A sealing aluminum foil gasket and a manufacturing method thereof

Abstract

The present application relates to the technical field of container closure manufacturing, and in particular to a closure aluminum foil gasket and a manufacturing method thereof. The method comprises the following steps: taking a paperboard and a polyolefin foam and stacking them according to the appropriate size, coating an adhesive on the contact surface of the two, and forming an upper layer; taking any one of PE, PP and PET film as a middle first layer and a middle third layer, and taking aluminum foil as a middle second layer, and forming a middle layer; taking PE, PP and PET film as a lower first layer and a heat-sealing functional layer, and taking aluminum foil as a lower second layer, and forming a lower layer; and sequentially adhering the upper layer, the middle layer and the lower layer from top to bottom to form a closure aluminum foil gasket. The present application adopts a three-layer composite structure design of upper layer + middle layer + lower layer to realize the optimization of the gasket in structural synergy, manufacturing quality stability and material adaptation flexibility, thereby significantly improving the sealing performance, durability and application range of the closure aluminum foil gasket.

Description

Technical Field

[0001] This invention relates to the field of container sealing component manufacturing technology, and in particular to a sealing aluminum foil gasket and its manufacturing method. Background Technology

[0002] In the packaging industry, sealing aluminum foil gaskets are widely used for sealing containers in the food, pharmaceutical, and daily chemical industries. However, existing products have significant defects in terms of structure, process, and material compatibility: the structure is mostly single-layer or simple double-layer, with poor functional synergy. For example, a single aluminum foil layer is easily damaged by scratches, leading to barrier failure; a single cardboard layer lacks cushioning and protection, making it easy to deform and damage the seal, and it is difficult to balance sealing, durability, and protection. The manufacturing process is rough; when the layers are laminated, direct overall pressure can easily leave air behind and form bubbles. The lamination of aluminum foil and film often uses full-area gluing or non-uniform pressure, which increases costs and easily causes aluminum foil wrinkles. The layering lacks precise positioning and force control, which can easily lead to alignment deviations and local loose bonding, resulting in large fluctuations in product quality and low pass rates. The material selection is fixed; the film material is only suitable for specific storage environments and cannot meet the requirements of high-temperature sterilization and low-temperature refrigeration. The heat-sealing functional layer is only suitable for a few sealing forms and is difficult to adapt to containers of different materials and non-heat-sealing structures, limiting the applicable scenarios and failing to meet diversified packaging needs. Summary of the Invention

[0003] Therefore, it is necessary to provide a sealing aluminum foil gasket and a method for manufacturing the same, in order to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above objectives, a sealing aluminum foil gasket includes an upper layer, a middle layer, and a lower layer, which are sequentially bonded together from top to bottom to form the sealing aluminum foil gasket. The upper layer is formed by bonding and hot-pressing cardboard and polyolefin foam together with adhesives; The middle layer is a three-layer composite structure, and is arranged sequentially along a direction perpendicular to the sheet surface and moving away from the upper layer: The first layer in the middle is any one of PE, PP or PET film that is in direct contact with the upper layer; The second layer in the middle is an aluminum foil that is in direct contact with the first layer in the middle. The third layer in the middle, wherein the third layer in the middle is any one of PE, PP or PET film that is in direct contact with the second layer in the middle; The lower layer is a three-layer composite structure, and is provided sequentially along the same vertical direction away from the middle layer as follows: The lower first layer is any one of PE, PP or PET film that is in direct contact with the middle third layer; The lower second layer is an aluminum foil that is in direct contact with the lower first layer; The lower third layer is a heat-sealing functional layer that is in direct contact with the lower second layer. The heat-sealing functional layer is composed of PE, PP, or PET film, or aluminum foil and paper film that do not have heat-sealing properties.

[0005] This invention also provides a method for manufacturing a sealing aluminum foil gasket, comprising the following steps: Step S1: Stack the cardboard and polyolefin foam according to the appropriate size, apply adhesive to the contact surface of the two, pre-press the edge area first, and then push and press towards the center to form the upper layer; Step S2: Take any one of PE, PP, or PET film as the first and third middle layers, and aluminum foil as the second middle layer. Apply adhesive in a dotted pattern to the film bonding surface, and roll the aluminum foil between the two film layers to form the middle layer. Step S3: Take PE, PP, and PET film as the first lower layer, aluminum foil as the second lower layer, and PE, PP, and PET film or paper film as the heat-sealing functional layer. Stack the three lower layers together to form the lower layer. Step S4: Align and stack the upper, middle, and lower layers according to the edge marks, apply adhesive or heat seal adjacent layers as needed, and apply symmetrical pressure to form an overall composite structure; Step S5: Adjust the temperature of the overall composite structure, divide the cutting lines according to the preset size, cut along the cutting lines and then polish to obtain the finished sealing aluminum foil gasket.

[0006] The beneficial effects of this invention are as follows: I. This sealing aluminum foil gasket adopts a three-layer composite structure of "upper layer + middle layer + lower layer", with each layer having a clear functional positioning and complementary synergy. The upper layer is achieved by bonding and heat-pressing cardboard and polyolefin foam, which retains the rigidity of the cardboard to ensure the gasket is formed neatly, while the cushioning properties of the polyolefin foam reduce the impact of collisions on the sealing performance during transportation or use. The middle layer uses a sandwich structure of "film + aluminum foil + film", utilizing the excellent barrier properties of aluminum foil (isolating oxygen and moisture), while the films on both sides protect the aluminum foil from scratches and damage, greatly improving the gasket's leak-proof and freshness-preserving capabilities. The lower layer is designed with a heat-sealing function layer for sealing needs, flexibly adapting to packaging containers of different materials. The close cooperation of the three layers gives the gasket a balanced advantage in sealing performance, durability, and adaptability.

