Plastic film finished product strength quality detection device and detection method thereof
By combining an electric push rod and a guide groove, the automatic clamping and continuous testing of the plastic film finished product strength quality testing device are realized, which solves the problem of cumbersome manual clamping in the existing technology and improves the accuracy and efficiency of testing.
Patent Information
- Application Number
- CN202512041688.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-02-27
AI Technical Summary
Existing plastic film strength quality testing devices require operators to manually insert the film at both ends and control the clamping mechanism to retract, making the testing process cumbersome.
An electric push rod is used to control the movement of the first clamping component, and the automatic clamping and fixing of the film is achieved through the cooperation of the guide groove and the telescopic rod. At the same time, the unwinding mechanism facilitates the continuous transport and release of the film.
It simplifies the clamping and fixing process of the film, improves the accuracy and continuity of the test, and reduces the tedious steps of manual operation.
Smart Images
Figure CN121577436A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of film testing equipment technology, and in particular to a device and method for testing the strength and quality of finished plastic films. Background Technology
[0002] Plastic film products are sheet-like materials made from polyethylene, polypropylene, polyvinyl chloride, polyester, and other main raw materials through processes such as extrusion, blow molding, casting, and calendering. During the production process, the plastic film products are subjected to pressure by quality testing devices to test their strength and quality, ensuring the production quality of the finished plastic film products. The quality testing devices generally use plastic film tensile strength testing machines for tensile monitoring.
[0003] Existing quality inspection devices require operators to insert both ends of the film into two clamping mechanisms, then control the clamping mechanisms to contract and clamp the film in place before tensile testing can be performed. Therefore, film inspection is quite cumbersome. Summary of the Invention
[0004] To improve the aforementioned quality inspection device, the operator needs to insert both ends of the film into the two clamping mechanisms, and then control the clamping mechanisms to contract and clamp the film in place before the film can be stretched and tested, which is a rather troublesome process for film testing.
[0005] This invention provides a device and method for testing the strength and quality of finished plastic films, employing the following technical solution: A device for testing the strength and quality of finished plastic film includes a control console and a housing. The housing is fixedly installed on the top of the control console. An electric push rod is fixedly inserted into the housing. A first clamping member is fixedly inserted into the extended end of the electric push rod. A second clamping member is fixedly connected to the side wall of the housing. An unwinding mechanism is rotatably inserted into the top of the housing. A control ring is fixedly connected to the extended end of the electric push rod. The control ring is movably sleeved on one end of the unwinding mechanism inserted into the housing and is used to control the rotation of the unwinding mechanism. A guide groove is provided on the side wall of the housing. The guide groove is used to control the retraction of the first clamping member. The movable ends of the first clamping member and the second clamping member are connected by a telescopic rod.
[0006] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the first clamping member includes a movable plate and a first fixed plate. One end of the movable plate is fixedly connected to the extended end of the electric push rod, and the other end of the movable plate extends out of the machine housing and is fixedly connected to the first fixed plate. A first clamping plate is movably inserted into the side wall of the first fixed plate.
[0007] Optionally, in the above-mentioned plastic film finished product strength quality testing device, both ends of the first clamping plate facing the machine housing are fixedly connected with round rods. The ends of the round rods are inserted into the guide grooves and fixedly connected with guide balls. The diameter of the guide balls is larger than the diameter of the round rods, and the guide balls slide in fit with the inner wall of the guide grooves.
[0008] Optionally, in the above-mentioned plastic film finished product strength quality testing device, a cutting blade is fixedly connected to the side of the first clamping plate facing the first fixed plate, and a blade groove corresponding to the cutting blade is opened on the first fixed plate. Foldable dust covers are fixedly connected to the top and bottom surfaces of the movable plate, and the foldable dust covers are used to seal the opening of the machine casing.
[0009] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the second clamping member includes a second fixing plate, the second fixing plate is fixedly connected to the side wall of the machine housing, the side wall of the second fixing plate is movably inserted with a second clamping plate, the lower end of the telescopic rod is fixedly connected to the second clamping plate, and the upper end of the telescopic rod is fixedly connected to the first clamping plate.
