A positive pressure-based film pasting device

Abstract

The utility model provides a kind of based on positive pressure's film sticking equipment, it is related to film sticking device technical field.The lower cavity structure includes first movement mechanism and the lower cavity and the jig platform located in lower cavity being set on the first movement mechanism, the jig platform is suitable for placing the workpiece to be pasted film in, and the workpiece top is suitable for fixedly placed film material;The first movement mechanism is suitable for driving the jig platform switches between material discharging station and film sticking station;The upper cavity structure includes first lifting mechanism, upper cavity and heating assembly being set in upper cavity are connected on the first lifting mechanism;When the lower cavity is in film sticking station, the upper cavity is suitable for descending to cooperate with the lower cavity and form the airtight cavity;The jig platform is suitable for separating the airtight cavity into upper seal cavity and lower seal cavity;Inflating system is connected in the upper seal cavity. By the present scheme, film can be pasted using positive pressure, and the quality of film sticking is improved.

Description

Technical Field

[0001] This utility model relates to the field of film application device technology, and more specifically, to a film application device based on positive pressure. Background Technology

[0002] Current mobile phone cases and other housings require the application of matte film, but due to the curved surfaces or corners of these housings, adhesion to curved or bent areas is difficult, easily leading to problems such as air bubbles. This is especially true at corners and curved surfaces, where conventional lamination equipment struggles to apply the film properly, resulting in bubbles. Traditional film lamination equipment typically uses simple mechanical pressing methods, which cannot effectively adapt to the needs of complex curved surfaces, leading to insufficient adhesion between the film and the workpiece surface, resulting in incomplete adhesion or residual air bubbles. Furthermore, existing equipment lacks precise control over key parameters such as temperature and air pressure during the lamination process, making it difficult to achieve uniform softening of the adhesive and accurate positioning of the film, further impacting lamination quality and efficiency. Therefore, existing technologies urgently need improvement to address these issues. Utility Model Content

[0003] This utility model discloses a film-applying device and its film-applying method, which has the advantages of improving the adhesion between the film material and the workpiece surface, reducing air bubble residue, and adapting to complex curved surface structures.

[0004] Specifically, a film-applying device includes: an upper cavity structure and a lower cavity structure adapted to form a sealed cavity; wherein, the lower cavity structure includes a first motion mechanism, a lower cavity body disposed on the first motion mechanism, and a fixture platform located within the lower cavity, the fixture platform being adapted to place a workpiece to be applied, and the film material being adapted to be fixedly placed above the workpiece; the first motion mechanism is adapted to drive the fixture platform to switch between a material feeding station and a film-applying station; the upper cavity structure includes a first lifting mechanism, an upper cavity body connected to the first lifting mechanism, and a heating component disposed within the upper cavity; when the lower cavity body is in the film-applying station, the upper cavity body is adapted to descend to cooperate with the lower cavity body to form a sealed cavity; an upper sealing cavity and a lower sealing cavity are respectively formed on the upper and lower sides of the fixture platform; an inflation system is connected to the upper sealing cavity; during film application, the heating component is adapted to act on the film material on the fixture platform to soften the adhesive of the film material; the inflation system is adapted to inflate the upper sealing cavity to increase the pressure above the film material, thereby causing the film material to be adhered to the outer surface of the workpiece by positive pressure.

[0005] Furthermore, this application also proposes that both the upper and lower sealing cavities are connected to a vacuum system to remove the gas from the upper and lower sealing cavities before applying the film.

[0006] Furthermore, this application also proposes that the lower cavity is provided with a lifting platform, the fixture platform is detachably installed on the lifting platform, and a sealing ring is provided between the fixture platform and the lifting platform.

[0007] Furthermore, this application proposes that the fixture platform is provided with several positioning pins for matching with positioning holes provided on the membrane material, for positioning the membrane material. Furthermore, this application also proposes that the fixture platform is provided with vacuum adsorption holes connected to a vacuum device around its perimeter for adsorbing the edges of the membrane material.

[0008] Furthermore, this application also proposes that the heating device employs a heating lamp assembly.

[0009] Furthermore, this application also proposes that air pressure detection sensors are installed in the upper and lower sealing cavities to monitor air pressure, so as to ensure that the pressure difference between the upper and lower cavities is kept within a preset error range when vacuuming is performed before applying the film.

