Packaging bags for sealing and storing metal foil

Abstract

In the field of packaging metal materials, a packaging bag for sealing and storing metal foil is provided. [Solution] The bag body 1 is formed by folding and sealing a single sheet material. The sheet material includes, in order from outside to inside, a first barrier layer, a printed layer, a second barrier layer, and a heat-sealing layer. The bag body defines an inner cavity for containing a metal foil 2. The head end and side edges of the sheet material are sealed to form a sealed portion 3, and the tail end of the bag body is a sealing end. The metal foil is inserted into the inner cavity through the sealing end, and an inert gas is filled into the inner cavity. After filling is complete, the sealing end is sealed to form a sealed portion, leaving the bag body sealed and in an expansion buffer state. This device not only seals and preserves the metal foil and prevents oxidation, but also effectively cushions external forces during transportation and storage, preventing damage to the metal foil by filling the inert gas into the packaging bag.

Description

[Technical Field]

[0001] The present invention relates to the field of packaging technology for metal materials, and more particularly to a packaging bag for sealing and storing metal foil. [Background technology]

[0002] This section provides a background or context for understanding the claimed embodiments of the present invention. This section is provided for reference only and does not constitute an admission or confirmation that any of the inventions are disclosed as prior art.

[0003] As metal materials are widely used in food packaging, decorative materials, electronic devices, and household applications, rolled metal foils (e.g., aluminum foil rolls) have become a common commercial product. While rolled structures are convenient for transportation and handling, metal foils are typically thin and highly ductile, which means they easily wrinkle, dent, or break during transportation, resulting in a decline in material performance and damage to appearance quality. Such damage not only impairs the user experience, but also wastes resources and results in economic losses. Buyers, especially in cases where appearance and integrity are important, do not want aluminum foil rolls that have already been damaged during transportation.

[0004] Furthermore, metal materials such as aluminum foil are susceptible to reaction with oxygen and moisture in the atmosphere, causing the surface to darken and lose its luster due to oxidation, which is unfavorable for long-term storage. The packaging bags commonly used on the market today are often made of single-layer plastic film or simple composite membrane structures, which have limited barrier performance and are unable to adequately block air and moisture. At the same time, conventional packaging bags lack a protective design for the edges of the metal foil roll, which often results in deformation or damage to the edges of the metal foil due to external forces during transportation and storage.

[0005] In summary, existing packaging methods are deficient in both protection and sealing, and improved packaging solutions are needed to improve the reliability of rolled metal foil during transportation and storage. Summary of the Invention

[0006] The object of the present invention is to provide a packaging bag for sealing and storing metal foil, which can seal and store the metal foil to prevent oxidation, and at the same time, use an inert gas filled in the packaging bag to put the packaging bag into an expansion buffer state, thereby effectively mitigating the action of external forces during transportation and storage, and preventing damage to the metal foil.

[0007] The present invention discloses a packaging bag for sealing and storing metal foil, The bag includes a bag body 1 formed by folding and sealing a single sheet material, the sheet material including, in order from the outside to the inside, a first barrier layer 11, a printed layer 12, a second barrier layer 13, and a heat seal layer 14, the bag body 1 defining an inner cavity for accommodating the metal foil 2; The head end and both side edges of the sheet material are sealed to form a sealed portion 3, and the tail end of the bag body 1 is a sealing end, Here, the metal foil 2 is loaded into the inner cavity through the closing end, and an inert gas is filled into the inner cavity. After filling is completed, the closing end is sealed to form the sealed portion 3, and the bag body 1 is in a sealed and expansion buffer state.

[0008] In a preferred example, the first barrier layer 11 is a PET layer, the second barrier layer 13 is a VMPET layer, and the heat seal layer 14 is a PE layer.

[0009] In a preferred example, the thickness of the PET layer is 10 to 20 μm, and preferably the thickness of the PET layer is 12 μm.

[0010] In a preferred example, the VMPET layer has a thickness of 10 to 20 μm, and preferably has a thickness of 12 μm.

[0011] In a preferred example, the thickness of the PE layer is 50 to 90 μm, and preferably the thickness of the PE layer is 70 μm.

[0012] In a preferred example, the metal foil 2 is any one of aluminum foil, copper foil, tin foil, nickel foil, and stainless steel foil.

[0013] In a preferred example, the bag body 1 assumes the form of a pillow-shaped bag or a self-standing bag after being gas-filled and sealed.

