CONTAINER, PARTICULARLY A BOTTLE, MADE OF A THERMOPLASTIC MATERIAL

Abstract

The invention relates to a vessel (1), mainly a bottle, of a thermoplastic material made by blowing or stretching-blowing a heated perform, the vessel comprising a bottom (2) and a neck (3) connected to a body (4), characterised in that the body (4) includes an axially central portion (5) surrounded by an axially lower portion (6) and an axially upper portion (7) defining a connection area respectively with the bottom (2) and the neck (3), the axially central portion (5) being essentially rigid while the axially upper and lower potions (6, 7) can be essentially deformed and a have shape-memory characteristics so that they can recover their initial shape under the hydrostatic pressure of the liquid content.

Description

The invention relates to a container, in particular of the bottle type, made of a thermoplastic material, obtained by blowing a plastic material blank, either by a heat treatment then blow moulding or stretch-blow moulding pre-injected preforms, or by extruding then blow moulding a parison.

In the context of storage and packaging of liquids, such as water, it is common to produce containers made of a thermoplastic material, such as polyethylene terephthalate (PET), polypropylene (PP) or HDPE (high-density polyethylene). However, the price of these thermoplastic materials, and in particular of PET, is rising constantly and significantly.

One solution for reducing the production costs of containers consists of reducing as much as possible the amount of thermoplastic material used to produce them.

Thus, the current trend is to reduce the weight of containers, and consequently to reduce the amount of thermoplastic material needed to produce a container, i.e. increasingly lightweight blanks (preforms or parisons) are used.

Document WO 03/033361 discloses a liquid product container with a fine deformable thermoplastic wall. However, the body of this container does not have gripping means, and this known container is intended essentially to be used in a lying position as a fountain.

It is also known from document EP 1 468 930 to produce containers with a fine semi-crystalline PET wall having a thickness below 0.1 mm comprising a central portion of reduced diameter. However, this container cannot, once open, be gripped without causing significant collapse capable of causing the liquid product contained therein to spill.

Thus, the fine wall containers according to the prior art are not designed so as to be capable of being properly gripped without causing the container body to collapse, causing the liquid product contained in the container to spill, once the container has been opened.

Moreover, the containers according to the prior art are sensitive to stress or crushing resulting in whitish bending lines, scratches or traces that can appear on the walls in the event of stress. These defects are visually unacceptable, given that the container cannot be offered for sale since customers prefer to purchase containers without visual defects over containers with defects. It would therefore be particularly beneficial to produce a fine-wall container capable of withstanding stress on its walls without causing the appearance of marks, scratches or white lines.

The present invention is intended to overcome the disadvantages of the containers of the prior art by providing a liquid product container that, for the same internal volume, requires less thermoplastic material than a classic container while being capable of being manually gripped on the body thereof without causing its body to collapse, which can cause the liquid product contained therein to spill once the container has been opened, and also capable of withstanding stress on lower and upper portions thereof.

The present invention relates to a container, in particular a bottle, made of a thermoplastic material produced by blow moulding or stretch-blow moulding a heated preform, which container has a base and a neck connected to a body, in which the neck and the base are substantially rigid and the body includes an axially central portion flanked by an axially lower portion and by an axially upper portion forming bonding zones respectively with the base and the neck, which container is characterized in that the axially central portion is substantially rigid and the axially upper and lower portions are substantially deformable with shape memory, so that they return to their initial shape under the hydrostatic pressure of the liquid contents without undergoing irreversible deformations, such as cracks, scratches, whitish bending lines or indentations, when the user grips the closed container with liquid content occupying substantially the whole of the internal volume of the container, in that said lower and upper portions have zones rigidified by relief alternating with zones not rigidified by relief so that the zones not rigidified by relief form zones of pivoting with respect to the zones rigidified by relief, and in that the thickness of said axially central portion is greater than the thickness of the axially upper and lower portions.

A container is thus obtained, having lower and upper flexible portions and therefore not requiring as much thermoplastic material, with a rigid central portion adapted for being manually gripped without risk of collapse of the container capable of causing the liquid product contained in the container to spill, once the container has been opened. Lower and upper portions adapted for being deformed in the zones not rigidified by relief are also obtained, in this case forming pivot zones, alternating with zones rigidified by relief, which form reinforcement zones of the wall forming said lower and upper portions.

Advantageously, the axially central portion includes reinforcement means in the form of at least one annular groove.

So as to reduce the amount of thermoplastic material needed to form the container according to the invention, the thickness of the lower and upper portions is substantially lower than 0.12 mm, the thermoplastic material being PET.