[0010] Furthermore, this application also proposes that the fixture platform is provided with at least two workpiece placement spaces, and each workpiece placement space is suitable for placing an independent film material above it.

[0011] Furthermore, this application also proposes that a sealing element be provided between the upper cavity and the lower cavity for sealing.

[0012] As can be seen from the above, the film-applying device provided in this application softens the adhesive through a heating component and applies positive pressure in combination with an inflation system, so that the film material can be accurately applied to the surface of the workpiece. It is especially suitable for curved or folded structures and has the advantages of improving the adhesion, reducing air bubble residue, and adapting to complex curved structures. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the lower cavity structure of a film-applying device in the material feeding position according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the lower cavity structure of a film-applying device in the film-applying position according to an embodiment of the present invention; Figure 3 This is a cross-sectional structural diagram of a film-applying device in the film-applying station according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the external structure of a film-applying device according to an embodiment of this utility model; Figure 5 This is a schematic diagram of the fixture platform structure of a film-applying device according to an embodiment of this utility model; Figure 6 This is an enlarged cross-sectional view of a film-applying device in the film-applying station according to an embodiment of the present invention. Reference numerals: 1. Upper cavity structure; 11. Upper cavity body; 12. Heating assembly; 13. Vacuum device; 14. First lifting mechanism; 15. Upper sealing cavity; Lower cavity structure 2, lower cavity body 21, lifting platform 22, jig platform 23, positioning pin 231, vacuum adsorption hole 232, sealing ring 24, lower sealing cavity 25, first motion mechanism 26; 3. Workpiece; 4. Membrane material; 5. Seal. Detailed Implementation

[0014] Combination Figures 1 to 6 As shown, this embodiment provides a film-applying device, including: an upper cavity structure 1 and a lower cavity structure 2 adapted to form a sealed cavity; wherein, the lower cavity structure 2 includes a first motion mechanism 26, a lower cavity body 21 disposed on the first motion mechanism 26, and a fixture platform 23 located within the lower cavity body 21, the fixture platform 23 is adapted to place a workpiece 3 to be applied, and the workpiece 3 is adapted to be fixedly placed above the film material 4; the first motion mechanism is adapted to drive the fixture platform 23 to switch between a material feeding station and a film-applying station; the upper cavity structure 1 includes a first lifting mechanism 14, and a [missing information - likely a component or component] connected to the first lifting mechanism 14. The upper cavity 11 and the heating component 12 disposed within the upper cavity 11; when the lower cavity 21 is in the film application position, the upper cavity 11 is adapted to descend to cooperate with the lower cavity 21 to form a sealed cavity; the upper and lower sides of the fixture platform 23 respectively form an upper sealing cavity 15 and a lower sealing cavity 25; an inflation system is connected inside the upper sealing cavity 15; during film application, the heating component 12 is adapted to act on the film material 4 on the fixture platform 23 to soften the adhesive of the film material 4; the inflation system is adapted to inflate the upper sealing cavity 15 to increase the pressure above the film material 4, thereby allowing the film material 4 to be bonded to the outer surface of the workpiece 3 by positive pressure.

[0015] The sealed cavity refers to the enclosed space formed by the docking of the upper and lower cavities 21, which can be achieved by combining a metal frame and sealing strips to establish an independent air pressure environment. The fixture platform 23 is the supporting structure that carries the workpiece 3 and the film material 4, which can be formed by machining an aluminum alloy plate. Its surface is equipped with positioning mechanisms, such as positioning grooves that match the workpiece 3, to ensure the positioning accuracy of the film material 4. The inflation system is a device for injecting gas into the sealed space, which can be a combination of an air pump and a pressure regulating valve to drive the film material 4 to extend by controlling the air pressure gradient. The heating component 12 is a device that provides heat energy, which can be an infrared lamp array or a resistance wire heater, used to activate the adhesive in the film material 4.

