HK1241331A1 - Container for liquids - Google Patents

Abstract

The application relates to container for liquids. 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 a stretch blow moulded polyester shell (9).

Description

Container for liquid

The present application is a divisional application of an application having an application date of 2011, 4, 26, and an application number of 201180029089.9, entitled "container for liquid".

The present invention relates to a container for liquids such as beverages (e.g. beer, soft drinks and wine) and liquids having a relatively high viscosity (e.g. edible oil), the container comprising: a blow molded polyester and preferably spherical or globular shell, a valve for dispensing liquid from the container, and an inlet for introducing a propellant, which is typically integrated into the valve. EP 862535 relates to a container for a fluid, the container comprising: an outer and preferably oval shell of a flexible pressure resistant material, an airtight inner shell of flexible material inside the outer shell, and a filling joint for filling the inner shell.

EP 1736421 relates to a lightweight container for a fluid, in particular a liquid such as beer or water, the container comprising: a spherical or globular shell, a valve portion for filling the container with fluid, and an outer package, usually made of cardboard, surrounding the shell. A similar lightweight container is known from EP 2038187. In one embodiment, the housing is made of blow molded PET.

Many containers for liquids are subjected to high internal pressures during use. For example, a beverage containing gas should be maintained at an elevated pressure, typically in the range from 1 to 4 bar (overpressure), in order to prevent the gas from escaping from the beverage. Also, liquids with relatively high viscosity and liquids dispensed from lower levels (e.g. from a cellar) require relatively high pressures in the container in order to overcome friction and hydrostatic pressure, respectively. High temperatures and non-compliance with safety guidelines may also result in high internal pressures.

During dispensing, the liquid content of the container is gradually replaced by pressurized gas. The pressurized gas has a high energy content, which means that if the container is cut, pierced or otherwise damaged and fails, the container will burst in an explosive manner. Explosive bursts can cause splatter and injury, such as damage to the hearing of people nearby.

In practice, explosive bursting occurs when the container has been installed for dispensing, for example by contact with the hot air outlet of a cigarette, cooler or a spike behind the rod, or due to stress cracking caused by exposure to aggressive (caustic) cleaning agents. An explosive burst can also occur when a user wants to discard an empty container and cut or pierce the container with a knife or other instrument regardless of safety guidelines. It is an object of the present invention to provide a container that is relatively lightweight and more resistant to explosive bursting.

To this end, the container according to the invention is characterized in that the shell is enclosed by a stretch blow molded polyester casing. In one embodiment, the shell supports the shell at least when the shell is pressurized, e.g., the internal pressure forces the shell against the shell.

It has been found that the stretch blow molded polyester casing provides a relatively high residual strength of the container after the casing and the shell have been cut, pierced or otherwise damaged, thereby increasing the threshold pressure at which the container explodes. Below this threshold, the pressurized gas inside the housing will typically be ejected rather than causing the container to explode. In addition, as will be explained in more detail below, the housing enables a greater design and/or improves design freedom, in particular with respect to external features (e.g. a stable base), than containers with cardboard or e.g. HDPE housings.

In one embodiment, the burst strength of the container is at least 20% higher, preferably at least 30% higher, than the burst strength of the shell alone. The burst strength is defined as the pressure in bar at which the container bursts relative to the shell when at 20 ℃ and when the pressure increases gradually at 1 bar per 10 seconds.

In another embodiment, the relative expansion rate of the container when exposed to an internal pressure of 5 bar and 40 ℃ for 2 days is less than 3%, preferably less than 2%, more preferably less than 1.5% higher than the expansion rate of the same container when exposed to an internal pressure of 2 bar and 20 ℃ for 2 days. Low expansion rates are particularly relevant for many liquids containing gases of low solubility. For example, nitrogen (N)₂) Have poor solubility in water and therefore only small amounts of nitrogen can be added to beer. When the volume of the container is only permanently increased by a small percentage, for example due to creep at elevated temperatures, a large percentage of nitrogen will escape from the beer and the taste, texture and dispensing behaviour of the beer will deteriorate. This phenomenon can be reduced with a housing according to the invention.