Also so as to reduce the amount of thermoplastic material in the formation of the container, while enabling the manual gripping zone of the container to be rigidified, the thickness of the axially central portion is substantially lower than 0.15 mm, the thermoplastic material being PET.

So as to enable automated labeling of the central portion of the container in order to apply a label and also to enable manual gripping of the container, the axially central portion is capable of radially resisting a force substantially less than 1.5 daN with a deflection substantially less than 3 mm.

In one implementation, in order to visually define the gripping zone of the container, the axially central portion has a transverse dimension substantially less than the transverse dimension of the axially upper and lower portions. It should nevertheless be noted that the axially central portion, owing to the position thereof, is naturally considered to be a gripping zone by the user.

This invention will now be described with examples provided solely to illustrate the invention without limiting the scope thereof, in reference to the appended drawings in which:

FIG. 1 is a perspective view of a first embodiment of a container according to the invention;

FIG. 2 is a partial perspective view of the upper portion of a second embodiment of a container according to the invention;

FIG. 3 is a partial perspective view of the upper portion of a third embodiment of a container according to the invention;

FIG. 4 is a perspective view of a fourth embodiment of a container according to the invention;

FIG. 5 is a partial perspective view of a fifth embodiment of a container according to the invention;

FIG. 6 is a partial perspective view of a sixth embodiment of a container according to the invention.

FIG. 1 shows a perspective view of a first embodiment of a container 1 according to the invention.

The container 1, in particular of the bottle type, is made of a thermoplastic material produced by blow moulding or stretch-blow moulding a heated preform, which container 1 has a substantially rigid base 2 and a substantially rigid neck 3 connected to a body 4.

The body 4 includes an axially central portion 5 flanked by an axially lower portion 6 and an axially upper portion 7 forming bonding zones respectively with the base 2 and the neck 3.

So as to enable gripping without collapse of the container, the axially central portion 5 is substantially rigid and the axially upper and lower portions 6, 7 are substantially flexible.

A “flexible” zone has to be understood as being a zone that deforms more, under the same given pressure, than a “rigid” zone.

The axially central portion 5 includes reinforcement means 8 in the form of at least one annular groove 9.

The lower and upper portions 6, 7 have zones 10 rigidified by relief alternating with zones 11 not rigidified by relief.

“Zones rigidified by relief” has to be understood as being both zones having reinforcements or impressions in the wall forming the container 1 and projection or protruding zones of said wall.

Due to the alternation of zones 10 rigidified by relief with zones 11 not rigidified by relief, a rigidification of the set of lower and upper portions 6, 7 is obtained, resulting in a deformation with shape memory of these two portions 6, 7, more specifically when a liquid content is present in the container 1. Thus, if pressure is applied to these lower and upper portions 6, 7, the zones 11 not rigidified by relief form zones of pivoting with respect to the zones 10 rigidified by relief.

The axially lower and upper portions 6, 7 are resiliently deformable with shape memory, so that they return to their initial shape under the hydrostatic pressure of the liquid content, or, in other words, so that, in the presence of a content occupying substantially the whole of the internal volume of the container, the hydrostatic pressure equalizes the external pressure. In this way, if the container 1 is closed with a content occupying substantially the whole of the internal volume of the container and the user grips the container 1 by one of the axially lower and upper portions 6, 7, the wall forming the axially lower and upper portions 6, 7 cannot be subjected to irreversible deformations, and no cracks, scratches, whitish bending lines or indentations in the wall appear.

The axially central portion 5 is adapted for radially resisting a force substantially less than 1.5 daN with a deflection substantially less than 3 mm. More generally, the axially central portion 5 is parameterized so that it is possible to grip the container 1 by this portion 5 without causing the container 1 to collapse. The axially central portion 5 is therefore rigid enough to enable the user to grip the container 1 and to use it without risking spillage of the liquid product from the internal volume of the container 1. In addition, the central portion 5 must be rigid enough to enable a label to be applied by a labeling machine that must press on said central portion 5 in order to apply said label.

Advantageously, the central portion S has a transverse dimensions substantially lower than the transverse dimension of the lower and upper portions 6, 7.

The thickness of the axially central portion 5 is greater than the thickness of the axially lower and upper portions 6, 7.

In the case where the thermoplastic material used to form the container is PET, the thickness of the lower and upper portions 6, 7 is substantially less than 0.12 mm, and the thickness of the axially central portion 5 is substantially less than 0.15 mm.

According to the various embodiments shown in FIGS. 1 to 6, the lower and upper portions 6, 7 have a substantially cylindrical rotation shape, with the maximum diameter of the lower and upper portions 6, 7 being greater than or equal to the diameter of the axially central portion 5.

