CONTAINER FOR HOT-FILLING LIQUIDS

Abstract

The invention relates to a packaging means, hereinbelow also: container, which is suitable for the hot-filling of food products in liquid form. The container comprises an upper base of a metal or of a metal alloy having an opening for receiving the liquid and a lower base of a metal or an alloy having an air admission. The upper base and the lower base are sealingly connected with a wall body of a metal or an alloy at a respective upper or lower end of the wall body and form a hollow space for receiving the liquid. Between the lower base and the lower end of the wall body sealingly engaging the lower base, a film is provided which can cause a volume reduction of the hollow space.

Description

PRIORITY CLAIM

Applicants claim the priority of German Patent Application No. DE 10 2015 111 113.6, filed on Jul. 9, 2015.

FIELD OF THE INVENTION

The invention relates to a packaging means, hereafter also container, which is suitable for hot-filling of food products in liquid form.

TECHNICAL BACKGROUND

The filling or bottling of liquids, in particular in the field of food products, poses high requirements to the packaging and the packaging process, because producers of food products strive to protect their product from the premature spoilage. Liquids are commonly introduced into a container, in particular bottles, in a so called fill and seal process by means of a fill and seal machine in a predetermined amount and are then sealed. The embodiment of the fill and seal machine is dependent on the liquid to be filled.

In order to allow for microbiological hygiene during the filling of the liquids so called aseptic filling machines can be employed. Aseptic filling machines are filling machines which fill sterile charge protected against a re-contamination into a packaging material which is usually pre-germinated or produced free of germs within the packaging machine (cf.: VDMA 8742, “Aspetische Verpackungsmaschinen für die Nahrungsmittelindustrie: Mindestanforderungen und Rahmenbedingungen für einen bestimmungsgemäβen Betrieb” (“Aseptic packaging machines for the food product industrie: Minimum requirements and border conditions for a compliant operation”), available at http://www.vdma.org).

Alternatively, filling systems for the hot-filling of food product can be used, in which the food product (liquid) is filled into the packaging means at temperatures of usually more than 80° C., wherein the microbiological hygiene can be ensured due to the high filling in temperature of the food product. The invention proposes a container which is in particular suitable for the hot-filling of food products, in particular of liquids.

In order to avoid the spoilage of the hot-filled food products as long as possible, it is also required to seal the packaging means after filling under hygienic border conditions such that no germs or mold fungi can get into the inside of the packaging. Therefore, gas-tight closures are mostly selected, which prevent not only the penetration of germs or fungi but also of gases, in particular oxygen, into the packaging inside and/or the exiting of gases (such as CO₂) from the packaging interior. When using containers which at least predominantly consist of metal (or a metal alloy), after closing the container, the volume reduction of the hot filled food product due to the cooling of the liquid leads to hydrostatic forces within the container which cause tensile forces in the upper base, the lower base and the wall body of the container which, dependent on the shape of the container lead to deformation of the container.

In particular for containers having a cylindrical base shape, due to deviations in the material of the wall body (for example in the thickness) the tensile forces cause usually local dents which are nevertheless very noticeable to the observer and greatly impair the aesthetic appearance of the container shape. Since the aesthetic appearance nowadays plays a very important role for the product purchase through the end-customer, it is desirable to avoid such deformations which impair the aesthetic appearance of the container.

SUMMARY OF THE INVENTION

It is therefore an objective of the invention to propose a container having a wall body (and optionally also a lower base and/or upper base) of metal (or a metal alloy) which does not go out of shape due to acting tensile forces after hot-filling and gas-tight sealing of the container, so that the aesthetic appearance of the container shape remains intact. Furthermore it is another objective of the invention to provide a particularly simple and/or inexpensive design of such a container.

It is another partial objective of the invention to design the container and in particular the closure such that changes in taste through contact of the metal constituents with the filled liquid are inhibited.

An aspect underlying the invention is the use of a film or foil, which is attached for example between the lower base and the lower end of the wall body of the container, sealingly engaging the lower base of the container. The film is selected with regard to its material properties such that it can cause a volume reduction of the container interior when the external pressure of the container (for example the atmospheric pressure) is larger than the pressure within the container interior.

