Drop-resistant shockproof corner air column bag

Abstract

The application discloses a kind of anti-shock corner air column bags, belong to packaging material technical field.The corner air column bag includes the bag body formed by multilayer composite film, and multilayer composite film includes the outer layer, middle layer and inner layer which are stacked and integrally combined by co-extrusion process;Multiple independent air column units are formed by heat-sealing line on the bag body;The bag body includes the first external buffer air column bag and the second internal buffer air column bag integrally formed by multilayer composite film, and first buffer cavity is formed between the two, and second buffer cavity is formed inside the second internal buffer air column bag;The bending part of L-shaped folding corner structure of bag body is integrated with elastic support structure, including elastic sheet, fixed strip and protective strip, and the elastic sheet has arch, wave or V-shaped bending structure;Self-adapting sealing inflation valve is provided on the bag body.The application improves the puncture resistance, anti-shock and long-term airtightness through the synergistic effect of multilayer co-extrusion composite film, integrally formed inner and outer double-layer air column and integrated elastic support structure.

Description

Technical Field

[0001] This invention relates to the field of packaging materials technology, and in particular to a shockproof and drop-resistant corner-protecting air column bag. Background Technology

[0002] Corner protection air column bags are packaging materials that use inflatable air columns to provide cushioning protection. They are widely used in the logistics and storage of products such as home appliances, furniture, and precision instruments to cover the corners of items to prevent damage caused by collisions, drops, etc.

[0003] Existing corner protector air column bags have the following main shortcomings: First, the air column bag membrane material is mostly a single-layer or double-layer polyethylene structure, which lacks sufficient puncture resistance and toughness, making it easily punctured by sharp objects during transportation, leading to air column leakage and failure. Although some use a nylon and polyethylene composite structure, it is mostly a two-layer composite, with each layer bonded by adhesives, resulting in insufficient interlayer bonding strength and easy delamination. Second, most existing corner protector air column bags are single-layer air column structures. Once a local air column is damaged, the cushioning and protective capacity of that area is completely lost. Although some products use a double-layer structure, they are mostly separable nested designs or multi-wall structures formed by bending a single-layer air column, rather than a one-piece molded inner and outer double-layer air column bag, resulting in poor structural stability and limited cushioning effect. Third, the cushioning support structure of existing air column bags is mostly an independent external accessory, such as a rubber sheet, V-shaped plate, or outer sleeve, which requires additional assembly and is inconvenient to use. Although there are technical solutions that incorporate elastic sheets and protective strips on the air column heat-sealing strip, the elastic sheets in these solutions are flat and located on the outer surface of the air column heat-sealing strip. The buffering mechanism is simplistic and not organically integrated with the angled structure of the air column bag. Fourth, the sealing performance of the inflation valve in existing air column bags deteriorates after prolonged use, making them prone to leakage.

[0004] Therefore, there is an urgent need for a shockproof and impact-resistant corner air column bag that combines puncture resistance, high toughness, an integrated inner and outer double-layer buffer structure, integrated elastic support, and durable sealing performance. Summary of the Invention

[0005] In view of this, the present invention provides a shockproof and drop-resistant corner protection air column bag, the purpose of which is to solve the technical problems of existing corner protection air column bags, such as insufficient puncture resistance, lack of an integrally molded inner and outer double-layer buffer structure, inconvenience in use due to the buffer support structure being an independent external accessory, simple buffer mechanism, and poor long-term sealing performance.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a shock-resistant and drop-proof corner protection air column bag, comprising: A bag body formed of a multilayer composite film, wherein the multilayer composite film comprises at least an outer layer, a middle layer and an inner layer stacked together, wherein the outer layer, the middle layer and the inner layer are all thermoplastic resin layers and are integrally bonded by a co-extrusion process; The bag body is provided with multiple rows of independent air column units separated by heat sealing lines. Each independent air column unit is completely isolated from the other by heat sealing lines, and each independent air column unit has an independent air storage chamber. The bag body includes an outer first buffer air column bag and an inner second buffer air column bag. The outer first buffer air column bag and the inner second buffer air column bag are an inner and outer double-layer structure integrally formed by multiple composite films. A first buffer cavity is formed between the outer first buffer air column bag and the inner second buffer air column bag, and a second buffer cavity is formed inside the inner second buffer air column bag. The L-shaped bend of the bag body also integrates an elastic support structure. The elastic support structure includes an elastic sheet, a fixing strip, and a protective strip. The fixing strip is fixedly connected to the outer surface of the bag body. One end of the elastic sheet is connected to the fixing strip, and the other end is connected to the protective strip. The elastic sheet has any one of an arched structure, a wave-shaped structure, or a V-shaped bend structure, which is used to undergo elastic deformation to absorb energy when subjected to impact. The bag is also equipped with an adaptive sealing inflation valve, which has a backflow valve diaphragm structure for automatically locking the gas after inflation is completed.

