Patent ID: 12202659

Like reference number denote similar features throughout the figures. Reference numbers may be omitted in some figures for better visibility, in which case reference is made to the other figures.

DETAILED DESCRIPTION

It is to be understood that the drawings are schematic and that individual components, such as layers of materials are not necessarily drawn to scale. The packaging container, transport closure, valve and plunger piston comprising the bottom plate shown in the figures are provided as examples only and should not be considered limiting to the disclosure. Accordingly, the scope of disclosure is determined solely by the scope of the appended claims.

FIG.1illustrates a packaging container1for bulk solids, such as pulverulent material, obtained by a method according to the present disclosure. The particular shape of the container1shown in the figures should not be considered limiting to the disclosure. Accordingly, a packaging container produced according to the disclosure may have any useful shape or size.

The packaging container1as illustrated inFIG.1comprises an inner compartment2comprising bulk solids (shown inFIG.3). The packaging container1comprises a tubular container body3having an upper end4with an upper body opening5and a bottom end6with a bottom body opening7. A container body wall8extends in a height direction H of the packaging container1between the upper body opening5and the bottom body opening7. The container body wall8comprises an inner surface9and an outer surface10, an upper end edge11and a bottom end edge12.

A transport closure13is provided over the inner compartment2, to keep the contents in the composite container fresh and protected against contamination up until a first opening of the packaging container1by a consumer. In thisFIG.1, the transport closure13is illustrated as an at least partly removable transport closure which may be removed by the end user by gripping the grip tab14and tearing off the transport closure13. The transport closure13comprises a first side13aand a second side13b, the second side13bfacing the inner compartment2and the first side13afacing away from the inner compartment2.

The transport closure13is provided with a valve15on the first side13athereof. The valve15is a one-way pressure relief valve allowing gas in the inner compartment2to exit therefrom. The transport closure13is provided with through perforations16which are covered by the valve15and which perforations allow gas to exit from the inner compartment2.

InFIG.1, the transport closure13is a laminate transport closure13comprising a top layer13′ and a bottom layer13″ laminated together. The top layer13′ is provided with an opening17within which the valve15is arranged. A surface area of the opening17is greater than a surface area of the valve15, such that an edge17aof the opening17is arranged at a distance from an edge15aof the valve15, providing a valve-free area between the opening edge17aand the valve edge15a. The transport closure13is attached via an outer edge portion18(shown inFIG.2) of the transport closure13surrounding a transport closure base portion19which has been flexed upwards during insertion forming a peripheral flange18′ during insertion of the transport closure13into the upper body opening5of the tubular container body2. The peripheral flange18′ of the bottom layer13″ is attached to the inner surface9of the container body wall8, such as by adhesive or by welding.

The container1is furthermore provided with a lid component including a top rim20and an openable and closable lid part21.

When the lid is part of a lid component, it is connected to the top rim20by means of a hinge. The hinge may be a live hinge, i.e. a bendable connection between the lid part21and the top rim20or frame structure. A live hinge may be formed integrally with the lid and/or with the top rim or frame structure or may be a separately formed element which is attached to the lid and to the top rim or frame structure. Alternatively, the hinge may be a two-part hinge, with a first hinge part arranged on the lid and a second hinge part arranged on the top rim or frame structure.

The packaging container1is a container for dry or moist goods, often referred to as “bulk solids”, in particular the bulk solids may be bulk solids emitting gas. Such products are non-liquid, generally particulate materials capable of being poured, scooped or taken by hand out of the cans.

The packaging container1is a disposable container, which are intended to be discarded after having been emptied of its contents.

FIG.2illustrates the transport closure13fromFIG.1prior to insertion into the packaging container1and prior to attachment to the inner surface9of the container body wall8(shown inFIG.1). The bottom layer13″ of the transport closure13is intended to face the inner compartment2of the packaging container1. The bottom layer13″ has a larger surface area than the top layer13′ and the outer edge portion18of the bottom layer13″ extends beyond the top layer13′ surrounding the transport closure base portion19forming a peripheral flange18′ (shown inFIG.1) when being flexed upwardly during insertion of the transport closure13into the upper body opening5of the tubular container body2(shown inFIG.1). The transport closure13is an at least partly removable transport closure which may be removed by the end user by gripping the grip tab14and tearing off the transport closure13.

