Experimental device and method for biaxially synchronously stretching film

Abstract

The invention discloses an experimental device and method for bidirectional synchronous stretching of a film, which solves the technical problems of unreasonable structural design, complex structure, inconvenient operation, poor film stretching effect, low yield rate and low production efficiency of the existing device. The device is provided with a main frame with a guide rail device at the bottom, a main frame with a slider, a main controller, and a clamping and fixing stretching device and a driving motor electrically connected to the main controller. The main frame slides horizontally on the guide rail through the driving slider of the driving motor; a fixed gripping area with a positioning and fixing platform and a heating and stretching area with a heating device are sequentially arranged on the guide rail of the main frame, and a clamping and fixing stretching device is also fixed on the main frame. The main controller drives the clamping and fixing stretching device to clamp and move in the fixed gripping area and clamp, stretch and move in the heating and stretching area by controlling the movement of the main frame. The device can be widely used in the field of polymer material processing technology.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material processing, and in particular relates to an experimental device and method for bidirectional synchronous stretching of a film. Background Art

[0002] In recent years, my country's demand for the production of special-purpose films has been growing. Years of production practice have proved that the production equipment of ordinary packaging films is no longer suitable for the production of special-purpose films. They have also reached the point where they need to improve their adaptability to products according to the requirements of different products. It is necessary to classify double-pull equipment according to its specific adaptability to improve the quality of special-purpose films.

[0003] The use of biaxial stretching technology to produce plastic film can improve the mechanical properties of the film, reduce the permeability to gas, water vapor, etc., improve the transparency of the film, surface gloss and other optical properties, reduce thickness deviation, and improve dimensional uniformity. "Biaxially Stretch Plastic Film" 1999, edited by Yin Yanping, Chemical Industry Press. The main public biaxial stretching equipment includes upper and lower belt roller pressure type, stretch chain type, screw drive type, roller group longitudinal stretching-guide rail transverse stretching combination type and linear magnetoelectric drive type. However, the one-time stretching method has not yet been popularized in the large-scale production of film. The main reasons are: the longitudinal stretching multiple of the upper and lower belt roller pressure type is not adjustable, and the production efficiency is low; the transmission system and longitudinal multiple adjustment system of the other equipment are very complicated; the longitudinal stretching multiple is not easy to be too large; the price of the equipment is very expensive. In addition, through the analysis of large deformation finite element, it can be seen that the stress state of the edge of the film under the action of the clamp is uneven, which makes it easy to break the film during the stretching process. Patent (CN102343669A) proposes a biaxial stretching machine for polyimide film, which stretches the film transversely through a motor and a vertical chain, and stretches the film longitudinally through a lead screw nut expansion mechanism, but its structure is complex, and the edge of the film is easily broken because it hangs on the needle plate. Patent (CN104723546A) proposes a stepless biaxial stretching method for film based on saddle-shaped surface transition, which uses two circular wheels symmetrically arranged at a certain angle to form a saddle-shaped surface to achieve longitudinal stretching, but the circular wheels occupy a large space, the longitudinal stretching ratio adjustment range is also limited, the production efficiency is slow, and the breakage rate is high, the yield is low, the material waste is relatively large, and the manufacturing cost is high. At the same time, solvent volatilization will occur during the film stretching process, causing environmental pollution and other problems. In view of the problems existing in the above-mentioned current biaxial stretching methods and equipment for films, it is of great significance to develop a new type of biaxial stretching device for films. Summary of the invention

[0004] In view of the shortcomings and deficiencies in the prior art, the present invention proposes an experimental device and method for biaxially stretching film based on the principles of fluid mechanics, which has a simple structure, is easy to operate, has a good film stretching effect, significantly improves the uniformity of the film, has a high yield rate, and significantly improves the production efficiency.

[0005] To this end, the present invention provides an experimental device for biaxially stretched film, which is provided with a main frame with a guide rail device at the bottom, a main frame with a slider, a main controller, and a clamping and fixing stretching device and a driving motor electrically connected to the main controller. The main frame slides horizontally on the guide rail through a driving slider of the driving motor; a fixed gripping area with a positioning and fixing platform and a heating and stretching area with a heating device are sequentially provided on the guide rail of the main frame, and a clamping and fixing stretching device is also fixed on the main frame. The main controller drives the clamping and fixing stretching device to clamp and move in the fixed gripping area and to clamp, stretch and move in the heating and stretching area by controlling the movement of the main frame.