[0007] Furthermore, the outer layer is a nylon layer to provide puncture resistance; the middle layer is a metallocene polyethylene layer to enhance toughness; and the inner layer is a linear low-density polyethylene layer to achieve heat sealing. The outer, middle, and inner layers are bonded together at the molecular level through a co-extrusion process.

[0008] Furthermore, each independent air column unit is isolated from each other and not connected to each other, forming an independent buffer structure. When a single independent air column unit is damaged, the remaining independent air column units maintain air pressure and maintain the overall buffer performance.

[0009] Furthermore, the outer first buffer air column bag and the inner second buffer air column bag constitute a dual buffering mechanism. When the outer first buffer air column bag is damaged and depressurized, the inner second buffer air column bag independently maintains the air pressure and continuously provides protection.

[0010] Furthermore, the elastic sheet has an arched structure. When impacted, the arched structure compresses and deforms to absorb some of the energy. At the same time, the protective strips transfer the remaining impact force to the air column of the bag, forming a synergistic buffer between the elastic body and the air column.

[0011] Furthermore, the total thickness of the multilayer composite film is 80~150μm, of which the thickness of the outer layer accounts for 20~30% of the total thickness of the multilayer composite film, the thickness of the middle layer accounts for 30~50% of the total thickness of the multilayer composite film, and the thickness of the inner layer accounts for 20~40% of the total thickness of the multilayer composite film.

[0012] Furthermore, the bag body has an L-shaped folded structure to accommodate the corner protection of items. Multiple rows of independent air column units are arranged along the length of the L-shaped folded structure, and the longitudinal axis of each independent air column unit extends parallel to the fold line of the L-shaped folded structure. The width of the heat seal line is 2~5mm, and the heat seal line is provided with arc-shaped reinforcing weld points arranged at intervals along its length.

[0013] Furthermore, the tensile strength of the outer nylon layer is ≥80MPa and the elongation at break is 100~200%; the interlayer peel strength between the middle metallocene polyethylene layer and the outer layer is ≥3N / 15mm; and the heat seal strength of the inner linear low-density polyethylene layer is ≥25N / 15mm.

[0014] Furthermore, the arch height of the elastic sheet's arched structure is 5~15mm, and the material of the elastic sheet is thermoplastic polyurethane elastomer or EPDM rubber.

[0015] Furthermore, the outer, middle, and inner layers are integrally bonded through a co-extrusion process with no adhesive between the layers.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. Improved puncture and impact resistance. This invention employs a three-layer co-extruded composite film structure of nylon / metallocene polyethylene / linear low-density polyethylene. The outer nylon layer provides puncture resistance, the middle metallocene polyethylene layer enhances overall toughness, and the inner linear low-density polyethylene layer enables reliable heat sealing. The three layers are bonded at the molecular level through a co-extrusion process, eliminating the need for adhesives and avoiding the delamination problem of traditional adhesive composite films. This allows the corner protector air column bag to possess tensile strength, puncture resistance, and heat-sealing properties. Testing showed that the puncture strength of Examples 1-3 is ≥50N, significantly higher than that of single-layer polyethylene film (18.6N) and nylon / polyethylene adhesive composite film (35.2N).

[0017] 2. One-piece molded inner and outer double-layer buffer structure. Existing double-layer air column bags are either detachable nested or single-layer bent. This invention adopts a multi-layer composite film one-piece molded inner and outer double-layer air column bag structure, forming a dual buffer mechanism of "first buffer chamber + second buffer chamber". When the outer air column is damaged, the inner air column can still independently maintain air pressure and provide protection. After 10 repeated drop tests from a height of 1.5m, the corner indentation depth of the test blocks in Examples 1-3 was ≤0.3mm, and the number of air column breakages was 0.

[0018] 3. Synergistic protection of independent air column units and dual buffer chambers. Each independent air column unit is isolated from each other and does not communicate with each other. When a single air column is damaged, the remaining air columns maintain air pressure. Combined with the first and second buffer chambers formed by the inner and outer double-layer structure, multi-dimensional buffer protection is achieved.