[0014] In a preferred example, a slit tear opening 4 is provided in advance on the side edge of the bag body 1 at a position close to the head end and / or the tail end.

[0015] In a preferred example, at least one corner of the bag body 1 has a rounded corner structure 5, and preferably all four corners of the bag body 1 have a rounded corner structure 5.

[0016] In a preferred example, the metal foil 2 is housed in the cavity in a rolled form.

[0017] In a preferred example, a paper roll core 6 is further accommodated in the cavity, and the metal foil 2 is wound around the paper roll core 6.

[0018] In a preferred example, the metal foil 2 is wound around the outside of the paper roll core 6 .

[0019] In a preferred example, the metal foil 2 is wound inside the paper roll core 6 .

[0020] In a preferred example, the paper roll core 6 has a hollow cylindrical structure.

[0021] In a preferred example, the diameter of the paper roll core 6 is 20 to 40 mm, and preferably the diameter of the paper roll core 6 is 28 mm.

[0022] In a preferred example, the metal foil 2 is wound around the inside and outside of the paper roll core 6 .

[0023] In a preferred example, the axial length of the paper roll core 6 is longer than the axial length of the metal foil 2, and after the metal foil 2 is wound around the paper roll core 6, both ends of the metal foil 2 are located within the ends of the paper roll core 6.

[0024] In a preferred example, the length of the paper roll core 6 is 20 cm to 30 cm, preferably the length of the paper roll core 6 is 23 cm to 27 cm, and more preferably the length of the paper roll core 6 is 25.8 cm.

[0025] In a preferred example, the axial length of the paper roll core 6 is 7 to 10 cm longer than the axial length of the metal foil 2, and preferably, the axial length of the paper roll core 6 is 8 cm longer than the axial length of the metal foil 2.

[0026] In a preferred example, both ends of the paper roll core 6 protrude from both ends of the metal foil 2 by 3.5 to 5 cm, and preferably, both ends of the paper roll core 6 protrude from both ends of the metal foil 2 by 4 cm.

[0027] In a preferred example, the gas filling pressure range in which the inert gas is filled into the cavity is 100 kPas / m 2 ~480kPas / m 2 Preferably, the gas filling pressure range in which the inert gas is filled into the cavity is 200 kPas / m 2 is.

[0028] In a preferred example, the inert gas is nitrogen, argon or carbon dioxide.

[0029] In one embodiment of the present invention, the sheet material is formed by sequentially combining a PET layer, a printed layer, a VMPET layer, and a PE layer. This gives the bag body high mechanical strength, excellent barrier properties, and reliable sealing performance. During use, the metal foil is inserted into the inner cavity through the sealing end, and after filling the interior with an inert gas, the sealing end is sealed. This creates a sealed inert atmosphere inside the bag body, and the gas filling creates an expanded buffer state, thereby effectively blocking external moisture and air and preventing oxidation and corrosion of the metal foil. At the same time, the expanded state of the bag body also cushions external forces and impacts, further improving the protective effect of the packaging.

[0030] Furthermore, the packaging bag of the present invention is applicable to materials that are easily oxidized, such as metal foil, especially aluminum foil. The aluminum foil or other metal foil is placed in a rolled form within the cavity and wound around a paper roll core. Since the paper roll core is axially longer than the width of the metal foil roll, both ends of the metal foil are protected by the paper roll core, preventing the ends from being pressed or worn, and improving the integrity and safety during transportation and storage.

[0031] Furthermore, the packaging bag can take the form of a pillow-shaped bag or a self-standing bag after being gas-filled and sealed, which makes it easy to load, store, and transport. At the same time, the side edges of the bag body can be pre-cut to tear, making it easy for users to open, and increasing convenience. The corners of the bag body can be designed with rounded corners, which can reduce the risk of injury to personnel and surrounding objects caused by sharp corners during transportation and loading.