[0006] Preferably, the heating device comprises an electric heating device, and the heating device is driven to move up and down by a movable cylinder.

[0007] Preferably, a matching fan and heating hood are also fixed on the main frame located above the front side of the heating device. When the stretching device is clamped and fixed to place the film in the heating and stretching area, the main controller controls the fan to blow the hot air in the heating hood above the film.

[0008] Preferably, an energy-gathering cover with a frame structure is provided around the heating area of ​​the heating device.

[0009] Preferably, it is also provided with a condensation system, a sealing protective cover is also provided outside the main frame, and an exhaust port is also provided on the sealing protective cover located on the upper rear side of the heating device, and the exhaust port is connected to the condensation system.

[0010] Preferably, the clamping and fixing stretching device includes a frame structure fixed on the main frame and formed by transverse support rods and longitudinal support rods, as well as a transverse sliding rod whose two ends can slide transversely on the two transverse support rods respectively, and a longitudinal sliding rod whose two ends can slide longitudinally on the two longitudinal support rods respectively. The transverse sliding rod and the longitudinal sliding rod are also respectively fixed with a longitudinally retractable transverse pneumatic clamping device and a longitudinally retractable transverse pneumatic clamping device electrically connected to the main controller, and the transverse pneumatic clamping device and the longitudinal pneumatic clamping device are located in the same horizontal plane; the pneumatic clamping device is clamped and released by the main controller, and the transverse sliding rod and the longitudinal sliding rod are respectively controlled by the main controller to slide on the transverse support rod and the longitudinal support rod, thereby driving the longitudinal extension and retraction of the transverse pneumatic clamping device and the transverse extension and retraction of the longitudinal pneumatic clamping device.

[0011] Preferably, nitrogen is introduced into the sealed protective cover.

[0012] Preferably, the main frame, the energy gathering cover, the transverse pneumatic clamping device and the longitudinal pneumatic clamping device are all made of heat-resistant structural steel and heat-resistant parts, and their parts can withstand temperatures up to 400°C.

[0013] A method for a biaxially stretched film experimental device, using any of the above-mentioned biaxially stretched film experimental devices, comprises the following steps in sequence:

[0014] 1) Sample loading process: Before use, the transverse sliding bar and the longitudinal sliding bar are respectively located at the two ends of the transverse support bar and the longitudinal support bar, that is, the transverse pneumatic clamping device and the longitudinal pneumatic clamping device are in a stretched state, and the fixed platform is located in the middle of the frame structure of the clamping and fixing stretching device. After the film to be stretched is placed on the positioning and fixing platform in the fixed gripping area, the power is turned on, and the main controller controls the transverse sliding bar and the longitudinal sliding bar of the clamping and fixing stretching device to move toward the middle of the frame structure at the same time, thereby driving the transverse pneumatic clamping device and the longitudinal pneumatic clamping device to shrink toward the middle of the frame structure at the same time. At the same time, the main controller controls the transverse pneumatic clamping device and the longitudinal pneumatic clamping device to open and clamp the film to be stretched, thereby completing the clamping and fixing of the film to be stretched;

[0015] 2) Preheating process: start the driving motor through the main controller to drive the main frame loaded with the film to be stretched to slide along the guide rail from the fixed gripping area to the heating and stretching area, align the film to be stretched directly above the heating device, control the fan through the main controller to blow the hot air in the heating cover to the top of the film, and then control the active cylinder through the main controller to drive the heating device to move upward to the specified position, and control the temperature so that the temperature is within the processing temperature range of the film stretchability;

[0016] 3) Stretching process: After reaching the appropriate temperature in step 2), the main controller controls the start of the transverse sliding rod and the longitudinal sliding rod of the clamping and fixing stretching device to move simultaneously from the middle of the frame structure to the two ends of the transverse support rod and the longitudinal support rod respectively, thereby driving the transverse pneumatic clamping jaw device and the longitudinal pneumatic clamping jaw device to stretch toward the middle of the frame structure at the same time to stretch the film;

[0017] 4) After the stretching process in step 3) is completed, the main controller controls the movable cylinder to drive the heating device to move downward to the specified position, and then turns off the heating device; the main controller controls the horizontal pneumatic clamping device and the longitudinal pneumatic clamping device to open to remove the stretched film product.