[0019] 4. Integrated arched elastic support structure. Unlike the flat elastic sheet set on the outer surface of the air column heat seal strip in the prior art, the present invention integrates the arched elastic support structure into the bending part of the L-shaped corner structure of the bag body. When subjected to impact, the arched structure absorbs energy through compression deformation, while the protective strip transfers the remaining impact force to the air column, forming a synergistic buffering mechanism between the elastic body and the air column.

[0020] 5. Airtight sealing performance. The adaptive sealing inflation valve adopts a reverse air shut-off valve diaphragm structure. During inflation, the gas pushes the valve disc to open. After inflation is completed, the internal air pressure makes the valve disc fit tightly to form an airtight seal. The air pressure retention rate is ≥97.5% after 72 hours.

[0021] 6. Optimized film layer thickness ratio and mechanical properties. By controlling the total thickness of the multilayer composite film within 80~150μm and optimizing the thickness ratio of each layer, the functions of each layer are fully utilized. The achievement of quantitative indicators such as tensile strength of nylon layer ≥80MPa, interlayer peel strength ≥3N / 15mm, and heat sealing strength of linear low-density polyethylene layer ≥25N / 15mm ensures the reliability and consistency of the product.

[0022] 7. Arc-shaped reinforced weld point design for the heat-sealing line. Intermittently arranged arc-shaped reinforced weld points are installed on the heat-sealing line to prevent tearing under long-term air pressure or repeated bending, thus extending the service life of the air column bag.

[0023] 8. Wide applicability. The L-shaped corner structure is suitable for corner protection of various square items. Multiple rows of independent air column units are arranged along the length of the corner and the longitudinal axis extends parallel to the crease line. The air column units have a continuous arc transition at the corner and a non-inflatable buffer zone is provided on the inside of the corner to ensure that the air column is not blocked at the bend and inflation is smooth. Detailed Implementation

[0024] This invention provides a shock-resistant and drop-proof corner protection air column bag, comprising: A bag body formed of a multilayer composite film, wherein the multilayer composite film comprises at least an outer layer, a middle layer and an inner layer stacked together, wherein the outer layer, the middle layer and the inner layer are all thermoplastic resin layers and are integrally bonded by a co-extrusion process; The bag body is provided with multiple rows of independent air column units separated by heat sealing lines. Each independent air column unit is completely isolated from the other by heat sealing lines, and each independent air column unit has an independent air storage chamber. The bag body includes an outer first buffer air column bag and an inner second buffer air column bag. The outer first buffer air column bag and the inner second buffer air column bag are an inner and outer double-layer structure integrally formed by multiple composite films. A first buffer cavity is formed between the outer first buffer air column bag and the inner second buffer air column bag, and a second buffer cavity is formed inside the inner second buffer air column bag. The L-shaped bend of the bag body also integrates an elastic support structure. The elastic support structure includes an elastic sheet, a fixing strip, and a protective strip. The fixing strip is fixedly connected to the outer surface of the bag body. One end of the elastic sheet is connected to the fixing strip, and the other end is connected to the protective strip. The elastic sheet has any one of an arched structure, a wave-shaped structure, or a V-shaped bend structure, which is used to undergo elastic deformation to absorb energy when subjected to impact. The bag is also equipped with an adaptive sealing inflation valve, which has a backflow valve diaphragm structure for automatically locking the gas after inflation is completed.

[0025] In this invention, the outer layer is a nylon layer, used to provide puncture resistance; the middle layer is a metallocene polyethylene layer, used to enhance toughness; and the inner layer is a linear low-density polyethylene layer, used to achieve heat sealing. The outer, middle, and inner layers are bonded at the molecular level through a co-extrusion process. The temperature conditions for the co-extrusion process are: nylon layer melt temperature 240~270℃, metallocene polyethylene layer melt temperature 180~220℃, linear low-density polyethylene layer melt temperature 170~200℃, co-extrusion die temperature 230~250℃, and traction speed 15~30m / min.

[0026] In this invention, each independent air column unit is isolated from each other and not connected to each other, forming an independent buffer structure. When a single independent air column unit is damaged, the remaining independent air column units maintain air pressure and maintain the overall buffer performance.

[0027] In this invention, the outer first buffer air column bag and the inner second buffer air column bag constitute a dual buffering mechanism. When the outer first buffer air column bag is damaged and depressurized, the inner second buffer air column bag independently maintains the air pressure and continuously provides protection.

