High-heat-resistant pet release film and preparation method thereof

Abstract

The application discloses a high-heat-resistant PET release film and a preparation method thereof, relates to the technical field of release films, and comprises a structure layer, an upper connecting layer, an outer contact layer, an outer contact layer, and an inner contact layer. The upper connecting layer is fixedly connected to the top of the structure layer, and the outer contact layer is fixedly connected to the top of the upper connecting layer. The outer contact layer is fixedly connected to the bottom of the structure layer, and the inner contact layer is fixedly connected to the bottom of the outer contact layer. The high-heat-resistant PET release film and the preparation method thereof are provided with a structure layer and a structure net fixedly connected inside the structure layer. In the process of using the release film, the release film is cut to a proper size, and then is folded to form a proper shape, so that the release film is attached to an object and wraps the outer surface of the object. In the storage, transportation and processing of the object, the release film will be stretched, the structure net supports the inside of the structure layer, and the structure layer supports the whole release film.

Description

Technical Field

[0001] This invention relates to the field of release film technology, specifically to a high heat-resistant PET release film and its preparation method. Background Technology

[0002] Release film is a thin film coated with a release agent on the surface of a substrate. It is mainly used to prevent adhesive materials from sticking together during storage, transportation and processing.

[0003] For example, a matte PET release film disclosed in CN104972724B comprises a first PET layer, a matte layer, a release agent layer, an adhesive layer, and a second PET layer. The matte layer includes the following materials in parts by weight: 100 parts by weight of polyurethane resin; 6-8 parts by weight of silica; and 3-4 parts by weight of PMMA particles. The polyurethane resin has a number-average molecular weight of 2900-3000 g / mol; the silica has a particle size of 80-90 nm and a specific surface area of ​​40-45 m² / g; and the PMMA particles have a particle size of 150-160 nm and a number-average molecular weight of 1500-1600 g / mol. This scheme improves and optimizes the formulation of the matte layer, enhancing its self-debubbling ability, resulting in a matte PET release film free of air bubbles and increasing the structural stability of the release film. It also improves the flatness and surface roughness of the release film, thereby enhancing its matte effect.

[0004] For example, CN113637208B discloses a PET recycling environmentally friendly release film and its preparation method. First, waste PET bottles are recycled and modified to prepare a modified PET recycling environmentally friendly substrate. Then, a coating liquid is coated on the modified PET recycling environmentally friendly substrate and cured into a film to obtain the PET recycling environmentally friendly release film. The coating liquid is prepared from modified PEDOT multifunctional polyurethane copolymer, polyacrylamide, inorganic particles, leveling agent, organic solvent, and photoinitiator. It has low surface energy and good mechanical properties. The PET recycling environmentally friendly release film of this invention realizes the reuse of PET and is environmentally friendly. It also has good corrosion resistance and adhesion, and is hydrophobic and oleophobic.

[0005] Most of the PET release films in the aforementioned comparative documents have improved their overall strength. However, most existing PET release films are fixed, integrated structures. When in contact with objects at high temperatures, they are prone to forming bubbles on the substrate surface, resulting in a poorer release film isolation effect. Furthermore, existing PET release films are made of a single material and do not have a reinforcing structure, making them prone to damage during storage, transportation, and processing. Summary of the Invention

[0006] The purpose of this invention is to provide a high heat-resistant PET release film and its preparation method, in order to solve the problems in the prior art where most existing PET release films are fixed and integral structures, which are prone to forming bubbles on the substrate surface when in contact with objects with high temperatures, resulting in poor isolation effect of the release film. In addition, existing PET release films are made of a single material and do not have a reinforcing structure, which easily leads to damage during storage, transportation and processing.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high heat-resistant PET release film, comprising a structural layer, an upper connecting layer, an outer contact layer, a lower connecting layer, and an inner contact layer;

[0008] The upper connecting layer is fixedly connected to the top of the structural layer, and the outer contact layer is fixedly connected to the top of the upper connecting layer. The lower connecting layer is fixedly connected to the bottom of the structural layer, and the inner contact layer is fixedly connected to the bottom of the lower connecting layer. The upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer are all made of PET material.

[0009] The structural layer, upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer are distributed from top to bottom in the order of outer contact layer, upper connecting layer, structural layer, lower connecting layer, and inner contact layer. Each of the structural layer, upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer is provided with a through hole. The through hole penetrates the interior of the structural layer, upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer, and extends to the top of the outer contact layer and the bottom of the inner contact layer.

