BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to the manufacturing of packages and in particular to the manufacturing of packages for powdered nutritional products such as infant nutrition or milk formula. The invention also relates to such a package.

Description of the Related Art

Powdered material, such as infant milk formula, has been sold in various forms of package for many years. Metal cans were initially the preferred container as they were relatively easy and cheap to produce and could be sealed for long term storage. The seal comprised an aluminium foil across the mouth of the container that was removed on first use. As a single container would be used for an extended period, the containers were provided with re-closable plastic lids which gripped over the outer rim of the metal can. A measuring scoop was frequently included with the container, either packaged separately or within the can itself. Such cans are however relatively heavy and expensive to produce.

More recently, alternative packaging forms have become available which improve on the existing cans. These include laminate container bodies and plastic hinged lid and rim structures, which may be glued to the container body. One such package is described in US 2008041861, having a seal for initially closing the package and a space between the seal and an upper edge of the container for partially receiving the scoop prior to use. The container part may consist of a laminate of carton, metal foil and plastic material. A further similar package is shown in WO2010071424. A disadvantage of composite packages is that they may be difficult to recycle. Proposals for multi-component packages have been made that allow disassembly for separate recycling but until the present, suitable manufacturing processes capable of achieving such packages have been absent.

It has been known to manufacture multi-component packages by providing a carton around a thermoformed containers prior to filling the container, for example by the use of a mandrel to support the container and form the carton around the container or by using a mould to support the carton prior to lining the carton with a thermoformed container. A disadvantage of such multi-component packages it that this way of manufacturing is undesirable for high-care products, such as infant formula.

In the light of these requirements, it would be desirable to provide a package capable of being assembled in a manufacturing process that can be disassembled for recycling purposes. It would also be desirable to provide a method by which such a package could be manufactured.

BRIEF SUMMARY OF THE INVENTION

According to the invention, there is provided a method of manufacturing and filling a package with a powdered nutritional product, the method comprising:

a) providing a thermoformed tub having sidewalls and a base defining a product receiving space, filling the product receiving space with the powdered nutritional product, and sealing a membrane across an open mouth of the tub to seal the product therein;

b) folding a carton blank with a plurality of panels around the filled tub to form a carton sleeve, wherein the carton sleeve comprises a peripheral wall enclosing at least the sidewalls of the tub.

If both parts of the packaging are manufactured separately both the inner tub and the outer sleeve will have dimensions that fall within tolerances. As the sleeve is slid over the inner tub, the sleeve will have to be able to receive even the largest inner tub within these tolerances. This may lead to a relatively small inner tub in a relatively large sleeve, such that the sleeve does not give as much support to the inner tub as desired. Additionally, the finish of such a combination of a relatively large sleeve and a small tub is unsightly, due to the gaps that appear along the edges and at the corners.

Folding the carton blank around the filled tub has the advantage that a sleeve formed from the carton blank engagingly encloses the thermoformed tub independent of the outer dimensions of the thermoformed tub. By folding the carton blank around the filled inner tub, the sleeve fittingly encloses the inner tub leading to a more acceptable final product. Additionally, the close fit between these two components provides maximum support to the inner tub, which is particularly important in the case of tubs having relatively thin walls.

Additionally, mandrels or male moulds to hold the thermoformed tub in shape can be omitted due to the form retention of the thermoformed tub by the powdered nutritional product. Adding mandrels or male moulds to a manufacturing machine is costly. Moreover, the thermoformed tub has inner dimensions falling within tolerances and even the smallest of the thermoformed tubs should fit over the male mould. This may lead to less support by the male mould in case of a relatively large thermoformed tub, such that the mould cannot give the support desired while folding the carton blank around the tub. More importantly, it is only possible to use a mandrel within the tub prior to filling. As will be described further below, for processes where filling takes place under high-care conditions, it may not be desirable for the carton sleeve to enter into the high-care zone and it is thus excluded that a mandrel based assembly be used.