[0010] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the top and bottom surfaces of the first fixing plate and the second fixing plate are fixedly connected with guide plates, the guide plates are arc-shaped, and the surfaces of the first fixing plate, the second fixing plate, the first clamping plate and the second clamping plate are all provided with anti-slip textures.
[0011] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the unwinding mechanism includes a disc and a vertical rod. The vertical rod is rotatably inserted into the inner top wall of the machine housing. The upper end of the vertical rod extends out of the machine housing and is fixedly connected to the disc. A U-shaped frame is fixedly connected to the side wall of the disc. Two guide rollers are rotatably inserted into the U-shaped frame. The ends of the two guide rollers are inserted into the U-shaped frame and fixedly fitted with gears. The two gears mesh with each other. A motor is fixedly installed on the side wall of the U-shaped frame. The rotating shaft of the motor is fixedly connected to the end of one of the guide rollers. Two support plates are fixedly connected to the top surface of the U-shaped frame. Grooves are formed on the two support plates. Film rollers are rotatably installed in the grooves. A spiral groove is formed at the lower end of the outer wall of the vertical rod, and a vertical groove is formed at the upper end of the outer wall of the vertical rod.
[0012] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the control ring includes a circular ring and a semi-circular block. The outer wall of the circular ring is fixedly connected to the extended end of the electric push rod. The circular ring is movably sleeved on the vertical rod. The semi-circular block is fixedly connected to the inner wall of the circular ring. The semi-circular block slides in cooperation with the inner wall of the spiral groove and the vertical groove.
[0013] Optionally, in the above-mentioned plastic film finished product strength quality testing device, the outer contour shape of the inner wall cross-section of the guide groove is L-shaped.
[0014] Another technical solution proposed in this invention: a method for testing the strength and quality of finished plastic films, comprising the following steps: S101: First, the guide roller is driven to rotate by the motor, and the two guide rollers are controlled by two gears to transport the film downward and make the film pass through the first clamping member and then insert into the second clamping member; S102: The first clamping member is moved by the electric push rod. At this time, the first clamping plate of the first clamping member is moved by the cooperation of the round rod, the guide ball and the guide groove. The film is cut by the cutting knife. At the same time, the second clamping plate of the second clamping member is moved by the telescopic rod. Thus, the two ends of the film are clamped and fixed by the cooperation of the first clamping plate and the second clamping plate. S103: When the first clamping member moves, it pulls one end of the film upward to continuously stretch the film. At the same time, the tensile strength of the film is detected by the force sensor and displacement sensor inside the housing. S104: Simultaneously, when the first clamping member moves, it drives the control ring to move synchronously. At this time, the control ring drives the unwinding mechanism to rotate, so as to cause the unwinding mechanism to drive the film to rotate, thereby reducing the possibility that the film may remain above the first clamping member and affect the movement of the first clamping member. S105: After the film test is completed, the first clamping component is reset by the electric push rod. At this time, the first clamping plate of the first clamping component is opened by the guide groove, guide ball and round rod. At the same time, the second clamping plate of the second clamping component is opened by the telescopic rod, so that the broken film loses its limit. Then, the new film is released by the unwinding mechanism for continuous testing to increase the accuracy of film testing.
[0015] In summary, the present invention has at least one of the following beneficial effects: The first clamping member is moved by an electric push rod and retracted by a guide groove to clamp and fix the film. At the same time, the second clamping member is retracted by a telescopic rod to clamp and fix the lower end of the film. Therefore, it is more convenient to clamp and fix the film. When the first clamping member is reset, it causes the first clamping member and the second clamping member to open, and the unwinding mechanism releases a new film, which facilitates continuous testing of the film through the device, thereby increasing the accuracy of film testing. Attached Figure Description
[0016] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a partial three-dimensional cross-sectional view of the guide groove of the present invention; Figure 3 This is a partial three-dimensional cross-sectional view of the housing of the present invention; Figure 4 This is a partial three-dimensional unfolded cross-sectional view of the first clamping member of the present invention; Figure 5 This is a partial three-dimensional unfolded structural diagram of the unwinding mechanism of the present invention.