[0016] After the workpiece 3 and the film material 4 are positioned on the fixture platform 23, the first motion mechanism 26 transfers them to the film application station. After the upper cavity 11 descends to form a sealed cavity, the fixture platform 23 rises, and a vacuum is drawn to prevent air bubbles from forming during film application. The heating component 12 then uniformly heats the film material 4, causing the adhesive on the film material 4 to reach its softening temperature. Subsequently, the inflation system injects gas into the upper sealed cavity 15, creating a pressure difference between the upper and lower surfaces of the film material 4, pushing the softened film material 4 to extend and adhere to the surface of the workpiece 3. During this process, the film material 4 achieves surface self-adaptation through the pressure difference without mechanical contact, avoiding stress concentration at the corners caused by traditional pressing methods.

[0017] By combining non-contact pneumatic drive and thermal activation, the film material 4 is uniformly stretched in a softened state, eliminating the problem of insufficient adhesion in corner areas. The sealed cavity structure provides a stable environment for pressure control, preventing external interference from affecting the film application accuracy. This achieves uniform adhesion of the film material 4 on complex curved shells, effectively eliminating defects such as air bubbles and wrinkles. The positive pressure drive method avoids damage to the film material 4 caused by mechanical contact, while the heating and softening process improves the adhesive's fluidity, ensuring a stable bond between the film material 4 and the workpiece 3 surface. This solution is particularly suitable for film application processing of electronic product shells with multi-curved structures.

[0018] In this embodiment, the lower cavity 21 is provided with a lifting platform 22, and a fixture platform 23 is detachably mounted on the lifting platform 22. A sealing ring 24 is provided between the fixture platform 23 and the lifting platform 22. The lifting platform 22 is a load-bearing structure capable of moving vertically, and can be implemented using a hydraulic cylinder, electric push rod, or lead screw mechanism to adjust the height of the fixture platform 23. Detachable mounting means that the fixture platform 23 and the lifting platform 22 are connected by bolts, clips, or quick-release structures. Specifically, it can be achieved by using a positioning pin 231 engaging with a slot, facilitating quick replacement of fixture platforms 23 of different specifications. The sealing ring 24 is an annular elastic element disposed between the contact surfaces of the fixture platform 23 and the lifting platform 22, and can be made of rubber or silicone to fill the gap between the contact surfaces and prevent gas leakage.

[0019] Specifically, during the film application process, the lifting platform 22 adjusts the fixture platform 23 to the appropriate height position through vertical movement. This allows the heating component 12 to act on the film material 4, and simultaneously forms an upper sealing cavity 15 and a lower sealing cavity 25 within the sealed chamber. The fixture platform 23 is detachably connected to the lifting platform 22, allowing for quick disassembly and replacement with a suitable fixture platform 23 when the workpiece type 3 needs to be changed. The sealing ring 24 is compressed between the fixture platform 23 and the lifting platform 22, eliminating the risk of air leakage caused by processing errors or assembly gaps at the contact surface, thereby ensuring the stability of the vacuum environment in the lower sealing cavity 25. This solution achieves height adjustment through the lifting platform 22 and combines it with the sealing ring 24 through a detachable structure, improving equipment compatibility and ensuring sealing reliability.

[0020] In this embodiment, the fixture platform 23 is provided with a plurality of positioning pins 231 for matching with positioning holes provided on the film material 4, for positioning the film material 4. The positioning pins 231 are protruding structures fixed to the surface of the fixture platform 23, specifically cylindrical or conical metal pins, whose dimensions form a clearance fit or interference fit with the positioning holes on the edge of the film material 4, mechanically limiting the planar movement of the film material 4. The positioning holes are through holes or grooves pre-machined on the edge of the film material 4, specifically made by stamping or laser cutting processes, their positions corresponding to the distribution of the positioning pins 231, physically fitting to fix the relative position of the film material 4 and the fixture platform 23. When the film material 4 is placed on the fixture platform 23, the operator aligns and assembles the positioning holes on the edge of the film material 4 with the positioning pins 231, preventing the film material 4 from shifting horizontally. During subsequent heating and pressurization, when the film material 4 expands due to heat or is disturbed by airflow, the engagement between the positioning pins 231 and the positioning holes can continuously maintain the precise position of the film material 4 relative to the workpiece 3, avoiding misalignment caused by film material 4 displacement. Here, the positioning pins 231 can be distributed around the perimeter of the workpiece 3. The mechanical positioning method using the positioning pins 231 and positioning holes eliminates the uncertainty caused by manual intervention. Furthermore, in existing technologies where vacuum adsorption is used to fix the film material 4, the film material 4 may shift due to insufficient adsorption force after softening due to heat. This solution, through the synergistic effect of physical limiting and vacuum adsorption, further improves positioning reliability. It ensures that the film material 4 maintains precise alignment with the workpiece 3 under high temperature and pressure variations, effectively solving the problem of poor adhesion caused by film material 4 displacement in curved or bent areas, reducing the probability of air bubble formation, and improving the film-coating yield of complex structure workpieces 3.