[0010] The structural layer has a fixing groove inside, and the fixing groove is distributed in a honeycomb structure. The through holes inside the structural layer do not interfere with each other and are located in the gaps formed by the fixing grooves. A structural mesh is fixedly connected inside the fixing groove, and the structural mesh is distributed in a honeycomb structure inside the structural layer. The through holes are located in the openings formed inside the structural mesh.

[0011] The bottom of both the upper and lower connecting layers are fixedly connected with multiple connecting strips that are equidistantly distributed, and a connecting channel is formed between every two connecting strips. The through holes provided inside the upper and lower connecting layers are fixedly connected to the connecting strips and the connecting channel.

[0012] The top of the outer contact layer is fixedly connected to a plurality of contact blocks arranged in a matrix, and the plurality of contact blocks arranged in a matrix form a mesh-like airway on the top of the outer contact layer.

[0013] Preferably, a plurality of equally spaced connecting strips at the bottom of the upper connecting layer are fixedly connected to the top of the structural layer, and a plurality of equally spaced connecting strips at the bottom of the lower connecting layer are fixedly connected to the top of the inner contact layer.

[0014] Preferably, the through hole extends through the upper and lower ends to the space between the outer contact layer and the inner contact layer, so that the top of the outer contact layer and the bottom of the inner contact layer are interconnected, thereby balancing the air pressure between the top of the outer contact layer and the bottom of the inner contact layer.

[0015] Preferably, the upper connecting layer and the lower connecting layer have the same structure, and a connecting channel is formed between every two connecting strips at the bottom of the upper connecting layer and the lower connecting layer, extending to both ends of the release film.

[0016] Preferably, the structural layer is made of silicone. When the structural layer deforms, the high extensibility of the silicone material allows the structural mesh inside the fixing groove to have sufficient room to move as it deforms along with the structural layer.

[0017] A method for preparing a high heat-resistant PET release film includes the following steps:

[0018] Step 1: Raw material preparation

[0019] In the production process, PET granular raw materials are prepared, and then a certain proportion of antioxidants and ultraviolet absorbers are added and mixed. The mixed PET granules and antioxidants and ultraviolet absorbers are heated so that the raw materials are in a molten state.

[0020] Prepare high-temperature vulcanizing silicone and a certain proportion of additives. Thoroughly stir the silicone base material with crosslinking agent, filler, plasticizer, etc. in a mixing device to ensure uniform dispersion. The mixed silicone material needs to be degassed to remove air bubbles introduced during the mixing process, ensuring the uniformity and quality of the finished product.

[0021] Step 2: Extrusion film formation

[0022] PET raw materials are added to the extrusion film production equipment to extrude the upper connecting layer, outer contact layer, lower connecting layer and inner contact layer. The extruder heats the PET raw materials to a certain temperature and then extrudes them through the die head. During the extrusion process, the die rollers come into contact with the uncooled upper connecting layer, outer contact layer and lower connecting layer, so that the upper connecting layer, outer contact layer and lower connecting layer form connecting strips, connecting channels, contact blocks and air passages respectively.

[0023] High-temperature vulcanized silicone raw materials are added to extrusion molding equipment for extrusion molding of structural layers. A screw extruder is used to extrude the uniformly mixed silicone material. After the silicone film is formed, it is laid flat, and then the structural mesh is placed between the two silicone films so that the two silicone films wrap the structural mesh from top to bottom. High-temperature vulcanized silicone needs to be cured in a heating furnace, usually at a temperature between 120°C and 180°C. During the heating process, the two silicone films are connected to each other to form a whole and form a structural layer.

[0024] Step 3: Stretching treatment

[0025] During film formation, the upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer are stretched to improve the film's strength and durability. The cooled PET film is then stretched longitudinally under the action of heated rollers, typically with a stretch ratio of 3-5 times, to improve the film's mechanical strength and transparency. The longitudinally stretched film is then fed into a transverse stretching machine and stretched transversely under heating, with a stretch ratio typically of 3-5 times, further improving the film's strength and dimensional stability. Finally, the biaxially stretched film undergoes heat setting to eliminate internal stress and stabilize the film's dimensions.