[0028] In this invention, the elastic sheet has an arched structure. When it is impacted, the arched structure undergoes compression deformation to absorb some of the energy. At the same time, the protective strip transmits the remaining impact force to the air column of the bag, forming a synergistic buffer between the elastic body and the air column. The arch height is the vertical distance between the top of the arch of the elastic sheet and the line connecting the two ends of the elastic sheet.

[0029] In this invention, the total thickness of the multilayer composite film is 80-150 μm, preferably 100-130 μm, and more preferably 110-120 μm; wherein the thickness of the outer layer accounts for 20-30% of the total thickness of the multilayer composite film, preferably 22-28%, and more preferably 25%; the thickness of the middle layer accounts for 30-50% of the total thickness of the multilayer composite film, preferably 35-45%, and more preferably 40%; and the thickness of the inner layer accounts for 20-40% of the total thickness of the multilayer composite film, preferably 25-35%, and more preferably 30%.

[0030] In this invention, the bag body has an L-shaped folded corner structure to adapt to the corner protection of the item. Multiple rows of independent air column units are arranged along the length direction of the L-shaped folded corner structure, and the longitudinal axis of each independent air column unit extends parallel to the fold line of the L-shaped folded corner structure. The air column units have a continuous arc transition at the fold, and the heat seal line at the fold is an arc-shaped heat seal line. A row of non-inflatable buffer intervals is provided on the inner side of the fold, and the width of the non-inflatable buffer intervals is 5~10mm. The width of the heat seal line is 2~5mm, preferably 3~4mm. Arc-shaped reinforcing weld points are provided on the heat seal line at intervals along its length direction.

[0031] In this invention, the arc-shaped reinforcing weld point is an arc-shaped protrusion structure formed by secondary hot pressing in a local area of ​​the heat-sealing line. The protrusion height is 0.5~1.5mm, the width is the same as the width of the heat-sealing line, and its cross-section is an arc-shaped bulge.

[0032] In this invention, the tensile strength of the outer nylon layer is ≥80MPa and the elongation at break is 100~200%; the interlayer peel strength between the middle metallocene polyethylene layer and the outer layer is ≥3N / 15mm; and the heat-sealing strength of the inner linear low-density polyethylene layer is ≥25N / 15mm.

[0033] In this invention, the arch height of the arched structure of the elastic sheet is 5~15mm, preferably 8~12mm, and more preferably 10mm; the material of the elastic sheet is thermoplastic polyurethane elastomer or EPDM rubber.

[0034] In this invention, the arch height of the arched structure of the elastic sheet is 5~15mm, preferably 8~12mm, and more preferably 10mm; the material of the elastic sheet is thermoplastic polyurethane elastomer or EPDM rubber.

[0035] In this invention, the adaptive sealing inflation valve is inflated by gas pushing the valve disc to open during inflation. After inflation is completed, the internal air pressure causes the valve disc to fit tightly to form an airtight seal, with an air pressure retention rate of ≥97% after 72 hours. The valve disc is a circular elastic diaphragm made of silicone or EPDM rubber. The valve body and the inner layer of the bag are fixed to the end of the air column bag by heat sealing. The valve body diameter is 8~15mm.

[0036] In this invention, the angle of the L-shaped bend structure is 85°~95°, preferably 90°.

[0037] In this invention, the ratio of the number of air columns between the outer first buffer air column bag and the inner second buffer air column bag is 1~2:1, preferably 1.2~1.8:1, and more preferably 1.5:1.

[0038] In this invention, the arc length of the arc-shaped reinforcing weld is 3-8 mm, preferably 4-6 mm, and more preferably 5 mm; the distance between two adjacent arc-shaped reinforcing welds is 10-20 mm, preferably 12-18 mm, and more preferably 15 mm.

[0039] In this invention, the total thickness of the multilayer composite film is 110~120μm, the thickness of the outer layer is 25~30μm, the thickness of the middle layer is 40~48μm, and the thickness of the inner layer is 32~42μm.

[0040] In this invention, the protective strip is a rigid strip with a width of 5-15mm and a thickness of 1-3mm, and is made of polypropylene or acrylonitrile-butadiene-styrene copolymer; the protective strip and the elastic sheet are integrally injection molded.

[0041] In this invention, the fixing strip is fixedly connected to the outer surface of the bag body by heat sealing or adhesive bonding.