[0007] Second, in the layer bonding process, by fixing the edges first and then applying pressure towards the center, the air between layers can be fully expelled, avoiding the formation of air bubbles after bonding that would cause the structure to become loose. The composite of aluminum foil and film adopts a dot-applied adhesive combined with rolling bonding, which can ensure sufficient bonding strength, reduce the amount of glue used, and lower costs. At the same time, the uniform pressure during the rolling process can prevent wrinkles in the aluminum foil, ensuring that the barrier performance is not affected. When each layer is stacked, the alignment accuracy is ensured by edge positioning marks, and the symmetrical pressure method is used to ensure that the composite structure is evenly stressed, avoiding gaps caused by localized loose bonding.

[0008] Third, the selectable design of materials for each functional layer allows the gasket to meet the packaging needs of different fields, significantly expanding its application range. The films on both sides of the middle section and the lower base film all support three materials: PE, PP, and PET. PE's low-temperature resistance is suitable for refrigerated food packaging, PP's high-temperature resistance meets the requirements of high-temperature sterilization products, and PET's high-strength characteristics are suitable for packaging heavy items. The lower heat-sealing functional layer can not only use heat-sealing films (PE / PP / PET) that match the container material, but can also be used with aluminum foil or paper films that do not have heat-sealing properties, and is suitable for non-heat-sealing sealing structures such as screw caps and snap caps. Attached Figure Description

[0009] Figure 1 A schematic diagram illustrating the steps involved in manufacturing a sealing aluminum foil gasket; Figure 2 This is a schematic diagram of a sealing aluminum foil gasket according to one embodiment; Figure 3 This is a perspective view of a pressure device according to one embodiment; Figure 4 This is a perspective view of an adhesive application apparatus according to one embodiment; Figure 5 This is a three-dimensional schematic diagram of a double-roller bonding mechanism according to one embodiment; Figure 6 This is a schematic diagram of the perimeter layout of a sealing aluminum foil gasket according to one embodiment; Figure 7 A physical diagram of a sealing aluminum foil gasket according to one embodiment; Figure 8 An assembly diagram of a sealing aluminum foil gasket according to one embodiment; The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0010] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0011] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0012] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0013] To achieve the above objectives, a sealing aluminum foil gasket includes an upper layer, a middle layer, and a lower layer, which are sequentially bonded together from top to bottom to form the sealing aluminum foil gasket. The upper layer is formed by bonding and hot-pressing cardboard and polyolefin foam together with adhesives; The middle layer is a three-layer composite structure, and is arranged sequentially along a direction perpendicular to the sheet surface and moving away from the upper layer: The first layer in the middle is any one of PE, PP or PET film that is in direct contact with the upper layer; The second layer in the middle is an aluminum foil that is in direct contact with the first layer in the middle. The third layer in the middle, wherein the third layer in the middle is any one of PE, PP or PET film that is in direct contact with the second layer in the middle; The lower layer is a three-layer composite structure, and is provided sequentially along the same vertical direction away from the middle layer as follows: The lower first layer is any one of PE, PP or PET film that is in direct contact with the middle third layer; The lower second layer is an aluminum foil that is in direct contact with the lower first layer; The lower third layer is a heat-sealing functional layer that is in direct contact with the lower second layer. The heat-sealing functional layer is composed of PE, PP, or PET film, or aluminum foil and paper film that do not have heat-sealing properties.

[0014] Please see Figures 1 to 8 A method for manufacturing a sealing aluminum foil gasket includes the following steps: Preferably, step S1: take the cardboard and polyolefin foam and stack them according to the appropriate size, apply adhesive to the contact surface of the two, pre-press the edge area first, and then push and press towards the center to form the upper layer; Please see Figure 3 The pressurization operation uses a pressure device equipped with a positioning sensor and a contact pressure head. The contact pressure head is divided into an arc-shaped pressure head and a flat pressure head. The pressurization process in step S1, which involves pushing the device towards the center, is as follows: An arc-shaped pressure head is used to cover the edge area of ​​the material. The pressure device is activated to apply initial pressure and maintain the preset pressure for a set time. Disassemble the arc-shaped pressure head and replace it with a flat pressure head. Use a positioning sensor to align the pressure head with the pre-compression edge. Start the pressure device and control the flat pressure head to move from the edge to the center while gradually increasing the pressure; After the pressure head completely covers the bonding surface, maintain the pressure for the preset time, then turn off the pressure device.

[0015] In this embodiment, food-grade cardboard with a thickness of 1.2 mm and polyolefin foam with a thickness of 0.8 mm are selected and stacked according to a suitable size of 460 mm wide and 210 mm long, ensuring that the lower surface of the cardboard is completely aligned with the upper surface of the polyolefin foam; a water-based acrylic adhesive with a solid content of 35% is uniformly coated on the contact surface of the two, and the coating amount is controlled at 18 g / m². 2 After applying the adhesive, let it stand for 5 minutes to allow the adhesive to initially penetrate.

[0016] It should be noted that the pressurization operation uses a pneumatic pressure device (e.g., model KTC-D100) with a positioning sensor and a contact pressure head (e.g., model QGS-500). Specifically, this invention does not limit the model of the device used.

[0017] In another embodiment, the contact pressure head includes an arc-shaped pressure head with a radius of curvature of 15 mm and a square flat pressure head with a side length of 500 mm. When pressing towards the center, the arc-shaped pressure head is first placed over a 20 mm wide area at the edge of the material, and the pressure device is activated to apply an initial pressure of 0.3 MPa, which is maintained for 12 seconds. The arc-shaped pressure head is then removed and replaced with the flat pressure head. The edge of the flat pressure head is aligned with the edge of the pre-pressed material using a positioning sensor. The pressure device is activated again, and the flat pressure head is moved from the edge to the center at a speed of 5 mm / s. During the movement, the pressure is gradually increased from 0.3 MPa to 0.8 MPa until the flat pressure head completely covers the entire bonding surface (460 mm wide × 210 mm long). After the flat pressure head completely covers the surface, the pressure of 0.8 MPa is maintained for 20 seconds, and then the pressure device is turned off to complete the molding of the upper layer.