According to a surprising effect of the present invention, it is believed that improved shape retention and support during folding the carton blank around the tub may be achieved due to the fact that the tub is filled with a powdered nutritional product, such as baby formula or infant nutrition. Powdered products such as baby formula or other powdered milk products tend to have higher resistance to deformation due to the flow properties of the powder, i.e. they may compress to a denser state or consolidate rather than flow out upon application of an external pressure , contrary to fluids. The consolidated product then can act as a shape retainer while folding the carton blank around the filled tub. This resistance to deformation results in a pressure force against the inner wall of the tub, thereby supporting the tub and retaining its shape. For other products such as liquids or granulated products, the content may not provide adequate resistance during a folding process and the resulting product may be less than adequate.

The bulk density of the powdered nutritional product may be between 0.4 and 0.7 g/ml, preferably between 0.45 and 0.6 g/ml.

According to the present method, the tub is filled with the powdered material prior to folding the carton sleeve around the tub and the product thus provides additional support to the peripheral wall of the tub. Additionally, the contents of the tub can exert an outward counter-force on the sleeve during the folding operation, thereby promoting the attachment between the tub and the sleeve. In addition, the membrane is provided over the top edge of the tub before folding the sleeve around the tub to give extra support to the tub and to protect the product from the environmental atmosphere. With the method according to the invention, it is believed that mandrel-less assembly of a multi-component package is achieved, while being able to maintain the high-care standards for the nutritional product.

The membrane seal may comprise a metal foil or may be a plastics-only foil. It may be removed in its entirety prior to use or may comprises a weakened tear line defining an opening region, and a pull tab. The membrane may be provided at various locations but most preferably, the membrane is sealed across the upper edge of the container. In particular, it will be understood that thermoformed tubs generally have an outwardly extending flange forming the upper edge and the membrane may be sealed across the flange. In an alternative embodiment, the membrane may be sealed to the lower frame to close the opening. In that case, the skilled person will understand that the connection between the lower frame and the upper edge of the container must be a sealed connection.

Preferably, the carton blank comprises a bottom panel and side wall panels and wherein, after folding the carton blank to a sleeve, the sleeve encloses the sidewalls and at least a part of the base of the tub. Such a sleeve provides additional support to the base of the thermoformed tub. More preferably, the carton blank is formed as a single piece blank with a plurality of panels.

The composite package can benefit from improved strength and the carton sleeve can be easily printed. Because the sleeve is added at a late stage in the production cycle, the sleeve design or language may be changed, even after the tub has been filled. For recycling, the sleeve and tub can be separated and disposed of as required.

According to another embodiment, step b) further comprises gluing the panels to the tub after folding towards the tub. Preferably, step b) further comprises gluing the bottom panel to the base of the tub. Connecting the panels of the sleeve to the tub ensures that the sleeve and the tub support each other. Additionally, the sleeve is formed from the carton blank and covers an outer surface of the tub in this way.

Preferably, step b) further comprises connecting the panels to each other after folding towards the tub, preferably by gluing. Preferably, the blank has the shape of a cross defining a base and four side panels. The side panels may be provided with lobes or tabs that engage with each other and may be glued or otherwise adhered together.

Preferably, step b) further comprises centering the carton blank and the thermoformed tub with respect to each other. Additionally, step b) may comprise gripping the tub at the lid assembly for transportation and to have free access to both the peripheral wall and the base of the tub. The carton blank may then be connected at the bottom panel to the base of the tub by an adhesive, such as glue. According to an embodiment, the side panels are folded towards the tub in pairs of opposite side panels. Preferably, the side panels provided with tabs are folded first towards the tub, after which the remaining side panels are folded towards the tub. The tabs are preferably provided at the side panels of the blank covering relatively longer side walls of the tub. In this embodiment, folding the side panels covering relatively shorter side walls of the tub over and connecting to the tabs provides more strength to the package. Furthermore, it is preferred that the tabs have such a length that they do not overlap each other upon folding around or onto the tub.

According to a further embodiment, step b) comprises applying a lateral displacement to the side panels to bring them into engagement with the sidewalls of the tub after folding towards the sidewalls of the tub. To firmly connect the side panels of the sleeve to the tub, a laterally applied force to press the side panels on the outer surface of the inner tub may be used. Pressure may be applied at regions at which glue has been applied in order to cause adhesion at these points. Preferably, pressure is applied at a centre of the side panels of the sleeve, close to an upper edge thereof.