[0042] In this invention, the adaptive sealing inflation valve is disposed at one end of the bag body and located on the outer surface of the outer first buffer air column bag.

[0043] In this invention, the width of each row of multiple independent air column units is 8~20mm, preferably 10~15mm.

[0044] In this invention, the oxygen permeability of the multilayer composite membrane is ≤50 cm³. 3 / (m 2 • 24h • 0.1MPa), water vapor transmission rate ≤ 5g / (m 2 •24h).

[0045] In this invention, the outer layer, middle layer and inner layer are integrally bonded by a co-extrusion process and there is no adhesive between the layers.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and comparative examples. However, it should be understood that the embodiments of this invention are not limited thereto; the following embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Example 1

[0048] This embodiment provides a shockproof and drop-resistant corner protection air column bag.

[0049] The multilayer composite film is formed using a three-layer co-extrusion casting process. The outer layer is a nylon layer (model: BASF Ultramid® C40L) with a thickness of 30μm; the middle layer is a metallocene polyethylene layer (model: ExxonMobil Enable). TM2705MC), with a thickness of 48μm; the inner layer is a linear low-density polyethylene layer (model: Dow DOWLEX). TM The multilayer composite film (2045G) has a thickness of 32 μm. The co-extrusion process conditions are: nylon layer melt temperature 255℃, metallocene polyethylene layer melt temperature 200℃, linear low-density polyethylene layer melt temperature 185℃, co-extrusion die temperature 240℃, and traction speed 20 m / min. The total thickness of the multilayer composite film is 110 μm, with the outer, middle, and inner layers accounting for 27.3%, 43.6%, and 29.1% of the total thickness, respectively. The tensile strength of the nylon layer is 85 MPa, and the elongation at break is 150%. The interlaminar peel strength between the metallocene polyethylene layer and the nylon layer is 3.5 N / 15 mm; the heat-sealing strength of the linear low-density polyethylene layer is 28 N / 15 mm. The oxygen permeability of the multilayer composite film is 42 cm³. 3 / (m 2 (24h·0.1MPa), water vapor transmission rate is 3.8g / (m²). 2 •24h).

[0050] The bag body has an L-shaped folded structure with a fold angle of 90°. The bag body is integrally formed from the aforementioned multi-layer composite film through a heat-sealing process, creating a double-layer structure with an outer first buffer air column bag and an inner second buffer air column bag. The heat-sealing temperature is 150℃, the heat-sealing pressure is 0.5MPa, and the heat-sealing time is 1s. A first buffer cavity is formed between the outer first buffer air column bag and the inner second buffer air column bag, and a second buffer cavity is formed inside the inner second buffer air column bag. The ratio of the number of air columns between the outer first buffer air column bag and the inner second buffer air column bag is 1.5:1.

[0051] The bag body has multiple rows of independent air column units separated by heat-sealing lines, each row being 12mm wide. These independent air column units are completely isolated from each other by the heat-sealing lines and are not interconnected. The heat-sealing lines are 3mm wide and have arc-shaped reinforcing weld points spaced along their length. Each arc-shaped reinforcing weld point is an arc-shaped protrusion formed by secondary heat pressing in a localized area of ​​the heat-sealing line. The protrusion is 1mm high and the same width as the heat-sealing line, with an arc-shaped bulge in its cross-section. The arc length of each arc-shaped reinforcing weld point is 5mm, and the spacing between adjacent weld points is 15mm. The longitudinal axis of each independent air column unit extends parallel to the crease line of the L-shaped angle structure. The air column units have a continuous arc transition at the angles, and the heat-sealing line at the angles is an arc-shaped heat-sealing line. Inside the angles, there is a row of non-inflatable buffer zones, each 8mm wide.

[0052] The L-shaped bend in the bag body integrates an elastic support structure. This structure includes an elastic sheet, a fixing strip, and a protective strip. The fixing strip is heat-sealed to the outer surface of the bag. The elastic sheet is arched, with an arch height (the vertical distance between the top of the arch and the line connecting the two ends of the elastic sheet) of 10mm. It is made of thermoplastic polyurethane elastomer with a Shore A hardness of 85. One end of the elastic sheet connects to the fixing strip, and the other end connects to the protective strip. The protective strip is a rigid strip, 10mm wide and 2mm thick, made of polypropylene. The protective strip and the elastic sheet are integrally injection-molded.

