Manufacturing method of package container with valve
Patent Information
- Application Number
- JP2023085677
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-25
- Filing Date
- 2023-05-24
- Publication Date
- 2026-01-23
AI Technical Summary
Existing packaging containers for bulk solids experience deformation and seal damage due to rapid pressure buildup during transportation, especially at higher altitudes or with gas-emitting products like coffee, as the initial release of gas through the shipping closure is slower than the pressure increase, leading to bulging and delamination.
A packaging container design with a one-way pressure relief valve and a through hole in the plunger piston, where the valve opening is larger than the surface area of the valve, allowing gas to escape through the bottom plate, thereby preconditioning the valve to reduce internal pressure and prevent deformation.
The solution effectively reduces the risk of packaging deformation and seal damage by ensuring faster gas release, maintaining the integrity of the container and seal, and optimizing production efficiency by minimizing complex preconditioning processes.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for manufacturing a packaging container for bulk solids.
[0002] [Cross - reference to related applications] This application claims the benefit of Swedish Patent Application No. 2250621 - 6, filed on May 25, 2022. The disclosure of Swedish Patent Application No. 2250621 - 6, filed on May 25, 2022, is incorporated herein by reference in its entirety for all purposes as if fully set forth herein.
Background Art
[0003] Consumer goods, especially bulk solids, are often packaged in relatively robust cardboard packaging containers that protect the bulk solids during transport and storage at the manufacturer and retailer ends, and further during storage and distribution at the consumer end. To keep the contents fresh and protected from contamination until the first opening of the packaging container by the consumer, the container can be provided with an inner transport closure that the consumer can completely or partially remove.
[0004] [[ID=,22]]During the transport of the packaging container at a higher altitude and / or for a package containing coffee that generates a certain amount of gas, a pressure exceeding the ambient pressure may be obtained inside the packaging container. Also, an increase in the pressure inside an internal compartment may result from a particular manufacturing method when pushing a transport closure into an opening at the top of the container body. The increase in internal pressure can cause the transport seal to bulge or many separations along the seal between the transport seal and the inner wall of the packaging container. Also, the container wall may bulge or the packaging container may be permanently deformed. To avoid this problem, the packaging container, more specifically the transport closure, may be provided with a valve, for example, that allows gas to escape from the internal compartment of the packaging container. However, it has been found that the accumulation of pressure inside the package can be faster than the first release, i.e., the first opening of the valve in the transport closure.
Summary of the Invention
[0005] The purpose of this disclosure is to provide an improved packaging container that reduces the risk of deformation of the packaging container and damage to the seal between the transport closure and the packaging container wall. [Means for solving the problem]
[0006] One or more of the above objectives can be achieved by the method for manufacturing a packaging container according to claim 1 and / or claim 14 as described in the claims. Further embodiments are described in the other dependent claims, the following description and drawings.
[0007] This disclosure relates to a method for manufacturing a packaging container for bulk solids, the packaging container comprising an internal compartment and a transport closure for closing the internal compartment, the transport closure comprising a top layer and a bottom layer, the top layer having an opening, the transport closure comprising a one-way pressure relief valve on a first side of the transport closure that allows gas in the internal compartment of the packaging container to be released therefrom, the valve being located in the opening and on the side of the bottom layer facing the top layer, the surface area of the opening being greater than the surface area of the valve, the transport closure comprising at least one through-hole covered by the valve on the first side of the transport closure, the method further comprising the following steps, a) A step of forming a tubular container body, wherein the container body has an upper end having an upper body opening, a lower end having a lower body opening, and a container body wall extending in the height direction of the packaging container between the upper body opening and the lower body opening, having an inner surface and an outer surface, and an upper edge and a lower edge of the container body, b) A step of presenting the container body to an upper body opening sealing area equipped with a plunger piston, which includes a bottom plate having a through hole extending from a second side of the bottom plate to a first side of the bottom plate, c) A step of closing the upper body opening by applying the first side of the bottom plate to the first side of the transport closure device such that, when viewed from the height direction, the through hole of the bottom plate at least partially overlaps the opening of the top layer, and by pushing the plunger piston including the bottom plate and the transport closure device into the upper body opening, thereby generating a pressure greater than the ambient pressure inside the tubular container body on the second side of the transport closure device, causing gas to exit the valve and preconditioning the valve; d) The step of attaching the transport closure device to the inner surface of the container body wall.