[0026] Step 4: Surface Treatment

[0027] PET surface treatment: The upper connecting layer, outer contact layer, lower connecting layer, and inner contact layer are treated with an alkaline solution to roughen their surfaces and introduce polar groups; Silicone surface treatment: The structural layer is treated with a silane coupling agent to form an active surface; The roughness of the PET and silicone surfaces is increased by polishing to enhance the mechanical bonding force of the adhesive;

[0028] Step 5: Adhesive

[0029] Using the structural layer as the base, the upper connecting layer and the outer contact layer are bonded to each other in sequence at the top. After the upper connecting layer and the outer contact layer are bonded to each other, the lower connecting layer and the inner contact layer are bonded to each other in sequence below the structural layer.

[0030] Clean the PET and silicone surfaces with isopropanol or acetone to remove grease, dust and impurities. Treat the PET and silicone surfaces according to the selected surface treatment method. Apply an appropriate amount of adhesive evenly to the treated PET and silicone surfaces. Align the PET and silicone as needed, apply appropriate pressure to ensure that the adhesive makes full contact and cures. After curing, clean up any excess adhesive to ensure that the bonding area is clean.

[0031] Step 7: Drill holes

[0032] After the release film is bonded, the drilling positions of the through holes are determined according to the structural mesh extending from the inside of the structural layer to the outside. The bonded release film is then placed inside the drilling machine to drill holes, so that the through holes are evenly distributed inside the release film.

[0033] Step 7: Quality Inspection

[0034] During the production process, it is necessary to strictly control various parameters to ensure the quality and performance of the membrane. After production is completed, it is necessary to test the connectivity of the through holes and the connectivity of the internal channels formed between the two connecting strips.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This invention relates to a high heat-resistant PET release film and its preparation method. The release film is provided with a structural layer and a structural mesh fixedly connected inside it. During the use of the release film, the entire release film is cut to a suitable size and then folded to form a suitable shape, so that the release film adheres to the object and wraps the outer surface of the object. During the storage, transportation and processing of the object, the release film will be stretched. The structural mesh supports the interior of the structural layer, and the structural layer supports the entire release film.

[0037] Furthermore, by limiting the degree of deformation of the release membrane when the structural layer deforms, and by strengthening the overall strength of the release membrane through the structural mesh, damage to the release membrane during the wrapping of the object is prevented. At the same time, the structural mesh is made of a flexible and elastic material, so that the structural mesh can correct excessive deformation of the release membrane as it deforms along with the release membrane. In addition, the structural mesh makes the release membrane elastic as a whole, allowing for more complete contact between the release membrane and the object.

[0038] Furthermore, ventilation holes are provided between through holes, connecting channels, and contact blocks. When the release film contacts a high-temperature object, the outer contact layer is located on the outside of the object, and the inner contact layer contacts the surface of the object. At the same time, the release film completely wraps the object. The high-temperature object will heat the gas inside the release film, causing the gas volume inside the release film to increase. At this time, multiple through holes connect the inside and outside of the release film, so that the through holes balance the gas pressure inside and outside the release film and prevent the release film from expanding when wrapping the high-temperature object.

[0039] Furthermore, ventilation holes are provided between the through holes, connecting channels, and contact blocks. When the release film is used between the mold and the product, it is installed inside the mold, which isolates the product from the mold. When the mold comes into contact with high-temperature materials, the gas inside the mold will be heated by the high-temperature materials, increasing the gas volume between the mold and the product. At this time, the air channels and connecting channels are interconnected through multiple through holes, allowing the gas to enter the connecting channels and air channels through the through holes. The increased gas volume is then discharged to the external environment through the connecting channels and air channels, preventing air bubbles from forming between the mold and the product, which could damage the product. Attached Figure Description

[0040] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of the network of the present invention;

[0042] Figure 3 For the present invention Figure 2 Enlarged structural diagram at point A in the middle;

[0043] Figure 4 This is a schematic diagram of the exploded structure of the present invention;

[0044] Figure 5 This is a schematic diagram of the connecting layer structure of the present invention;

[0045] Figure 6 This is a schematic diagram of the cross-sectional structure of the structural layers of the present invention;

[0046] Figure 7 This is a schematic diagram of the exploded structure of the structural layers of the present invention.