[0032] The specification of the present invention describes numerous technical features, which are scattered across various technical inventions. If all possible combinations of technical features (i.e., technical inventions) of the present invention were to be listed, the specification would become excessively lengthy. To avoid this problem, the technical features disclosed in the above description of the present invention, the technical features disclosed in the following embodiments and examples, and the technical features disclosed in the accompanying drawings may be freely combined with each other to form various new technical inventions (all of which are deemed to have been previously described in this specification), unless such a combination of technical features is technically impossible. For example, if one example discloses features A+B+C and another example discloses features A+B+D+E, and features C and D are equivalent technical means performing the same function, technically either one can be selected and cannot be employed simultaneously. Since feature E can be technically combined with feature C, the invention A+B+C+D is technically impossible and is not deemed to be described, but the invention A+B+C+E is deemed to be described. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a schematic diagram showing the structure of a packaging bag for sealing and storing metal foil according to one embodiment of the present invention; [Figure 2] 1 is a schematic diagram showing the layer structure of a main body of a packaging bag for sealing and storing metal foil according to one embodiment of the present invention; [Figure 3] 2 is a schematic diagram of the structural relationship between the paper roll core and the metal foil according to one embodiment of the present invention; FIG. [Figure 4] 2 is a schematic diagram of the structural relationship between the paper roll core and the metal foil according to one embodiment of the present invention; FIG. [Figure 5] 1 is a schematic view of a packaging bag for sealing and storing metal foil according to one embodiment of the present invention after being filled with gas and expanded; [Figure 6] 1 is a schematic diagram showing the structure of a packaging bag for sealing and storing metal foil according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0034] In the following description, many technical details are presented to help readers better understand the present invention, but those skilled in the art will understand that the technical invention claimed by the present invention can be realized without these technical details and various changes and modifications based on the following embodiments.

[0035] term As used herein, "PET layer" refers to a thin film layer formed from a polyethylene terephthalate (PET) material. PET layers generally have excellent mechanical strength, abrasion resistance, and transparency, as well as certain heat and chemical resistance. Those skilled in the art will understand that PET layers can be manufactured by extrusion film formation, stretching film formation, or other known methods, and may be coated, composited, or surface-treated as needed. The term "PET layer" in this invention is used only to indicate the material properties and function of the layer in a composite structure, and is not intended to limit the specific manufacturing method, thickness, or modification method of PET.

[0036] As used herein, the term "VMPET layer" refers to a metallized film (VCM) formed on the surface of a polyethylene terephthalate (PET) base film by a vacuum deposition process. This layer generally possesses excellent barrier properties, effectively blocking the penetration of external media such as oxygen and moisture, while also providing a certain degree of optical reflectivity. Those skilled in the art will appreciate that while the metallized material for the VMPET layer is typically aluminum, other suitable metals or alloys may be selected as needed, and the thickness and processing conditions can be adjusted according to specific applications. The term "VMPET layer" in this invention is used solely to indicate the functional attributes of the layer and its role in the composite structure, and is not intended to limit the specific metal species, thickness of the deposited layer, or manufacturing method.

[0037] As used herein, "PE layer" refers to a thin film layer made of polyethylene (PE) material. This layer generally has excellent flexibility, low-temperature resistance, and sealing performance, and can be combined with other layers by heat and pressure or other methods to ensure reliable sealing when sealing a packaging bag. Those skilled in the art should understand that the PE layer can be low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), or modified materials, and that the thickness and manufacturing method can be adjusted depending on the application. In this invention, the term "PE layer" is used only to indicate the material properties of the layer and its function in the composite structure, and is not intended to limit its specific type, thickness, or molding process.

[0038] As used herein, the term "head end" refers to one end of the bag body, which is sealed after molding and is typically used to define one side of the lumen. The term "tail end" refers to the end opposite the head end, which is open during molding, used to insert metal foil, and sealed after gas filling. Those skilled in the art should understand that the terms "head end" and "tail end" are used merely to conveniently distinguish different positions on the bag body and are not intended to limit the scope of protection of the present invention.

[0039] The present invention has at least the following advantages:

[0040] 1. The product of this invention can not only be used to refill aluminum foil for household use, but also effectively protects the rolled aluminum foil during transportation and storage due to the expansion and cushioning state created by filling and sealing, allowing the product to maintain good foil quality even without a packaging box. Therefore, when actually used, the product can be directly loaded as a refill roll into an existing aluminum foil packaging box, allowing the packaging box to be reused and paper waste to be reduced, while simultaneously meeting the requirements of both preserving and protecting the metal foil and protecting the environment.

[0041] 2. In this invention, nitrogen is filled into the packaging bag during the packaging process, thereby creating an inert atmosphere inside the packaging bag, protecting the metal foil roll placed inside and preventing direct contact with external environmental elements (such as moisture and air). This reduces the possibility of corrosion due to oxidation during storage and transportation, and ensures the stability and long-term storage performance of the metal foil roll.