[0017] In the diagram: 1. Control console; 2. Housing; 3. Electric push rod; 4. First clamping component; 41. Movable plate; 42. First fixed plate; 43. First clamping plate; 44. Round rod; 45. Guide ball; 46. Cutting blade; 47. Folding dust cover; 5. Second clamping component; 51. Second fixed plate; 52. Second clamping plate; 53. Guide plate; 6. Unwinding mechanism; 61. Disc; 62. Vertical rod; 63. U-shaped frame; 64. Guide roller; 65. Gear; 66. Motor; 67. Support plate; 68. Groove; 69. Film roller; 610. Spiral groove; 611. Vertical groove; 7. Control ring; 71. Circular ring; 72. Semicircular block; 8. Guide groove; 9. Telescopic rod. Detailed Implementation
[0018] The following is in conjunction with the appendix Figures 1-5 The present invention will be described in further detail below.
[0019] Please refer to the attached diagram in the instruction manual. Figures 1-5 The present invention provides an embodiment of a plastic film finished product strength quality testing device, comprising a control console 1 and a housing 2. The housing 2 is fixedly installed on the top of the control console 1, and an electric push rod 3 is fixedly inserted inside the housing 2. It should be noted that the force sensor and displacement sensor inside the housing 2 are existing products, used to test the stress strength of the film and the displacement of the electric push rod 3, and simultaneously transmit the signal to the control console 1 to display the test data. Film tensile testing is existing technology.
[0020] The extended end of the electric push rod 3 is fixedly connected to a first clamping member 4. The first clamping member 4 includes a movable plate 41 and a first fixed plate 42. One end of the movable plate 41 is fixedly connected to the extended end of the electric push rod 3, and the other end of the movable plate 41 extends out of the housing 2 and is fixedly connected to the first fixed plate 42. A first clamping plate 43 is movably inserted into the side wall of the first fixed plate 42. The electric push rod 3 facilitates the synchronous movement of the movable plate 41, the first fixed plate 42 and the first clamping plate 43, so as to adjust the height of the movable plate 41, the first fixed plate 42 and the first clamping plate 43.
[0021] A cutting blade 46 is fixedly connected to the side of the first clamping plate 43 facing the first fixed plate 42. The first fixed plate 42 has a blade groove corresponding to the cutting blade 46. Foldable dust covers 47 are fixedly connected to the top and bottom surfaces of the movable plate 41. The foldable dust covers 47 are used to seal the opening of the housing 2. When the first clamping plate 43 moves, it drives the cutting blade 46 to move synchronously. At this time, the film is cut by the cutting blade 46 cooperating with the blade groove. The foldable dust cover 47 facilitates the sealing of the opening of the housing 2 to reduce the possibility of foreign matter entering the interior of the housing 2.
[0022] A second clamping member 5 is fixedly connected to the side wall of the housing 2. An unwinding mechanism 6 is rotatably inserted into the top of the housing 2. A control ring 7 is fixedly connected to the extended end of the electric push rod 3. The control ring 7 is movably sleeved on one end of the unwinding mechanism 6 inserted into the housing 2 and is used to control the rotation of the unwinding mechanism 6. The unwinding mechanism 6 includes a disc 61 and a vertical rod 62. The vertical rod 62 is rotatably inserted into the inner top wall of the housing 2. The upper end of the vertical rod 62 extends out of the housing 2 and is fixedly connected to the disc 61. A U-shaped frame 63 is fixedly connected to the side wall of the disc 61. Two U-shaped frames are rotatably inserted into the U-shaped frame 63. The guide rollers 64 are inserted into the U-shaped frame 63 at their ends and are fitted with gears 65. The two gears 65 mesh with each other. A motor 66 is fixedly installed on the side wall of the U-shaped frame 63. The rotating shaft of the motor 66 is fixedly connected to the end of one of the guide rollers 64. Two support plates 67 are fixedly connected to the top surface of the U-shaped frame 63. Grooves 68 are provided on the two support plates 67. A film roller 69 is rotatably installed in the grooves 68. A spiral groove 610 is provided at the lower end of the outer wall of the vertical rod 62, and a vertical groove 611 is provided at the upper end of the outer wall of the vertical rod 62.