[0018] Preferably, in step S2: take any one of PE, PP, or PET film as the first and third middle layers, and take aluminum foil as the second middle layer. Apply adhesive in a dotted pattern on the film bonding surface, and sandwich the aluminum foil between the two film layers for rolling bonding to form the middle layer. Please see Figure 4 The process includes an applicator head with a dispensing hole of a set diameter. Step S2, applying adhesive in a dotted pattern to the film bonding surface, includes: Keep the applicator head parallel to the bonding surface of the first layer of film in the middle; The glue applicator head moves according to the set row and column spacing, and controls the glue to be dispensed each time it moves to the set position, forming dotted glue dots. After completing the first layer of film coating in the middle, align the coating head with the bonding surface of the third layer of film in the middle and replicate the coating path and dispensing operation. After applying the adhesive, place the first and third layers of film in the middle flat and let them stand for the preset time.

[0019] In one embodiment, for the dot-like adhesive application operation on the bonding surface of the first layer of film in the middle, a pneumatic adhesive applicator with an adhesive outlet hole of 0.8 mm in diameter is selected. The adhesive applicator is first adjusted to be completely parallel to the bonding surface of the first layer of film in the middle (a PET film with a width of 460 mm and a thickness of 0.05 mm can be selected), ensuring that the vertical distance between the center of the adhesive outlet hole of the adhesive applicator and the bonding surface of the film is maintained at 1.2 mm.

[0020] In another embodiment, according to the set parameters of 15mm horizontal row-column spacing and 12mm vertical row-column spacing, the glue applicator is controlled by a CNC drive system to move along the film bonding surface. Every time it moves to the set position, the glue applicator dispenses glue under the action of 0.3MPa air pressure, and the amount of glue dispensed at one time is controlled to be 0.02g, forming dot-shaped glue dots with a diameter of about 3mm on the film bonding surface, until the glue application operation of the entire 460mm wide first layer film bonding surface is completed.

[0021] It should be noted that after completing the first layer of film coating, the coating head is precisely aligned with the bonding surface of the third layer of film (a PET film with the same specifications as the first layer, 460mm wide and 0.05mm thick). The parameter program used when coating the first layer of film is called through the CNC system to replicate the same coating path and dispensing operation, ensuring that the dotted adhesive distribution on the bonding surface of the third layer of film is completely consistent with that of the first layer.

[0022] In addition, after the adhesive coating process is completed, place the two coated PET films flat on a clean acrylic platform and let them stand for a preset time of 8 minutes to allow the adhesive dots to initially cure and maintain their shape stability.

[0023] Please see Figure 5 It also includes a double-roller bonding mechanism, with the upper roller being a hard rubber roller and the lower roller being a stainless steel roller. Step S2, where the aluminum foil is sandwiched between the two layers of film for rolling bonding, specifically involves: The three layers of material in the middle are fed into the double roller bonding mechanism so that the edges of the material are aligned with the guide reference line of the double roller bonding mechanism. Calculate the total thickness of the three layers of material in the middle section, and adjust the distance between the two rollers accordingly. Based on the preset speed matching between the two rollers, the double rollers are driven to rotate, and the material is pulled through the gap between the two rollers at a uniform speed. Once the material has completely passed through, maintain the pressure of the two rollers for the preset time, then stop the two roller drive.

[0024] In this embodiment, a double-roller bonding mechanism equipped with an upper roller and a lower roller is used. The upper roller is a nitrile rubber roller with a Shore hardness of 75D, and the lower roller is a smooth roller made of 304 stainless steel with a surface roughness Ra≤0.8μm. The first layer of PET film (460mm wide and 0.05mm thick) with dot-coated adhesive, the pure aluminum foil (460mm wide) with a thickness of 0.03mm and the third layer of PET film (460mm wide and 0.05mm thick) with dot-coated adhesive are stacked in the following order: the adhesive side of the first layer of film is facing up, the aluminum foil covers the adhesive dots of the first layer of film, and the adhesive side of the third layer of film is facing down and covers the aluminum foil. This forms a three-layer material assembly in the middle.

[0025] In one embodiment, the three-layer material assembly is fed into the feed end of the double-roller bonding mechanism. The material position is adjusted by the laser positioning component on the side of the mechanism so that the two sides of the three-layer material are completely aligned with the guide reference line of the double-roller bonding mechanism (set along the roller axis, 5mm away from the roller edge).

[0026] In another embodiment, the total thickness of the three layers of material is measured by micrometer. The total thickness of the first film layer (0.05 mm), aluminum foil layer (0.03 mm), and third film layer (0.05 mm) is measured to be 0.13 mm. Based on this total thickness, the distance between the two rollers of the double roller bonding mechanism is adjusted to 0.15 mm (leaving a 0.02 mm pressing allowance).

[0027] It should be noted that, based on the adjusted 0.15mm gap between the two rollers, and matching the preset double roller rotation speed parameters, the speed of the lower roller drive motor is set to 15r / min. Through gear transmission, the upper roller and the lower roller rotate synchronously, pulling the three-layer material assembly through the gap between the two rollers at a linear speed of 0.8m / min.

[0028] It should be noted that after the end of the three-layer material assembly has completely passed through the gap between the two rollers, the current bonding pressure of 0.3MPa is maintained on the two rollers and continues to act for a preset duration of 15 seconds. Then the dual roller drive motor is turned off to complete this rolling bonding operation.

[0029] Optionally, the middle layer treatment in step S2, which involves sandwiching the aluminum foil between two thin films and then rolling and bonding them, specifically involves: The initially formed middle layer is sent into the hot air drying channel, and the hot air temperature and wind speed parameters are set. After drying for the preset time, remove the middle layer and place it flat on the testing platform; According to the preset detection point distribution, use a thickness gauge to detect and record the thickness of each area of ​​the middle layer; For areas where the thickness deviation exceeds the standard, mark them, place the middle layer into a local pressure device, apply the set pressure to the deviation area, and maintain it for a preset time.

