Packaging bags for sealing and storing thin metal sheets

Abstract

This application relates to the field of metal material packaging technology and discloses a packaging bag for sealing and storing thin metal sheets. The packaging bag includes a bag body formed by folding and sealing a sheet of material. The sheet includes a first barrier layer, a printed layer, a second barrier layer, and a heat-sealing layer arranged sequentially from the outside to the inside. The bag body defines an inner cavity for accommodating the thin metal sheets. The head end and two side edges of the sheet are sealed to form a sealing portion, and the tail end of the bag body is the unsealed end. The thin metal sheets are inserted into the inner cavity through the unsealed end, and inert gas is injected into the inner cavity. After inflation, the unsealed end is sealed to form a sealing portion, and the bag body achieves a sealed and expansion-buffered state. This application achieves sealed storage of the thin metal sheets and prevents oxidation, while the injected inert gas keeps the packaging bag in an expansion-buffered state, effectively mitigating external forces during transportation and storage and preventing damage to the thin metal sheets.

Description

Technical Field

[0001] This application relates to the field of metal material packaging technology, specifically to a packaging bag for sealing and preserving thin metal sheets. Background Technology

[0002] This section is intended to provide background or context for the embodiments of this application as set forth in the claims. The content in this section is for reference only and does not constitute an admission or confirmation that it is prior art that has been disclosed.

[0003] With the widespread use of metal materials in food packaging, decorative materials, electronic components, and household applications, rolled metal sheets (such as aluminum foil rolls) have become a common commodity. While the rolled structure facilitates storage, transportation, and use, the thinness and ductility of metal sheets make them highly susceptible to wrinkling, dents, and even breakage during handling and transport, leading to a decline in material performance or damage to appearance. This damage not only affects the user experience but can also result in resource waste and economic losses. Especially in situations where appearance and integrity are critical, buyers often do not want to receive aluminum foil rolls damaged during transit.

[0004] On the other hand, metal materials such as aluminum foil are prone to oxidation when exposed to air and oxygen and moisture, resulting in a dull, lackluster surface that is unsuitable for long-term preservation. Currently, most packaging bags on the market use single-layer plastic film or simple composite film structures, which have limited barrier properties and are insufficient to effectively isolate air and moisture. Furthermore, traditional packaging bags lack additional protection for the ends of the rolled metal sheets, making them susceptible to edge deformation or end damage during transportation and storage due to external forces.

[0005] In summary, existing packaging methods are inadequate in terms of both protection and sealing, and there is an urgent need for an improved packaging solution to enhance the reliability of rolled metal sheets during transportation and storage. Summary of the Invention

[0006] The purpose of this application is to provide a packaging bag for sealing and storing metal sheets. While achieving sealed storage and preventing oxidation of the metal sheets, the packaging bag is in an expanded buffer state by filling it with inert gas, thereby effectively reducing the impact of external forces during transportation and storage and avoiding damage to the metal sheets.

[0007] This application discloses a packaging bag for sealing and storing thin metal sheets, comprising:

[0008] A bag body 1 is formed by folding and sealing a sheet of material. The sheet of material includes a first barrier layer 11, a printed layer 12, a second barrier layer 13 and a heat-sealing layer 14 arranged sequentially from the outside to the inside. The bag body 1 defines an internal cavity for accommodating the metal sheet 2.

[0009] The head end and two sides of the sheet are sealed to form a sealing part 3, and the tail end of the bag body 1 is the end to be sealed.

[0010] The metal sheet 2 is inserted into the inner cavity through the end to be sealed, and inert gas is filled into the inner cavity. After the gas filling is completed, the end to be sealed is sealed to form a sealing part 3, and the bag body 1 forms a sealed and expansion buffer state.

[0011] In a preferred embodiment, the first barrier layer 11 is a PET layer, the second barrier layer 13 is a VMPET layer, and the heat-sealing layer 14 is a PE layer.

[0012] In a preferred embodiment, the thickness of the PET layer is 10-20 micrometers; more preferably, the thickness of the PET layer is 12 micrometers.

[0013] In a preferred embodiment, the thickness of the VMPET layer is 10-20 micrometers; more preferably, the thickness of the VMPET layer is 12 micrometers.