According to the first embodiment shown in FIG. 1, the height of the lower portion 6 is substantially equal to the height of the upper portion 7. Nevertheless, it is also possible for the height of the lower portion 6 to be less than the height of the upper portion 7 (see FIG. 4) or for the height of the lower portion 6 to be greater than the height of the upper portion 7 (se FIG. 6).

According to the embodiments shown in FIGS. 1, 2 and 6, the zones 10 rigidified by relief are in the form of grooves.

More specifically, according to the first embodiment of the invention shown in FIG. 1, each zone 10 rigidified by relief is in the form of a star 12 with a central point 13 from which a plurality of branches 14 radiate.

The zones 11 not rigidified by relief are in the form of a smooth wall.

According to an embodiment, the zones 10 rigidified by relief are in the form of a plurality of pimples, pivotably connected to one another by zones 11 not rigidified by relief. Thus, the wall forming the lower and upper walls 6, 7 has the general form of a wall with a granulated texture.

According to the second embodiment shown in FIG. 2, the zones 10 rigidified by relief are in the form of vertical grooves 15 connected to one another by inclined grooves 16, so as to form substantially trapezoidal zones 11 not rigidified by relief.

According to the third embodiment shown in FIG. 3, each zone 10 rigidified by relief is in the form of an elliptical impression 17. The elliptical impressions 17 have large axes and small axes of different dimensions, so as to be capable of covering substantially the entire surface of the lower and upper portions 6, 7. Alternatively, the zones 10 rigidified by relief are circular impressions with different diameters and depths.

According to the fourth embodiment shown in FIG. 4, the zones 10 rigidified by relief are in the form of impressions 18 regularly distributed over the lower and upper portions 6, 7, defining a plurality of lines and columns of impressions 18 regularly spaced apart and aligned.

As an alternative to the fourth embodiment shown in FIG. 4, two columns of impressions 18 immediately adjacent to one another are vertically offset from one another so that the respective impressions 18 of the two columns are not opposite one another on the same substantially horizontal line.

Each zone 10 rigidified by relief can be in the form of a pyramidal impression 18. Nevertheless, it is possible to have any and every shape of impression 18 in the lower and upper portions 6, 7.

According to the fifth embodiment shown in FIG. 5, each zone 10 rigidified by relief is in the form of a plurality of circular concentric projections 19.

According to the sixth embodiment of the container according to the invention shown in FIG. 6, each of the lower and upper portions 6, 7 has zones 10 rigidified by relief in the form of at least one substantially sinusoidal cylindrical groove 20 and at least one substantially vertical groove 21, 22, pointing toward either an apex or a base of said at least one substantially sinusoidal cylindrical groove 20.

Thus vertical grooves 22 can be provided on the lower portion 6 and starting from the base 2 of the container 1.

Alternatively, the zones 10 rigidified by relief can include ramified grooves, undulated grooves with a substantially axial orientation, intersecting grooves or at least two parallel grooves through which inclined grooves pass, so that he zones not rigidified by relief define triangular zones.

According to the preferred embodiment, the container 1 according to the invention is closed by a so-called snap-on cap 23.

Claims

1. Container, in particular a bottle, made of a thermoplastic material produced by blow moulding or stretch-blow moulding a heated preform, which container has a base and a neck connected to a body, in which the neck and the base are substantially rigid and the body includes an axially central portion flanked by an axially lower portion and by an axially upper portion forming bonding zones respectively with the base and the neck,

wherein the axially upper and lower portions are substantially cylindrical of revolution shaped,

wherein the axially central portion is substantially rigid and the axially upper and lower portions are deformable with shape memory, whereby, when the container is closed with a liquid content occupying substantially the whole of the internal volume of the container, said axially upper and lower portions, when having been deformed due to an external pressure, return to their initial shape under the hydrostatic pressure of the liquid content without undergoing irreversible deformations,

wherein said lower and upper portions have zones rigidified by relief alternating with zones not rigidified by relief, the zones not rigidified by relief forming zones of pivoting with respect to the zones rigidified by relief, and

wherein the thickness of said axially central portion is greater than the thickness of the axially upper and lower portions.

2. Container according to claim 1, wherein said axially central portion includes reinforcement means in the form of at least one annular groove.

3. Container according to claim 1, wherein the thermoplastic material is PET and Wherein the thickness of said lower and upper portions is substantially less than 0.12 mm.

4. Container according to claim 1, wherein the thermoplastic material is PET and wherein the thickness of said axially central portion is substantially less than 0.15 mm.

5. Container according to claim 1, wherein the axially central portion is adapted for radially resisting a force substantially less 1.5 daN with a deflection substantially less 3 mm.

6. Container according to claim 1, wherein the axially central portion has a transverse dimension substantially lower than the transverse dimension of the axially upper and lower portions.