[0030] In one embodiment, when processing the preliminary shaped middle layer (460mm wide, composed of a 0.05mm thick PET film, a 0.03mm thick pure aluminum foil, and a 0.05mm thick PET film) formed by rolling and bonding aluminum foil between two layers of film, the middle layer is first flattened and sent into a continuous hot air drying channel. The hot air temperature in the channel is set to 65°C, the hot air velocity is set to 2.5m / s, and the vertical distance between the hot air outlet and the upper surface of the middle layer is maintained at 150mm.

[0031] It should be noted that after drying for the preset 12-minute drying time, the discharge door of the hot air drying channel is opened, and the middle layer is taken out by a robotic arm with a silicone anti-slip pad. It is then placed flat on a marble inspection platform with a surface flatness error of ≤0.02mm / m, and the four corners of the middle layer are fixed by adjustable magnetic blocks to prevent displacement.

[0032] It should be noted that, according to the preset distribution rules of the detection points (one detection point is set every 50mm along the width direction of the middle layer and one detection point is set every 60mm along the length direction, for a total of 45 detection points), the thickness of each detection point of the middle layer is detected one by one using a digital thickness gauge with a range of 0-1mm and an accuracy of 0.001mm, and the data is recorded. The acceptable thickness range is set to 0.12mm-0.14mm (corresponding to a deviation of ±0.01mm from the total thickness of the three layers of material of 0.13mm).

[0033] In another embodiment, for deviation areas whose thickness exceeds the range of 0.12mm-0.14mm after detection, the boundary of the area is marked on the surface of the middle layer with a marker (marking line width ≤ 0.5mm). Then, the middle layer is transferred to the worktable of a local pressurization device with vacuum adsorption function. The deviation area is aligned with the CCD vision positioning system of the device, the position of the pressurization head (the area of ​​the pressurization head is 10% larger than that of the deviation area) is adjusted, a set pressure of 0.5MPa is applied, and the pressure is maintained for a preset duration of 8s to complete the local pressurization treatment of the deviation area.

[0034] Optionally, the aluminum foil clamping in step S2 is specifically as follows: Lay an anti-static protective film on the workbench, then lay the first layer of film in the middle after applying the adhesive on it, with the adhesive side facing up. Fix the aluminum foil with a fixture with positioning scale, and adjust the fixture to align the aluminum foil with the edge of the film; Lower the fixture and place the aluminum foil in the film adhesive dot area; With the adhesive-coated side of the third layer of film facing down, align it with the edge of the aluminum foil to complete the overlay.

[0035] In one embodiment, during the aluminum foil clamping operation, a 0.1mm thick aluminum foil with a surface resistivity of 10 is first laid on a 1000mm × 800mm stainless steel workbench. 6 ~10 9 Use an Ω-sized PET antistatic protective film to ensure that the film completely covers the work surface without wrinkles. Then, lay the first layer of film (460mm wide, 0.05mm thick PET film) with the adhesive already applied in dots on the antistatic protective film, with the adhesive side of the film facing up, the long side of the film parallel to the long side of the work surface, and the left edge of the film aligned with the left baseline of the work surface.

[0036] In another embodiment, an aluminum alloy fixture with millimeter-level positioning scale (scale accuracy 0.1mm) is used. A pure aluminum foil with a thickness of 0.03mm and a width of 460mm is laid flat in the positioning area of ​​the fixture. By adjusting the adjustment knobs on both sides of the fixture, the aluminum foil is pushed so that the left edge, right edge, front edge, and rear edge of the aluminum foil completely coincide with the 0mm line, 460mm line, 0mm line, and 210mm line on the positioning scale of the fixture, respectively, thereby fixing the aluminum foil.

[0037] In another embodiment, the pneumatic lifting assembly of the tooling is activated, and the tooling is controlled to lower the aluminum foil at a speed of 5 mm / s until the lower surface of the aluminum foil contacts the adhesive coating surface of the first layer of film in the middle, so that the aluminum foil is accurately placed in the adhesive dot distribution area of ​​the film (the adhesive dots are distributed at a horizontal spacing of 15 mm and a vertical spacing of 12 mm), and then the tooling is raised and reset.

[0038] In another embodiment, the third layer film, which has the same specifications as the first layer film (460mm wide and 0.05mm thick) and has been dotted with adhesive, is taken and placed with the adhesive side down. The left and front edges of the third layer film are aligned with the left and front edges of the first layer film using the positioning pins on the edge of the worktable. It is then slowly covered onto the surface of the aluminum foil to complete the stacking operation of the three layers of material.

[0039] Of particular importance is the film treatment in step S2, which includes plasma processing equipment and airflow cleaning devices, before the aluminum foil is sandwiched between two layers of film for rolling bonding: PE, PP, and PET films are placed in a plasma treatment device, and the treatment parameters are set so that the plasma acts on the film bonding surface. After processing, place the film in a dustproof and clean tray to prevent the bonding surface from contacting other objects; Place the aluminum foil into the grinding equipment, install the appropriate grinding components, and grind the upper and lower surfaces of the aluminum foil. After polishing, start the airflow cleaning device, adjust the airflow parameters, and remove aluminum powder from the surface of the aluminum foil.

[0040] In one embodiment, when performing film treatment before rolling lamination of aluminum foil sandwiched between two films, a PET film with a width of 460mm and a thickness of 0.05mm is selected as the film to be treated. It is placed in a low-temperature plasma treatment device (processing chamber size 500mm×300mm×100mm) with the film lamination surface facing the plasma emission electrode. The processing parameters are set as follows: radio frequency power 300W, processing gas pressure 0.08MPa, processing time 40s, and argon gas with a purity of 99.99% is used as the plasma gas. The device is then started to allow the plasma to act on the film lamination surface.