In a preferred embodiment, step b) further comprises providing the carton blank from a carton blank magazine holding multiple carton blanks. The filled and sealed thermoformed tub is provided from the filling and sealing machines to the assembly line by a carrier device. The carton blank is then provided separately, preferably from a carton blank magazine or cartridge holding multiple carton blanks to allow a continuous assembly of the packages.

In a preferred embodiment of the method, step a) may further comprise fitting a lower rim to an upper edge of the tub. This rim may advantageously assist in strengthening the otherwise relatively thin thermoformed tub. The lower rim is preferably adhered or welded on top of the membrane seal although it is not excluded that it may be connected to the upper edge of the tub directly before applying the membrane. The lower rim is preferably formed of the same class of material as the tub such that both may be recycled together. According to an important aspect of the invention, the step of applying the lower rim may further comprise centering the tub with respect to the lower rim prior to connection. In this manner, the lower rim may subsequently serve as a guide for further operations on the tub. In a further preferred embodiment of the invention, step a) further comprises fitting a lid assembly to the tub, the lid assembly comprising an upper rim and a recloseable lid. The upper rim is preferably circumferential, defining an access opening and the lid can be hingedly attached to the upper rim for closing the access opening. This allows the tub to be opened by a user by removal of the membrane seal and subsequently opened and resealed using the lid to close the access opening. A catch on the front edge of the lid can engage with a rib on the upper frame to maintain the lid closed. The lid can comprise a support surface at an outside of the lid assembly to support a base of another package thereon upon stacking of the packages.

In a most preferred embodiment, the upper rim and the lower rim are

mechanically connected together in an interference fit. The lower rim thus has the function of strengthening the upper edge of the tub allowing the upper rim and lid to be effectively connected thereto.

Of significant importance, for powdered nutritional products and especially for infant nutrition, all elements of the package that come into contact with the product must be manufactured according to strict norms. To address this need, certain manufacturing steps are preferably carried out in a high-care environment. Additional components such as scoops and the lid or closure are also manufactured according to the same standards if they are to come into contact with the product. According to one important aspect of the invention, step a) may take place in a high-care zone. In this context, it is understood that all of the individual actions included in step a) should take place within this high-care zone. Thus the package is filled and sealed and all element surfaces coming into contact with the powdered nutritional product are only exposed to the high-care zone.

For the purpose of the present invention, high-care is intended to denote that the environment is at an over pressure with respect to atmospheric pressure, preferably an overpressure of between 5 Pa and 50 Pa, more preferably an overpressure of between 5 Pa and 30 Pa, most preferably between 5 Pa and 20 Pa. The temperature in the high- care zone is preferably kept between 18 °C and 25 °C, more preferably between 19 °C and 23°C and the relative humidity is preferably controlled between 20% RH and 80% RH, more preferably between 30% RH and 60% RH, most preferably between 35% RH and 50%) RH. Also, the atmosphere within the high-care environment is preferably filtered to remove particulates, such as with a HEPA (High-efficiency particulate absorption) filter including a H10 filter or higher according to EN 1822:2009.

Preferably, all components entering into contact with the product are cleaned by sterile, ionized air jet and checked with a vision system for imperfections or foreign bodies.

Furthermore, the package is filled in a low-oxygen atmosphere. This may include flushing with nitrogen and/or carbon dioxide before and during the filling procedure and prior to applying the membrane. Nevertheless, the skilled person will understood that other criteria may be applied to this zone if required e.g. by local regulations. Using a low-oxygen atmosphere, in particular a carbon dioxide atmosphere, during filling has the advantage that the powdered material is relatively dry compared to ambient atmosphere. Furthermore, after filling, certain powders absorb the carbon dioxide causing a slight underpressure in the package. Therefore the powder can be consolidated even further than under ambient atmosphere, such that the form retaining function of the contents of the tub is enhanced.

As bloating of food comprising container is generally associated with spoilage of the contained food, such an impression is preferably avoided as much as possible. Due to the relatively thin thermoformed tub, the package of the present invention may be more sensitive to a bloated appearance than containers made of thicker, more rigid plastic, e.g. formed by injection moulding. Thicker, more rigid plastic walls are less susceptible to the force exerted by the content of the containers than the relatively thin thermoformed peripheral wall of the tub. It is therefore preferred that the thermoformed tub is filled with powdered material having a particular temperature. This may be of particular importance in case the finished package contains infant formula or food since such shelf-stable products are placed under less conditioned circumstances on the shelf in stores in contrast to packages containing fresh products such as yoghurt. Thus, in a preferred embodiment, the powdered nutritional product has a temperature between 10 to 30°C, more preferably between 15 to 25°C when the tub is filled therewith.