[0021] Combination Figures 5 to 6As shown, in a preferred embodiment, the jig platform 23 is provided with vacuum adsorption holes 232 connected to the vacuum device 13 around its perimeter for adsorbing the edges of the film material 4. The vacuum adsorption holes 232 refer to airflow channels located in the edge region of the jig platform 23, which can be implemented using a ring-shaped array of micro-through-hole structures. A fixing force is applied to the edges of the film material 4 through negative pressure adsorption. The vacuum device 13 refers to the power source that generates a negative pressure environment, which can be implemented using a vacuum pump or a negative pressure generator, forming a connected loop with the vacuum adsorption holes 232 through a pipeline. When the film material 4 is placed on the jig platform 23 and positioned by the positioning pin 231, the vacuum device 13 is activated, creating a negative pressure area at the vacuum adsorption holes 232. The edges of the film material 4 are adsorbed and tightly adhered to the surface of the jig platform 23. During the film application process, the fixing force on the edges of the film material 4 prevents it from shifting due to heating or inflation pressure, ensuring the alignment accuracy between the film material 4 and the workpiece 3, and effectively straightening the film material 4. For example, the distribution density of the vacuum adsorption holes 232 can be set to 2-4 per square centimeter, and the adsorption pressure can be controlled within the range of -50kPa to -80kPa. The continuous negative pressure area formed by the vacuum adsorption holes 232 can fix the edges of the film material 4 circumferentially, eliminating bonding defects caused by edge loosening. This effectively solves the problem of easy displacement of the film material 4 edges during curved surface lamination, and avoids bonding bubbles caused by film material 4 deformation. Especially in the corners or curved areas of the workpiece 3, the film material 4 can maintain a stable pre-tightened state, thereby improving the lamination yield.

[0022] The heating device described in this embodiment can be a heating lamp assembly, positioned directly above the interior of the upper cavity 11. The heating lamp assembly refers to a light-emitting heating element that transfers heat through radiation; specifically, it can be implemented using an array of infrared lamps. Infrared lamps have a wavelength range of 800 to 1500 nanometers, enabling them to penetrate the surface of the film material 4 and uniformly transfer heat to the adhesive layer. When the fixture platform 23 moves to the film-applying station, the upper cavity 11 descends via a lifting mechanism, forming a sealed cavity with the lower cavity 21. At this time, the heating lamp assembly is activated and projects heat energy onto the surface of the film material 4. Because the lamp assembly is arranged in an array, its coverage area matches the size of the fixture platform 23, ensuring uniform heat distribution. The adhesive layer gradually softens during heating, while the inflation system fills the upper sealed cavity 15 with gas, creating a positive pressure environment above the film material 4. Under pressure, the softened adhesive uniformly fills the curved and corner areas of the workpiece 3 surface. Uniform heating control of the adhesive layer 4 of the film material was achieved, ensuring that the adhesive was fully softened in complex curved surfaces and corner areas, thereby eliminating bubbles and poor bonding caused by incomplete softening of local adhesive.