[0018] Preferably, in step 3), the film is stretched at a speed of 1-400 mm / s and a stretching ratio of 1-9 times.

[0019] The beneficial effects of the present invention are:

[0020] (1) The experimental device for biaxially stretched film of the present invention has a simple structure, is easy to operate, has a good film stretching effect, significantly improves the uniformity of the film, and has a high yield rate; at the same time, the production efficiency is significantly improved.

[0021] (2) The experimental device and method for the biaxially stretched film of the present invention adopt biaxial stretching. Biaxial stretching is the process of stretching a polymer in the longitudinal and transverse directions. During the stretching process, the polymer chains are oriented in two perpendicular directions, resulting in a polymer film with balanced longitudinal and transverse properties. At the same time, due to the long-chain nature of semi-crystalline polymers, stretching treatment is an effective method to change the crystallization characteristics of the polymer, eliminate the anisotropy of the film in optical properties, maintain the smooth surface formed by the film during high-temperature shaping, and obtain a film with excellent mechanical, optical and thermal properties. Using the experimental device for the biaxially stretched film of the present invention, the properties of the stretched film prepared by multi-point synchronous stretching can be significantly improved. For example, first, the tensile strength and elastic modulus are increased; second, the impact strength and bending strength are increased; third, the cold resistance and heat resistance are improved; fourth, the material utilization rate is improved; and fifth, the electrical insulation is improved.

[0022] The experimental device and method of the biaxially stretched film of the present invention have simple structure, convenient operation, good film stretching effect, film with excellent mechanical, optical and thermal properties, significantly improved film uniformity, high utilization rate of stretched film materials, high yield rate, and significantly improved production efficiency. During the use of the device, the power consumption of the equipment is low, energy-saving, and environmental pollution is reduced to the maximum extent, which meets the green environmental protection and energy-saving concept pursued today. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention;

[0024] Figure 2 yes Figure 1 A schematic diagram of the structure of the central main frame located in the heating and stretching area;

[0025] Figure 3 It is a schematic diagram of the structure of the present invention (with a sealing protective cover);

[0026] Figure 4 It is a schematic diagram of the structure of the clamping and fixing stretching device in a compressed state;

[0027] Figure 5 It is a structural schematic diagram of a clamping and fixing stretching device in a stretching state;

[0028] Figure 6 yes Figure 1 A structural schematic diagram of a left-side cross-sectional view;

[0029] Figure 7 yes Figure 6 Schematic diagram of the structure of the partial enlarged view of A in the figure.

[0030] Markings in the figure: 1. Main frame, 2. Main frame, 3. Guide rail, 4. Fixed platform, 5. Heating device, 6. Movable cylinder, 7. Fan, 8. Heating cover, 9. Energy gathering cover, 10. Sealing protective cover, 11. Exhaust port, 12. Transverse support rod, 13. Longitudinal support rod, 14. Transverse sliding rod, 15. Longitudinal sliding rod, 16. Transverse pneumatic clamping device, 17. Longitudinal pneumatic clamping device. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercial products unless otherwise specified.

[0032] like Figure 1-Figure 7 As shown, the present invention provides an experimental device for biaxially stretched film, which is provided with a main frame 1 with a guide rail device at the bottom, a main frame 2 with a slider, a main controller, and a clamping and fixing stretching device and a driving motor electrically connected to the main controller, and the main frame slides horizontally on the guide rail 3 through the driving slider of the driving motor; the guide rail 3 of the main frame 1 is provided with a fixed gripping area with a positioning and fixing platform 4 and a heating and stretching area with a heating device 5 in sequence, and the main frame 2 is also fixedly provided with a clamping and fixing stretching device, and the main controller drives the clamping and fixing stretching device to clamp and move in the fixed gripping area and to clamp, stretch and move in the heating and stretching area by controlling the movement of the main frame 2.

[0033] like Figure 6 and Figure 7 As shown, the heating device 5 includes an electric heating device, which adopts an infrared module for heating, and the heating is uniform and the temperature is adjustable. The heating device is driven up and down by a movable cylinder 6 to control the temperature within the processing temperature range of the film stretchability. A matching blower 7 and a heating cover 8 are also fixed on the main frame 1 located above the front side of the heating device 5. When the film is placed in the heating and stretching area by clamping and fixing the stretching device, the main controller controls the blower 7 to blow the hot air in the heating cover 8 to the top of the film. A frame structure energy-gathering cover 9 is also provided around the heating area of ​​the heating device 5.