[0047] In the diagram: 1. Structural layer; 2. Upper connecting layer; 3. Outer contact layer; 4. Lower connecting layer; 5. Inner contact layer; 6. Through hole; 7. Fixing groove; 8. Structural mesh; 9. Connecting strip; 10. Connecting channel; 11. Contact block; 12. Air passage. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] In a further preferred embodiment of the present invention, such as Figure 1 - Figure 7 As shown, a method for preparing a high heat-resistant PET release film includes the following steps:

[0050] Step 1: Raw material preparation

[0051] In the production process, PET granular raw materials are prepared, and then a certain proportion of antioxidants and ultraviolet absorbers are added and mixed. The mixed PET granules and antioxidants and ultraviolet absorbers are heated so that the raw materials are in a molten state.

[0052] Prepare high-temperature vulcanizing silicone and a certain proportion of additives. Thoroughly stir the silicone base material with crosslinking agent, filler, plasticizer, etc. in a mixing device to ensure uniform dispersion. The mixed silicone material needs to be degassed to remove air bubbles introduced during the mixing process, ensuring the uniformity and quality of the finished product.

[0053] Step 2: Extrusion film formation

[0054] PET raw material is added to the extrusion film production equipment for extrusion molding of upper connecting layer 2, outer contact layer 3, lower connecting layer 4 and inner contact layer 5. The extruder heats the PET raw material to a certain temperature and then extrudes it through the die head. During the extrusion process, the die rollers come into contact with the uncooled upper connecting layer 2, outer contact layer 3 and lower connecting layer 4, so that the upper connecting layer 2, outer contact layer 3 and lower connecting layer 4 form connecting strip 9, connecting channel 10, contact block 11 and air channel 12 respectively.

[0055] High-temperature vulcanized silicone raw material is added to the extrusion molding production equipment for extrusion molding of structural layer 1. The uniformly mixed silicone material is extruded using a screw extruder. After the silicone film is formed, it is laid flat, and then the structural mesh 8 is placed between the two silicone films, so that the two silicone films wrap the structural mesh 8 from top to bottom. The high-temperature vulcanized silicone needs to be cured in a heating furnace, usually at a temperature between 120°C and 180°C. During the heating process, the two silicone films are connected to each other to form a whole to form structural layer 1.

[0056] Step 3: Stretching treatment

[0057] During the film formation process, the upper connecting layer 2, outer contact layer 3, lower connecting layer 4, and inner contact layer 5 are stretched to improve the film's strength and durability. The cooled PET film is then stretched longitudinally under the action of heated rollers, typically with a stretch ratio of 3-5 times, to improve the film's mechanical strength and transparency. The longitudinally stretched film is then fed into a transverse stretching machine and stretched transversely under heating, typically with a stretch ratio of 3-5 times, to further improve the film's strength and dimensional stability. The biaxially stretched film undergoes heat setting to eliminate internal stress and stabilize the film's dimensions.

[0058] Step 4: Surface Treatment

[0059] PET surface treatment: The upper connecting layer 2, outer contact layer 3, lower connecting layer 4 and inner contact layer 5 are treated with an alkaline solution to roughen their surfaces and introduce polar groups; Silicone surface treatment: The structural layer 1 is treated with a silane coupling agent to form an active surface; The roughness of the PET and silicone surfaces is increased by polishing to increase the mechanical bonding force of the adhesive;

[0060] Step 5: Adhesive

[0061] Using structural layer 1 as the base, it is bonded to upper connecting layer 2 and outer contact layer 3 in sequence at the top. After upper connecting layer 2 and outer contact layer 3 are bonded to each other, lower connecting layer 4 and inner contact layer 5 are bonded to structural layer 1 in sequence below.

[0062] Clean the PET and silicone surfaces with isopropanol or acetone to remove grease, dust and impurities. Treat the PET and silicone surfaces according to the selected surface treatment method. Apply an appropriate amount of adhesive evenly to the treated PET and silicone surfaces. Align the PET and silicone as needed, apply appropriate pressure to ensure that the adhesive makes full contact and cures. After curing, clean up any excess adhesive to ensure that the bonding area is clean.

[0063] Step 7: Drill holes

[0064] After the release film is bonded, the drilling position of the through hole 6 is determined according to the structural mesh 8 extending from the inside of the structural layer 1 to its outside. The bonded release film is then placed inside the drilling machine to drill holes, so that the through holes 6 are evenly distributed inside the release film.

[0065] Step 7: Quality Inspection

[0066] During the production process, it is necessary to strictly control various parameters to ensure the quality and performance of the membrane. After production is completed, it is necessary to check the connectivity of the through hole 6 and the connectivity of the internal channel 10 formed between the two connecting strips 9.