[0023] In a preferred embodiment, pressure sensors (not shown) are installed in the upper sealing cavity 15 and the lower sealing cavity 25 to monitor air pressure, ensuring that the pressure difference between the upper and lower cavities remains within a preset error range during vacuuming before film application. The pressure sensor is a device capable of measuring the gas pressure within a sealed cavity in real time; it can be a piezoresistive sensor or a piezoelectric sensor, used to synchronously collect air pressure data in the upper sealing cavity 15 and the lower sealing cavity 25 during vacuuming. The preset error range refers to the maximum threshold range within which the pressure difference between the upper and lower cavities 21 is allowed to fluctuate. This range can be set to a fixed value or dynamically adjusted by the control system to ensure uniform pressure distribution on the film material 4. During the vacuuming stage before film application, the air pressure in the upper sealing cavity 15 and the lower sealing cavity 25 is simultaneously removed. At this time, the pressure sensors monitor the pressure changes within the two cavities in real time. When the pressure difference between the upper and lower cavities 21 exceeds the preset range, the inflation system or vacuum system is triggered to adjust the air pressure, for example, by replenishing gas or extending the vacuuming time, to restore the pressure difference to the allowable range. This ensures that the film material 4 is subjected to uniform force during the subsequent pressure bonding process, avoiding uneven glue distribution or air bubble residue due to excessive local pressure difference.

[0024] This solution, through the implementation of a dual-chamber air pressure detection and closed-loop control mechanism, can more accurately balance the pressure environment of the upper and lower surfaces of the film material 4, thereby eliminating bonding defects caused by pressure difference fluctuations. It effectively solves the problem of loose bonding of the film material 4 due to uneven pressure differences at curved or corner locations, effectively reducing bubble formation, and is particularly suitable for film bonding processes on workpieces 3 with complex three-dimensional structures.

[0025] In this embodiment, after the film is applied, heating continues to fully activate the adhesive, followed by a pressure holding period of a preset duration to cure the film 4, and finally, pressure is released to separate the upper and lower cavities 21. Specifically, after the film 4 is initially bonded, the heating component 12 continuously applies heat to the adhesive to eliminate the problem of insufficient adhesive activity caused by temperature drop. During the pressure holding stage, a constant pressure is maintained to ensure that the adhesive on the edges and curved surfaces of the film 4 spreads evenly to fill the gaps under continuous pressure. The pressure release operation is performed in stages after the adhesive has cured. First, the pressure in the upper sealing cavity 15 is reduced to balance with that in the lower sealing cavity 25, and then the cavity seal is released. By extending the pressure application time during the pressure holding stage, combined with continuous heating, the adhesive is ensured to flow fully to fill the microscopic gaps, especially forming a gradual pressure release mechanism for corner areas. This solves the bonding defects caused by insufficient adhesive curing in curved surfaces and corner areas. Through staged pressure control, the film 4 maintains close contact with the surface of the workpiece 3 throughout the curing process, significantly improving the film application yield of complex curved workpieces 3.

[0026] In a preferred embodiment, the fixture platform 23 is provided with at least two workpiece 3 placement spaces, and each workpiece 3 placement space is suitable for placing an independent film material 4 above it.

[0027] The workpiece 3 placement space refers to the groove or positioning structure on the fixture platform 23 used to fix the workpiece 3. Its size and shape are matched according to the shape of the workpiece 3 to ensure that the workpiece 3 remains stable during the film application process. The independent film material 4 refers to the single film material corresponding to each workpiece 3 placement space. Specifically, it can be a pre-cut sheet material, which is fixed above the corresponding workpiece 3 by an independent positioning mechanism to avoid interference or misalignment between film materials 4 when multiple workpieces 3 are filmed. When the fixture platform 23 moves to the film application station, multiple workpieces 3 are simultaneously placed in the workpiece 3 placement space. The independent film material 4 corresponding to each workpiece 3 is initially fixed by the positioning pin 231 or vacuum adsorption hole 232. After the heating component 12 softens the film material 4, the inflation system creates a positive pressure environment in the upper sealing cavity 15, so that each film material 4 is respectively adhered to the surface of the corresponding workpiece 3. Since each film material 4 is independently positioned and the pressure is evenly distributed, edge warping or air bubble residue caused by overlapping film materials 4 or uneven pressure can be avoided when multiple workpieces 3 are filmed.