The valve15is arranged within the opening17of the top layer13′ of the laminate transport closure13and on the bottom layer13″, more specifically on a surface of the bottom layer13″ facing away from the inner compartment2. A surface area of the opening17is greater than a surface area of the valve15, such as at least 20% greater, optionally within the range from 20% to 200% greater. The valve15is arranged over opening17, here provided in the bottom layer13″. The valve15may have a thickness of less than 600 μm. The thickness of the top layer13′ may be approximately the same or greater than the thickness of the valve15. The thickness of the valve15may for example be in the range of 25% to 200% of the thickness of the top layer13′. In absolute numbers the thickness of the valve15may be in the range of 150 μm to 600 μm. The thickness of the top layer13′ may be less than 600 μm, such as less than 500 μm, such as less than 300 μm, such as less than 200 μm, such as less than 150 μm. The top layer13′ may have an essentially uniform thickness.

The valve15illustrated inFIGS.1and2includes an upper barrier layer22and two elongated adhesive material strips23arranged between the upper barrier layer22and on the first side13aof the transport closure13and on a respective lateral side of the perforations16in the transport closure13. The valve15further comprises a sealing lubricant24, such as oil, applied over the perforations16.

The valve15is a pressure-relief valve allowing gas in the inner compartment2to exit therefrom, when the gas pressure inside exceeds the target pressure, by opening of the pressure-relief valve15. When the gas exits the perforations16provided in the transport closure13, the upper barrier layer22is pressed upwardly and the arrows shown in the figure indicates the gas passage during exit. It has been found by the present inventors, that when the valve15has been activated once, the required opening pressure may be lower and the gas flow through the valve may be larger in a shorter period of time, thus allowing an increasing internal pressure to be reduced faster. However, to precondition the valves prior to providing the transport closures into the packaging containers may imply higher production costs and a more complex production.

FIG.3discloses a method of producing and filling a packaging container1with bulk solids according to the present disclosure. In a first step, a tubular container body3is formed from a paperboard sheet3′ by bringing together the side edges of the paperboard sheet3′, thus causing the material to assume a tubular shape. The side edges of the paperboard sheet3′ are then sealed together thus forming a tubular container body3. Sealing of the side edges may be made by any suitable method as known in the art, such as by welding or gluing, with welding being preferred. The side edges of the container body sheet3′ may be sealed using a sealing strip. The container body3has an upper end4with an upper body opening5and a bottom end6with a bottom body opening7, the container body3is here shown with the bottom end6and the bottom body opening7directed upwardly. A container body wall8extends in a height direction H of the packaging container1, between the upper body opening5and the bottom body opening7, the container body wall8having an inner surface9and an outer surface10, an upper end edge11and a bottom end edge12. The method further comprising the step of closing the bottom body opening7, here with a bottom disc25being pressed into the bottom body opening7and sealed against the inner surface9of the container body3. Optionally, a bottom rim25amay be attached to the bottom end edge12of the container body3, alternatively, the bottom end edge may be curled inwards to form a curled bottom end edge. The container body3is then turned, such that the upper end4is directed upwards in the vertical direction and the bottom end5is directed downwards in the vertical direction. The method then comprises the step of presenting the container body3to a filling station26and filling bulk solids27into the container body3through the upper body opening5. The container body3is subsequently presented to an upper body opening sealing station28comprising a plunger piston29including a bottom plate30. The bottom plate30has a through hole31extending from a first side30aof the bottom plate30to a second side30bof the bottom plate30(shown inFIG.4). The bottom plate30may extend in a direction substantially perpendicular to a pressing direction of the plunger piston29. The bottom plate30may extend in a direction substantially perpendicular to the height direction H of the packaging container1, that is substantially parallel to the top layer17, when the packaging container1is presented to the upper body opening sealing station28. The first side30aand the second side30bof the bottom plate30may be opposing sides. The through hole31may extend in the height direction H of the packaging container1. The upper body opening5is closed by applying the bottom plate30against the first side13aof the transport closure13and pressing the transport closure disc13as illustrated inFIG.2, by means of the plunger piston29comprising the bottom plate30into the upper body opening such that a pressure above an ambient pressure is produced within the packaging container1and at the second side13bof the transport closure13. The first side30aof the bottom plate30being applied against the first side13aof the transport closure13such that the through hole31of the bottom plate30is arranged to partly or completely overlap with the opening17of the top layer13′, as seen in the height direction H, allowing gas to exit the valve15and the valve15to be pre-conditioned.