[0067] In a further preferred embodiment of the present invention, such as Figure 1 - Figure 7As shown, a high heat-resistant PET release film includes a structural layer 1, an upper connecting layer 2, an outer contact layer 3, a lower connecting layer 4, and an inner contact layer 5. The upper connecting layer 2 is fixedly connected to the top of the structural layer 1, and the outer contact layer 3 is fixedly connected to the top of the upper connecting layer 2. The lower connecting layer 4 is fixedly connected to the bottom of the structural layer 1, and the inner contact layer 5 is fixedly connected to the bottom of the lower connecting layer 4. The upper connecting layer 2, outer contact layer 3, lower connecting layer 4, and inner contact layer 5 are all made of PET material. The structural layer 1, upper connecting layer 2, outer contact layer 3, lower connecting layer 4, and inner contact layer 5 are arranged from top to bottom as follows: outer contact layer 3, upper connecting layer 2, structural layer 1, lower connecting layer 4, and inner contact layer 5. The structure is distributed in a honeycomb pattern, with through holes 6 in each of the following layers: structural layer 1, upper connecting layer 2, outer contact layer 3, lower connecting layer 4, and inner contact layer 5. The through holes 6 penetrate the interior of each layer and extend to the top of the outer contact layer 3 and the bottom of the inner contact layer 5. The structural layer 1 contains fixing grooves 7 arranged in a honeycomb structure. The through holes 6 and fixing grooves 7 do not interfere with each other, and the through holes 6 are located within the gaps formed by the fixing grooves 7. A structural mesh 8 is fixedly connected inside the fixing grooves 7, and the structural mesh 8 is also arranged in a honeycomb structure within the structural layer 1. The through holes 6 are located within the gaps formed by the fixing grooves 7. The openings formed inside the structural mesh 8; multiple equidistant connecting strips 9 are fixedly connected to the bottom of both the upper connecting layer 2 and the lower connecting layer 4, and a connecting channel 10 is formed between every two connecting strips 9; the through holes 6 inside the upper connecting layer 2 and the lower connecting layer 4 are fixedly connected to the connecting strips 9 and the connecting channel 10; multiple matrix-distributed contact blocks 11 are fixedly connected to the top of the outer contact layer 3, and the multiple matrix-distributed contact blocks 11 form a mesh-like air passage 12 on the top of the outer contact layer 3; multiple equidistant connecting strips 9 at the bottom of the upper connecting layer 2 are fixedly connected to the top of the structural layer 1; multiple equidistant connecting strips 9 at the bottom of the lower connecting layer 4 are fixedly connected to the top of the structural layer 1; The connecting strip 9 of the fabric is fixedly connected to the top of the inner contact layer 5. The through hole 6 extends through the upper and lower ends to the space between the outer contact layer 3 and the inner contact layer 5, so that the top of the outer contact layer 3 and the bottom of the inner contact layer 5 are interconnected, thereby balancing the air pressure between the top of the outer contact layer 3 and the bottom of the inner contact layer 5. The upper connecting layer 2 and the lower connecting layer 4 have the same structure, and a connecting channel 10 is formed between every two connecting strips 9 at the bottom of the upper connecting layer 2 and the lower connecting layer 4, extending to both ends of the release film. The structural layer 1 is made of silicone. When the structural layer 1 deforms, the high extensibility of the silicone material allows the structural mesh 8 inside the fixing groove 7 to have sufficient room to move when it deforms along with the structural layer 1.

[0068] During the use of release film, the release film is cut to the appropriate size and then folded to form the appropriate shape so that the release film adheres to the object and wraps the outer surface of the object. During the storage, transportation and processing of the object, the release film will be stretched. The structural mesh 8 supports the interior of the structural layer 1, and the structural layer 1 supports the entire release film.

[0069] By limiting the degree of deformation of the release film when the release film in structural layer 1 deforms, and strengthening the overall strength of the release film through structural mesh 8, damage to the release film during the process of wrapping the object is prevented. At the same time, structural mesh 8 is made of a flexible and elastic material, so that structural mesh 8 can correct excessive deformation of the release film as it deforms. In addition, the setting of structural mesh 8 makes the release film elastic, allowing the release film to make more sufficient contact with the object.