[0053] One end of the bag is equipped with an adaptive sealing inflation valve, which is a backflow valve diaphragm structure located on the outer surface of the first outer buffer air column bag. The valve disc is a circular elastic diaphragm made of silicone. The valve body is heat-sealed to the end of the air column bag, and the valve body has a diameter of 12mm. During inflation, the gas pushes the valve disc open, and after inflation is complete, the internal air pressure causes the valve disc to fit tightly together, forming an airtight seal.

[0054] Example 2

[0055] The difference between this embodiment and Embodiment 1 is as follows: the total thickness of the multilayer composite film is 120 μm, with an outer layer thickness of 30 μm (25%), a middle layer thickness of 48 μm (40%), and an inner layer thickness of 42 μm (35%). The co-extrusion process conditions are the same as in Embodiment 1. The elastic sheet material is EPDM rubber with a Shore A80 hardness. The arch height is 12 mm. The ratio of the number of air columns between the outer first buffer air column bag and the inner second buffer air column bag is 1.2:1. The protective strip material is acrylonitrile-butadiene-styrene copolymer. The valve disc material is EPDM rubber with a valve body diameter of 10 mm. The remaining structure and parameters are the same as in Embodiment 1.

[0056] Example 3

[0057] The difference between this embodiment and Embodiment 1 is as follows: the total thickness of the multilayer composite film is 100 μm, with the outer layer being 25 μm (25%), the middle layer being 40 μm (40%), and the inner layer being 35 μm (35%); the elastic sheet's buffer structure is a wave-shaped structure with a wave crest height (vertical distance between the wave crest and wave trough) of 10 mm; the heat-sealing line width is 4 mm; the arc length of the arc-shaped reinforcing weld is 6 mm, and the spacing between adjacent welds is 18 mm; the width of each air column unit is 15 mm; the protective strip is 12 mm wide and 1.5 mm thick; and the width of the non-inflatable buffer interval is 6 mm. The remaining structures and parameters are the same as in Embodiment 1.

[0058] Comparative Example 1 This comparative example provides a single-layer air column bag, the membrane material being a single-layer polyethylene film (model: Dow DOWLEX).TM The bag is 2045G thick, 110μm, and blow-molded. The bag body is a single-layer L-shaped structure, without inner or outer double-layer design or elastic support structure. The inflation valve is a standard one-way valve (model: Shanghai Zhenhua ZH-QD-01). The remaining structure is the same as the L-shaped angled structure of this invention.

[0059] Comparative Example 2 This comparative example provides a double-layer nested air column bag, in which the outer and inner air column bags are manufactured independently and then nested together for use. The membrane material is a nylon / polyethylene double-layer composite membrane (adhesive composite, solvent-based polyurethane adhesive, adhesive layer thickness 3μm), the nylon layer thickness is 30μm, the polyethylene layer thickness is 80μm, and the total thickness is 110μm. There is no elastic support structure. The remaining structure is the same as the L-shaped angle structure of this invention.

[0060] Comparative Example 3 This comparative example provides an air column bag with a flat elastic sheet, prepared according to Example 1 of CN113086392B. The membrane material is a single-layer polyethylene film (same model as Comparative Example 1). The elastic sheet has a flat structure (30mm long, 10mm wide, and 2mm thick), is disposed on the outer surface of the air column heat seal strip, is not an arched structure, and is not integrated into the corner. There is no inner and outer double-layer design. The remaining structure is the same as the L-shaped corner structure of this invention.

[0061] Comparative Example 4 The difference between this comparative example and Example 1 is that the total thickness of the multilayer composite film is 60 μm, the outer layer thickness is 10 μm (accounting for 16.7%), the middle layer thickness is 35 μm (accounting for 58.3%), and the inner layer thickness is 15 μm (accounting for 25%). The co-extrusion process conditions are the same as in Example 1. The remaining structure and parameters are the same as in Example 1.

[0062] Performance testing 1. Puncture resistance test: Referring to GB / T 10004-2008 standard, a puncture testing machine (Jinan Langguang XLW-PC type) was used. A steel needle with a diameter of 1.0 mm and a tip radius of 0.5 mm was vertically inserted into the specimen at a speed of (50±5) mm / min, and the maximum puncture force (N) was recorded. The specimen width was 50 mm, and the clamp spacing was 50 mm. Five specimens were tested for each example / comparative example, and the arithmetic mean was taken.