A surface area of the plunger piston29and/or bottom plate30may be equal to or not less than 85% of a surface area of the transport closure base portion19, optionally equal to, or not less than 90% of a surface area of the transport closure base portion19. Such size ratios may prevent gas from escaping from the inner compartment at the edges of the transport closure13and the plunger piston29and/or bottom plate30.

To further prevent air to exit the inner compartment2between the transport closure13and the inner surface9of the container body8when pressing the transport closure into upper body opening, a size ratio of the surface area of the transport closure13to a surface area of the upper body opening5surface area may be at least 1.01, such that the outer edge portion18of the transport closure13is shaped and flexed when the transport closure13is pressed into the upper body opening5. The outer edge portion18of transport closure forming a peripheral flange18′ projecting out of a main plane of the transport closure13, the peripheral flange18′ being aligned with the inner surface9of the container body wall8.

InFIG.3, a lid component including a top rim20and an openable and closable lid part21is connected to the packaging container1by connecting the top rim20to the upper end edge11. The top rim20may for example be attached by adhesive or by welding.

FIG.4illustrates an upper part of the packaging container1and a cross-sectional of the plunger piston29from the method step inFIG.3of closing the upper body opening of the packaging container1. As shown in this figure, the plunger piston29comprising the bottom plate30has pressed the transport closure13into the upper body opening5. The plunger piston29may include a plunger32made in a flexible material, such as rubber, which presses the peripheral flange18′ against the inner surface9of the tubular body3. The through hole31in the bottom plate30may have a minimum cross-section width Wh of 4 mm, such as within the range of from 4 mm to 35 mm, such as within the range of from 5 mm to 25 mm. Alternatively, or additionally, the bottom plate may comprise two or more through holes, such as three or more through holes according to the present disclosure. The minimum cross-section width of the through holes in the bottom plate, if the bottom plate comprises two or more, or three or more though holes according to the present disclosure, may be 1 mm or 2 mm.

InFIG.4, the transport closure13comprises a top layer13′ and a bottom layer13″, the top layer13′ being provided with an opening17, the valve15being arranged within the opening17and on the bottom layer13″, more specifically on a surface of the bottom layer13″ facing the top layer13′. The through hole31in the bottom plate30is arranged to at least partly overlap with the opening17of the top layer13′ of the transport closure. The through hole31may be arranged to partly or completely overlap with a valve-free area of the opening17, i.e., an area between an edge17aof the opening17and an edge15aof the valve15.

FIG.5illustrates an optional step of the method according to the present disclosure wherein the transport closure13is pressed into the upper body opening5with a length L1in the height direction H, as measured between the upper end edge11and the transport closure base portion19, the length L1may be 2 mm or more, such as within the range of from 2 mm and 50 mm.

InFIG.5, the upper body sealing station28comprises a guiding member forming an, as seen from the upper end4, upwardly extending guiding channel33, the guiding channel33extending away from the container body3, in the height direction H, with a length L2, as measured from the upper end edge11of the container body3. The length L2is at least 20 mm. The transport closure13is pressed through the guiding channel33and into the upper body opening5, thus providing a higher pressure at the second side13bof the transport closure13for preconditioning of the valve15. The plunger piston29includes the bottom plate30comprising the through hole31and the plunger32made in a flexible material, such as rubber, which presses the peripheral flange18′ against the inner surface9of the tubular body3. The peripheral flange18′ is attached by welding members34.

The sum of the length L1and the length L2may be from 22 mm, such as within the range of from 22 mm and 305 mm.