volume (5) is of the order of 46mm, to within 5%.

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