[0063] 2. Drop Impact Test: Air column bags from each embodiment and comparative example were used to cover the eight corners of a standard test block (300mm × 300mm × 300mm, 10kg, Q235 steel, 2mm chamfer radius), inflating it to 0.15MPa (using a digital precision pressure gauge, accuracy 0.001MPa). The covered test block was then dropped freely from a height of 1.5m onto a concrete surface, repeated 10 times. After each drop, the damage to the test block's corners was checked (dent depth measured with calipers, accuracy 0.01mm) and the number of broken air column bags were recorded. Three parallel tests were performed for each embodiment / comparative example, and the arithmetic mean was taken.

[0064] 3. Air tightness test: After inflating each air column bag to 0.15 MPa, it was placed in an environment of (23±2)℃ and (50±5)% relative humidity for 72 hours. The air pressure retention rate was measured using a digital barometer (accuracy 0.001 MPa). Air pressure retention rate (%) = (air pressure after 72 hours ÷ initial air pressure) × 100%. Five samples were tested for each example / comparative example, and the arithmetic mean was taken.

[0065] 4. Interlayer peel strength test: Following GB / T 8808-1988 standard, a universal tensile testing machine (Instron 5967) was used. The specimen width was 15 mm, the clamp spacing was 50 mm, and a T-type peel test was performed at a speed of 300 mm / min. The maximum peel force (N / 15 mm) was recorded. Five specimens were tested for each example / comparative example, and the arithmetic mean was taken.

[0066] 5. Heat seal strength test: Referring to the QB / T 2358-1998 standard, a heat seal strength testing machine (Jinan Langguang HST-H3 type) was used. The sample width was 15mm, and the test was conducted at a speed of 300mm / min. The maximum heat seal force (N / 15mm) was recorded. Five samples were tested for each example / comparative example, and the arithmetic mean was taken.

[0067] The test results for all tests are shown in Table 1 below.

[0068] Table 1. Test Results of Performance Testing

[0069] As shown in Table 1, the puncture resistance of Examples 1-3 is ≥50N, which is higher than that of Comparative Example 1 (18.6N), Comparative Example 3 (19.1N), and Comparative Example 2 (35.2N). This indicates that the three-layer co-extruded composite film structure of nylon / metallocene polyethylene / linear low-density polyethylene of the present invention improves the puncture resistance, and the interlayer bonding method without adhesives in the co-extrusion process is superior to the adhesive composite method (Comparative Example 2).

[0070] In the test of repeated drops from a height of 1.5m 10 times, the maximum indentation depth of the test blocks in Examples 1-3 was ≤0.3mm, and the number of air column bag breaks was 0; while Comparative Example 1 showed 5 air column breaks with an indentation depth of 2.8mm, Comparative Example 2 showed 2 air column breaks with an indentation depth of 1.2mm, Comparative Example 3 showed 3 air column breaks with an indentation depth of 1.5mm, and Comparative Example 4 showed 1 air column break with an indentation depth of 0.8mm. This shows that the synergistic buffering mechanism of the present invention, consisting of "integrated double-layer structure + independent air column unit + arched elastic support structure", is effective.

[0071] The 72-hour air pressure retention rate of Examples 1-3 was ≥97.5%, which was higher than that of Comparative Example 1 (82.3%), Comparative Example 3 (83.1%), and Comparative Example 2 (91.5%). This indicates that the adaptive sealing inflation valve of the present invention and the heat sealing strength of the multilayer co-extruded composite film together ensure airtightness.

[0072] The interlayer peel strength of Examples 1-3 was ≥3.3 N / 15 mm, which was higher than that of Comparative Example 2 (1.8 N / 15 mm) and Comparative Example 4 (2.9 N / 15 mm). This indicates that the interlayer bonding strength of the co-extrusion process (without adhesive) is better than that of the adhesive bonding method, and that the film thickness ratio has an impact on the interlayer bonding strength - Comparative Example 4 had an interlayer peel strength of 2.9 N / 15 mm because the total thickness was relatively thin (60 μm) and the thickness ratio of each layer deviated from the preferred range.