[0034] The experimental device of a biaxially stretched film of the present invention is also provided with a condensation system, and a sealing protective cover 10 is also provided outside the main frame 1 to reduce the pollution or interference of the external environment on the film during the film stretching process. The sealing protective cover 10 located on the upper rear side of the heating device 5 is also provided with an exhaust port 11, and the exhaust port 11 is connected to the condensation system. Compressed nitrogen is introduced into the sealing protective cover 10 to prevent the adverse effects of oxygen on the film during the heating and stretching process, so that the film is in the best stretching state, and the film after stretching is ensured to have high transparency and good mechanical properties.

[0035] like Figure 4-Figure 7 As shown, the clamping and fixing stretching device includes a frame structure fixed on the main frame 2 and surrounded by transverse support rods 12 and longitudinal support rods 13, as well as a transverse slide bar 14 whose two ends can slide transversely on the two transverse support rods 12 respectively, and a longitudinal slide bar 15 whose two ends can slide longitudinally on the two longitudinal support rods 13 respectively. The transverse slide bar 14 and the longitudinal slide bar 15 are also respectively fixed with a transverse pneumatic clamping device 16 and a longitudinal pneumatic clamping device 17 that can be longitudinally extended and retracted electrically connected to the main controller, and the transverse pneumatic clamping device 16 and the longitudinal pneumatic clamping device 17 are located in the same horizontal plane; the pneumatic clamping device is clamped and released by the main controller, and the transverse slide bar 14 and the longitudinal slide bar 15 are respectively controlled by the main controller to slide on the transverse support rod 12 and the longitudinal support rod 13, thereby driving the transverse pneumatic clamping device 16 to extend and retract longitudinally and the longitudinal pneumatic clamping device 17 to extend and retract transversely. The main frame 2, energy gathering cover 9, transverse pneumatic clamping device 16 and longitudinal pneumatic clamping device 17 are all made of heat-resistant structural steel and heat-resistant parts, and their parts can withstand temperatures above 400°C, which improves the applicability of the equipment to heat-resistant films, saves costs and extends its service life.

[0036] A method for testing a biaxially stretched film, using the above-mentioned biaxially stretched film testing device, comprises the following steps in sequence:

[0037] 1) Sample loading process: Before use, the transverse slide bar 14 and the longitudinal slide bar 15 are respectively located at the two ends of the transverse support bar 12 and the longitudinal support bar 13, that is, the transverse pneumatic clamping jaw device 16 and the longitudinal pneumatic clamping jaw device 17 are in a stretched state, and the fixed platform 4 is located in the middle of the frame structure of the clamping and fixing stretching device. After the film to be stretched is placed on the positioning and fixing platform 4 in the fixed gripping area, the power is turned on, and the main controller controls the transverse slide bar 14 and the longitudinal slide bar 15 of the clamping and fixing stretching device to move toward the middle of the frame structure at the same time, thereby driving the transverse pneumatic clamping jaw device 16 and the longitudinal pneumatic clamping jaw device 17 to shrink toward the middle of the frame structure at the same time. At the same time, the main controller controls the transverse pneumatic clamping jaw device 16 and the longitudinal pneumatic clamping jaw device 17 to open and clamp the film to be stretched, thereby completing the clamping and fixing of the film to be stretched;

[0038] 2) Preheating process: The main controller starts the driving motor to drive the main frame 2 loaded with the film to be stretched to slide along the guide rail 3 from the fixed gripping area to the heating and stretching area, align the film to be stretched directly above the heating device 5, and control the fan 7 through the main controller to blow the hot air in the heating cover 8 to the top of the film, and then control the active cylinder 6 through the main controller to drive the heating device 5 to move upward to the specified position. The infrared rays emitted by the heating device 5 pass through the energy-gathering cover 9 to approach the film, and control its temperature so that the temperature is controlled within the processing temperature range of the film stretchability;

[0039] 3) Stretching process: After reaching the appropriate temperature in step 2), the main controller controls the start of the transverse slide bar 14 and the longitudinal slide bar 15 of the clamping and fixing stretching device to move simultaneously from the middle of the frame structure to the two ends of the transverse support rod 12 and the longitudinal support rod 13, respectively, thereby driving the transverse pneumatic clamping jaw device 16 and the longitudinal pneumatic clamping jaw device 17 to stretch toward the middle of the frame structure at the same time to stretch the film;