[0014] In a preferred embodiment, the thickness of the PE layer is 50-90 micrometers, and more preferably, the thickness of the PE layer is 70 micrometers.

[0015] In a preferred embodiment, the metal sheet 2 is one of aluminum foil, copper foil, tin foil, nickel foil, or stainless steel foil.

[0016] In a preferred embodiment, the bag body 1, after being inflated and sealed, takes the form of a pillow bag or a stand-up pouch.

[0017] In a preferred embodiment, the bag body 1 has a pre-cut tear opening 4 on its side near the head end and / or the tail end.

[0018] In a preferred embodiment, at least one corner of the bag body 1 is a rounded corner structure 5; more preferably, all four corners of the bag body 1 are rounded corner structures 5.

[0019] In a preferred embodiment, the metal sheet 2 is housed in the internal cavity in a rolled-up form.

[0020] In a preferred embodiment, the content cavity also accommodates a paper roll core 6, on which the metal sheet 2 is wound.

[0021] In a preferred embodiment, the metal sheet 2 is wound around the outside of the paper roll core 6.

[0022] In a preferred embodiment, the metal sheet 2 is wound inside the paper roll core 6.

[0023] In a preferred embodiment, the paper roll core 6 is a hollow cylindrical structure.

[0024] In a preferred embodiment, the diameter of the paper core 6 is 20-40 mm; more preferably, the diameter of the paper core 6 is 28 mm.

[0025] In a preferred embodiment, the metal sheet 2 is wound around the inside and outside of the paper roll core 6.

[0026] In a preferred embodiment, the axial length of the paper core 6 is greater than the axial length of the metal sheet 2, such that after the metal sheet 2 is wound around the paper core 6, both ends of the metal sheet 2 are located inside the ends of the paper core 6.

[0027] In a preferred embodiment, the length of the paper core 6 is 20cm-30cm; more preferably, the length of the paper core 6 is 23cm-27cm; even more preferably, the length of the paper core 6 is 25.8cm.

[0028] In a preferred embodiment, the paper core 6 is 7-10 cm longer in the axial direction than the metal sheet 2; more preferably, the paper core 6 is 8 cm longer in the axial direction than the metal sheet 2.

[0029] In a preferred embodiment, both ends of the paper roll core 6 extend 3.5-5 cm beyond both ends of the metal sheet 2; more preferably, both ends of the paper roll core 6 extend 4 cm beyond both ends of the metal sheet 2.

[0030] In a preferred embodiment, the inert gas is introduced into the inner cavity at a pressure ranging from 100 kPas / m. 2 Up to 480 kPas / m 2 Preferably, the inflation pressure of the inert gas into the inner cavity is in the range of 200 kPas / m³. 2 .

[0031] In a preferred embodiment, the inert gas is nitrogen, argon, or carbon dioxide.

[0032] In this embodiment, the sheet is designed to be formed by sequentially composited PET layer, printing layer, VMPET layer and PE layer, so that the bag body has high mechanical strength, good barrier and reliable sealing performance. In use, the metal sheet is inserted into the inner cavity through the end to be sealed, and after inert gas is filled into it, the end to be sealed is sealed, so that a sealed inert atmosphere environment is formed inside the bag body, and it is in an expanded buffer state due to the inflation. This can effectively isolate external moisture and air, prevent the metal sheet from oxidation and corrosion, and at the same time, the expanded state of the bag body can also buffer external impact, further improving the protective effect of the packaging.

[0033] Furthermore, the packaging bag of this application is applicable to metal sheets, especially easily oxidized materials such as aluminum foil. By storing aluminum foil or other metal sheets in a roll within the inner cavity and winding them onto a paper core, with the paper core being longer than the width of the metal sheet roll in the axial length, both ends of the metal sheet are protected by the paper core, thereby preventing the ends from being squeezed or worn, and improving the integrity and safety during transportation and storage.

[0034] Furthermore, after inflation and sealing, the packaging bag can take the form of a pillow bag or a stand-up pouch, which is convenient for stacking and storage. At the same time, the side of the bag is equipped with a pre-cut tear-out opening, which makes it easy for users to open and improves the convenience of use. The corners of the bag can be designed with rounded corners to reduce the damage to personnel and surrounding items caused by sharp edges during handling and stacking.