In an embodiment of the invention, the film can decrease the volume in the container interior such that after hot-filling a liquid into the container and after the air-tight (or gas-tight) sealing or closing thereof, the compression forces occurring due to the subsequent cooling of liquid are absorbed. The absorption of the compression forces leads to deformation only of the film causing the volume reduction of the container interior. Thereby it can be ensured that the wall body forming the side wall of the container is not deformed through the tensile forces acting thereon in a manner which impairs the aesthetic appearance thereof.

According to one embodiment of the invention, a container for receiving a liquid is provided. The container comprises an upper base made of a metal or of a metal alloy. The upper base can also be called first base, top end or upperside. The upper base has an opening for receiving the liquid. The filling, in particular the hot-filling, of the liquid into the container may be performed by (hot-) filling the liquid through the opening of the upper base into the container. The container further comprises a lower base, which can also be called second base, bottom end, or underside. The lower base may be made of a metal or a metal alloy. The lower base has an air admission or air passage, which for example can be realized by one or more holes which are large enough to let air pass through. The upper base and the lower base are connected with a wall body made of a metal or of a metal alloy at a respective upper or lower end of the wall body so that a hollow space for receiving the liquid is formed. This hollow space for receiving the liquid is hereafter also referred to as a container interior. The wall body can also be referred to as side wall of the container or container sidewall. Between the lower base and the lower end of the wall body sealingly engaging with the lower base, furthermore, a film is provided which can cause a volume reduction of the hollow space. The intermediate space between the film deformed for volume reduction and the lower base of the container shall not contain the liquid to be received by the container and is therefore not part of the hollow space.

In an exemplary embodiment of the invention, the wall body (and optionally the upper base and/or the lower base) are deformation-rigid in relation to the film. In particular, the material of the wall body, the upper base and/or the lower base can to this end have a modulus of elasticity which is at least 5 times, preferably at least 10 times, further preferred at least 100 times, as large as of the modulus of elasticity of the film material.

In an exemplary embodiment of the invention, the film absorbs the compression forces caused by cooling of the hot-filled liquid after air-tight sealing of the opening. It it can thus be possible that the film completely absorbs the compression forces caused during the cooling of the liquid (insofar as possible). Ideally, the material of the film, in comparison to the material of the wall body (and optionally of the upper base and/or of the lower base), is selected such that the film compensates the compression forces such that the outer shape of the wall body of the container does not visibly (for a human observer) deform during cooling of the hot-filled liquid due to tensile forces.

The wall body of the container is in one embodiment formed as a hollow cylinder. The cylinder edges are sealingly connected with the lower base and to the upper base. The material properties of the film are laid out such that the film advantageously absorbs the compression forces so (completely) that the cylindrical shape of the wall body is maintained after cooling of the liquid.

In a further embodiment, the film is sealingly connected with the lower base and to the wall body through a seam, in particular through a roll seam. In another embodiment, the film is sealingly connected with the lower end of the wall body by means of a flange, which could also be called raised edge or flared tube end. Optionally, a sealing adhesive can be inserted into the seam or flange. In a further embodiment, the film is connected with the lower base by means of an adhesion-connection, by sealing or through a form-fitting-(positive-locking fit) connection.

In a further embodiment, the upper base is sealingly connected with the wall body through a seam, in particular a roll seam, or a flange.

The opening in the upper base can, in accordance with a further exemplary embodiment of the invention, be realized as a screwing funnel having a screw thread for a screw cap or a cam screw cap. In this case, only the screwing funnel or the upper base including the screwing funnel can consist for example of aluminum (or an aluminum alloy). In a further embodiment, the container comprises a screwing- or cam-screw-connection made of a metal. The screwing- or cam-screw-connection can for example (also) consist of aluminum (or of an aluminum alloy). Optionally, the screwing- or cam-screw-connection can be coated or lacquered with a bisphenol A (BPA)-free lacquer at least on those surfaces which, after filling, may come into contact with the liquid.

The cap or closure can comprise an inlying seal, for example made of a polymer. The polymer should be selected such that it does not liquefy or otherwise to decompose and contaminate the filled liquid at filling-temperatures of about 80° C. or more.