[0008] When a transport closure, including a valve, is pushed into the container body, pressure may build up in the internal compartment of the packaging container. To avoid this, excess gas can be released from the packaging container at the side of the transport closure. The solution of this disclosure is to prevent gas from being released at the side of the transport closure instead by providing a through-hole in the bottom plate of the plunger piston, which is positioned to partially or completely overlap with the opening of the top layer. When the transport closure is pushed down into the top body opening, the pressure buildup opens the valve, and gas is released through the valve into the space provided by the opening of the top layer, i.e., between the first side of the transport closure and the bottom plate. The gas is then released through the through-hole in the bottom plate, thereby reducing the internal pressure of the packaging container and preconditioning the valve. When the valve is preconditioned, i.e., after one operation, the opening pressure required thereafter is lower, and the gas flow through the valve may increase in a shorter time. However, preconditioning valves before supplying transport closures to packaging containers can sometimes mean higher production costs and more complex production processes.
[0009] The surface area of the top layer opening may be at least 20% larger than the surface area of the valve, and optionally the surface area of the opening may be at least 20% to 250% larger than the surface area of the valve. The surface area of the top layer opening may be at least 25% larger than the surface area of the valve, such as at least 30% larger. The surface area of the opening may be at least 25% to 200% larger than the surface area of the valve. Optionally, the surface area of the opening may be at least 25% to 150% larger than the surface area of the valve. The top layer opening of the transport closure may be optimized accordingly to provide sufficient space for the gas to exit the valve in order to prevent excessive pressure buildup between the transport closure and the bottom plate before the gas escapes through the through-opening in the bottom plate.
[0010] The thickness of the top layer is approximately the same as or greater than the thickness of the valve. The thickness of the top layer may be 10% greater than the thickness of the valve. Optionally, the thickness of the top layer may be 20% greater than the thickness of the valve, and may be, for example, 20% to 400% greater. The thickness of the top layer may be 30% greater than the thickness of the valve. This provides a wider area outside the pressure valve, a valve-free area, at a lower pressure applied by the bottom plate, allowing gas to leak out of the valve before it flows out through the through-holes in the bottom plate.
[0011] The through-hole may be positioned to partially or completely overlap the valve-free region of the top layer opening, i.e., the region between the end of the top layer opening and the end of the valve.
[0012] This disclosure further relates to an alternative method for producing and filling a packaging container with bulk solids, the packaging container comprising an internal compartment and a transport closure for closing the internal compartment, the transport closure comprising a one-way pressure relief valve for allowing gases in the internal compartment of the packaging container to be released therefrom, the method, a) A step of forming a container body, wherein the container body comprises an upper end having an upper body opening, a lower end having a bottom body opening, and a container body wall having an inner surface that extends in the height direction of the packaging container between the upper body opening and the bottom body opening, b) A step of presenting the container body to an upper opening sealing unit equipped with a plunger piston, which includes a bottom plate having a through hole extending from a first side of the bottom plate to a second side of the bottom plate, c) A step of closing the upper body opening by applying the first side of the bottom plate to the first side of the transport closure so that the through hole is positioned above the valve, and pushing the plunger piston including the bottom plate and the transport closure into the upper body opening so that a pressure greater than the ambient pressure is generated in the tubular container body on the second side of the transport closure, causing gas to exit the valve and preconditioning the valve; d) The step of attaching the transport closure device to the inner surface of the container body wall.
[0013] In relation to the first method, the second method provides a solution to the problem of preconditioning a valve provided in a transport closure for a packaging container. The solution of the second method, like the first method, prevents gas from escaping from the side of the transport closure and provides a bottom plate of a plunger piston with a through hole. In the second method, the through hole allows gas to be discharged from the valve to exit through the through hole in the bottom plate. When the transport closure is pushed down into the upper body opening, the accumulated pressure opens the valve and gas is released from the valve so that the valve is preconditioned by being discharged through the through hole in the bottom plate.
[0014] The transport closure of the second method is a single-layer or multi-layer (e.g., two-layer) transport closure. The transport closure comprises one layer, and the valve may be located on a first side of the top layer, moving from the packaging container toward the inner compartment. The transport closure instead comprises a top layer and a bottom layer, and may also include one or more intermediate layers positioned between the top layer and the bottom layer as needed, and the valve may be located on a first side of the top layer. In yet another method, the transport closure comprises a top layer and a bottom layer, and the valve may be an integrated part of the top layer, in which case the barrier layer of the valve is the same as that of the top layer, and the barrier layer is separated from the rest of the top layer by scoring the top layer and separating the valve from the top layer.
[0015] The following applies to both methods described here unless otherwise specified.
[0016] To control pressure buildup, the plunger piston speed can be adjusted to increase or decrease. An appropriate speed is in the range of 100 to 400 mm / s, corresponding to 50 to 25 packaging containers per minute. Excessive pressure buildup can compromise the integrity of the packaging. The plunger piston must push the transport closure into the upper body opening at a certain speed so that the gas inside the packaging container is compressed during pressing, and the pressure inside the internal compartment exceeds a set pressure for the valve to open and release excess gas.