[0042] 3. This invention adopts a bag body structure in which a PET layer, a printing layer, a VMPET layer, and a PE layer are sequentially compositely formed. The PET layer provides excellent mechanical strength and abrasion resistance, ensuring that the packaging bag is not easily damaged during transportation and handling. The printing layer is located on the inside of the outer layer, preventing wear and peeling due to external friction during use, thereby ensuring the integrity of the appearance and labeling. The VMPET layer has excellent barrier properties and can effectively prevent the penetration of oxygen and moisture. The inner PE layer provides even more reliable sealing performance, allowing the bag body to maintain good sealing even after filling with nitrogen. Due to the synergistic functions of the above layers, this four-layer composite structure simultaneously possesses high strength, excellent barrier properties, durable appearance, and reliable sealing.

[0043] In order to make the objectives, technical means and advantages of the present invention clearer, the following describes in more detail the embodiments of the present invention with reference to the accompanying drawings.

[0044] This invention relates to a packaging bag for sealing and storing metal foil, the structure of which is shown in Figures 1 to 7. It includes a bag body 1 formed by folding and sealing a single sheet of material. The sheet material includes, from outside to inside, a first barrier layer 11, a printed layer 12, a second barrier layer 13, and a heat-sealing layer 14. The bag body 1 defines an inner cavity for containing metal foil 2. The head end and both side edges of the sheet material are sealed to form a sealing portion 3, and the tail end of the bag body 1 is a sealing end. Here, metal foil 2 is inserted into the inner cavity through the sealing end, and the inner cavity is filled with an inert gas. After filling is complete, the sealing end is sealed to form the sealing portion 3, and the bag body 1 is in a sealed and inflation-resistant state. In one alternative embodiment, the first barrier layer 11 is preferably a PET layer, the second barrier layer 13 is preferably a VMPET layer, and the heat seal layer 14 is a PE layer. That is, the PET layer, the printing layer 12, the VMPET layer, and the PE layer are laminated in this order from the outside to the inside to form the sheet material.

[0045] In one alternative embodiment, the thickness of the PET layer is 10 to 20 μm, and preferably the thickness of the PET layer is 12 μm.

[0046] In one alternative embodiment, the printing layer 12 is a printing pattern layer formed inside the PET layer. This layer may be an ink layer that can be printed directly on the inner surface of the PET layer and then laminated with the outer surface of the VMPET layer, or an ink-carrying intermediate layer made of a transparent or translucent material that carries the ink and is used to laminate with the inner surface of the PET layer and the outer surface of the VMPET layer. The specific structure and method of forming the printing layer 12 can be selected according to the process needs, including, but not limited to, an ink layer formed by gravure printing, flexographic printing, or digital printing, or a carrier coating layer formed by a coating method. The material may be polyurethane, polyester, or other transparent polymers.

[0047] In one alternative embodiment, the VMPET layer has a thickness of 10-20 μm, preferably 12 μm.

[0048] In one alternative embodiment, the thickness of the PE layer is 50 to 90 μm, and preferably the thickness of the PE layer is 70 μm.

[0049] In one alternative embodiment, the sheet material is a single-layer film structure formed by a dry lamination process. Specifically, a first barrier layer 11, a printing layer 12, a second barrier layer 13, and a heat-sealing layer 14 are laminated together by dry lamination to form an integrated composite sheet material. When used, the sheet material is first processed into a flat, single-piece structure, and then the single piece is folded lengthwise or widthwise and the edges of the folded three sides are heat-sealed to form a bag body with an opening at one end.

[0050] In an alternative embodiment, the metal foil 2 is either an aluminum foil, a copper foil, a tin foil, a nickel foil, or a stainless steel foil, or any other metal material suitable for being in foil or roll form. Preferably, the metal foil 2 is an aluminum foil.

[0051] In one alternative embodiment, the length of the bag body 1 is 320 mm to 400 mm, and the width is 70 mm to 110 mm, preferably the length is 350 mm and the width is 90 mm. The width of the sealed portion 3 (also called the heat-sealed portion) formed by sealing both the left and right sides of the bag body 1 is 5 mm to 15 mm, and the width of the heat-sealed portion formed by sealing the head end and tail end is 10 mm to 20 mm, preferably the width of the heat-sealed portion on both the left and right sides is 10 mm, and the width of the heat-sealed portion at the head end and tail end is 15 mm.