[0035] The specification of this application contains numerous technical features distributed across various technical solutions. Listing all possible combinations of these technical features (i.e., technical solutions) would make the specification excessively lengthy. To avoid this problem, the various technical features disclosed in the above-described invention, the various technical features disclosed in the following embodiments and examples, and the various technical features disclosed in the accompanying drawings can be freely combined to form various new technical solutions (all of which are considered to have been described in this specification), unless such a combination of technical features is technically infeasible. For example, one example discloses feature A+B+C, and another example discloses feature A+B+D+E. Features C and D are equivalent technical means that serve the same function, and technically only one needs to be used; they cannot be used simultaneously. Feature E can technically be combined with feature C. Therefore, the solution A+B+C+D should not be considered as described because it is technically infeasible, while the solution A+B+C+E should be considered as described. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a packaging bag for sealing and storing metal sheets according to one embodiment of this application;

[0037] Figure 2 This is a schematic diagram of the layered structure of a packaging bag for sealing and storing metal sheets according to one embodiment of this application;

[0038] Figure 3 This is a schematic diagram of the structural relationship between a paper roll core and a metal sheet according to one embodiment of this application;

[0039] Figure 4 This is a schematic diagram of the structural relationship between a paper roll core and a metal sheet according to one embodiment of this application;

[0040] Figure 5 This is a schematic diagram of a packaging bag for sealing and storing metal sheets after inflation, according to one embodiment of this application.

[0041] Figure 6 This is a schematic diagram of the structure of a packaging bag for sealing and storing metal sheets according to one embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1-Bag

[0044] 11-First Barrier Layer

[0045] 12-Printing layer

[0046] 13-Second Barrier Layer

[0047] 14-Heat-sealing layer

[0048] 2-Metal sheet

[0049] 3-Sealing part

[0050] 4-Pre-cut tear strip

[0051] 5-Rounded corner structure

[0052] 6-Paper roll core Detailed Implementation

[0053] In the following description, many technical details are presented to help the reader better understand this application. However, those skilled in the art will understand that the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0054] the term

[0055] As used herein, "PET layer" refers to a thin film layer formed from polyethylene terephthalate (PET). PET layers typically possess good mechanical strength, abrasion resistance, and transparency, and also exhibit certain heat and chemical resistance. Those skilled in the art will understand that PET layers can be prepared by extrusion, stretching, or other conventional methods, and can be coated, laminated, or surface-treated as needed. The term "PET layer" used in this application is only intended to indicate the material properties of the layer and its role in the composite structure, and is not intended to limit the specific preparation process, thickness, or modification method of PET.

[0056] As used herein, "VMPET layer" refers to a metal-coated film (Vacuum Metallized PET) formed on the surface of a polyethylene terephthalate (PET) base film through a vacuum evaporation process. This layer typically possesses excellent barrier properties, effectively blocking the penetration of external media such as oxygen and water vapor, while also exhibiting certain optical reflective properties. Those skilled in the art will understand that the metal coating material of the VMPET layer is typically aluminum, but other suitable metals or alloys can be selected as needed, and its thickness and process conditions can be adjusted according to specific applications. The term "VMPET layer" used in this application is only used to indicate the functional attributes of the layer and its role in the composite structure, and is not intended to limit its specific metal type, coating thickness, or preparation method.

[0057] As used herein, "PE layer" refers to a thin film layer formed of polyethylene (PE) material. This layer typically possesses good flexibility, low-temperature resistance, and sealing performance, and can be laminated with other layers through hot pressing or other methods to ensure reliable sealing of the packaging bag upon closure. Those skilled in the art will understand that the PE layer can be low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), or modified materials thereof, and the thickness and specific preparation method can be adjusted according to application requirements. The term "PE layer" in this application is used only to indicate the material properties of the layer and its role in the composite structure, and is not intended to limit its specific type, thickness, or molding process.

[0058] As used herein, "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 internal cavity. "Tail end" refers to the end opposite the head end, which is open during molding and is used to insert a metal sheet and seal it after inflation. Those skilled in the art should understand that the terms "head end" and "tail end" are used only to distinguish different positions of the bag body and are not intended to limit the scope of protection of this application.