[0070] When the release film comes into contact with a high-temperature object, the outer contact layer 3 is located on the outside of the object, and the inner contact layer 5 is in contact with the surface of the object. At the same time, the release film completely wraps the object. The high-temperature object will heat the gas inside the release film, causing the gas volume inside the release film to increase. At this time, multiple through holes 6 connect the inside and outside of the release film, so that the through holes 6 balance the gas pressure inside and outside the release film and prevent the release film from expanding when wrapping the high-temperature object.

[0071] The release film is provided with ventilation holes formed between through holes 6, connecting channels 10, and air passages 12. When the release film is used between the mold and the product, it is installed inside the mold to isolate the product from the mold. When the mold comes into contact with high-temperature materials, the gas inside the mold will be heated by the high-temperature materials, causing the gas volume between the mold and the product to increase. At this time, the air passages 12 and connecting channels 10 are interconnected through multiple through holes 6, allowing the gas to enter the connecting channels 10 and air passages 12 through the through holes 6. The increased gas volume is then discharged to the external environment through the connecting channels 10 and air passages 12, preventing air bubbles from forming between the mold and the product and causing product damage.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0073] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high heat-resistant PET release film, comprising a structural layer (1), an upper connecting layer (2), an outer contact layer (3), a lower connecting layer (4), and an inner contact layer (5); Its features are: The upper connecting layer (2) is fixedly connected to the top of the structural layer (1), and the outer contact layer (3) is fixedly connected to the top of the upper connecting layer (2). The lower connecting layer (4) is fixedly connected to the bottom of the structural layer (1), and the inner contact layer (5) is fixedly connected to the bottom of the lower connecting layer (4). The upper connecting layer (2), outer contact layer (3), lower connecting layer (4) and inner contact layer (5) are all made of PET material. The structural layer (1), upper connecting layer (2), outer contact layer (3), lower connecting layer (4), and inner contact layer (5) are distributed from top to bottom as outer contact layer (3), upper connecting layer (2), structural layer (1), lower connecting layer (4), and inner contact layer (5). Each of the structural layer (1), upper connecting layer (2), outer contact layer (3), lower connecting layer (4), and inner contact layer (5) is provided with a through hole (6). The through hole (6) penetrates the interior of the structural layer (1), upper connecting layer (2), outer contact layer (3), lower connecting layer (4), and inner contact layer (5), and the through hole (6) extends to the top of the outer contact layer (3) and the bottom of the inner contact layer (5). The structural layer (1) is provided with a fixing groove (7) inside, and the fixing groove (7) is distributed in a honeycomb structure. The through hole (6) provided inside the structural layer (1) does not interfere with the fixing groove (7), and the through hole (6) is located in the gap formed by the fixing groove (7). The fixing groove (7) is fixedly connected with a structural mesh (8), and the structural mesh (8) is distributed in a honeycomb structure inside the structural layer (1). The through hole (6) is located in the opening formed inside the structural mesh (8). The bottom of the upper connecting layer (2) and the lower connecting layer (4) are fixedly connected with multiple connecting strips (9) that are evenly distributed, and a connecting channel (10) is formed between every two connecting strips (9). The through holes (6) provided inside the upper connecting layer (2) and the lower connecting layer (4) are fixedly connected to the connecting strips (9) and the connecting channel (10). The top of the outer contact layer (3) is fixedly connected with a plurality of contact blocks (11) arranged in a matrix, and the plurality of contact blocks (11) arranged in a matrix form a mesh structure airway (12) on the top of the outer contact layer (3).

2. The high heat-resistant PET release film according to claim 1, characterized in that: The upper connecting layer (2) has multiple connecting strips (9) arranged at equal intervals at the bottom, which are fixedly connected to the top of the structural layer (1), and the lower connecting layer (4) has multiple connecting strips (9) arranged at equal intervals at the bottom, which are fixedly connected to the top of the inner contact layer (5).

3. The high heat-resistant PET release film according to claim 1, characterized in that: The through hole (6) extends through the upper and lower ends to the space between the outer contact layer (3) and the inner contact layer (5), so that the top of the outer contact layer (3) and the bottom of the inner contact layer (5) are connected to each other, thereby balancing the air pressure between the top of the outer contact layer (3) and the bottom of the inner contact layer (5).

4. The high heat-resistant PET release film according to claim 1, characterized in that: The upper connecting layer (2) and the lower connecting layer (4) have the same structure, and a connecting channel (10) is formed between every two connecting strips (9) at the bottom of the upper connecting layer (2) and the lower connecting layer (4) and extends to both ends of the release film.