[0052] In one alternative embodiment, all four sides of the bag body 1 are sealed using a heat sealing process to form the sealed portion 3. Specifically, during the forming process of the bag body 1, a heat sealing device is used to apply a predetermined temperature and pressure to the edges of the bag body 1, melting and adhering the heat-sealed layers 14 on the inner surface of the bag body 1 to form a strong sealing structure after cooling. This pre-seals the head and side edges of the bag body 1, leaving only the tail end as a pre-sealed end, allowing for the subsequent process of inserting the metal foil 2 into the bag body 1 and filling it with gas. The sealed portion 3 not only ensures the integrity of the sealing on all three sides of the bag body 1, but also serves as a reference for the subsequent sealing of the tail end, thereby ensuring the overall geometric shape of the bag body 1 and facilitating stacking or hanging.

[0053] In one alternative embodiment, the bag body 1 assumes the form of a pillow-shaped bag (as shown in FIG. 5 ) or a free-standing bag after filling and sealing. Specifically, a pillow-shaped bag is a pouch-like structure formed by sealing the head and tail ends of the bag body 1 in the same plane, and after inflation, the height of the central portion is higher than the end portions. A free-standing bag has a folded portion or an unfolded surface at the bottom of the bag body 1. Before gas filling, the folded portion or unfolded surface is in a folded, deflated state. After gas filling, the folded portion or unfolded surface juts out to form a flat bottom structure, allowing the bag body 1 to stand upright on a flat surface after gas filling. In certain embodiments, the bag body 1 can be further designed as a pillow-shaped bag with a bottom folded portion or a free-standing bag with side folded portions to accommodate different storage and display needs.

[0054] In one alternative embodiment, a pre-cut tear opening 4 is provided on the side edge of the bag body 1 near the head end and / or tail end. Optionally, the tear opening is configured by pre-cutting the edge of the bag body 1, and its shape is arc-shaped, semicircular, or triangular, where arc-shaped is a common shape and allows the user to easily tear the bag body 1 along the cut while maintaining the strength of the entire bag body 1. In a specific embodiment, the pre-cut tear opening 4 is further designed as a V-shaped or U-shaped cut to accommodate different opening needs.

[0055] Preferably, a certain distance is maintained between the tear opening and the metal foil 2 contained within the cavity of the bag body 1 to prevent the user from scratching, damaging, or contaminating the metal foil 2 when tearing the bag body 1. The distance is determined based on the dimensions of the bag body 1 and the specifications of the metal foil 2, and may be, for example, 1 mm, 2 mm, 5 mm, 10 mm, or more, to ensure that the metal foil 2 remains within a safe distance range even during the opening process.

[0056] In one alternative embodiment, at least one corner of the bag body 1 has a rounded corner structure 5, and preferably, all four corners of the bag body 1 have rounded corner structures 5. The rounded corner structure 5 may be an arc-shaped, elliptical, or other curved transition structure, and the radius of the round corner may be designed to be 3 mm, 5 mm, or more based on the dimensions of the bag body 1. The rounded corner design prevents sharp right angles from causing abrasions to operators during conveying, loading, or contacting processes, and simultaneously reduces pressure and damage to other packaged items. Furthermore, the rounded corner structure 5 better distributes stress after the bag body 1 is filled with gas, reducing the risk of corner rupture or swelling, thereby improving the safety and durability of the entire packaging bag.

[0057] In one alternative embodiment, the metal foil 2 is housed in a lumen in a rolled form.

[0058] In an alternative embodiment, a paper roll core 6 is further housed within the lumen, and the metal foil 2 is wound around the paper roll core 6 .

[0059] In one alternative embodiment, the metal foil 2 can be wound around the outside of a paper roll core 6, as shown in FIG.

[0060] In one alternative embodiment, as shown in FIG. 4, the metal foil 2 can be wound inside the paper roll core 6, and is shown in dashed lines because the metal foil 2 cannot be directly observed.

[0061] In one alternative embodiment, the paper roll core 6 is a hollow cylindrical structure.

[0062] In one alternative embodiment, the diameter of the paper roll core 6 is 20-40 mm, preferably the diameter of the paper roll core 6 is 28 mm.

[0063] In one alternative embodiment, the metal foil 2 is wrapped around the inside and outside of the paper roll core 6 .

[0064] In one alternative embodiment, the axial length of the paper roll core 6 is longer than the axial length of the metal foil 2, and after the metal foil 2 is wound around the paper roll core 6, both ends of the metal foil 2 are located within the ends of the paper roll core 6.