In one embodiment which incidentally is also useful in containers comprising a shell and an outer shell made of other polymers, the outer shell comprises two separate parts, for example, separated along the perimeter of the outer shell, and at least one of the parts, preferably the top part, is clip-mounted on the shell when the shell is put under pressure. The housing may be blow molded from a preform and additional devices, such as a cover necessary to insert the housing into the housing, and subsequent closing of the housing may be avoided. In this context, clamp mounting implies that a force of at least 300N, preferably at least 500N, is required in the axial direction to separate the parts of the housing from the housing. That is, when a container containing twenty liters, or thirty or fifty liters, as the case may be, of a beverage is lifted through the housing, the housing will not slide relative to the housing.

The remaining part of the housing may be fastened by clamping, gluing and/or welding in the bottom side of the part that is clamp-mounted on the housing.

In one embodiment, the two portions overlap, preferably by at least 1 cm, more preferably by at least 5 cm. This overlap may extend, for example, beyond the entire cylindrical portion of the container, forming a three-layer structure in this portion of the container.

A separately formed base, optionally made of a different material, may be secured within the housing and/or to the housing in place of the remainder of the housing.

In another embodiment, the edge of one portion of the housing overlaps the edge of another portion of the housing. In another embodiment, the parts of the casing are glued or glued to the shell.

The stretch blow molded enclosure inhibits or prevents explosive bursting even in elongated containers, such as containers having relatively high aspect ratios (L/D) and/or relatively long cylindrical sections. Such a shape is advantageous for logistics, e.g. more containers can be placed on a tray, and for cooling, e.g. four containers fit into a standard size refrigerator. In one embodiment, the housing has an internal volume of at least 10, preferably at least 15, more preferably at least 20 litres and the aspect ratio (L/D) of the housing exceeds 1.5, preferably exceeds 2. In another embodiment, the container comprises a cylindrical portion extending over at least 25%, preferably at least 40%, more preferably at least 50% of the height of the container.

In one embodiment, the wall thickness of both the shell and the outer shell is in the range from 0.1mm to 1.0mm, preferably in the range from 0.3mm to 0.6mm, providing a total wall thickness of up to 2.0mm, and for example locally even up to 3.0mm when portions of the outer shell overlap each other, which is not possible at present by blowing a single preform.

The puncture resistance is further improved if the casing is embossed around its circumference in order to increase the actual or at least effective thickness in the radial direction. Also, embossing reduces the risk of damaging the container when the container is rolled over a rough surface (e.g. from a truck to a store).

In another embodiment the container is filled with a pressurized gas and is free of beverage, i.e. the container is pressurized with e.g. air or carbon dioxide and/or nitrogen at a pressure of more than 1.5 bar before filling. Thus, the container can be easily filled with a liquid containing a gas, such as beer.

WO 00/78665 relates to a beer container comprising: an inner hollow shell of blow molded PET for containing beer; an outer hollow shell of molded High Density Polyethylene (HDPE) enclosing and supporting the inner shell; and a spear structure comprising a distributor tube extending from the bottom interior region of the inner housing to a distribution outlet at the top end of the outer housing. When the container has been emptied of beer, the outer housing can be easily separated from the inner housing and spear structure to allow separate recovery of HDPE and PET. A 30 litre keg of this type typically weighs about 3 kg. In addition, extrusion blow molded HDPE is inferior when it comes to preventing explosive bursting of containers containing higher pressure gases.

US 2010/0077790 relates to a plastic beer keg comprising an outer container and an inner liner. A removable lid is secured over an opening of the container to close the liner. In use, the lid may be removed and ice placed directly on the liner in the container, the ice flowing into voids between the liner and the container to provide rapid cooling of the contents of the liner. The liner may be PET and the container and lid may be HDPE, polypropylene or another suitable material.

EP 389191 relates to a container for transporting, storing and dispensing beverages such as beer, comprising: an outer container (12) of plastic, such as PET, and an inner bag (20) of flexible material, such as layered polyethylene.

In the framework of the present invention, "stretch blow molding" refers to blow molding a preform and thus stretching in the circumferential (ring) direction as well as in the radial direction.

The term "spherical" includes any shape produced by a circle or a square or rectangle with rounded corners or an ellipse or oval rotated half-way around its major or minor axis.

The present application also relates to the following:

1) container for liquids such as beverages and oils, comprising: a blow molded polyester case, a valve for dispensing liquid from the container, and an inlet for introducing a propellant, characterized in that the case is enclosed by a stretch blow molded polyester casing.

2) The container of item 1), wherein the shell supports the shell at least when pressure is applied to it.

3) The container according to item 1) or item 2), wherein the shell comprises two separate parts, for example separated along a perimeter of the shell, and at least one of the parts is clip-mounted on the shell when the shell is pressurized.