The container can for example be closable with a crown cork instead of a screwing- or cam-screw-closure. Generally and in particular when sealing the container with a crown cork, the opening can be reinforced at its top edge.

In a further embodiment, the lower base and/or the wall body comprises a sheet metal, in particular tinplate. In a further embodiment, the upper base at least partially comprises a sheet metal, in particular tinplate. In more general terms, the wall body and optionally the upper base and/or the lower base can contain iron and in particular be a steel, preferably a stainless high-grade-steel.

In a further embodiment of the invention, the relation of the film thickness and the thickness of the sheet is at least 1.5:1 and preferably 2:1.

In a further embodiment, the surfaces of the upper base and/or of the wall body made of tinplate which are, after filling, in contact with the liquid, are provided with a BPA-free coating. It can furthermore be advantageous if at least the junctions or interfaces of the upper base and/or of the wall body are provided with a BPA-free powder seam cover. The coating can for example be realized with a BPA-free powder coating.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is described on the basis of embodiments that refer to the attached figures. Corresponding components of the details in the figures are provided with the same reference numerals.

FIG. 1 shows a section view (cf. line E in FIG. 6) of a container according to one embodiment of the invention;

FIG. 2 shows a further sectional view (cf. FIG. 6) of the container according to FIG. 1, wherein, however, the film 16 extends dome-like into the inner space of the container;

FIG. 3 shows a magnified view of detail A of FIG. 2;

FIG. 4 shows a magnified view of detail B of FIG. 1;

FIG. 5 shows a magnified view of detail C of FIG. 2;

FIG. 6 shows a view on the lower base of the container according to one embodiment of the invention;

FIG. 7 shows a view onto the lower base of the container according to another embodiment of the invention;

FIG. 8 shows a perspective view of the container according to one embodiment of the invention;

FIG. 9 shows a sectional view (cf. Line E in FIG. 6) of a container according to a further embodiment of the invention;

FIG. 10 shows a view of a octagonal lower base of a container according to another embodiment of the invention;

FIG. 11 shows a perspective view of the octagonal container;

FIG. 12 shows a view of an oval lower base of a container according to another embodiment of the invention; and

FIG. 13 shows a perspective view of the oval container.

DETAILED DESCRIPTION

The invention relates to a container suitable for hot-filling of food products in liquid form. In embodiments of the invention, the container is made of metal or of a metal alloy. An exemplary container according to one such embodiment of the invention is shown in a perspective view in FIG. 8. The container shown therein is designed in bottle-shape. The shape of the container is essentially defined by its lower base 11, its upper base 12 and a wall body 13 forming a side wall, which in this embodiment is designed as a hollow cylinder (cf. FIG. 6 and the sectional view in FIG. 1 along the section-line E indicated in FIG. 4). The lower base 11 and the upper base 12 are in this embodiment correspondingly formed circularly. Furthermore, the container also comprises a film 16 provided between the lower base 11 and the lower end of the sidewall 13. The terms “upper” and “lower” as used herein can refer to the preferred position of the respective components of the container, particularly in an upright position in which (only) the lower base 11 is in contact with a ground on which container stands (for example when the container is filled with a liquid), such that the opening 14 for receiving and/or dispensing the liquid faces upwards (and so that no liquid is lost in this position).

The lower base 11 consists of a metal (or a metal alloy) the lower base comprises an air admission or passage 41 which,—as will be explained in detail below—allows replenishing flow of (surrounding) air when the film 16 deforms in order to realize a volume reduction of the bottle interior.

The upper base 12 also consists of a metal (or of a metal alloy). The upper base 12 comprises an opening for receiving the fluid. The opening 14 of the upper base 12 is arranged axially centric (cf. also FIG. 6). Naturally, it is also possible not to arrange the opening of the container centrally, for example offset towards the edge of the upper base 12.

The upper base 12 is realized funnel-shaped in the shown embodiment and can thus also be called a funnel. The opening 14 of the upper base 12 can for example be formed as a screwing-funnel having a thread 15 and a screwing- or cam-screw-closure 81. The closure or cap 81 is an optional element of the container. A thread for closing or sealing the container is not necessarily required. For example, the container can alternatively also be closed with a crown cork or with a swing top (also referred to as flip top). In particular when closing the container with a crown cork it is reasonable to provide a reinforcement at the upper edge or end of the opening 14.