[0017] The cardboard materials used herein are primarily made from cellulose fibers or paper fibers. Sheet materials may be supplied in the form of a continuous web or as individual material sheets. Cardboard materials may be single-ply or multi-ply materials, or laminates comprising one or more layers of materials such as polymer films and coatings, or metal foils. Polymer films and coatings may contain or consist of thermoplastic polymers. The cardboard materials disclosed herein may also be referred to as corrugated cardboard or carton materials.
[0018] As used herein, the term “bulk solid” refers to bulk material. Bulk material can be dry or wet. Bulk solid can take the form of particles, granules, crushed material, plant flakes, short fibers, flakes, seeds, pasta, and other molded material pieces. Bulk solid suitable for packaging into packaging containers, as disclosed herein, may be fluid, meaning that the required amount of product can be poured or scooped out of the packaging container, or it may take the form of inconspicuous material pieces that allow only a portion of the contents within the packaging container to be removed.
[0019] As used here, "powdered material" refers to any material that takes the form of particles, granules, crushed material, plant fragments, short fibers, flakes, etc.
[0020] A partially or completely removable transport closure means a component that can be completely or partially removed by the user to provide initial access to the internal compartment of the packaging container by breaking the seal between the transport closure and the inner surface of the container wall, or by tearing the transport closure itself or otherwise breaking it. A tearable transport closure may have one or more predefined weak points (e.g., holes or notches penetrating part of the component).
[0021] Partially or completely removable transport closures are airtight or gas-permeable. Airtight members can be manufactured from any material or combination of materials suitable for providing an airtight seal to the compartment separated by the transport closure, such as aluminum foil, silicone-coated paper, plastic film, or laminates thereof. Airtight members are advantageous when bulk solids, such as powdery substances stored in the packaging container, are sensitive to air and / or moisture, and it is desirable to avoid contact between the packaged bulk solids and ambient air. According to this disclosure, airtight transport closures are preferred because they are intended to generate and maintain a controlled pressure within the packaging container.
[0022] In the assembled and filled packaging containers disclosed herein, a peelable or releasable transport closure forms a cross-section seal between an internal compartment of the container body and the container opening. The inner peelable or releasable transport closure is a transport and storage seal and is ultimately damaged or removed by the end-user of the packaging container.
[0023] A packaging container having a volume of about 1 l may be considered airtight when it is Modified Atmosphere Packing (MAP).
[0024] "Ambient pressure" means the pressure that surrounds the packaging container and contacts the packaging container.
[0025] Optionally, the valve includes an upper barrier layer and two elongated adhesive material strips, the two elongated adhesive material strips being disposed between the upper barrier layer and the first side of the transport closure and the sides of the through-hole of the transport closure respectively, and the valve further includes a seal lubricant such as oil disposed above the through-hole.
[0026] Optionally, the transport closure includes a peripheral flange surrounding the base portion of the transport closure, the peripheral flange being bent towards the upper end of the container body in the height direction. The transport closure can be attached to the packaging container by welding to the inner surface of the container body wall. Also, the transport closure can be attached with an adhesive. By providing a peripheral flange bent towards the upper end of the container in the height direction on the transport closure, when pushing the transport closure into the upper opening, instead of accumulating pressure on the second side of the transport closure opposite to the first side of the transport closure, it further prevents gas from escaping from the internal compartment on the side of the transport closure, makes it easier to open the valve, and can be pre-conditioned.
[0027] Optionally, the surface area of the bottom plate is 85% or more of the surface area of the base of the transport closure, and if necessary, 90% or 95% or more of the surface area of the base of the transport closure. This prevents gas from escaping from the sides of the transport closure and the sides of the plunger piston, and ensures that when the transport closure is pushed down into the upper body opening, pressure accumulates on the second side of the transport closure, exceeding the set pressure at which the valve activates and releases excess gas.
[0028] Optionally, step c) includes pushing the transport closure into the upper body opening by a length L1 of 2 mm or more, such as 2 mm to 50 mm, measured between the edge of the top end and the base of the transport closure in the height direction. This can provide a controlled and improved pressure buildup to ensure that the valve is accurately pre-conditioned during the manufacturing of the packaging container.
[0029] Optionally, the sealing station includes a guide member that forms a guide channel extending upward when viewed from the bottom end, the guide channel extending a length L2 from the container body in the height direction, within a range of 20 mm to 255 mm when measured from the edge of the top end, and step c) includes pushing a transport closure into the upper body opening through the guide channel. This can provide controlled and improved pressure accumulation to ensure that the valve operates correctly and is preconditioned during the manufacturing of the packaging container.
[0030] The sum of length L1 and length L2 is within the range of 22 mm and 305 mm, and can start from 22 mm.