4) The container according to item 3), wherein the remaining part is fastened in the open end of the part which is clip-mounted on the housing.

5) The container of item 3) or item 4), wherein the two portions overlap, preferably by at least 1 centimeter.

6) A container according to any one of the preceding claims, wherein the burst strength of the container is at least 20% higher, preferably at least 30% higher, compared to the burst strength of the shell.

7) The container according to any one of the preceding claims, wherein the relative expansion of the container upon exposure to an internal pressure of 5 bar and 40 ℃ for 2 days is less than 3%, preferably less than 2%, more preferably less than 1.5%.

8) Container according to any one of the preceding claims, wherein the housing has an internal volume of at least 10 litres and wherein the aspect ratio (L/D) of the housing is more than 1.5, preferably more than 2 and/or wherein the container comprises a cylindrical portion extending over at least 25%, preferably at least 40%, more preferably at least 50% of the height of the container.

9) A container according to any one of the preceding claims, wherein the wall thickness of the shell in combination with the outer shell is more than 0.8mm, preferably more than 1.0 mm.

10) A container according to any one of the preceding claims, wherein the outer shell is embossed around its circumference to increase the actual or at least effective thickness in the radial direction.

11) A container according to any one of the preceding claims, comprising a liquid-tight inner container of a flexible material located inside the housing for containing the liquid and communicating with the valve.

12) The container according to item 11), wherein the shell is impermeable to carbon dioxide, oxygen and/or nitrogen.

13) A container according to any one of the preceding claims, wherein the housing is pre-filled with a pressurised gas.

14) The container according to any one of the preceding claims, wherein the polyester of the shell and the outer shell is polyethylene terephthalate (PET), preferably recycled polyethylene terephthalate (PET).

15) A container according to any one of the preceding claims, wherein the housing and the outer shell are transparent.

16) A container according to any one of the preceding claims, wherein the housing comprises at least one blow moulded handle and/or a blow moulded base.

The invention will now be explained in more detail with reference to the drawings, which show a preferred embodiment of the invention. Fig. 1A and 1B show a cross-section and a detail of a container according to the invention.

Fig. 2 to 4 show a stack and variants of the containers in fig. 1A and 1B.

Fig. 5A/5B and 6A/6B show cross-sectional and bottom views of containers with a base providing enhanced stability according to the present invention.

Fig. 7A-7C show cross-sections of a container according to the invention comprising a cylindrical portion with increased wall thickness. The drawings are not necessarily to scale and details which are not necessary for an understanding of the invention may have been omitted. In addition, elements that are at least substantially identical or that perform at least substantially the same function are denoted by the same numerals.

Fig. 1 shows a container 1 for a beverage containing a gas, in particular beer, comprising a housing 2 made by stretch blow moulding a polyester preform, in particular PET (polyethylene terephthalate). The housing 2 includes a generally cylindrical middle portion 2A and top and bottom domes 2B, 2C. The top dome 2B has a central opening 3 formed by the undeformed portion of the preform.

A valve portion 4 for dispensing beverage from the container is snap-fitted to the opening 3. In this example, the valve portion 4 comprises an outer jacket 5, an inner jacket 6 slidably received inside the outer jacket 5, and a closure element 7 in turn slidably received inside the inner jacket 6. The inner jacket and the closure element can be made of a polyolefin, such as PE or PP. In general, it is preferred that the valve part, preferably in its entirety, is made of PA or PET. For more details on this or other suitable valve parts, see international patent application WO 00/07902 (see page 8, line 12 and below, especially in connection with fig. 4A and 4B).

In this example, an air-tight bag 8 for containing beverage is connected to the valve portion 4 and positioned inside the housing 2. In this example, the bag 8 comprises a gas and liquid impermeable laminate material, preferably two polygonal flexible sheets of the following laminate material comprising: a sealing layer (e.g. PE or PP), a barrier layer (e.g. aluminium) and one or more further layers (e.g. PA and/or PET) which are sealed together along their edges, for example by welding. In general, the barrier function may be shared with or transferred to the housing, making the housing impermeable to carbon dioxide, oxygen, and/or nitrogen. To this end, the housing may contain additives, a coating or layers.