[0041] In another embodiment, after processing, the plasma processing equipment chamber door is opened, and the film is removed using a robotic arm wearing silicone gloves. It is immediately placed into a dustproof clean tray (500mm x 400mm, ABS resin, with a sealing cap) lined with a 0.02mm thick lint-free cloth (Class 100 cleanliness), ensuring the film's bonding surface does not contact the tray's inner wall or other objects. Then, a 460mm wide, 0.03mm thick pure aluminum foil is taken and placed into a CNC grinding machine (grinding platform size 600mm x 400mm), and a suitable silicon carbide grinding assembly (800-mesh grinding disc, 50mm grinding head diameter) is installed.

[0042] It should be noted that the grinding parameters are set as follows: grinding speed 1500r / min, grinding pressure 0.1MPa, grinding path is a reciprocating linear motion along the length of the aluminum foil (single reciprocating stroke 210mm), and the upper and lower surfaces of the aluminum foil are ground twice each.

[0043] In another embodiment, after polishing, the matching airflow cleaning device (outlet diameter 10mm, airflow type is compressed air) is activated, and the airflow parameters are adjusted as follows: airflow pressure 0.2MPa, airflow speed 15m / s, vertical distance between the outlet and the aluminum foil surface 20mm, and the outlet is controlled to move along the aluminum foil surface at a horizontal spacing of 30mm and a vertical spacing of 25mm to remove aluminum powder from the aluminum foil surface. The cleaning time lasts for 60s.

[0044] Preferably, in step S3: take PE, PP, or PET film as the lower first layer, take aluminum foil as the lower second layer, and take PE, PP, or PET film or paper film as the heat-sealing functional layer, and stack the three lower layers together to form the lower layer; Optionally, the three-layer overlapping in step S3 specifically involves: When the heat-sealing functional layer is a film, the film is placed in the heating equipment so that the heating element contacts the film bonding surface, and the heating parameters are set. After heating, the film is removed, aligned and bonded to the aluminum foil using a positioning fixture, and then fed into a pressurizing device to apply pressure and maintain it for a preset time. When the heat-sealing functional layer is a paper film, apply adhesive to the aluminum foil bonding surface using a metering adhesive applicator along a preset trajectory. After the adhesive is applied, the paper film and aluminum foil are aligned and stacked by the positioning component, and then sent into the pressure mechanism to apply pressure and maintain it for a preset time.

[0045] In one embodiment, a PET film with a width of 460mm and a thickness of 0.05mm is selected as the lower first layer, and a pure aluminum foil with the same width of 460mm and a thickness of 0.03mm is selected as the lower second layer. When the heat-sealing functional layer is a PET film (width of 460mm and thickness of 0.04mm), the PET film is placed in a constant temperature heating device (heating chamber size 500mm×400mm×50mm), so that the stainless steel heating element (heating surface area is the same as the film bonding surface, 460mm×210mm) in the device is in complete contact with the film bonding surface, and the heating parameters are set as heating temperature 85℃ and heating time 25s.

[0046] It should be noted that after heating is complete, open the heating equipment door, take out the film with high-temperature resistant silicone clips, and immediately place it into the aluminum alloy positioning fixture with positioning pins, so that the left edge and front edge of the film are aligned with the 0mm baseline of the fixture. Then, lay the aluminum foil (which has been cleaned by airflow) as the second layer on the positioning fixture, so that the edge of the aluminum foil is completely aligned with the edge of the film and adhered. Then, send the two layers of material into the pneumatic pressurizing equipment (pressurizing surface size 480mm×230mm), set the pressurizing pressure to 0.4MPa, and maintain this pressure for 18s.

[0047] In another embodiment, when the heat-sealing functional layer is a paper film (460mm wide, 0.06mm thick, made of food-grade kraft paper), a quantitative glue application tool with a 0.5mm diameter glue outlet (glue head movement accuracy ±0.1mm) is used to apply glue to the aluminum foil bonding surface, which is the second layer below, according to a preset trajectory (a dotted trajectory with a horizontal spacing of 12mm and a vertical spacing of 10mm, covering the entire 460mm×210mm bonding surface), and the glue application amount is controlled to be 0.015g / dot.

[0048] It should be noted that after the adhesive is applied, the paper film and aluminum foil are aligned using a positioning component with CCD vision positioning (positioning accuracy ±0.05mm), so that the edges of the paper film and aluminum foil are completely overlapped and superimposed. Then, the superimposed two layers of material are fed into an electric pressure mechanism (the pressure plate is made of polytetrafluoroethylene to avoid adhesive sticking), the pressure is set to 0.3MPa, and the pressure is maintained for 22s, finally completing the superposition and bonding of the three layers of material in the lower layer.

[0049] Preferably, in step S4: the upper layer, middle layer, and lower layer are stacked in alignment according to the edge marks, and adjacent layers are coated with adhesive or heat-sealed as needed, and symmetrical pressure is applied to form an integral composite structure; Please see Figure 2 In step S4, the bonding of the upper layer and the middle layer specifically involves: If adhesive bonding (glue lamination) is selected, the adhesive is evenly applied to the upper surface of the middle layer, wherein the application range is adapted to the size of the lower surface of the upper layer; Align the lower surface of the upper layer with the adhesive area of ​​the middle layer, cover and press to initially bond the upper and middle layers together; If wax bonding (wax layer composite) is selected, the wax is heated to a molten state and a quantitative wax coating device is used to form a uniform wax layer on the upper surface of the middle layer; When the wax layer cools to a semi-solid state, the lower surface of the upper layer is attached to the wax layer, and a preset pressure is applied and held for a preset time to complete the bonding between the upper and middle layers.