[0031] Optionally, step c) includes a size ratio of at least 1.01:1 between the surface area of the transport closure and the surface area of the upper body opening, so that when the bottom disc is pressed into the body bottom opening, the outer edge portion of the bottom disc is formed and bent to form a flange projecting from the main plane of the bottom disc, the flange conforming to the inner surface of the container body wall. This prevents gas from escaping from the sides of the transport closure so that when the transport closure is pressed into the upper body opening, the accumulated pressure opens the valve and releases the pressure through the valve and the through-hole in the bottom plate. Optionally, step c) includes a size ratio of at least 1.05:1, for example, 1.1:1 between the surface area of the transport closure and the surface area of the upper body opening.
[0032] Optionally, the minimum cross-sectional width of the through-hole in the bottom plate is 4 mm, or for example, at least 5 mm. Optionally, the minimum cross-sectional width of the through-hole in the bottom plate is in the range of 4 mm to 35 mm. Optionally, the through-hole in the bottom plate is 7 mm or larger, such as 8 mm or 10 mm or larger. Optionally, it is in the range of 5 mm to 25 mm.
[0033] Alternatively, the bottom plate may include two or more through holes, such as three or more through holes according to the Disclosure. If the bottom plate includes two or more through holes, or three or more through holes according to the Disclosure, the minimum cross-sectional width of the through holes in the bottom plate may be 1 mm or 2 mm.
[0034] If the method is the method relating to the second method, the through-hole in the bottom plate may be at least 5% larger than the surface area of the valve, for example, at least 8%, or at least 10% or at least 12% larger than the surface area of the valve. Optionally, the surface area of the through-hole in the bottom plate may be in the range of 5% to 50% larger than the surface area of the valve.
[0035] Either method may be a method of filling the packaging container with bulk solid through the upper opening, which may then include the step preceding step b), which is closing the bottom opening of the container body and presenting the container body to the filling station, and filling the container body with bulk solid through the upper opening.
[0036] Either method may be a method of filling the packaging container with bulk solid into the bottom body opening. This method may include a step after step d) in which the container body is rotated so that the bottom body opening is facing upward, the container body is placed on a filling station, the container body is filled with bulk solid through the bottom body opening, and finally the bottom body opening of the container body is closed. According to this variation, the upper body opening is closed with a transport closure before the container body is filled and the bottom body opening is closed, so that the transport closure covers the bottom body opening and pushes into the upper body opening of the container body, while pushing the transport closure into the upper body opening of the container body so that it has a support surface below the bottom body opening of the container body, thereby preventing or reducing the amount of gas that can escape from the bottom body opening.
[0037] This disclosure will be further described below with reference to non-limiting examples and accompanying drawings. [Brief explanation of the drawing]
[0038] [Figure 1] The packaging container related to this disclosure is shown. [Figure 2] This disclosure shows a transport closure device equipped with the valve described herein. [Figure 3] Figure 1 schematically shows the method for manufacturing and filling the packaging container. [Figure 4] The diagram shows the upper cross-section of the packaging container relating to this disclosure, and a cross-sectional view of the plunger piston after the transport closure disc has been pushed into the upper body opening to close it. [Figure 5] This diagram shows a cross-sectional view of a packaging container while the transport closure device relating to this disclosure is being pushed into the upper body opening, and shows the sealing unit including the guide member. [Modes for carrying out the invention]
[0039] Similar reference numbers indicate similar features throughout the figure. In some figures, reference numbers may be omitted for better visibility; in such cases, refer to other figures.
[0040] It should be understood that the drawings are schematic, and individual components such as material layers are not necessarily drawn to scale. The packaging container, transport closure, valve, and plunger piston, including the bottom plate, shown in the drawings are provided as examples only and should not be considered as limiting the disclosure. Therefore, the scope of the disclosure is determined solely by the scope of the attached claims.
[0041] Figure 1 shows a packaging container 1 for a bulk solid, such as a powder, obtained by the method relating to this disclosure. The specific shape of the container 1 shown in the figure should not be considered limiting to the disclosure. Therefore, packaging containers manufactured in accordance with the disclosure may have any useful shape or size.
[0042] The packaging container 1 shown in Figure 1 includes an internal compartment 2 containing bulk solid (shown in Figure 3). The packaging container 1 includes a tubular container body 3 having an upper end 4 with an upper body opening 5 and a lower end 6 with a bottom body opening 7. The container body wall 8 extends in the height direction H of the packaging container 1 between the upper body opening 5 and the bottom body opening 7. The container body wall 8 includes an inner surface 9, an outer surface 10, an upper edge 11, and a lower edge 12.