The upper base 12 and the lower base 11 are sealingly connected at their respective end area with the outside wall 13 of the container, which is in this embodiment cylindrical, so that the hollow space is formed into which for example a liquid can be filled. The container is therefore formed single-walled and the inserted or filled liquid is situated in a direct contact with the side wall 13 (i.e.: at least parts of the sidewall 13).

Between the lower base 11 and lower end of the sidewall of 13, sealingly engaging the lower base 11, a film 16 is provided. The film 16 can cause a volume reduction of the hollow space, as exemplarily shown in FIG. 2. When the bottle is sealed gas-tight, for example after hot-filling the container with the liquid, differences between the pressure within the hollow space of the container and the atmospheric pressure outside of the container can be balanced through a corresponding deformation of the film 16, causing a volume reduction of the inner space of the container. For example after hot-filling of the container with a liquid, and after closing the container in a state with a still hot liquid, and subsequent cooling of the liquid, an under pressure can occur in the inside of the container. The volume reduction required for pressure-compensation between the atmospheric pressure of the interior pressure of the container can be realized with the aid of the film 16. The film 16 absorbs the arising tensile forces and deform relative to the lower base 11 towards the interior of the hollow space of the container in a dome- or cupola-like manner, as for example shown in FIG. 2. In other terms, the difference between the interior pressure of the container and the atmospheric exterior pressure is compensated through deforming the film 16 due to the pressure-force resulting from the pressure-difference (elastically and/or plastically) such that an effective decrease of the volume of the container interior occurs. The compression of the liquid following its cooling thus causes a corresponding size reduction of the volume of the container interior due to the deformation of the film. In this way it is avoided that a visible deformation of the sidewall 13 and/or of the upper base 12 occurs by avoiding the occurrence of pressure forces acting on to the sidewall 13 and onto the upper base 12 which achieve a magnitude sufficient for their respective deformation.

In order to ensure that the required volume reduction is significantly achieved through the deformation of the film 16 and in particular that the sidewall 13 remains in its cylindrical basic shape, the material of the sidewall 13 is for example to be selected such that it is deformation-rigid in contrast to the material of the film 16. The lower base 11 comprises in the embodiment a centrally formed air admission 41 (cf. FIG. 4) through which, during the deformation of the film 16 towards the inside of the container, air can flow into the forming intermediate space 21 between the lower base 11 and the film 16.

In one embodiment, the sidewall (wall body) 13 is formed of a sheet metal, in particular of a tinplate. The film 16 can also be made of a metal (or of a metal alloy) however, also other material can be considered, such as polymers. For example, the film 16 can also consist of a polycarbonate, such as polyester. Since the film 16 is in contact with the liquid after hot-filling the container, it is important that no chemical reaction occurs between the material of the film 16 and the liquid changing the taste of the food product within the container. This is of importance in particular for the filling of sugar-containing food products, in particular syrup (such as maple syrup) since it has been shown that sheets (tinplate) in direct contact with sugar-containing syrup (in particular maple syrup) experience chemical reactions and that this results in detrimental changes of the taste of the food product.

In an advantageous embodiment, the film 16 is made of aluminum (or an aluminum alloy). It has been shown in experiments that, when aluminum is used, no change of the taste can be noticed of the maple syrup which has been filled into the container. Accordingly, it is reasonable also to make the upper base 12 from aluminum (or an aluminum alloy). It is also, optionally, possible to make the sidewall 13 of aluminum (or an aluminum alloy). For example, the mentioned aluminum can be pure aluminum (i.e. the film consists to at least 98% of aluminum).

When also the sidewall 13 consists of aluminum (or an aluminum alloy) this significantly increases the production costs of the container, so that the complete cost of the container may no longer be competitive. Therefore, in another embodiment of the invention, the sidewall 13 is made of a single piece of drawn sheet metal, in particular tinplate. Surfaces of the wall body which can come into contact with the filled liquid can be lacquered or coated. This is reasonable in particular if it otherwise comes to a chemical reaction between the liquid of the wall body and if such a reaction can be avoided with use of this measure. Advantageously, a BPA-free lacquer or a BPA-free coating is used for lacquering or coating.