[0050] In one embodiment, when bonding the upper and middle layers, if an adhesive is used, the dimensions of the lower surface of the upper layer are first determined to be 460mm wide × 210mm long. Then, an adhesive applicator with an automatic scraping function (applicator head width 460mm, scraping accuracy ±0.02mm) is used to apply water-based polyurethane adhesive to the upper surface of the middle layer (460mm wide × 210mm long, composed of PET film + aluminum foil + PET film). The application area is strictly controlled to be 460mm wide × 210mm long, and the amount of adhesive applied is set to 20g / m². 2 Ensure the adhesive is evenly applied without any gaps. After the adhesive is applied, use a transfer mechanism with infrared positioning (positioning accuracy ±0.1mm) to grab the upper layer (composed of 1.2mm thick cardboard and 0.8mm thick polyolefin foam, dimensions 460mm wide × 210mm long), so that the lower surface of the upper layer is completely aligned with the edge of the adhesive area of ​​the middle layer. After slowly covering, start the pre-press component of the mechanism to apply 0.1MPa pressure and hold for 5 seconds to achieve the initial bonding of the upper and middle layers.

[0051] In another embodiment, if wax bonding is used, food-grade microcrystalline wax with a melting point of 65°C is placed in a temperature-controlled wax heating tank (5L capacity, temperature control accuracy ±1°C) and heated to 75°C to completely melt the wax. Then, a quantitative wax coating device (2mm diameter nozzle, spiral waxing path, 10mm pitch) is activated to form a uniform wax layer of 0.08mm thickness on the upper surface of the middle layer (460mm wide × 210mm long). The wax coating amount is controlled at 15g / m². 2 After the waxing device is turned off, the temperature of the wax layer is monitored in real time by a temperature sensor. When the temperature of the wax layer drops to 50℃ (in a semi-solid state), the lower surface of the upper layer is aligned and bonded to the edge of the wax layer by an infrared positioning and transfer mechanism. Then, the bonded assembly is sent into a constant temperature and pressure device (pressure temperature is maintained at 50℃, pressure plate size is 500mm×250mm), a preset pressure of 0.2MPa is applied, and the pressure is maintained for 12s to complete the bonding of the upper layer and the middle layer.

[0052] Of particular importance is that the symmetrical pressurization in step S4 is specifically as follows: Install pressure blocks of the same specifications on the left and right sides of the composite structure, and adjust the contact area of ​​the pressure blocks to be the same and symmetrically distributed by the positioning component; Start the pressurization device to apply initial pressure to the two pressure blocks simultaneously and maintain the preset initial pressure for a set duration; Simultaneously increase the pressure of the briquette to the set value and continue to maintain the preset initial pressure for the duration; After the pressure holding period ends, perform the pressure release operation, and then remove the pressure block after the pressure release is complete.

[0053] In one embodiment, during the symmetrical pressurization operation, the dimensions of the composite structure of the upper and middle layers to be pressurized are first determined to be 460mm wide × 210mm long. Then, rectangular metal blocks of the same specifications (made of No. 45 steel, each block is 210mm long, 50mm wide, and 20mm thick, matching the length of the composite structure) are installed on the left and right sides of the composite structure. The positions of the two blocks are adjusted by a positioning component with laser ranging function (positioning accuracy ±0.05mm) so that the distance between the right edge of the left block and the left edge of the composite structure is 20mm, and the distance between the left edge of the right block and the right edge of the composite structure is 20mm. This ensures that the contact area between the two blocks and the composite structure is 210mm × 50mm and is symmetrically distributed from left to right.

[0054] In another embodiment, a CNC pneumatic pressurization device (equipped with a dual-channel synchronous pressure output module with a pressure control accuracy of ±0.01MPa) is activated to simultaneously apply an initial pressure of 0.15MPa to the two pressure blocks and maintain this preset initial pressure for 8 seconds. After the initial pressure is maintained, the pressure of the two pressure blocks is synchronously increased to the set value of 0.4MPa through the pressure adjustment module of the device, and this pressure is maintained for another 15 seconds. After the pressure is maintained, the depressurization program of the device is activated to control the pressure of the two pressure blocks to decrease uniformly to 0MPa at a rate of 0.05MPa / s. After the depressurization is completed, a special tooling fixture is used to remove the pressure blocks on the left and right sides from the composite structure, completing the symmetrical pressurization operation.

[0055] Please see Figure 2 Step S5: Adjust the temperature of the overall composite structure, divide the cutting lines (die-cutting lines) according to the preset size, cut along the dividing lines and then polish to obtain the finished sealing aluminum foil gasket.

[0056] Most importantly, in step S5, the cutting lines (die-cutting lines) are divided according to the preset dimensions, and the subsequent sanding along the cutting lines is specifically as follows: Fix the composite structure to the cutting worktable and calibrate its position using a positioning device; set the cutting path according to the finished product size and start the equipment to cut along the path. After cutting, the finished product is sent to the grinding equipment, the matching grinding head is installed, and the grinding parameters are set. Start the grinding equipment to grind the edges of the finished product, and monitor the edge flatness during the grinding process.

[0057] In one embodiment, the overall composite structure (460mm wide and 210mm long) formed by bonding the upper layer, middle layer and lower layer is placed on a CNC cutting workbench (workbench surface size 600mm×400mm, surface flatness error ≤0.02mm). The edges of the composite structure are fixed by four sets of pneumatic positioning fixtures (fixture pressure 0.08MPa) equipped on the workbench. At the same time, the CCD vision positioning device (positioning accuracy ±0.05mm) built into the workbench is activated to calibrate the position of the composite structure and ensure that its center coincides with the cutting origin of the workbench.

[0058] It should be noted that, according to the preset size of the finished sealing aluminum foil gasket (a circle with a diameter of 50mm, 8 finished products are obtained in a single cut, with a cutting center every 55mm along the 460mm width of the composite structure and every 52mm along the 210mm length), a circular cutting path is set. The CNC cutting equipment (the cutting blade is a carbide circular blade with a blade diameter of 60mm and a speed of 3000r / min) is started, and the blade is controlled to cut along the set circular path. The cutting depth is set to 1.1 times the total thickness of the overall composite structure (1.2mm cardboard + 0.8mm polyolefin foam + 0.13mm middle layer + 0.18mm bottom layer, total thickness 2.31mm) to ensure complete cut without damaging the worktable.