[0043] A transport closure 13 is provided above the internal compartment 2 to keep the contents of the composite container fresh and protected from contamination until the consumer first opens the packaging container 1. In Figure 1, the transport closure 13 is shown as a transport closure that can be removed by the end user by grasping the grip tab 14 and tearing off the transport closure 13. The transport closure 13 includes a first side 13a and a second side 13b, the second side 13b facing the internal compartment 2 and the first side 13a facing away from the internal compartment 2.
[0044] A valve 15 is provided on the first side 13a of the transport closure device 13. The valve 15 is a one-way pressure relief valve that allows gas from the internal compartment 2 to be discharged from there. The transport closure device 13 is covered by the valve 15 and has a through hole 16 that allows gas to be discharged from the internal compartment 2.
[0045] In Figure 1, the transport closure 13 is a laminated type transport closure 13 in which a top layer 13' and a bottom layer 13'' are laminated together. An opening 17 is provided in the top layer 13', and a valve 15 is placed inside it. The surface area of the opening 17 is larger than the surface area of the valve 15, and as a result, the end 17a of the opening 17 is positioned away from the end 15a of the valve 15, providing a valve-free area between the opening end 17a and the valve end 15a. The transport closure 13 is attached to the upper body opening 5 of the tubular container body 2 via the outer edge portion 18 (shown in Figure 2) of the transport closure 13, which surrounds the base portion 19 of the transport closure that is bent upward during insertion and forms a peripheral flange 18'. The peripheral flange 18' of the bottom layer 13'' is attached to the inner surface 9 of the container body wall 8 by adhesive, welding, or the like.
[0046] The container 1 is further provided with a lid component including a top rim 20 and an openable / closable lid portion 21.
[0047] If the lid is part of the lid component, it is connected to the top rim 20 by a hinge. The hinge may be a live hinge, i.e., a bendable connection between the lid 21 and the top rim 20 or frame structure. The live hinge may be formed integrally with the lid and / or the top rim or frame structure, or it may be a separately formed element attached to the lid and the top rim or frame structure. Alternatively, the hinge may be a two-part hinge, where the first hinge portion is located on the lid and the second hinge portion is located on the top rim or frame structure.
[0048] Packaging container 1 is a container for dry or wet goods, often referred to as "bulk solids," which may in particular be gaseous bulk solids. Such products are not liquids and are generally particulate matter that can be poured, scooped, or taken by hand from a can. Packaging container 1 is a single-use container and is intended to be discarded after its contents have been emptied.
[0049] Figure 2 shows the transport closure 13 from Figure 1 before insertion into the packaging container 1 and before attachment to the inner surface 9 (shown in Figure 1) of the container body wall 8. The bottom layer 13” of the transport closure 13 is intended to face the internal compartment 2 of the packaging container 1. The bottom layer 13” has a larger surface area than the top layer 13', and the outer edge 18 of the bottom layer 13” extends beyond the top layer 13', which surrounds the base portion 19 of the transport closure, forming a peripheral flange 18' (shown in Figure 1) when the transport closure 13 is bent upward when inserted into the upper body opening 5 of the tubular container body 2 (shown in Figure 1). The transport closure 13 is at least partially removable, and the end user can remove it by gripping the grip tab 14 and tearing off the transport closure 13.
[0050] The valve 15 is positioned within the opening 17 of the top layer 13' of the stacked transport closure 13, and on the bottom layer 13'', more specifically, on the surface of the bottom layer 13'' opposite to the internal compartment 2. The surface area of the opening 17 is at least 20% larger than the surface area of the valve 15, and optionally within a range of 20% to 200% larger. The valve 15 is positioned above the opening 17 and is located in the bottom layer 13''. The thickness of the valve 15 may be less than 600 μm. The thickness of the top layer 13'' may be approximately the same as or greater than the thickness of the valve 15. The thickness of the valve 15 may be in the range of, for example, 25% to 200% of the thickness of the top layer 13''. In absolute terms, the thickness of the valve 15 may be in the range of 150 μm to 600 μm. The thickness of the top layer 13'' may be less than 600 μm, for example less than 500 μm, for example less than 300 μm, for example less than 200 μm, for example less than 150 μm. The thickness of the top layer 13'' may be essentially uniform.
[0051] The valve 15 shown in Figures 1 and 2 includes an upper barrier layer 22 and two elongated adhesive material strips 23 positioned between the upper barrier layer 22 and the first side surface 13a of the transport closure 13, and on each side of the through hole 16 of the transport closure 13. The valve 15 further includes a sealing lubricant 24, such as oil, applied over the through hole 16.