Fundamentally, it is also possible that any surfaces of the upper base 12 and the lower base 11 which are in touch with the liquid after filling are also provided with a BPA-free coating. The coating can for example be a BPA-free powder coating.

The seams of the upper base 12 and/or of the wall body 13, which are in contact with the liquid after filling, can optionally be provided with a powder seam cover.

FIG. 3 shows the detail magnification A of FIG. 2. As shown in FIG. 3, the film 16 can for example be fastened between the lower base 11 sidewall 13 of the cylindrical hollow body of the container. Preferably, the three layers, that is: the lower end of the hollow body of the sidewall 13, the film 16, and the edge section of the lower base 11, are sealingly connected with one another through a seam, in particular a roll seam. Alternatively it is also possible to sealingly connect the 3 layers with one another through a flange. Optionally, a sealing adhesive can be used in the contact area of the sidewall 13 of the film 16 and of the lower base 11 for both the seam as well as the flange. Thereby it should be ensured that the sealing adhesive does not extend between the film 16 and the inside of the wall 13 towards the container interior so that it does not come into contact with the filled-in liquid.

FIG. 4 shows a detail magnification of FIG. 1. In the original (non-deformed) state of the film 16, the film 16 lies engaging on the lower base 11, wherein, for example centrally or axially centered, one air passage 41 is provided in the lower base.

FIG. 5 shows a detail magnification of detail C in FIG. 2. As apparent from FIG. 5, due to a deformation of the film 16 through the air passage 41 (surrounding-) air can flow into the arising hollow space 21 between the film 16 and the lower base, so that the atmospheric outside pressure of the container also prevails in the intermediate space 21 and no underpressure is created in the intermediate space 21.

FIG. 6 shows a cross-section of the container of FIG. 1 along the section line D shown therein, wherein the film 16 is not illustrated. In the shown embodiment, the air passage 41 is arranged centrally in the lower base 11. The air passage can, however, also be arranged at another position, as long as it is ascertained, that the (surrounding) air can keep streaming through the air passage 41 into the space 21 which is formed during deformation of the film 16 between the lower base 11 and the film 16. It is also possible to provide multiple air passages in the lower base 11. FIG. 7 shows an exemplary further embodiment of the lower base 11 comprising 5 air passages 41a-41e. The air passage or the air passages, respectively, 41 can for example be realized by drilling, stamping, or the like.

Alternative to the solution shown in FIG. 4, the film seam could also be connected with the lower base 11 through an adhesive connection or through sealing. In these alternatives, the shape and/or area of the film 16 does not need to be equal to the shape or area of the lower base 11. The film 16 could for example be designed smaller. One example is shown in FIG. 9, in which a circular film 16 has a smaller base area than the lower base 11 and is adhered along its circumference in an area 92. In case the container is intended for hot-filling, the melting point of the (hardened) adhesive 91 should lie above the filling temperature of the liquid so as to avoid melting of the adhesive 91.

A further possibility lies in connecting the film 16 to the lower base 11 to be form-fitted.

The shape of the container is not limited to a cylindrical wall body 13 and correspondingly formed lower base 11 and upper base 12. FIG. 10 and FIG. 11 show further embodiments of the container having an octagonal lower base 101, and octagonal upper base 102, and a corresponding octagonal cylinder sidewall 103. A further possible embodiment of the container is shown in FIGS. 12 and 13. The container shown therein comprises an oval (elliptic) lower base 121, an oval upper base 122 and, and a corresponding oval cylinder is a sidewall 123.

As illustrated in FIGS. 11 and 13, the opening 14 can also in these embodiments comprise a thread 15. The opening 14 can also, as in the previous embodiments, for example be closed with a screw- or cam-screw-closure 81. The provision of a thread 15 for closing the container with a screw- or cam-screw-81 is not mandatorily required. For example, the container as shown in FIGS. 11 and 13 could alternatively be closed with a crown-cork or flip-top (also referred to as a spring-top). In such cases it is possible to reinforce the opening or aperture 14 of the container.