[0059] In another embodiment, after cutting, eight circular finished products are separated from the composite structure waste by a vacuum suction cup robot (40mm diameter suction cup, -0.06MPa adsorption pressure) and fed into an automatic grinding equipment. A suitable nylon grinding head (60mm diameter, 1200 mesh grit) is installed on the equipment, and the grinding parameters are set as follows: grinding speed 1500r / min, grinding pressure 0.05MPa, grinding time 15s, and the grinding area is a 5mm wide area around the edge of the finished product. The grinding equipment is started to grind the edge of the finished product, while the edge flatness is monitored in real time by the equipment's laser profilometer (measurement accuracy ±0.01mm) to ensure that the edge flatness error of the finished product after grinding is ≤0.03mm. After grinding, the equipment is turned off, completing the production of the finished product sealing aluminum foil gasket.

[0060] Preferably, a method for manufacturing a sealing aluminum foil gasket further includes the fabrication of a middle layer dividing line: After the middle layer is rolled and dried, the middle layer is fixed on the scoring table and its position is calibrated using the positioning components. Select a scoring tool with a preset texture and set the scoring path according to the size of the middle layer, wherein the dividing lines are distributed along the preset trajectory; Start the scoring equipment and control the scoring tool to score the dividing line on the surface of the middle layer at a set depth. The scoring depth is one-third to one-half of the total thickness of the middle layer. After the scoring is completed, use compressed air to remove the scoring debris from the surface of the middle layer, thus completing the creation of the middle layer dividing line.

[0061] In one embodiment, the middle layer (460mm wide and 210mm long, composed of a 0.05mm thick PET film, a 0.03mm thick pure aluminum foil, and a 0.05mm thick PET film, with a total thickness of 0.13mm) that has been rolled and dried with hot air (hot air temperature 65℃, wind speed 2.5m / s, drying time 12min) is placed on a scoring worktable (table size 500mm×300mm, surface flatness error ≤0.02mm). The middle layer is pushed by the electric positioning components on both sides of the worktable (positioning accuracy ±0.05mm) so that the left edge of the middle layer is aligned with the left reference line of the worktable and the front edge is aligned with the front reference line of the worktable. At the same time, the vacuum adsorption device at the bottom of the worktable (adsorption pressure -0.07MPa) is activated to fix the middle layer.

[0062] In another embodiment, a tungsten steel scoring tool with a continuous straight preset pattern (blade width 0.1mm, blade tip angle 60°) is selected. The scoring path is set according to the dimensions of the middle layer, which is 460mm wide and 210mm long. The dividing lines are distributed along the length of the middle layer, with a total of 9 dividing lines. The distance between adjacent dividing lines is 50mm. The length of each dividing line is the same as the length of the middle layer (210mm), and the two ends of the dividing line are 5mm away from the edge of the middle layer.

[0063] In another embodiment, a CNC scoring device is activated, and the scoring tool is controlled by the device's servo drive system to move along a set path at a speed of 5 mm / s. Simultaneously, the scoring depth is set to 0.05 mm of the total thickness of the middle layer (0.13 mm) (within one-third to one-half of the total thickness), ensuring that the scoring penetrates the outer PET film without damaging the inner PET film. After scoring is completed, a matching compressed air cleaning device (outlet diameter 8 mm, airflow pressure 0.25 MPa, airflow speed 18 m / s) is activated. The outlet is controlled to move along the surface of the middle layer at a horizontal spacing of 20 mm and a vertical spacing of 15 mm to remove scoring debris from the surface of the middle layer. The cleaning time lasts for 40 seconds, completing the fabrication of the middle layer dividing line.

[0064] Please see Figure 2 The backing of the sealing aluminum foil gasket is made of cardboard or PE foam.

[0065] Please see Figure 6 This is a schematic diagram of the perimeter layout of the sealing aluminum foil gaskets, showing their specifications and arrangement parameters on the production plate. The overall width of the plate is 460mm, with a 5mm margin along the perimeter (vertical) edge. In the horizontal layout, the left and right sides are each 210mm wide, with 10mm and 5mm intervals in the middle area. The sealing aluminum foil gaskets are circular and distributed in an array within the plate. The horizontal and vertical intervals between adjacent gaskets are determined by the dimensions marked in the diagram (such as 10mm and 5mm). The overall layout is used to guide the cutting and segmentation processes during production, clarifying the number of aluminum foil gaskets that can be produced per plate and the relative positional relationship of each gasket.

[0066] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0067] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A sealing aluminum foil gasket, characterized in that, include: It consists of an upper layer, a middle layer, and a lower layer, which are bonded together from top to bottom to form a sealing aluminum foil gasket; The upper layer is formed by bonding and hot-pressing cardboard and polyolefin foam together with adhesives; The middle layer is a three-layer composite structure, and is arranged sequentially along a direction perpendicular to the sheet surface and moving away from the upper layer: The first layer in the middle is any one of PE, PP or PET film that is in direct contact with the upper layer; The second layer in the middle is an aluminum foil that is in direct contact with the first layer in the middle. The third layer in the middle, wherein the third layer in the middle is any one of PE, PP or PET film that is in direct contact with the second layer in the middle; The lower layer is a three-layer composite structure, and is provided sequentially along the same vertical direction away from the middle layer as follows: The lower first layer is any one of PE, PP or PET film that is in direct contact with the middle third layer; The lower second layer is an aluminum foil that is in direct contact with the lower first layer; The lower third layer is a heat-sealing functional layer that is in direct contact with the lower second layer. The heat-sealing functional layer is composed of PE, PP, or PET film, or aluminum foil and paper film that do not have heat-sealing properties.