5. The high heat-resistant PET release film according to claim 1, characterized in that: The structural layer (1) is made of silicone. When the structural layer (1) deforms, the high extensibility of the silicone material allows the structural mesh (8) inside the fixing groove (7) to have sufficient space to move when it deforms along with the structural layer (1).

6. The method for preparing a high heat-resistant PET release film according to claim 1, characterized in that, Includes the following steps: Step 1: Raw material preparation In the production process, PET granular raw materials are prepared, and then a certain proportion of antioxidants and ultraviolet absorbers are added and mixed. The mixed PET granules and antioxidants and ultraviolet absorbers are heated so that the raw materials are in a molten state. Prepare high-temperature vulcanizing silicone and a certain proportion of additives. Thoroughly stir the silicone base material with crosslinking agent, filler, and plasticizer in a mixing device to ensure uniform dispersion. The mixed silicone material needs to be degassed to remove air bubbles introduced during the mixing process, ensuring the uniformity and quality of the finished product. Step 2: Extrusion film formation PET raw material is added to the extrusion film production equipment to extrude the upper connecting layer (2), the outer contact layer (3), the lower connecting layer (4) and the inner contact layer (5). The extruder heats the PET raw material to a certain temperature and then extrudes it through the die head. During the extrusion process, the die roller is brought into contact with the uncooled upper connecting layer (2), the outer contact layer (3) and the lower connecting layer (4), so that the upper connecting layer (2) and the lower connecting layer (4) form connecting strips (9) and connecting channels (10) respectively, and the outer contact layer (3) forms contact blocks (11) and air channels (12). High-temperature vulcanized silicone raw material is added to the extrusion molding production equipment to extrude the structural layer (1). The uniformly mixed silicone material is extruded using a screw extruder. After the silicone film is formed, the silicone film is laid flat, and then the structural mesh (8) is placed between the two silicone films so that the two silicone films wrap the structural mesh (8) from top to bottom. The high-temperature vulcanized silicone needs to be cured in a heating furnace at a temperature between 120°C and 180°C. The two silicone films are connected to each other to form a whole to form the structural layer (1) during the heating process. Step 3: Stretching treatment During the film formation process, the upper connecting layer (2), outer contact layer (3), lower connecting layer (4) and inner contact layer (5) are stretched to improve the strength and durability of the film; the cooled PET film is stretched longitudinally under the action of heated rollers with a stretch ratio of 3-5 times to improve the mechanical strength and transparency of the film; the longitudinally stretched film is fed into a transverse stretching machine and stretched transversely under heating with a stretch ratio of 3-5 times to further improve the strength and dimensional stability of the film; the biaxially stretched film is heat-set to eliminate internal stress and stabilize the size of the film. Step 4: Surface Treatment PET surface treatment: The upper connecting layer (2), outer contact layer (3), lower connecting layer (4) and inner contact layer (5) are treated with an alkaline solution to roughen their surfaces and introduce polar groups; Silicone surface treatment: The structural layer (1) is treated with a silane coupling agent to form an active surface; The roughness of the PET and silicone surfaces is increased by polishing to increase the mechanical bonding force of the adhesive; Step 5: Adhesive Using the structural layer (1) as the base, the upper connecting layer (2) and the outer contact layer (3) are bonded to each other in sequence at the top. After the upper connecting layer (2) and the outer contact layer (3) are bonded to each other, the lower connecting layer (4) and the inner contact layer (5) are bonded to each other in sequence below the structural layer (1). Clean the PET and silicone surfaces with isopropanol or acetone to remove grease, dust and impurities. Treat the PET and silicone surfaces according to the selected surface treatment method. Apply an appropriate amount of adhesive evenly to the treated PET and silicone surfaces. Align the PET and silicone as needed, apply appropriate pressure to ensure that the adhesive makes full contact and cures. After curing, clean up any excess adhesive to ensure that the bonding area is clean. Step 6: Drilling holes After the release film is bonded, the drilling position of the through hole (6) is determined according to the structural mesh (8) extending from the inside of the structural layer (1) to its outside. The bonded release film is then placed inside the drilling machine to drill holes, so that the through hole (6) is evenly distributed inside the release film. Step 7: Quality Inspection During the production process, it is necessary to strictly control various parameters to ensure the quality and performance of the membrane. After the production is completed, it is necessary to check the connectivity of the through hole (6) and the connectivity of the connecting channel (10) formed between the two connecting strips (9).

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