[0052] Valve 15 is a pressure relief valve that releases gas from the internal compartment 2 by opening the pressure relief valve 15 when the internal gas pressure exceeds the target pressure. When the gas is released through the through-hole 16 provided in the transport closure 13, the upper barrier layer 22 is pushed upward, and the arrow shown in the figure indicates the gas passage during release. The inventors have found that once valve 15 is activated, the required release pressure is lower, the gas flow through the valve increases in a shorter time, and the increasing internal pressure can be reduced more quickly. However, pre-adjusting the valve before supplying the transport closure to the packaging container may mean higher production costs and more complex production.
[0053] Figure 3 discloses a method for manufacturing a packaging container 1 and filling it with bulk solid according to the present disclosure. In the first step, the side edges of the cardboard 3' are joined to form a tubular container body 3 from the cardboard 3' and to tubularize the material. The side edges of the cardboard 3' are joined and sealed to form a tubular container body 3. The sealing of the side edges can be done by any suitable method known in the art, such as welding or bonding, and welding is preferred. The side edges of the container body sheet 3' can be sealed using a sealing band. The container body 3 has an upper end 4 having an upper body opening 5 and a lower end 6 having a bottom body opening 7, where the container body 3 is shown with the bottom body opening 7 of the lower end 6 facing upward. The container body wall 8 extends between the upper body opening 5 and the bottom body opening 7 in the height direction H of the packaging container 1, and the container body wall 8 has an inner surface 9 and an outer surface 10, an upper edge 11 and a lower edge 12. This method further includes the step of closing the bottom body opening 7, where the bottom disc 25 is pressed into the bottom body opening 7 and sealed against the inner surface 9 of the container body 3. If necessary, the bottom rim 25a can be attached to the lower edge 12 of the container body 3, or the lower edge can be rounded inward to form a curved lower edge. Then the container body 3 is rotated so that the upper end 4 is vertically upward and the lower end 5 is vertically downward. Next, this method includes the step of placing the container body 3 in the filling station 26 and filling the container body 3 with bulk solid 27 through the upper body opening 5. Subsequently, the container body 3 is placed in the upper body opening sealing station 28 which includes a plunger piston 29 including a bottom plate 30. The bottom plate 30 has a through hole 31 that extends from the first surface 30a of the bottom plate 30 to the second surface 30b of the bottom plate 30 (shown in Figure 4). The bottom plate 30 may extend in a direction substantially perpendicular to the pressing direction of the plunger piston 29. The bottom plate 30 may extend in a direction substantially perpendicular to the height direction H of the packaging container 1, i.e., substantially parallel to the top layer 17, when the packaging container 1 is placed in the upper body opening sealing area 28. The first surface 30a and the second surface 30b of the bottom plate 30 may be opposing surfaces. The through hole 31 may extend in the height direction H of the packaging container 1.The bottom plate 30 is placed against the first side surface 13a of the transport closure 13, and as shown in Figure 2, the transport closure disc 13 is pushed into the upper body opening 5 by the plunger piston 29 including the bottom plate 30 so that a pressure greater than atmospheric pressure is generated inside the packaging container 1 and on the second side surface 13b of the transport closure 13, thereby closing the upper body opening 5. The first side surface 30a of the bottom plate 30 is placed against the first side surface 13a of the transport closure 13, and when viewed in the height direction H, the through hole 31 of the bottom plate 30 is positioned so that it partially or completely overlaps with the opening 17 of the top layer 13', thereby allowing gas to be discharged from the valve 15 and preconditioning the valve 15.
[0054] The surface area of the plunger piston 29 and / or bottom plate may be 85% or more of the surface area of the base 19 of the transport closure, and optionally 90% or more of the surface area of the base 19 of the transport closure. Such a size ratio can prevent gas from escaping from the internal compartment at the ends of the transport closure 13 and the plunger piston 29 and / or bottom plate 30.
[0055] To further prevent air from escaping from the internal compartment 2 between the transport closure 13 and the inner surface 9 of the container body 8 when the transport closure is pushed into the upper body opening, the outer edge 18 of the transport closure 13 may be shaped and bend when the transport closure 13 is pushed into the upper body opening 5, so that the size ratio of the surface area of the transport closure 13 to the surface area of the upper body opening 5 may be at least 1.01. The outer edge 18 of the transport closure, which forms a peripheral flange 18' projecting from the main plane of the transport closure 13, has its peripheral flange 18' coincide with the inner surface 9 of the container body wall 8.
[0056] In Figure 3, the lid component, including the top rim 20 and the openable / closable lid portion 21, is connected to the packaging container 1 by connecting the top rim 20 to the upper edge 11. The top rim 20 can be attached, for example, by adhesive.