[0040] 4) Heating and drying process: The wind speed of the fan 7 is controlled by the main controller, and the hot protective gas is blown out through the heating cover 8 to disturb the air flow, thereby increasing the volatilization of the solvent in the film. The hot protective gas is discharged through the exhaust port 11 and enters the condensation system, realizing the recovery of the volatile solvent in the heating process and obtaining the stretched film after drying; at the same time, the solvent residue in the box of the sealing protective cover 10 is reduced, which is more conducive to the production of high-quality film;

[0041] 5) After the stretched film is dried in step 4), the main controller controls the movable cylinder 6 to move the heating device 5 downward to the specified position, and then turns off the heating device 5; the main controller controls the transverse pneumatic clamping device 16 and the longitudinal pneumatic clamping device 17 to open and remove the stretched film product.

[0042] The experimental device for the biaxially stretched film of the present invention has a simple structure, convenient operation, good film stretching effect, and significantly improves the uniformity of the film; at the same time, the production efficiency is significantly improved. Biaxial stretching is the process of stretching a polymer in the longitudinal and transverse directions. During the stretching process, the polymer chains are oriented in two perpendicular directions to produce a polymer film with longitudinal and transverse balanced properties. At the same time, due to the long-chain nature of semi-crystalline polymers, stretching treatment is an effective method to change the crystallization characteristics of the polymer, eliminate the anisotropy of the film in optical properties, maintain the smooth surface formed by the film during high-temperature shaping, and obtain a film with excellent mechanical, optical and thermal properties. Using the experimental device for the biaxially stretched film of the present invention, the properties of the stretched film prepared by multi-point synchronous stretching can be significantly improved. For example, first, the tensile strength and elastic modulus are increased; second, the impact strength and bending strength are increased; third, the cold resistance and heat resistance are improved; fourth, the material utilization rate is improved; and fifth, the electrical insulation is improved.

[0043] When the material of the film to be stretched is PE or PI, the film is stretched at the following parameters in step 3): a stretching speed of 1-400 mm / s and a stretching ratio of 1-9 times, which achieves the best effect.

[0044] The experimental device for biaxially stretched film of the present invention can significantly improve the flatness of the film by adjusting the finishing of the main frame and leveling the transverse pneumatic clamping device 16 and the longitudinal pneumatic clamping device 17 for clamping and fixing the stretching device.

[0045] In summary, the experimental device and method for biaxially stretched film of the present invention have simple structure, convenient operation, good film stretching effect: film with excellent mechanical, optical and thermal properties, significantly improved uniformity of film, high utilization rate of stretched film materials, high yield rate, and significantly improved production efficiency. During the use of the device, the power consumption of the equipment is low, energy-saving, and environmental pollution is minimized, which is in line with the green environmental protection and energy-saving concept pursued today.

[0046] The above are merely embodiments of the present invention. For example, in step 3), the film stretching parameters are selected, and specific optimization selection can be performed based on the selected material of the film to be stretched.

[0047] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "top", "bottom", "front", "back", "inside", "outside", "middle", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] However, what is described above is only a specific embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by the claims of the present invention.