[0059] This application has at least the following advantages:

[0060] 1. The product of this application can not only be used as a refill for household aluminum foil, but also provides effective protection for the roll of aluminum foil during transportation and storage due to the expansion and cushioning effect formed by the air-sealed system, ensuring it remains in good condition even after being removed from its original packaging. Therefore, in actual use, users can directly pack this product into existing aluminum foil packaging boxes as a refill, achieving the reuse of packaging boxes, thereby reducing paper waste and meeting both the needs of metal foil preservation and environmental protection.

[0061] 2. In the packaging process, nitrogen gas is introduced to create an inert atmosphere inside the packaging bag, thereby protecting the metal sheet roll placed inside and preventing direct contact with external environmental factors (such as moisture and air). This minimizes the possibility of corrosion due to oxidation during storage and transportation, ensuring the stability and long-term preservation performance of the metal sheet roll.

[0062] 3. This application adopts a bag structure formed by sequentially laminating a PET layer, a printing layer, a VMPET layer, and a PE layer. The PET layer provides good mechanical strength and abrasion resistance, ensuring that the packaging bag is not easily damaged during handling and transportation. The printing layer is located on the inner side of the outer layer, which can prevent wear or detachment due to external friction during use, thereby ensuring the integrity of the appearance and label. The VMPET layer has excellent barrier properties, which can effectively block the penetration of oxygen and water vapor. The inner PE layer further provides reliable sealing performance, ensuring that the bag can still maintain good sealing after being filled with nitrogen. Through the synergistic effect of the functions of the above layers, the four-layer composite structure has the advantages of high strength, good barrier properties, durable appearance, and reliable sealing.

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0064] This application relates to a packaging bag for sealing and storing thin metal sheets, the structural diagram of which is shown below. Figure 1-6 As shown, the bag includes: a bag body 1 formed by folding and sealing a sheet of material. The sheet includes, from the outside to the 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 accommodating a metal sheet 2. The head end and two side edges of the sheet are sealed to form a sealing portion 3, and the tail end of the bag body 1 is the end to be sealed. The metal sheet 2 is inserted into the inner cavity through the end to be sealed, and inert gas is injected into the inner cavity. After inflation, the end to be sealed is sealed to form the sealing portion 3, and the bag body 1 forms a sealed and expansion-buffered state.

[0065] In an optional embodiment, the first barrier layer 11 is preferably a PET layer, the second barrier layer 13 is preferably a VMPET layer, and the heat-sealing layer 14 is a PE layer. That is, the PET layer, the printing layer 12, the VMPET layer, and the PE layer are sequentially combined from the outside to the inside to form a sheet.

[0066] In one optional embodiment, the thickness of the PET layer is 10-20 micrometers; preferably, the thickness of the PET layer is 12 micrometers.

[0067] In an optional embodiment, the printed layer 12 is a printed pattern layer formed inside the PET layer. This layer can be an ink layer, which can be directly printed on the inner surface of the PET layer and then laminated with the outer surface of the VMPET layer. Alternatively, it can be an intermediate layer carrying the ink layer, made of a transparent or translucent material, used to carry the ink and then laminated with the inner surface of the PET layer and the outer surface of the VMPET layer. The specific composition and formation method of the printed layer 12 can be selected according to process requirements, including but not limited to ink layers formed by gravure printing, flexographic printing, or digital printing, or carrier coatings formed by coating methods, the material of which can be polyurethane, polyester, or other transparent polymers.

[0068] In one optional embodiment, the VMPET layer has a thickness of 10-20 micrometers; preferably, the VMPET layer has a thickness of 12 micrometers.

[0069] In one optional embodiment, the thickness of the PE layer is 50-90 micrometers, preferably 70 micrometers.

[0070] In an optional embodiment, the sheet is a single-layer film structure formed by a dry lamination process. Specifically, the first barrier layer 11, the printed layer 12, the second barrier layer 13, and the heat-sealing layer 14 are laminated together by a dry lamination method to obtain an integral composite sheet. When in use, the sheet is first processed into a flat single-sheet structure, then the single sheet is folded along its longitudinal or transverse direction, and the three edges after folding are heat-sealed to form a bag with an opening at one end.

