CONTAINER FOR LIQUIDS

Abstract

The invention relates to a container (1) for liquids such as beverages and oils comprising a blow moulded polyester casing (2), a valve (4) for dispensing the liquid from the container and an inlet for introducing a propellant. The casing (2) is enveloped by an stretch blow moulded polyester shell (9).

Claims

1. A container for liquids, such as beverages and oils, comprising a blow moulded polyester casing, a valve for dispensing the liquid from the container, and an inlet for introducing a propellant, wherein the casing is enveloped by a stretch blow moulded polyester shell.

2. The container according to claim 1, wherein the shell supports the casing at least when the latter is pressurized.

3. The container according to claim 1, wherein the shell comprises two separate parts, e.g. divided along a circumference of the shell, and at least one of the parts is clamp fitted on the casing when the latter is pressurized.

4. The container according to claim 3, wherein the remaining part is secured in the open end of the part that is clamp fitted on the casing.

5. The container according to claim 3, wherein the two parts overlap, preferably by at least 1 centimeter.

6. The container according to claim 1, wherein the burst strength of the container is at least 20%, preferably at least 30% higher than the burst strength of the casing.

7. The container according to claim 1, wherein the relative expansion of the container when exposed to 5 bar internal pressure and 40 C. during 2 days is less than 3%, preferably less than 2%, more preferably less than 1.5%.

8. The container according to claim 1, wherein the casing has an internal volume of at least 10 liters and wherein the length to width ratio of the casing is in excess of 1.5, preferably in excess of 2 and/or wherein the container comprises a cylindrical portion that extends over at least 25%, preferably at least 40%, more preferably at least 50% of the height of the container.

9. The container according to claim 1, wherein the combined wall thickness of the casing and the shell is in excess of 0.8 mm, preferably in excess of 1.0 mm.

10. The container according to claim 1, wherein the shell is embossed about its circumference, thus increasing the actual or at least the effective thickness in the radial direction.

11. The container according to any claim 1, comprising a liquid-tight inner container of a flexible material located inside the casing for containing the liquid and communicating with the valve.

12. The container according to claim 11, wherein the casing is impermeable to carbon dioxide, oxygen and/or nitrogen.

13. The container according to claim 1, wherein the casing is pre-filled with a pressurized gas.

14. The container according to claim 1, wherein the polyester of the casing and the shell is polyethylene terephthalate, preferably recycled polyethylene terephthalate.

15. The container according to claim 1, wherein the casing and the shell are transparent.

16. The container according to claim 1, wherein the shell comprises at least one blow moulded handle and/or a blow moulded foot.

Description

[0025] The invention will now be explained in more detail with reference to the drawings, which show a preferred embodiment of the present invention.

[0026] FIGS. 1A and 1B show a cross-section through and a detail of a container according to the present invention.

[0027] FIGS. 2 to 4 show a stack and variations of the container in FIGS. 1A and 1B.

[0028] FIGS. 5A/5B and 6A/6B show cross-sections and bottom views of containers according to the present invention with a base providing enhanced stability.

[0029] FIGS. 7A to 7C show cross-sections of a container according to the present invention comprising a cylindrical portion with increased wall thickness.

[0030] The drawings are not necessarily to scale and details, which are not necessary for understanding the present invention, may have been omitted. Further, elements that are at least substantially identical or that preform an at least substantially identical function are denoted by the same numeral.

[0031] FIG. 1 shows a container 1 for a beverage containing a gas, in particular beer, comprises a casing 2 made by stretch blow moulding a polyester preform, in particular PET (polyethylene terephthalate). The casing 2 comprises a substantially cylindrical middle portion 2A and top and bottom domes 2B, 2C. The top dome 2B has a central opening 3 formed by the non-deformed part of the preform.

[0032] A valve part 4 for dispensing the beverage from the container is snap-fitted to the opening 3. In this example, the valve part 4 comprises an outer jacket 5, an inner jacket 6 slidably received inside the outer jacket 6, and a closing element 7 which, in turn, is slidably received inside the inner jacket 6. The inner jacket and the closing element can be made of a polyolefin such as PE or PP. In general, it is preferred that the valve part is made of PA or PET, preferably in its entirety. For more details on this and other suitable valve parts reference is made to International patent application WO 00/07902 (see especially page 9, line 12 ff. in conjunction with FIGS. 4A and 4B).

[0033] In this example, a gastight bag 8 for receiving the beverage is connected to the valve part 4 and located inside the casing 2. The bag 8 comprises two, in this example polygonal, flexible sheets of a gas and liquid tight laminate, preferably a laminate comprising a sealing layer (e.g., PE or PP), a barrier layer (e.g. aluminum) and one or more further layers (e.g. PA and/or PET), sealed together along their edges, e.g. by means of welding. In general, the barrier function can be shared with or shifted to the casing rendering the casing impermeable to carbon dioxide, oxygen and/or nitrogen. To this end, the casing may comprise additives, a coating or a plurality of layers.

[0034] In accordance with the invention, the casing 2 is enveloped by a stretch blow moulded polyester shell 9. In the example shown in FIG. 1, the shell comprises two parts 9A, 9B, separated along a circumference, i.e. in hoop direction, of the shell 9. When pressurized, the casing 2 expands and firmly abuts the inner wall of the shell 9. Thus, the parts 9A, 9B are both clamp fitted on the casing 2.

[0035] The shell was blow moulded from a preform similar to that used for the casing but with a different rim. Also, in contrast to the casing, which preferably should have a smooth shape defined by a cylinder and two domes to withstand internal pressure and to avoid damage to the bag containing a beverage, the shell may be provided with one or more features providing additional functionality.