A further aspect of the invention further relates to a filling method, in which the container according to the invention is hot-filled with the liquid, in particular with a food product in liquid or viscous form/state, for example through the funnel and/or the opening in the upper base. The food product can for example be a highly sugar-containing food product, such as a syrup (for example maple syrup). During hot filling, the container according to the invention is filled with the hot liquid. The liquid had for example a temperature of at least 80° C. In another example, the filling temperature lies between 80° C. and 100° C., or between 85° C. and 90° C.

During filling of the container, hot liquid does not need to be foamed with water or water-steam before closing the container, nor does an inert gas (shielding gas) have to be inserted between the upper rim of the opening 14 and the surface of the liquid, so that the container is particularly suitable for the use in a simple fill and seal method with a simply constructed fill and seal machine.

Claims

1. A container for receiving a liquid, wherein the container comprises: an upper base made of a metal or an alloy having an opening for receiving the liquid;a lower base made of a metal or an alloy having an air admission, wherein the upper base and the lower base are sealingly connected with a wall body at the upper end and the lower end of the wall body, respectively, to form a hollow space for receiving the liquid, said wall body being made of a metal or an alloy; and,a film that can realize a volume reduction of the hollow space is provided between the lower base and the lower end of the wall body that is sealingly in contact with the lower base.

2. A container according to claim 1, wherein the wall body and optionally the upper base and/or the lower base are deformation-resistant in relation to the film.

3. A container according to claim 1, wherein the film compensates compression forces such that the outer shape of the wall body of the container does not deform due to tensile forces during cooling of a hot-filled liquid.

4. A container according to claim 1, wherein the film compensates compression forces such that the outer shape of the entire container does not deform due to tensile forces during cooling of the hot-filled liquid.

5. A container according to one of the claim 1, wherein the wall body is realized as a hollow cylinder.

6. A container according to claim 5, wherein the material properties of the film absorb the compression forces so entirely that the cylindrical shape of the wall body remains intact after cooling of the liquid.

7. A container according to claim 1, wherein the film together with the lower base and the wall body are sealingly connected with one another through a seam, in particular a roll seam.

8. A container according to claim 1, wherein the film together with the lower base and the wall body are sealingly connected with one another through a flange.

9. A container according to claim 7, wherein a sealing adhesive is inserted into the seam.

10. A container according to claim 1, wherein the film is connected with the lower base by means of an adhesive connection, by sealing or through a positive-locking fit connection.

11. A container according to claim 1, wherein the upper base is sealingly connected with the wall body through a seam, in particular a roll seam, or a flange.

12. A container according to claim 1, wherein the opening is realized as a screwing funnel having screw threads for a screw cap or a cam screw cap.

13. A container according to claim 12, wherein only the screwing funnel or the upper base including the screwing funnel consist of aluminum or an aluminum alloy.

14. A container according to claim 12, further comprising a screw cap or cam screw cap including an inlying seal, said screw cap or cam screw cap made of metal, optionally of aluminum or an aluminum alloy, and further wherein the screw cap or cam screw cap is coated with a BPA-free lacquer at least on the surfaces which can come into contact with the liquid after filling.

15. (canceled)

16. (canceled)

17. A container according to claim 1, wherein the container further comprises a swing top.

18. A container according to claim 1, wherein the opening is reinforced at the upper end thereof.

19. (canceled)

20. A container according to claim 1, wherein the lower base, the wall body, and at least a portion of the upper base, are made of a sheet metal, in particular tinplate, and the relation between the thickness of the film and the thickness of the sheet metal is at least 1.5:1 and preferably 2:1.

21. (canceled)

22. (canceled)

23. (canceled)

24. A container according to claim 1, wherein the surfaces of the upper base and of the wall body which after filling are in contact with the liquid are made of tinplate and are provided with a BPA-free coating.

25. A container according to claim 1, wherein at least the junctions of the upper base and of the wall body which are in contact with the liquid after filling are provided with a BPA-free powder seam cover, optionally a BPA-free powder coating.

26. (canceled)

27. A container according to claim 1, wherein the wall body and optionally the upper base and/or the lower base comprise iron and are in particular a steel.

28. A container according to claim 8, wherein a sealing adhesive is inserted into the flange.