[0065] In one alternative embodiment, the length of the paper roll core 6 is 20 cm to 30 cm, preferably the length of the paper roll core 6 is 23 cm to 27 cm, and more preferably the length of the paper roll core 6 is 25.8 cm.

[0066] In one alternative embodiment, the axial length of the paper roll core 6 is 7 to 10 cm longer than the axial length of the metal foil 2, and preferably, the axial length of the paper roll core 6 is 8 cm longer than the axial length of the metal foil 2.

[0067] In one alternative embodiment, both ends of the paper roll core 6 protrude from both ends of the metal foil 2 by 3.5 to 5 cm, and preferably both ends of the paper roll core 6 protrude from both ends of the metal foil 2 by 4 cm.

[0068] In each of the above embodiments, different winding methods can be selected for the metal foil 2 according to actual needs, including winding it alone and placing it directly inside the lumen, or winding it in combination with the paper roll core 6 to improve stability during storage and transportation. In different embodiments, the metal foil 2 can be wound on the outside of the paper roll core 6, wound inside the paper roll core 6, or even wound simultaneously on both the inside and outside of the paper roll core 6, allowing the winding structure to be flexibly adjusted according to the thickness, length, and application of the metal foil 2. The above various winding and supporting methods ensure good dimensional stability of the metal foil 2 when stored inside a packaging bag and prevent damage caused by loosening, bending, or impacts to the edges.

[0069] In one alternative embodiment, the filling pressure range for filling the lumen with an inert gas is 100 kPa / m 2 ~480kPas / m 2 Preferably, the pressure range for filling the cavity with the inert gas is 200 kPas / m 2 In another embodiment, the gas filling pressure is 150 kPas / m 2 , 250kPas / m 2 or 300kPas / m 2 can be selected according to the size of the bag body 1 or the storage needs of the coil material of the metal foil 2. This pressure range ensures that the bag body 1 maintains a stable cushioning shape after filling, and prevents insufficient support for the bag body 1 due to too low a pressure, while also preventing damage to the material of the bag body 1 or poor sealing due to too high a pressure.

[0070] In one alternative embodiment, the inert gas is nitrogen, argon, or carbon dioxide. Those skilled in the art should understand that the inert gas can be used alone or in the form of a mixture of the above gases, and can balance gas cost, sealing performance, and protection performance according to actual needs.

[0071] In order to better understand the technical solution of the present invention, specific examples are used below for explanation, and the details listed in the examples are for ease of understanding, and do not limit the protection scope of the present invention.

[0072] Example 1 As shown in Figure 6, in this example, a packaging bag made of four layers of composite film is prepared, with the bag body 1 having a length of 35 cm and a width of 9 cm, the head end and both side edges of the bag body 1 being pre-sealed, and the tail end being left open and functioning as an opening for accommodating metal foil 2. The metal foil 2 to be stored is an aluminum foil roll wound around a hollow paper roll core 6, which has a diameter of approximately 28 mm and a length of approximately 25.8 cm, and is configured so that both ends of the aluminum foil roll are located approximately 4 mm inward from the ends of the paper roll core 6, thereby preventing damage to the ends during transportation.

[0073] When packaging, the aluminum foil roll is first inserted into the cavity of the bag body 1 together with the paper roll core 6 from the tail end, and placed in the center of the bag body 1. After insertion is complete, the tail end is placed in the clamp mouth of the gas filling device, and while both sides of the bag mouth are fixed with the clamp mouth, a gas filling nozzle is inserted and nitrogen gas is filled into the inside of the bag body 1 through the nozzle. The gas filling pressure is approximately 200 kPas / m 2 The pressure is controlled so that the bag body 1 gradually expands to create a buffer state. After gas filling is complete, the nozzle is pulled out, and while the bag mouth is temporarily closed with the clamp mouth, the tail end is heat-sealed using a heat sealing device to form a highly reliable seal.

[0074] After sealing, the entire packaging bag has the shape of a pillow-shaped bag, with both ends sealed and the center slightly inflated due to the gas filling.

[0075] During storage, the packaging bag can be stored directly in a warehouse, a transport container, or on a shelf as needed. Furthermore, to make it easier for users to open, small arc-shaped tear openings are provided near the top end of each side edge of the bag body 1, and users can quickly open the bag by tearing along these openings when using it.