According to the invention, the housing 2 is enclosed by a stretch blow molded polyester casing 9. In the example shown in fig. 1, the casing comprises two parts 9A, 9B separated along one circumference, i.e. in the circumferential direction of the casing 9. When pressurized, the housing 2 expands and firmly abuts against the inner wall of the casing 9. Thus, both parts 9A, 9B are clamp mounted on the housing 2.

The housing is blow molded from a preform similar to that used for the shell but having a different edge. Also, the casing may be provided with one or more features providing additional functionality compared to the shell (which preferably should have a smooth shape defined by a cylinder and two domes in order to withstand internal pressure and to avoid damage to the bag containing the beverage).

For example, the housing may comprise one or more handles defined, in particular, in the top portion. Examples of such handles include: a slot 10 across the perimeter of the housing 9 as shown in fig. 1A, 3 and 4, or two handles on opposite sides of the housing or a radial flange 11 extending from the upper edge of the housing as shown in fig. 2.

In the example shown in fig. 1A, 3 and 4, the top portion 9A of the housing further comprises a collar 12 extending around and protecting the valve portion.

The base 9B may be provided with features that enable the container to be in a stable upright position. In this example, the housing includes a petaloid base 12 similar to those employed in 1.5-liter bottles for soft drinks. In addition to providing a stable base, the base provides an anti-collapse zone that protects the container when it is dropped.

In addition, as shown in FIG. 4, the top and base of the housing are preferably formed such that the container is stackable. The base comprises a recess complementary to the collar, or the lobes of the petaloid base define a (discontinuous) recess corresponding to the collar.

The vessel had an overall length of approximately 57cm and a width of approximately 24cm, giving an L/D of 2.4. The cylindrical body portion has a length of approximately 65% of the total length of the container.

The puncture resistance is further improved if the casing is embossed around its circumference in order to increase the actual or at least effective thickness in the radial direction. In general, the embossing may include a large number of small protrusions on the outer surface of the shell to create a raised surface, and/or may include rings around the perimeter of the container and/or ribs extending in a radial direction. Also, embossing may provide other additional functions. In one embodiment, the housing comprises at least two rings extending around the perimeter of the housing and radially spaced apart. Such a ring facilitates rolling the container, e.g. from a truck into a store, and reduces the risk of damage to the inner shell due to small tips on the surface.

Fig. 5A and 5B show another embodiment of a container according to the present invention. In this embodiment, the housing 2 is also enclosed by a stretch blow molded polyester casing 9. The shell comprises two parts 9A, 9B separated along a circumference, i.e. in the circumferential direction, of the shell 9, relatively close to the bottom of the shell, so that the top part of the shell is longer than the shell. Thus, the lower edge of the upper portion of the outer shell extends beyond the bottom of the housing and serves as a base or part of a base of the container. To further improve stability it is preferred that the wall is corrugated at the edge to increase its effective thickness and stiffness and/or that the wall is actually thicker than the wall of the cylindrical portion of the housing, preferably at least twice as thick.

The base 9B may be discarded or used to further increase the strength and stability of the base. In this example, the base portion has creased and radially extending segments to increase the rigidity of the base, thereby contributing to the stable upright position of the container and to provide a shatter-resistant zone protecting the container when it is dropped. More specifically, the base portion defines a petaloid base 12 and is positioned, e.g., pressed, inside the bottom end of the top portion of the housing. The base portion may be clamped, glued and/or welded into the top portion of the housing.

In the embodiment shown in fig. 6A and 6B, the base portion is inverted prior to being inserted into the bottom end of the top portion, thereby significantly increasing (e.g., doubling) the wall thickness at the lower edge of the housing. The center of the base is shaped to complement the bottom end of the housing, providing support over a relatively large area.

As is clear from fig. 5B and 6B, the cross-section of the upper edge of the base portion differs from the cross-section of the lower edge of the top portion of the housing both in diameter and shape. The housing is thus preferably formed with a transition between the two parts 9A, 9B, and the parts are each separated from the transition, for example by two (laser) cuts in the circumferential direction of the housing 9.

Figures 7A to 7C show a container according to the invention which is in most respects identical to that shown in figures 1A and 1B, but in which the housing 2 and the casing 9 have an L/D of approximately 1 and a relatively short cylindrical portion. The housing is significantly longer than the housing, preferably by a length corresponding to the length of the cylindrical portion of the housing. In other words, the length of the cylindrical portion of the housing is twice the length of the cylindrical portion of the housing. When the shell is separated along a circumference, i.e. in the circumferential direction and preferably in the middle of the height of the shell 9, the shell is clamped inside the upper half and the upper half now containing the shell is clamped in the lower half, the wall thickness of the shell doubling at the cylindrical part.