[0071] In an optional embodiment, the metal sheet 2 is one of aluminum foil, copper foil, tin foil, nickel foil, or stainless steel foil, or other metal materials suitable for being in sheet or roll form. Preferably, the metal sheet 2 is aluminum foil.

[0072] In one optional embodiment, the length of the bag body 1 is 320mm to 400mm and the width is 70mm to 110mm; preferably, the length of the bag body 1 is 350mm and the width is 90mm. The width of the sealing part 3 (also the heat-sealed part) formed after sealing the left and right sides of the bag body 1 is 5mm to 15mm, and the width of the heat-sealed part formed after sealing the head and tail ends is 10mm to 20mm; preferably, the width of the heat-sealed part on the left and right sides is 10mm, and the width of the heat-sealed part at the head and tail ends is 15mm.

[0073] In an optional embodiment, all four sides of the bag body 1 are sealed by a heat-sealing process to form a sealing portion 3. Specifically, during the forming process of the bag body 1, a certain temperature and pressure are applied to the edges of the bag body 1 using a heat-sealing device, causing the heat-sealing layer 14 of the inner layer of the bag body 1 to melt and adhere to each other, forming a strong sealing structure after cooling. Thus, the head end and two sides of the bag body 1 are pre-sealed, leaving only the tail end as the end to be sealed, so that the metal sheet 2 can be placed into the bag body 1 and inflated. The sealing portion 3 not only ensures the sealing integrity of the three sides of the bag body 1, but also provides a reference point when sealing the tail end, thereby ensuring that the geometry of the entire bag body 1 is regular and conducive to stacking or hanging.

[0074] In an optional embodiment, the bag 1, after inflation and sealing, takes the form of a pillow-shaped bag (e.g., ...). Figure 5 (As shown) or a stand-up pouch. Specifically, a pillow bag is a bag-shaped structure formed by sealing the head and tail ends of the bag body 1 in the same plane, with the middle height being higher than the ends after inflation; a stand-up pouch has a folded edge or an extended surface at the bottom of the bag body 1. Before inflation, the folded edge or extended surface is in a folded and contracted state. After inflation, the folded edge or extended surface is stretched to form a flat bottom structure, so that the bag body 1 can stand upright independently on a plane after inflation. In some embodiments, the bag body 1 can be further designed as a pillow bag with a bottom folded edge, or a stand-up pouch with a side folded edge, to adapt to different storage and display needs.

[0075] In an optional embodiment, the bag body 1 has a pre-cut tear opening 4 on its side near the head and / or tail end. Optionally, the tear opening can be a notch pre-cut into the edge of the bag body 1, and its shape can be an arc-shaped opening, a semi-circular opening, or a triangular opening, with an arc-shaped opening being the most common form. This allows the user to easily tear open the bag body 1 along the cut while maintaining the overall strength of the bag body 1. In some embodiments, the pre-cut tear opening 4 can also be designed as a V-shaped notch or a U-shaped notch to adapt to different opening requirements.

[0076] Preferably, a certain distance is maintained between the tear opening and the metal sheet 2 housed within the inner cavity of the bag body 1 to avoid scratching, damage, or contamination of the metal sheet 2 when the user tears open the bag body 1. The distance can be determined according to the size of the bag body 1 and the specifications of the metal sheet 2, for example, it can be 1mm, 2mm, 5mm, 10mm or larger, to ensure that the metal sheet 2 remains within a safe distance range during the tear opening process.

[0077] In an optional embodiment, at least one corner of the bag body 1 is a rounded corner structure 5; preferably, all four corners of the bag body 1 are rounded corner structures 5. The rounded corner structure 5 can be an arc, an ellipse, or other curved transition structure, and its radius of curvature can be designed to be 3mm, 5mm, or larger depending on the size of the bag body 1. By adopting a rounded corner design, it is possible to avoid sharp right angles causing scratches to operators during handling, stacking, or contact, while reducing the squeezing and damage to other packaged items; in addition, the rounded corner structure 5 can better distribute stress after the bag body 1 is inflated, reducing the risk of corner breakage or bulging, thereby improving the overall safety and durability of the packaging bag.