Preferably, a scoop is provided within the package and may be located above the membrane seal prior to use. It is also conceivable that a scoop is integrally formed with the lid construction and separated at first use. In either case, the scoop is preferably also included within the package in step a) and may therefore also be handled exclusively in the high-care zone.

In a preferred embodiment, the scoop is positioned above the membrane seal when the sleeve is folded around the tub, whereby a distance between the scoop and the membrane seal is limited to less than 4 mm, preferably less than 3 mm, most preferably less than 2 mm. Limiting the distance between the spoon and the membrane seal, i.e. limiting excess space in the package, is beneficial for reducing plastic waste.

A further important point in defining the actions carried out in the high-care zone is to specify that step b) takes place outside the high-care zone. These actions may thus be characterised as ones that may not be permitted within the high-care zone. In particular, carton handling may be associated with considerable process debris and should be kept separate from the actions taking place in step a). For the purpose of the present invention, low-care is intended to denote that the environment thereof is kept at ambient conditions. This includes ambient pressure, meaning no overpressure situation is created. Furthermore, the temperature in the low-care zone is preferably less strictly controlled compared to the high-care conditions, meaning that the temperature in the low-care can be between 12 °C and 30°C, more preferably 15 °C and 26°C. Particulate filtration may be installed in the low-care area or installed for flow of air into the low- care zone but FIEPA filtration is preferably not implemented to save costs

It will be understood that the gluing can be a construction step in erecting the carton blank and/or an assembly step in joining the tub to the sleeve. Preferably the connection between the tub and the sleeve can easily be broken to allow for disassembly on recycling of the package after use. The glue is preferably a hot-melt adhesive and is applied at locations on the inner surface of the carton blank and/or on the outer surface of the inner tub before folding the respective panels towards the filled thermoformed tub.

According to a still further aspect of the invention, the tub is a pre-formed, size- stabilised tub of thermoplastic material. In the present context, pre-formed is understood to require that the tub has been formed at least 24 hours and preferably at least 48 hours prior to filling. This allows for residual stresses within the tub, due to the thermoforming process, to be relaxed.

The invention is particularly applicable to thin-walled tubs and in particular to tubs defining a single compartment. Such tubs may be relatively inexpensive due to the use of minimal amounts of plastics. Additional strength is provided by the carton sleeve. Preferably, the tub has a wall thickness of about 0.10 mm to 0.50 mm, preferably between 0.15 and 0.40 mm. It will be understood by the skilled person that, due to the thermoforming process, the wall thickness may not be uniform over the whole tub. In particular, the upper edge of the tub may form a flange having greater thickness and stiffness. The tub may be manufactured of any appropriate material capable of being thermoformed. A most suitable material is polypropylene. However, other polymer materials such as polyethylene terephthalate (PET) or polyethylene (PE) can be used as well. Multi-layer materials may also be used, subject to the requirements of recycling. Most preferably, the tub comprises a multi-layer laminate including a central barrier layer having reduced oxygen transmission, i.e. forming a barrier to oxygen, such as EVOH or the like.

As indicated above, the strength of the package may be achieved by the combined strengths of the tub and the sleeve. The sleeve thus also has a structural function in addition to providing a printable surface. Preferably, the carton used for the blank has a weight of between 50 g/m2and 400 g/m2, preferably from 100 g/m2 to 300 g/m2. The wording carton blank is defined as a blank comprising carton material. The blank material can further comprise other suitable materials, such as a coating to protect the outer surface against environmental influences. In general, the carton blank material has greater weight and thickness than the sidewalls of the tub. It may have a wall thickness of between 0.10 mm to 0.50 mm and may even have a wall thickness of 0.6 mm. The carton blank may have a thickness that is at least twice the wall thickness of the sidewalls.