[0036] E.g., the shell may comprise one or more handles defined in, in particular, the top portion. Examples of such handles include a notch 10 spanning the circumference of the shell 9, as shown in FIGS. 1A, 3 and 4, or two grips on opposite sides of the shell or a radial flange 11 extending from the upper rim of the shell, as shown in FIG. 2.

[0037] In the example shown in FIGS. 1A, 3 and 4, the top part 9A of the shell further comprises a collar 12 extending around the valve part and protecting the same.

[0038] The base 9B can be provided with features enabling a stable upright position of the container. In the example, the shell comprises a petaloid foot 12, similar to those employed in 1.5 liter bottles for soft drink. In addition to providing a stable base, the foot provides a crumble zone protecting the container when it falls.

[0039] Further, the top and base of the shell are preferably shaped to render the container stackable, as shown in FIG. 4. The base comprises a recess which is complementary to the collar or the lobs of the petaloid base define a (non-continuous) recess which corresponds to the collar.

[0040] The container has an overall length of approximately 57 cm and a width of approximately 24 cm, yielding an L/D of 2.4. The cylindrical portion has a length of approximately 65% of the overall length of the container.

[0041] Puncture resistance is further improved if the shell is embossed about its circumference sc as to increases the actual or at least effective thickness in the radial direction. In general, embossing nay comprises a large number of small protrusions on the outer surface of the shell, yielding e.g. a knurled surface, and/or nay comprise a plurality of rings about the circumference of the container and/or a plurality of ribs extending in axial direction. Also, embossing may provide other, additional functions. In an embodiment, the shell comprises at least two rings extending about the circumference of the shell and spaced apart in axial direction. Such rings facilitate rolling the container e.g. from a truck to storage and reduce the risk of damage to the inner casing inflicted by small sharps on the surface.

[0042] FIGS. 5A and 5B show a further embodiment of the container according to the present invention. In this embodiment, the casing 2 is again enveloped by a stretch blow moulded polyester shell 9. The shell comprises two parts 9A, 9B, separated along a circumference, i.e. in hoop direction, of the shell 9, relatively close to the bottom of the shell, such that the top part of the shell is longer than the casing. As a result, the lower rim of the upper part of the shell extends beyond the bottom of the casing and serves as the foot or part of the foot of the container. To further increase stability, it is preferred that, at the rim, the wall is corrugated to increase its effective thickness and stiffness and/or the wall is actually thicker, preferably at least two times thicker, than the wall of the cylindrical section of the shell.

[0043] The base 9B can be discarded or be used to further increase the strength and stability of the foot. In this example, the base part is provided with creased and radially extending segments to enhance the stiffness of the base, in turn facilitating a stable upright position of the container, and to provide a crumble zone protecting the container when it falls. More specifically, the base part defines a petaloid foot 12 and is placed, e.g. pressed, inside the bottom end of the top part of the shell. The base part can be clamped, glued, and/or welded into the top part of the shell.

[0044] In the embodiment shown in FIGS. 6A and 6B, the base part was reversed before being inserted in the bottom end of the top part, thus significantly increasing, e.g. doubling, the wall thickness at the lower rim of the shell. The center of the base is shaped complementary to the bottom end of the casing, thus providing support over a relatively large area.

[0045] As is apparent from FIGS. 5B and 6B, the cross-section of the upper rim of the base part differs from that of the lower rim of the top part of the shell, both in diameter and in shape. Thus, the shell is preferably formed with a transition between the two parts 9A, 9B and these parts are each separated from the transition, e.g. by two (laser) cuts in the hoop direction of the shell 9.

FIGS. 7A to 7C show a container according to the present invention which in most respects corresponds to the container shown in FIGS. 1A and 1B but with a casing 2 and shell 9 having an L/D of approximately 1 and a relatively short cylindrical section. The shell is considerably longer than the casing, preferably by a length that corresponds to the length of the cylindrical portion of the casing. In other words, the length of the cylindrical portion of the shell is twice the length of the cylindrical portion of the casing. When the shell is separated along a circumference, i.e. in hoop direction and preferably halfway the height of the shell 9, the casing is clamped inside the upper half and the upper half, now containing the casing, is clamped in the lower half, the wall thickness of the shell is doubled at the cylindrical portion.

[0046] Further, the container shown in FIGS. 7A to 7C comprises an external thread or annular protrusion about the top opening for screwing or snapping e.g. grips onto the container.

[0047] In the above examples, the shell was blow moulded from a preform similar to that used for the casing but with a different rim. Also, in contrast to the casing, which preferably should have a smooth shape defined by a cylinder and two domes to withstand internal pressure and to avoid damage to the bag containing a beverage, the shell may be provided with one or more features providing additional functionality.

[0048] The stretch blow moulded polyester shell was found to provide a relatively high retained strength of the container when the shell and casing are punctured, thus avoiding explosive bursting and enabling a more gradual blowing off of the pressurized gas inside the casing. In addition, the shell is resistant to water and enables a design that is lighter and stronger than containers having a cardboard shell. Due to the increased strength, the container according to the present invention is in principle suitable for beverages containing high concentrations of gas, e.g. 7 gram/liter carbon dioxide, at higher temperatures, e.g. 40 C.

[0049] Further, as both the casing and the shell are stretch blow moulded from a preform, logistics can be simplified e.g. by supplying just preforms and bags to brewers the containers can be mold blown and assembled on site, avoiding bulky transport.

[0050] The invention is not restricted to the above-described embodiments which can be varied in a number of ways within the scope of the claims. For instance, instead of a bag for containing the beverage, the container can be equipped with a spear extending from the valve part to the bottom of the casing.