[0078] In an optional embodiment, the metal sheet 2 is housed in the content cavity in a rolled-up form.

[0079] In an optional embodiment, the content cavity also accommodates a paper roll core 6, with a metal sheet 2 wound around the paper roll core 6.

[0080] In an optional embodiment, such as Figure 3 As shown, the metal sheet 2 can be wound around the outside of the paper roll core 6.

[0081] In an optional embodiment, such as Figure 4 As shown, the metal sheet 2 can be wound inside the paper roll core 6. Since the metal sheet 2 is not directly observable, it is shown as a dashed line.

[0082] In an optional embodiment, the paper roll core 6 is a hollow cylindrical structure.

[0083] In one optional embodiment, the diameter of the paper core 6 is 20-40 mm; preferably, the diameter of the paper core 6 is 28 mm.

[0084] In an alternative embodiment, the metal sheet 2 is wound inside and outside the paper roll core 6.

[0085] In an optional embodiment, the axial length of the paper core 6 is greater than the axial length of the metal sheet 2, such that after the metal sheet 2 is wound around the paper core 6, both ends of the metal sheet 2 are located inside the ends of the paper core 6.

[0086] In one optional embodiment, the length of the paper core 6 is 20cm-30cm; more preferably, the length of the paper core 6 is 23cm-27cm; even more preferably, the length of the paper core 6 is 25.8cm.

[0087] In one optional embodiment, the paper core 6 is 7-10 cm longer in the axial direction than the metal sheet 2; preferably, the paper core 6 is 8 cm longer in the axial direction than the metal sheet 2.

[0088] In one optional embodiment, both ends of the paper roll core 6 extend 3.5-5 cm beyond both ends of the metal sheet 2; preferably, both ends of the paper roll core 6 extend 4 cm beyond both ends of the metal sheet 2.

[0089] In the above embodiments, the metal sheet 2 can be wound in different ways according to actual needs: it can be wound alone and directly placed into the inner cavity, or it can be wound in conjunction with the paper core 6 to improve stability during storage and handling. In different implementations, the metal sheet 2 can be wound around the outside of the paper core 6, or around the inside of the paper core 6, or even simultaneously around both the inner and outer sides of the paper core 6, thus flexibly adjusting the winding structure according to the thickness, length, and application scenario of the metal sheet 2. Through these diverse winding and support methods, the metal sheet 2 can maintain good morphological stability when stored inside the packaging bag, and damage caused by loosening, folding, or impact to the ends can be avoided.

[0090] In an optional embodiment, the inflation pressure of the inert gas into the inner cavity is in the range of 100 kPas / m. 2 Up to 480 kPas / m 2 Preferably, the inflation pressure of the inert gas into the inner cavity is in the range of 200 kPas / m³. 2 In another embodiment, the inflation pressure can be selected as 150 kPas / m. 2 250 kPas / m 2 or 300 kPas / m 2 This is designed to accommodate the storage needs of different sizes of bag 1 or rolls of metal sheet 2. The pressure range ensures that bag 1 maintains a stable cushioning shape after inflation, avoiding both insufficient support due to low pressure and damage to the bag 1 material or insecure sealing due to excessive pressure.

[0091] In one optional embodiment, the inert gas is nitrogen, argon, or carbon dioxide. Those skilled in the art will understand that the inert gas can be used alone or in a mixture of the above gases to achieve a balance between gas cost, sealing performance, and protective capabilities, depending on actual requirements.

[0092] To better understand the technical solution of this application, a specific example is provided below. The details listed in this example are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0093] Example 1

[0094] like Figure 6As shown, in this embodiment, a packaging bag composed of four layers of composite film is prepared. The bag body 1 is 35cm long and 9cm wide. The head and two sides of the bag body 1 are pre-sealed, while the tail end remains open, serving as the opening for inserting the metal sheet 2. The metal sheet 2 to be stored is an aluminum foil roll, which is first wound onto a hollow paper roll core 6. The paper roll core 6 has a diameter of approximately 28mm and a length of approximately 25.8cm, ensuring that both ends of the aluminum foil roll are approximately 4mm inside the ends of the paper roll core 6, thereby preventing edge damage during transportation.