Claims

1. An experimental device for biaxially stretched film, characterized in that: It is provided with a main frame with a guide rail device at the bottom, a main frame with a slider, a main controller, and a clamping, fixing and stretching device and a driving motor electrically connected to the main controller, wherein the main frame drives the slider to slide horizontally on the guide rail through the driving motor; a fixed gripping area with a positioning and fixing platform and a heating and stretching area with a heating device are provided on the guide rail of the main frame in sequence, and a clamping, fixing and stretching device is also fixed on the main frame, and the main controller drives the clamping, fixing and stretching device to clamp and move in the fixed gripping area and to clamp, stretch and move in the heating and stretching area by controlling the movement of the main frame; the heating device includes an electric heating device, which is driven to move up and down by a movable cylinder, so that the temperature is controlled within the processing temperature range where the film can be stretched; a matching fan and a heating cover are also fixed on the main frame located above the front side of the heating device, and when the clamping, fixing and stretching device places the film in the heating and stretching area, the main controller controls the fan to blow the hot air in the heating cover to the top of the film; the heating area of ​​the heating device The square is also covered with an energy-gathering cover of a frame structure; it is also provided with a condensing system, and a sealing protective cover is also provided outside the main frame, and an exhaust port is also provided on the sealing protective cover located on the upper rear side of the heating device, and the exhaust port is connected to the condensing system; the clamping and fixing stretching device includes a frame structure fixed to the main frame surrounded by transverse support rods and longitudinal support rods, as well as a transverse sliding rod whose two ends can slide transversely on the two transverse support rods respectively, and a longitudinal sliding rod whose two ends can slide longitudinally on the two longitudinal support rods respectively, and the transverse sliding rod and The longitudinal slide bar is also respectively fixed with a transverse pneumatic clamping jaw device which is longitudinally retractable and electrically connected to the main controller, and the transverse pneumatic clamping jaw device and the longitudinal pneumatic clamping jaw device are located in the same horizontal plane; the pneumatic clamping jaw device is clamped and released by the main controller, and the transverse slide bar and the longitudinal slide bar are respectively controlled by the main controller to slide on the transverse support rod and the longitudinal support rod, thereby driving the transverse pneumatic clamping jaw device to longitudinally retract and the longitudinal pneumatic clamping jaw device to transversely retract; The method of using the experimental device of the biaxially stretched film comprises the following steps in sequence: 1) Sample loading process: before use, the transverse slide bar and the longitudinal slide bar are respectively located at the two ends of the transverse support bar and the longitudinal support bar, that is, the transverse pneumatic clamping device and the longitudinal pneumatic clamping device are in a stretched state, and the fixed platform is located in the middle of the frame structure of the clamping and fixing stretching device. After the film to be stretched is placed on the positioning and fixing platform in the fixed gripping area, the power is turned on, and the main controller controls the transverse slide bar and the longitudinal slide bar of the clamping and fixing stretching device to move toward the middle of the frame structure at the same time, thereby driving the transverse pneumatic clamping device and the longitudinal pneumatic clamping device to shrink toward the middle of the frame structure at the same time. At the same time, the main controller controls the transverse pneumatic clamping device and the longitudinal pneumatic clamping device to open and clamp the film to be stretched, thereby completing the clamping and fixing of the film to be stretched; the material of the film to be stretched is PE or PI; 2) Preheating process: start the driving motor through the main controller to drive the main frame loaded with the film to be stretched to slide along the guide rail from the fixed gripping area to the heating and stretching area, align the film to be stretched directly above the heating device, control the fan through the main controller to blow the hot air in the heating cover to the top of the film, and then control the active cylinder through the main controller to drive the heating device to move upward to the specified position, and control the temperature so that the temperature is within the processing temperature range of the film stretchability; 3) Stretching process: After reaching the appropriate temperature in step 2), the main controller controls the start of the transverse sliding rod and the longitudinal sliding rod of the clamping and fixing stretching device to move simultaneously from the middle of the frame structure to the two ends of the transverse support rod and the longitudinal support rod respectively, thereby driving the transverse pneumatic clamping jaw device and the longitudinal pneumatic clamping jaw device to stretch toward the middle of the frame structure at the same time to stretch the film; 4) Heating and drying process: The wind speed of the fan is controlled by the main controller, and the hot protective gas is blown out through the heating cover to disturb the air flow, thereby increasing the volatilization of the solvent in the film. The hot protective gas is discharged through the exhaust port and enters the condensation system, realizing the recovery of the volatile solvent in the heating process and obtaining the stretched film after drying; at the same time, it also reduces the solvent residue in the sealed protective cover box, which is more conducive to the production of high-quality film; 5) After the stretched film is dried in step 4), the main controller controls the movable cylinder to move the heating device downward to the specified position and turns off the heating device; the main controller controls the horizontal pneumatic clamping device and the longitudinal pneumatic clamping device to open and remove the stretched film product.

2. The experimental device for biaxially stretched film according to claim 1, characterized in that: Nitrogen is introduced into the sealed protective cover.

3. The experimental device for biaxially stretched film according to claim 1, characterized in that: The main frame, the energy gathering cover, the transverse pneumatic clamping device and the longitudinal pneumatic clamping device are all made of heat-resistant structural steel and heat-resistant parts, and their parts can withstand temperatures up to 400°C.

4. The experimental device for biaxially stretched film according to claim 1, characterized in that: In step 3), the film is stretched at the following parameters: stretching speed 1-400 mm / s, and stretching ratio 1-9 times.

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