According to the invention, the tub and the sleeve support each other in order to provide a wall structure that is stronger than would be the case for each of the elements when taken alone. It will be understood that the sleeve base may be either open or at least partially closed. It will be understood that the weight of the powder contents can assist in pressing the sidewalls into contact with the sleeve. The sidewalls of the inner tub and the sleeve are preferably slightly tapered. The taper of the outer sleeve and/or tub may be between 1° and 7°, preferably around 3°. An advantage of such a tapered shape is that the tubs can be stacked inside one another.

Additionally, a top edge of the sleeve may be at a distance different from the top edge of the tub. In order for the sleeve to adequately support the tub, the top edge of the sleeve does not necessarily have to coincide with the top edge of the tub. When a relatively small distance is maintained between the top edges, the tolerances of the respective heights of the tub and the sleeve can be accommodated such that the support of the sleeve to the tub can be optimized. This distance may be at most 5.0 mm, preferably 2 mm, more preferably 1 mm, whereby the sidewalls are supported up to the top edge, without the tub actually being suspended from its top edge.

The membrane used to seal across the open mouth of the tub may be any conventional membrane of metal foil or plastic film or combination thereof. The membrane may function as a seal to protect the product from the environmental atmosphere, i.e. forms a barrier against oxygen, and preferably moisture. Preferably, the membrane comprises a weakened tear line defining an opening region, and a pull tab for removing the membrane prior to use. The membrane may seal to an inside surface of the sidewalls. Most preferably however, the tub comprises an outwardly extending flange at the top edge to which flange the membrane is connected.

The invention also relates to a package for a powdered nutritional product , the package being manufactured according to any of the embodiments of the method as described above. The resulting package may be easy to produce and dispose of. Other advantages will be apparent on the basis of the further description below.

The invention is particularly applicable to infant formula and most preferably the package is filled with powdered infant milk formula.

Preferably, a scoop is provided within the package and may be located above the membrane seal prior to use. It is also conceivable that a scoop is integrally formed with the lid construction and separated at first use.

According to a still further aspect of the invention, the process is particularly applicable to wide access packages of the type wherein the tub is rectangular and has an access opening with a minimum dimension of at least 70 mm, more preferably around 100 mm and an area of at least 100 cm ² . The overall length of the package may be between 150 mm and 250 mm, preferably about 185 mm. The width of the package may be between 100 mm and 150 mm, preferably around 120 mm. The package may be available in multiple heights according to volume required, varying from 80 mm to 150 mm. In this context, rectangular is understood to include square and does not exclude the presence of rounded corners. The volume of the package may be between 0.8 litre or 800 ml and 3 litres, or 3000 ml, preferably around 1.5 litres, or 1500 ml. Such wide access packages are particularly susceptible to the problems of wall strength. BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will be further appreciated upon reference to the following drawings of a number of exemplary embodiments, in which: Figure 1 shows a package for powdered nutritional products manufactured according to the method of the invention.

Figure 2 shows a semi-finished package for assembly of the package of Fig. 1 in an exploded view.

Figure 3 shows a carton blank and the semi-finished package of Fig. 2 for assembling the package of Fig. 1.

Figure 4 shows side panels of the carton blank of Fig. 3 folded towards the thermoformed tub; and

Figure 5 shows a schematic flow diagram of the production of the package of Fig.

1.

DESCRIPTION OF ILLUSTRATIVE EMBODFMENTS

Figure 1 shows in perspective view a package 1 manufactured according to the present invention. The package 1 is in its completed state and includes a tub 2, enclosed by a sleeve 4, and a lid assembly 3.

Figure 2 shows a partially exploded view of the tub 2 and the lid assembly 3 showing further a membrane 6, a lower rim 8, an upper rim 10 and a lid 12 forming a first assembly part of the package 1. The tub 2 is thermoformed of a laminate of inner and outer relatively thin polypropylene material layers and an intermediate EVOH barrier layer. It includes a base 14 and a peripheral wall 16 defining a product containing space 20, i.e. the tub 2 is filled with a powdered nutritional product 21 before the membrane 6 is connected over the open mouth 15 of the tub. The peripheral wall 16 extends to an upper edge 18 having an outwardly directed flange 19.