[0095] During packaging, the aluminum foil roll, along with the paper roll core 6, is first inserted into the inner cavity of the bag body 1 from the tail end, positioning it in the center of the bag body 1. After insertion, the tail end is placed at the clamp of the inflation device, the clamp is tightened on both sides of the bag opening, and the inflation nozzle is inserted. Nitrogen gas is then injected into the bag body 1 through the nozzle. The inflation pressure is controlled at approximately 200 kPas / m³. 2 This causes the bag body 1 to gradually inflate and form a cushioned state. After inflation is complete, the nozzle is pulled out, the clamp keeps the bag opening temporarily closed, and then the tail end is heat-sealed by a heat-sealing device to form a reliable seal.

[0096] The sealed packaging bag is shaped like a pillow, with both ends sealed and the middle slightly bulging due to inflation.

[0097] When storing, the packaging bags can be placed directly in warehouses, transport containers, or on shelves as needed. To facilitate user access, a small, rounded tear-off opening is pre-set on each side of the bag body near the head. Users can tear along the tear opening to quickly open the packaging when needed.

[0098] Example 2

[0099] This embodiment has a basically the same overall structure as Embodiment 1, the difference being that the paper core 6 is not provided. When the paper core 6 is not used, the metal sheet can be stored directly in the inner cavity of the bag in a horizontally laid-out form instead of being wound. In this way, damage such as flattening and wrinkling of the metal sheet due to pressure can be avoided when it is wound, thus ensuring the integrity and usability of the metal sheet during transportation and storage.

[0100] The embodiments described above are merely preferred embodiments of this utility model and should be understood as not intended to limit the scope of protection of this utility model. For those skilled in the art, any combination or substitution of the technical features of the above embodiments can be made without departing from the concept of this utility model, and such combinations or substitutions should also be considered to fall within the scope of protection of this utility model.

[0101] It should be noted that in this patent application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this patent application, if it refers to performing an action according to an element, it means performing the action at least according to that element, including two cases: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "repeatedly," and "various" include two, two times, two kinds, and more than two, more than two times, and more than two kinds.

[0102] Furthermore, it should be understood that after reading the above disclosure of this application, those skilled in the art can make various alterations or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A packaging bag for sealing and storing thin metal sheets, characterized in that, include: A bag (1) is formed by folding and sealing a sheet of material, the sheet of material including a first barrier layer (11), a printing layer (12), a second barrier layer (13) and a heat-sealing layer (14) arranged sequentially from the outside to the inside, the bag (1) defining an internal cavity for accommodating the metal sheet (2); The head end and two sides of the sheet are sealed to form a sealing part (3), and the tail end of the bag body (1) is the end to be sealed; The metal sheet (2) is inserted into the inner cavity through the end to be sealed, and inert gas is filled into the inner cavity. After the gas filling is completed, the end to be sealed is sealed to form a sealing part (3), and the bag body (1) forms a sealed and expansion buffer state.

2. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The first barrier layer (11) is a PET layer, the second barrier layer (13) is a VMPET layer, and the heat-sealing layer (14) is a PE layer.

3. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The metal sheet (2) is one of aluminum foil, copper foil, tin foil, nickel foil or stainless steel foil.

4. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The bag body (1) has a pre-cut tear opening (4) on the side near the head end and / or the tail end.

5. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, At least one corner of the bag body (1) is a rounded corner structure (5).

6. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The metal sheet (2) is rolled up and stored in the internal cavity.

7. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The content cavity also contains a paper roll core, and the metal sheet (2) is wound around the paper roll core (6).

8. The packaging bag for sealing and storing metal sheets as described in claim 7, characterized in that, The paper core (6) is longer in the axial direction than the metal sheet (2) in the axial direction, so that after the metal sheet (2) is wound around the paper core (6), both ends of the metal sheet (2) are located inside the end of the paper core (6).

9. The packaging bag for sealing and storing metal sheets as described in claim 1, characterized in that, The inert gas is introduced into the inner cavity at a pressure range of 100 kPas / m. 2 Up to 480 kPas / m 2 .

10. The packaging bag for sealing and storing metal sheets as described in any one of claims 1-9, characterized in that, The inert gas is nitrogen, argon, or carbon dioxide.

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