[0073] Example 1 (total thickness 110 μm, layer proportions 27.3% / 43.6% / 29.1%) exhibits the best overall performance. Comparative Example 4, due to its thinner total thickness and layer proportions deviating from the preferred range, shows a decrease in all performance indicators. This demonstrates that the 80-150 μm total thickness and layer proportions of 20%-30%, 30%-50%, and 20%-40% specified in this invention have a synergistic optimization effect.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A shockproof and drop-resistant corner protection air column bag, characterized in that, include: A bag body formed of a multilayer composite film, wherein the multilayer composite film comprises at least an outer layer, a middle layer and an inner layer stacked together, wherein the outer layer, the middle layer and the inner layer are all thermoplastic resin layers and are integrally bonded by a co-extrusion process; The bag body is provided with multiple rows of independent air column units separated by heat sealing lines. Each independent air column unit is completely isolated from the other by heat sealing lines, and each independent air column unit has an independent air storage chamber. The bag body includes an outer first buffer air column bag and an inner second buffer air column bag. The outer first buffer air column bag and the inner second buffer air column bag are an inner and outer double-layer structure integrally formed by multiple composite films. A first buffer cavity is formed between the outer first buffer air column bag and the inner second buffer air column bag, and a second buffer cavity is formed inside the inner second buffer air column bag. The L-shaped bend of the bag body also integrates an elastic support structure. The elastic support structure includes an elastic sheet, a fixing strip, and a protective strip. The fixing strip is fixedly connected to the outer surface of the bag body. One end of the elastic sheet is connected to the fixing strip, and the other end is connected to the protective strip. The elastic sheet has any one of an arched structure, a wave-shaped structure, or a V-shaped bend structure, which is used to undergo elastic deformation to absorb energy when subjected to impact. The bag is also equipped with an adaptive sealing inflation valve, which has a backflow valve diaphragm structure for automatically locking the gas after inflation is completed.

2. The shock-resistant and drop-proof corner protection air column bag according to claim 1, characterized in that, The outer layer is a nylon layer, which provides puncture resistance; the middle layer is a metallocene polyethylene layer, which enhances toughness; the inner layer is a linear low-density polyethylene layer, which enables heat sealing; the outer, middle and inner layers are bonded at the molecular level through a co-extrusion process.

3. The shock-resistant and drop-proof corner protection air column bag according to claim 1, characterized in that, Each independent air column unit is isolated from each other and not connected to each other, forming an independent buffer structure. When a single independent air column unit is damaged, the remaining independent air column units maintain air pressure and maintain the overall buffer performance.

4. The shock-resistant and drop-proof corner protection air column bag according to claim 3, characterized in that, The outer first buffer air column bag and the inner second buffer air column bag constitute a dual buffering mechanism. When the outer first buffer air column bag is damaged and depressurized, the inner second buffer air column bag independently maintains the air pressure and continuously provides protection.

5. The shock-resistant and drop-proof corner protection air column bag according to claim 4, characterized in that, The elastic sheet has an arched structure. When it is impacted, the arched structure compresses and deforms to absorb some of the energy. At the same time, the protective strips transfer the remaining impact force to the air column of the bag, forming a synergistic buffer between the elastic body and the air column.

6. The shock-resistant and drop-proof corner protection air column bag according to any one of claims 1 to 5, characterized in that, The total thickness of the multilayer composite film is 80~150μm, of which the outer layer accounts for 20~30% of the total thickness of the multilayer composite film, the middle layer accounts for 30~50% of the total thickness of the multilayer composite film, and the inner layer accounts for 20~40% of the total thickness of the multilayer composite film.

7. The shock-resistant and drop-proof corner protection air column bag according to claim 6, characterized in that, The bag body has an L-shaped folded structure to adapt to the corner protection of items. Multiple rows of independent air column units are arranged along the length of the L-shaped folded structure, and the longitudinal axis of each independent air column unit extends parallel to the fold line of the L-shaped folded structure. The width of the heat seal line is 2~5mm, and there are arc-shaped reinforcing welding points arranged at intervals along its length on the heat seal line.

8. The shockproof and drop-resistant corner protection air column bag according to claim 2, characterized in that, The tensile strength of the outer nylon layer is ≥80MPa and the elongation at break is 100~200%; the interlayer peel strength between the middle metallocene polyethylene layer and the outer layer is ≥3N / 15mm; and the heat seal strength of the inner linear low-density polyethylene layer is ≥25N / 15mm.

9. The shock-resistant and drop-proof corner protection air column bag according to claim 8, characterized in that, The arch height of the elastic sheet's arched structure is 5~15mm, and the elastic sheet is made of thermoplastic polyurethane elastomer or EPDM rubber.

10. The shock-resistant and drop-proof corner protection air column bag according to claim 1, characterized in that, The outer, middle, and inner layers are bonded together in one piece through a co-extrusion process, with no adhesive between the layers.

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