[0076] Example 2 This embodiment has substantially the same overall structure as that of Example 1, except that it does not include a paper roll core 6. Without the paper roll core 6, the metal foil 2 does not need to be stored in a rolled state, but can be stored directly in a horizontally expanded state within the lumen of the bag body. This method prevents damage such as crushing or wrinkling that can occur when the metal foil is compressed in a rolled state, thereby ensuring the integrity and usability of the metal foil 2 during transportation and storage.

[0077] It should be understood that the above-described embodiments are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. Those skilled in the art can arbitrarily combine or replace the technical features of the above embodiments without departing from the concept of the present invention, and such combinations or replacements are also deemed to fall within the scope of protection of the present invention.

[0078] In the invention document for this utility model, the use of relational terms such as "first," "second," etc., is merely used to distinguish one entity or operation from another and does not necessarily require or imply a real relationship or order between those entities or operations. Furthermore, the terms "comprise," "include," and any other variations thereof are intended to mean an inclusive inclusion, such that a process, method, article, or device comprising a set of elements includes not only those elements but also other elements not expressly listed or inherent in the process, method, article, or device. Unless further limited, an element defined as "comprising one" does not exclude the presence of other identical elements in the process, method, article, or device that includes the element. When the invention document for this utility model describes performing an action based on a certain element, it means performing the action based on at least that element, including both performing the action based on that element alone and performing the action based on that element and other elements. Expressions such as "plurality," "multiple times," and "multiple types" include two, two times, two types, and more than two, two or more times, and more than two types.

[0079] It should be further understood that, after reading the above disclosure of the present invention, those skilled in the art can make various changes and modifications to the present invention, and these equivalent forms also fall within the scope of protection claimed by the present invention. [Explanation of symbols]

[0080] 1 bag 11 First barrier layer 12 printing layer 13 Second barrier layer 14 Heat seal layer 2. Metal foil 3 Sealed part 4 Pre-cut tear opening 5 Rounded corner structure 6 Paper roll cores

Claims

1. A packaging bag for sealing and storing metal foil, The bag includes a bag body (1) formed by folding and sealing a single sheet material, the sheet material including, in order from the outside to the inside, a first barrier layer (11), a printed layer (12), a second barrier layer (13), and a heat seal layer (14), the bag body (1) defining an inner cavity for accommodating the metal foil (2); The head end and both side edges of the sheet material are sealed to form a sealed portion (3), and the tail end of the bag body (1) is a sealing end, Here, the metal foil (2) is loaded into the inner cavity through the closing end, an inert gas is filled into the inner cavity, and after filling is completed, the closing end is sealed to form a sealed portion (3), and the bag body (1) is in a sealed and expansion-buffered state.

2. The first barrier layer (11) is a PET layer, the second barrier layer (13) is a VMPET layer, and the heat seal layer (14) is a PE layer. A packaging bag for sealing and storing the metal foil according to claim 1.

3. The metal foil (2) is any one of aluminum foil, copper foil, tin foil, nickel foil, and stainless steel foil. A packaging bag for sealing and storing the metal foil according to claim 1.

4. The bag body (1) is characterized in that a pre-cut tear opening (4) is provided on the side edge of the bag body (1) near the head end and / or the tail end. A packaging bag for sealing and storing the metal foil according to claim 1.

5. At least one corner of the bag body (1) is characterized by a rounded corner structure (5). A packaging bag for sealing and storing the metal foil according to claim 1.

6. The metal foil (2) is wound and accommodated in the cavity. A packaging bag for sealing and storing the metal foil according to claim 1.

7. A paper roll core (6) is further accommodated in the inner cavity, and the metal foil (2) is wound around the paper roll core (6). A packaging bag for sealing and storing the metal foil according to claim 1.

8. The axial length of the paper roll core (6) is longer than the axial length of the metal foil (2), and after the metal foil (2) is wound around the paper roll core (6), both ends of the metal foil (2) are located within the ends of the paper roll core (6). A packaging bag for sealing and storing the metal foil according to claim 7.

9. The gas filling pressure range in which the inert gas is filled into the cavity is 100 kPa / m ２ ~480kPas / m ２ characterized in that A packaging bag for sealing and storing the metal foil according to claim 1.

10. The inert gas is nitrogen, argon, or carbon dioxide. A packaging bag for sealing and storing the metal foil according to any one of claims 1 to 9.

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