Lower rim 8 is formed as a flat annular ring of a similar dimension to the outwardly directed flange 19. The lower rim 8 is injection moulded of polypropylene, although it will be understood that other appropriate materials could also be employed. The upper rim 10 and lid 12 form the lid assembly 3 and are also formed of injection moulded polypropylene. The upper rim 10 is designed to mechanically engage with the lower rim 8 in an interference fit including snap connectors, not shown. The seal 6 includes a tear line 22 defining an opening region 24 and includes a pull tab 26.

The production line 40 of the package 1, of which a flow diagram is shown in Figure 5, is divided into a number of zones, defined as a first low-care zone 41, a high- care zone 42, a second low-care zone 43 and a third low-care zone 44. The tub 2, lower rim 8, lid assembly 3 and membrane 6 are all delivered via the first low-care zone 41, to the high-care zone 42. It is noted that the tubs 2 are pre-formed, size-stabilised thermoformed tubs that have been formed at least 48 hours previously. In the high-care zone 42, after initial cleaning and flushing operations have been performed, the tub 2 is filled with milk powder 21. Subsequently, membrane 6 is applied to close the product containing space 20 and hermetically seal the milk powder within the tub 2.

Afterwards, lower rim 8 is applied over the membrane 6 onto the outwardly directed flange 19 at the upper edge 18 of the peripheral wall 16 and subsequently welded into position.

Thereafter, the lid assembly 3 is applied onto the lower rim 8 and clicked into position. At this point, all of the components that enter into contact with the milk powder 21 are enclosed within a semi-finished package , shown in Fig. 2. This can now proceed from the high-care zone 42 into the second low care zone 43. It will be understood that only the processes relevant to the present invention have been described at this point and that many other further operations may take place within the high-care zone 42, including cleaning, inspecting, testing and the like.

Within the second low-care zone 43 the sleeve 4 will be formed around the semifinished package 1 ' to form a final package 1 as will be described in further detail below. The final package 1 is passed to the third low-care zone 44 for onward shipment.

Figure 3 shows a perspective view of a blank 28 used to form the sleeve 4 and the filled and sealed tub 2 centered on a bottom panel (not shown) of the blank 28. The blank material may be polyethylene (PE) coated, high-quality card of 300 g/cm ² . The blank 28 defines a number of side panels 30 and the bottom panel (not shown), corner sections 32 and connection tabs 34.

Figure 4 shows a perspective view of the assembly of the package 1 by first folding side panels 30" towards the side walls 16" of the tub 2. Before folding the side panels 30" a layer of adhesive, or glue, is provided in an adhesive area 31. After connection of the side panels 30" to the side walls 16" by the adhesive, connection tabs 34 are folded towards the side walls 16' and connected to the side walls 16' by gluing.

Secondly, the side panels 30' are provided with a layer of adhesive, or glue, provided in an adhesive area 33. Side panels 30' are then folded towards the side walls 16' of the tub 2 and connected to both the connection tabs 34 and the tub 2 by gluing. Upon folding the side panels 30, the corner sections 32 fold around the rounded corners of the tub 2. The blank 28 is now formed into a sleeve 4 that encloses the tub 2 by covering the side walls 16 and the base 14 and which supports the relatively thin walls of the tub 2. The adhesive is a hot-melt adhesive available as TECHNOMELT™ SUPRA 325 HT from Henkel AG and having an application temperature of between 160° C and 190° C. It will be understood that although it has been indicated that the adhesive is applied in the designated adhesive areas 31, 33, this may be applied at any desired location using an appropriate robotic glue actuator and may even be applied to the walls of the tub itself.

Thus, the invention has been described by reference to certain embodiments discussed above. It will be recognized that many modifications in addition to those described above may be made to the structures and techniques described herein without departing from the spirit and scope of the invention. Accordingly, although specific embodiments have been described, these are examples only and are not limiting upon the scope of the invention.

LIST OF PARTS

1. Final package

. Semi-finished package 2. Tub

3. Lid assembly

4. Sleeve

6. Membrane

8. Lower rim

10. Upper rim

12. Lid

14. Base

15. Open mouth

16. Peripheral wall

18. Upper edge

19. Flange

20. Product containing space

21. Powdered product

22. Tear line

24. Opening region

26. Pull tab

28. Blank

30. Side panel

31. Adhesive area

32. Corner section

33. Adhesive area

34. Connection tabs

40. Production line

41. First low-care zone 42. High-care zone

43. Second low-care zone

44. Third low-care zone