[0057] Figure 4 shows a cross-section of the top of the packaging container 1 and the plunger piston 29, following the steps of the method of closing the upper body opening of the packaging container 1 as shown in Figure 3. As shown in this figure, the plunger piston 29, including the bottom plate 30, pushes the transport closure 13 into the upper body opening 5. The plunger piston 29 may include a plunger 32 made of a flexible material such as rubber, which presses its peripheral flange 18' against the inner surface 9 of the tubular body 3. The through-hole 31 of the bottom plate 30 has a minimum cross-sectional width Wh of 4 mm, which may be in the range of, for example, 4 mm to 35 mm, or for example, 5 mm to 25 mm. Alternatively, the bottom plate may include two or more through-holes, such as three or more through-holes according to the present disclosure. If the bottom plate includes two or more through-holes, or three or more through-holes according to the present disclosure, the minimum cross-sectional width of the through-holes of the bottom plate may be 1 mm or 2 mm.
[0058] In Figure 4, the transport closure 13 includes a top layer 13' and a bottom layer 13'', the top layer 13' having an opening 17, and the valve 15 is located inside the opening 17 and on the surface of the bottom layer 13'', more specifically on the bottom layer 13'' facing the top layer 13'. The through-hole 31 of the bottom plate 30 is positioned to at least partially overlap the opening 17 of the top layer 13' of the transport closure. The through-hole 31 may also be positioned to partially or completely overlap the valve-free region of the opening 17, i.e., the region between the end 17a of the opening 17 and the end 15a of the valve 15.
[0059] Figure 5 shows an arbitrary step of the method according to this disclosure in which the transport closure device 13 is pushed into the upper body opening 5 by a length L1 in the height direction H, and when measured between the upper edge 11 and the base portion 19 of the transport closure device, the length L1 may be 2 mm or more, such as in the range of 2 mm to 50 mm.
[0060] In Figure 5, the upper body sealing section 28 includes a guide member that extends upward from the upper end 4 and forms a guide channel 33 with a length L2 when measured from the upper edge 11 of the container body 3 in the height direction H. The distance is at least 20 mm. The transport closure 13 is pushed into the upper body opening 5 via the guide channel 33, thereby providing higher pressure on the second side 13b of the transport closure 13 for preconditioning of the valve 15. The plunger piston 29 includes a bottom plate 30 that forms a through hole 31 and a plunger 32 made of a flexible material such as rubber, the plunger 32 pressing its peripheral flange 18' against the inner surface 9 of the tubular body 3. The peripheral flange 18' is attached by a welded member 34.
[0061] The sum of lengths L1 and L2 can be within the range of 22mm and 305mm, starting from 22mm.
Claims
1. 1. A method for manufacturing a packaging container for bulk solids, comprising: a packaging container comprising an internal compartment and a transport closure for closing the internal compartment, the transport closure including a top layer and a bottom layer, the bottom layer facing the internal compartment and having an opening in the top layer; the transport closure comprising a one-way pressure relief valve on a first side of the transport closure for allowing gas in the internal compartment of the packaging container to be released therefrom, the valve being located within the opening and on a side of the bottom layer facing the internal compartment, the surface area of the opening being greater than the surface area of the valve; and the transport closure comprising at least one through-hole covered by the valve on the first side of the transport closure, The manufacturing method includes: forming a tubular container body having a top end with a top body opening, a bottom end with a bottom body opening, and a container body wall extending in a height direction of the packaging container between the top and bottom body openings and having inner and outer surfaces, and upper and lower edges of the container body; presenting a container body to an upper body opening seal with a plunger piston including a bottom plate having a through hole extending from a second side of the bottom plate to a first side of the bottom plate opposite the second side; applying the first side of the bottom plate against the first side of the shipping closure so that the through-hole of the bottom plate is positioned to at least partially overlap the opening of the top layer, and forcing the plunger piston and the shipping closure including the bottom plate into the upper body opening, thereby generating a pressure above ambient pressure within the tubular container body at the second side of the shipping closure, causing gas to exit the valve and precondition the valve, thereby closing the upper body opening; and attaching the shipping closure to the inside surface of the container body wall.
2. 10. The method of claim 1, wherein the surface area of the opening in the top layer is at least 20% greater than the surface area of the valve.
3. The method of claim 1 , wherein the valve comprises an upper barrier layer and two elongated strips of adhesive material.
4. 4. The method of claim 3, wherein the two elongated strips of adhesive material are disposed between the upper barrier layer and the first side of the shipping closure, on either side of the through hole in the shipping closure.
5. The method of claim 4 , wherein the valve further comprises a seal lubricant provided over the throughbore.
6. 2. The method of claim 1, wherein the shipping closure includes a peripheral flange surrounding a base portion of the shipping closure, the peripheral flange curving in height toward the upper end of the container body.
7. 7. The method of claim 6, wherein the surface area of the bottom plate is at least 85% of the surface area of the base portion of the shipping closure.