[0028] In some specific embodiments, the workpiece 3 placement space can be set as symmetrically arranged rectangular grooves, the depth of which is slightly less than the thickness of the workpiece 3 to facilitate placement and removal; the independent film material 4 can be a whole sheet of film with pre-cut parting lines, which is separated along the parting lines after film application. Through the multi-station parallel film application design, production efficiency is significantly improved while ensuring the film application accuracy of each workpiece 3. At the same time, the independent film material 4 avoids the problem of poor edge bonding caused by stretching deformation when multiple workpieces 3 share a whole sheet of film. It realizes simultaneous film application of multiple workpieces 3 without interference, effectively solving the problems of residual air bubbles at the corners of curved workpieces 3 and low utilization rate of film material 4 in mass production, which is especially suitable for the large-scale processing of multi-curved workpieces 3 such as mobile phone cases.

[0029] In this embodiment, a sealing element 5 is provided between the upper cavity 11 and the lower cavity 21. The sealing element 5 is located in the annular groove at the contact edge between the upper cavity 11 and the lower cavity 21, which can be achieved by pre-embedding or snap-fit ​​fixing. When the cavity is closed, it is deformed under pressure to form a continuous sealing strip.

[0030] It should be noted that the lifting component or lifting device mentioned in this embodiment can adopt existing lifting cylinders, lifting motors, or other mechanisms, and is equipped with guide rods to improve lifting stability. The first motion mechanism can adopt existing ball screw and nut mechanisms or other linear motion mechanisms.

[0031] The solution in this embodiment can improve the quality and efficiency of film application on workpiece 3.

[0032] It should be understood that the above are only preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited to the above embodiments. All technical solutions that fall within the scope of the present utility model are protected by the present utility model.

[0033] The accompanying drawings used in the above description of the embodiments only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

Claims

1. A positive pressure-based film pasting apparatus, characterized by comprising: include: An upper cavity structure and a lower cavity structure are suitable for forming a sealed cavity; wherein, the lower cavity structure includes a first motion mechanism, a lower cavity body disposed on the first motion mechanism, and a fixture platform located in the lower cavity body, the fixture platform is suitable for placing a workpiece to be coated, and the workpiece is suitable for fixing the film material above it; the first motion mechanism is suitable for driving the fixture platform to switch between a material feeding station and a film coating station; The upper cavity structure includes a first lifting mechanism, an upper cavity body connected to the first lifting mechanism, and a heating component disposed in the upper cavity body; when the lower cavity body is in the film-applying position, the upper cavity body is adapted to descend to cooperate with the lower cavity body to form the sealed cavity; The fixture platform has an upper sealing cavity and a lower sealing cavity formed on its upper and lower sides, respectively; an inflation system is connected inside the upper sealing cavity; During film application, the heating component is adapted to act on the film material on the fixture platform to soften the adhesive of the film material; the inflation system is adapted to inflate the upper sealed cavity to increase the pressure above the film material, thereby causing the film material to be bonded to the outer surface of the workpiece by positive pressure.

2. The positive pressure-based film attaching apparatus according to claim 1, wherein Both the upper and lower sealing cavities are connected to a vacuum system to remove the gas from the upper and lower sealing cavities before applying the film.

3. The positive pressure-based film application device according to claim 1, characterized in that, The lower cavity is provided with a lifting platform, the fixture platform is detachably mounted on the lifting platform, and a sealing ring is provided between the fixture platform and the lifting platform.

4. The positive pressure-based film application device according to claim 1, characterized in that, The fixture platform is provided with several positioning pins for matching with positioning holes provided on the film material, for positioning the film material.

5. The positive pressure-based film application device according to claim 4, characterized in that, The fixture platform is provided with vacuum adsorption holes connected to a vacuum device around its perimeter for adsorbing the edges of the film material.

6. The positive pressure-based film application device according to claim 1, characterized in that, The heating device uses a heating lamp assembly.

7. The positive pressure-based film application device according to claim 1, characterized in that, The upper and lower sealing cavities are equipped with air pressure sensors to monitor air pressure, ensuring that the pressure difference between the upper and lower cavities remains within a preset error range during vacuuming before film application.

8. The positive pressure-based film application device according to claim 1, characterized in that, The upper and lower sealing cavities are equipped with air pressure sensors to monitor air pressure, ensuring that the pressure difference between the upper and lower cavities remains within a preset error range during vacuuming before film application.

9. The positive pressure-based film application device according to claim 1, characterized in that, The fixture platform has at least two workpiece placement spaces, and each workpiece placement space is suitable for placing an independent film material above it.

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