2. A method for manufacturing a sealing aluminum foil gasket, characterized in that, Includes the following steps: Step S1: Stack the cardboard and polyolefin foam according to the appropriate size, apply adhesive to the contact surface of the two, pre-press the edge area first, and then push and press towards the center to form the upper layer; Step S2: Take any one of PE, PP, or PET film as the first and third middle layers, and aluminum foil as the second middle layer. Apply adhesive in a dotted pattern to the film bonding surface, and roll the aluminum foil between the two film layers to form the middle layer. Step S3: Take PE, PP, and PET film as the first lower layer, aluminum foil as the second lower layer, and PE, PP, and PET film or paper film as the heat-sealing functional layer. Stack the three lower layers together to form the lower layer. Step S4: Align and stack the upper, middle, and lower layers according to the edge marks, apply adhesive or heat seal adjacent layers as needed, and apply symmetrical pressure to form an overall composite structure; Step S5: Adjust the temperature of the overall composite structure, divide the cutting lines according to the preset size, cut along the cutting lines and then polish to obtain the finished sealing aluminum foil gasket.

3. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The method also includes the creation of middle layer dividing lines: After the middle layer is rolled and dried, the middle layer is fixed on the scoring table and its position is calibrated using the positioning components. Select a scoring tool with a preset texture and set the scoring path according to the size of the middle layer, wherein the dividing lines are distributed along the preset trajectory; Start the scoring equipment and control the scoring tool to score the dividing line on the surface of the middle layer at a set depth. The scoring depth is one-third to one-half of the total thickness of the middle layer. After the scoring is completed, use compressed air to remove the scoring debris from the surface of the middle layer, thus completing the creation of the middle layer dividing line.

4. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The pressurization operation uses a pressure device equipped with a positioning sensor and a contact pressure head. The contact pressure head is divided into an arc-shaped pressure head and a flat pressure head. The pressurization process in step S1, which involves pushing the device towards the center, is as follows: An arc-shaped pressure head is used to cover the edge area of ​​the material. The pressure device is activated to apply initial pressure and maintain the preset pressure for a set time. Disassemble the arc-shaped pressure head and replace it with a flat pressure head. Use a positioning sensor to align the pressure head with the pre-compression edge. Start the pressure device and control the flat pressure head to move from the edge to the center while gradually increasing the pressure; After the pressure head completely covers the bonding surface, maintain the pressure for the preset time, then turn off the pressure device.

5. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, Including a dispensing head with a dispensing orifice of a set diameter, step S2 involves applying adhesive in a dotted pattern to the film bonding surface, including: Keep the applicator head parallel to the bonding surface of the first layer of film in the middle; The glue applicator head moves according to the set row and column spacing, and controls the glue to be dispensed each time it moves to the set position, forming dotted glue dots. After completing the first layer of film coating in the middle, align the coating head with the bonding surface of the third layer of film in the middle and replicate the coating path and dispensing operation. After applying the adhesive, place the first and third layers of film in the middle flat and let them stand for the preset time.

6. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The mechanism includes a double-roller lamination system, with the upper roller being a hard rubber roller and the lower roller being a stainless steel roller. Step S2, which involves sandwiching the aluminum foil between the two layers of film for rolling lamination, specifically involves: The three layers of material in the middle are fed into the double roller bonding mechanism so that the edges of the material are aligned with the guide reference line of the double roller bonding mechanism. Calculate the total thickness of the three layers of material in the middle section, and adjust the distance between the two rollers accordingly. Based on the preset speed matching between the two rollers, the double rollers are driven to rotate, and the material is pulled through the gap between the two rollers at a uniform speed. Once the material has completely passed through, maintain the pressure of the two rollers for the preset time, then stop the two roller drive.

7. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The specific process of the middle layer treatment after rolling and bonding the aluminum foil between the two films in step S2 is as follows: The initially formed middle layer is sent into the hot air drying channel, and the hot air temperature and wind speed parameters are set. After drying for the preset time, remove the middle layer and place it flat on the testing platform; According to the preset detection point distribution, use a thickness gauge to detect and record the thickness of each area of ​​the middle layer; For areas where the thickness deviation exceeds the standard, mark them, place the middle layer into a local pressure device, apply the set pressure to the deviation area, and maintain it for a preset time.

8. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The aluminum foil clamping in step S2 is specifically as follows: Lay an anti-static protective film on the workbench, then lay the first layer of film in the middle after applying the adhesive on it, with the adhesive side facing up. Fix the aluminum foil with a fixture with positioning scale, and adjust the fixture to align the aluminum foil with the edge of the film; Lower the fixture and place the aluminum foil in the film adhesive dot area; With the adhesive-coated side of the third layer of film facing down, align it with the edge of the aluminum foil to complete the overlay.

9. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The three-layer overlay combination in step S3 is specifically as follows: When the heat-sealing functional layer is a film, the film is placed in the heating equipment so that the heating element contacts the film bonding surface, and the heating parameters are set. After heating, the film is removed, aligned and bonded to the aluminum foil using a positioning fixture, and then fed into a pressurizing device to apply pressure and maintain it for a preset time. When the heat-sealing functional layer is a paper film, apply adhesive to the aluminum foil bonding surface using a metering adhesive applicator along a preset trajectory. After the adhesive is applied, the paper film and aluminum foil are aligned and stacked by the positioning component, and then sent into the pressure mechanism to apply pressure and maintain it for a preset time.

10. The method for manufacturing a sealing aluminum foil gasket according to claim 2, characterized in that, The bonding of the upper and middle layers in step S4 is specifically as follows: If adhesive bonding is used, the adhesive is evenly applied to the upper surface of the middle layer, wherein the application range is adapted to the size of the lower surface of the upper layer; Align the lower surface of the upper layer with the adhesive area of ​​the middle layer, cover and press to initially bond the upper and middle layers together; If wax bonding is used, the wax is heated to a molten state and a metering waxing device is used to form a uniform wax layer on the upper surface of the middle layer; When the wax layer cools to a semi-solid state, the lower surface of the upper layer is attached to the wax layer, and a preset pressure is applied and held for a preset time to complete the bonding between the upper and middle layers.

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