8. When the transport closure is pushed into the upper body opening, a length L is measured between the edge of the upper end and the transport closure in the height direction. １ and pressing the length L １ The method of claim 6, wherein the distance is at least 2 mm.
9. The upper body opening seal includes a guide member that forms a guide channel, and the guide channel is spaced apart from the container body by a length L in the height direction measured from the edge of the upper end. ２ and the length L ２ 2. The method of claim 1, wherein the distance between the upper body opening and the shipping closure is at least 20 mm, and the step of forcing the shipping closure into the upper body opening is performed through the guide channel.
10. 2. The method of claim 1, wherein in the step of forcing the shipping closure into the upper body opening, an outer edge portion of the shipping closure is molded and bent when the shipping closure is forced into the upper body opening, wherein the outer edge portion of the shipping closure forms a peripheral flange that protrudes from a major plane of the shipping closure, and the size ratio of the surface area of the shipping closure to the surface area of the upper body opening is 1.01:1 so that the peripheral flange is aligned with the inner surface of the container body.
11. The method of claim 1 , wherein the through hole in the bottom plate has a minimum cross-sectional width of at least 4 mm.
12. 10. A method of manufacturing a packaging container and filling it with bulk solids, comprising the steps of closing the bottom body opening of the container body, presenting the container body to a filling station, and filling the bulk solids into the container body through the top body opening.
13. 10. The method of claim 1, wherein the method comprises the steps of: rotating the container body, presenting the container body to a filling station, filling the bulk solids into the container body through a bottom opening, and closing the bottom opening of the container body.
14. 1. A method for producing a bulk solids packaging container, comprising: A packaging container comprising an internal compartment and a shipping closure for closing the internal compartment, the shipping closure comprising a one-way pressure relief valve for allowing gas within the internal compartment of the packaging container to escape therefrom, The manufacturing method includes: forming a container body having an upper end with a top body opening, a lower end with a bottom body opening, and a container body wall having an inner surface extending in a height direction of the packaging container between the top body opening and the bottom body opening; presenting a container body to an upper opening seal with a plunger piston including a bottom plate having a through hole extending from a first side of the bottom plate to a second side of the bottom plate; applying the first side of the bottom plate against a first side of the shipping closure so that the through-hole is positioned above the valve, and forcing the plunger piston and the shipping closure including the bottom plate into the upper body opening, thereby generating a pressure greater than ambient pressure within the tubular container body at the second side of the shipping closure, causing gas to exit the valve and precondition the valve, thereby closing the upper body opening; and attaching the shipping closure to the inside surface of the container body wall.
15. 15. The method of claim 14, wherein the shipping closure has at least one through hole on the first side of the shipping closure that is covered by the valve, the first side of the shipping closure facing away from the internal compartment.
16. 15. The method of claim 14, wherein the valve has a thickness of less than 600 μm.
17. The method of claim 14 , wherein the surface area of the through-hole is greater than the surface area of the valve.
18. The method of claim 14 , wherein the valve comprises an upper barrier layer and two elongated strips of adhesive material.
19. 20. The method of claim 18, wherein the two elongated adhesive strips are positioned between the upper barrier layer and the first side of the shipping closure, on either side of at least one through hole in the shipping closure.
20. 20. The method of claim 19, wherein the valve further comprises a seal lubricant provided over the at least one through-hole.
21. 15. The method of claim 14, wherein the shipping closure includes a peripheral flange surrounding a base portion of the shipping closure, the peripheral flange curving in height toward the top end of the container body.
22. When the transport closure is pushed into the upper body opening, a length L is measured between the edge of the upper end and the transport closure in the height direction. １ and pressing the length L １ 15. The method of claim 14, wherein is at least 2 mm.
23. The sealing portion includes a guide member that forms a guide channel, and the guide channel has a length L in the height direction measured from the interior of the top end away from the container body. ２ and the length L ２ 15. The method of claim 14, wherein the distance between the upper body opening and the shipping closure is at least 20 mm, and the step of forcing the shipping closure into the upper body opening is performed through the guide channel.
24. 15. The method of claim 14, wherein an outer edge portion of the shipping closure is molded and bent when the shipping closure is forced into the upper body opening, whereby the outer edge portion of the shipping closure forms a peripheral flange that protrudes from a major plane of the shipping closure and that aligns with the inner surface of the container body.
25. 15. A method of manufacturing a packaging container and filling it with bulk solids, comprising the steps of closing the bottom body opening of the container body, presenting the container body to a filling station, and filling the bulk solids into the container body through the top body opening.
26. 15. The method of claim 14, comprising rotating the container body, presenting the container body to a filling station to fill the container body with the bulk solids through a bottom body opening, and closing the bottom body opening of the container body.