In addition, the container shown in fig. 7A-7C includes external threads or annular protrusions around the top opening for tightening or snapping, for example, a handle onto the container.

In the above example, the housing was blow molded from a preform similar to that used for the shell but with different edges. Also, the casing may be provided with one or more features providing additional functionality compared to the shell (which preferably should have a smooth shape defined by a cylinder and two domes in order to withstand internal pressure and avoid damage to the bag containing the beverage).

It has been found that the stretch blow molded polyester shell provides a relatively high residual strength of the container when the shell and the shell are pierced, thereby avoiding explosive bursting and enabling a more gradual ejection of pressurized gas inside the shell. Furthermore, the shell is water resistant and allows to achieve a design that is lighter and stronger compared to containers with cardboard shells. Due to the increased strength, the container according to the invention is in principle suitable for beverages containing a high gas concentration (e.g. 7 g/l carbon dioxide) at a relatively high temperature (e.g. 40 ℃).

In addition, since both the shell and the outer shell are stretch blow molded from a preform, logistics can be simplified, such as the ability to blow mold and assemble the containers in situ by supplying only preforms and bags to a brewery, avoiding bulky shipping.

The invention is not limited to the embodiments described above, which can be varied in a number of ways within the scope of the claims. For example, instead of a bag for containing a beverage, the container may be equipped with a spear extending from the valve portion towards the bottom of the housing.

Claims (16)

1. Container (1) for liquids such as beverages and oils, comprising: a blow moulded polyester casing (2), a valve (4) for dispensing liquid from the container, and an inlet for introducing a propellant, characterised in that the casing (2) is enclosed by a stretch blow moulded polyester casing (9).

2. Container (1) according to claim 1, wherein the outer shell (9) supports the casing (2) at least when it is pressurized.

3. Container (1) according to claim 1 or 2, wherein the outer shell (9) comprises two separate parts (9A, 9B), e.g. separated along a circumference of the outer shell, and at least one of the parts (9A) is clamp-mounted on the housing (2) when the housing is put under pressure.

4. Container (1) according to claim 3, wherein the remaining part (9B) is fastened in the open end of the part (9A) which is clip-mounted on the housing.

5. Container (1) according to claim 3 or 4, wherein the two parts overlap, preferably by at least 1 cm.

6. Container (1) according to any one of the preceding claims, wherein the burst strength of the container (1) is at least 20% higher, preferably at least 30% higher, compared to the burst strength of the housing (2).

7. Container (1) according to any one of the preceding claims, wherein the relative expansion of the container upon exposure to an internal pressure of 5 bar and 40 ℃ for 2 days is less than 3%, preferably less than 2%, more preferably less than 1.5%.

8. Container (1) according to any one of the preceding claims, wherein the housing (2) has an internal volume of at least 10 litres and wherein the aspect ratio (L/D) of the housing (2) is more than 1.5, preferably more than 2 and/or wherein the container (1) comprises a cylindrical portion (2A) extending over at least 25%, preferably at least 40%, more preferably at least 50% of the height of the container (1).

9. Container (1) according to any one of the preceding claims, wherein the wall thickness of the shell (2) in combination with the outer shell (9) is more than 0.8mm, preferably more than 1.0 mm.

10. Container (1) according to any one of the preceding claims, wherein the outer shell (9) is embossed around its circumference, thereby increasing the actual or at least effective thickness in radial direction.

11. Container (1) according to any one of the preceding claims, comprising a liquid-tight inner container (4) of a flexible material located inside the housing for containing the liquid and communicating with the valve (4).

12. Container (1) according to claim 11, wherein the housing (2) is impermeable for carbon dioxide, oxygen and/or nitrogen.

13. Container (1) according to any one of the preceding claims, wherein the housing (2) is pre-filled with a pressurized gas.

14. Container (1) according to any one of the preceding claims, wherein the polyester of the casing (2) and the outer shell (9) is polyethylene terephthalate (PET), preferably recycled polyethylene terephthalate (PET).

15. Container (1) according to any one of the preceding claims, wherein the housing (2) and the outer shell (9) are transparent.

16. Container (1) according to any one of the preceding claims, wherein the housing (9) comprises at least one blow-moulded handle (10) and/or a blow-moulded base (12).