[0023] The control ring 7 facilitates the rotation of the vertical rod 62, which in turn drives the disc 61 and the U-shaped frame 63 to rotate synchronously. This causes the disc 61 and the U-shaped frame 63 to move to a misalignment with the first clamping member 4 when the first clamping member 4 moves upward, thereby reducing the possibility of the film obstructing the normal movement of the first clamping member 4. When the U-shaped frame 63 is reset, the motor 66 facilitates the rotation of the guide roller 64, and the two guide rollers 64 are controlled to rotate through the cooperation of two gears 65, so as to facilitate the downward conveying of the film. The support plate 67 facilitates the installation of the film roller 69.
[0024] The control ring 7 includes a circular ring 71 and a semicircular block 72. The outer wall of the circular ring 71 is fixedly connected to the extended end of the electric push rod 3. The circular ring 71 is movably sleeved on the vertical rod 62. The semicircular block 72 is fixedly connected to the inner wall of the circular ring 71. The semicircular block 72 slides in cooperation with the inner walls of the spiral groove 610 and the vertical groove 611. When the electric push rod 3 is running, it drives the circular ring 71 and the semicircular block 72 to move synchronously. At this time, the semicircular block 72 slides along the inner walls of the spiral groove 610 and the vertical groove 611. When the semicircular block 72 slides along the inner wall of the spiral groove 610, it causes the vertical rod 62 to drive the disc 61 to rotate. When the semicircular block 72 slides along the inner wall of the vertical groove 611, it causes the vertical rod 62 and the disc 61 to remain stationary.
[0025] The side wall of the housing 2 is provided with a guide groove 8, which is used to control the retraction of the first clamping member 4. The outer contour shape of the inner wall cross section of the guide groove 8 is L-shaped. The guide groove 8, the guide ball 45 and the round rod 44 cooperate to facilitate the control of the movement of the first clamping plate 43.
[0026] Both ends of the first clamping plate 43 facing the housing 2 are fixedly connected to round rods 44. The ends of the round rods 44 are inserted into the guide groove 8 and fixedly connected to guide balls 45. The diameter of the guide balls 45 is larger than the diameter of the round rods 44. The guide balls 45 slide in contact with the inner wall of the guide groove 8. When the first clamping plate 43 moves upward, it drives the round rods 44 and the guide balls 45 to move synchronously. At this time, the guide balls 45 slide along the inner wall of the guide groove 8, thereby controlling the round rods 44 and the first clamping plate 43 to move toward the first fixed plate 42 through the guide balls 45. Then, the upper end of the film is clamped and fixed by the cooperation of the first clamping plate 43 and the first fixed plate 42.
[0027] The movable ends of the first clamping member 4 and the second clamping member 5 are connected by a telescopic rod 9. The second clamping member 5 includes a second fixed plate 51, which is fixedly connected to the side wall of the housing 2. A second clamping plate 52 is movably inserted into the side wall of the second fixed plate 51. The lower end of the telescopic rod 9 is fixedly connected to the second clamping plate 52, and the upper end of the telescopic rod 9 is fixedly connected to the first clamping plate 43. When the first clamping plate 43 moves, it drives the telescopic rod 9 to move synchronously. Then, the telescopic rod 9 controls the second clamping plate 52 to move toward the second fixed plate 51. Thus, the second clamping plate 52 and the second fixed plate 51 cooperate to clamp and fix the lower end of the film. As the first clamping plate 43 moves, the telescopic rod 9 extends and retracts, thereby enabling the first clamping plate 43 to move smoothly up and down.
[0028] The top and bottom surfaces of the first fixing plate 42 and the second fixing plate 51 are both fixedly connected to guide plates 53. The guide plates 53 are arc-shaped. The surfaces of the first fixing plate 42, the second fixing plate 51, the first clamping plate 43, and the second clamping plate 52 are all provided with anti-slip textures. The guide plates 53 facilitate the guidance of the film, so that the film can pass smoothly through the first clamping plate 43 and the first fixing plate 42 and enter between the second clamping plate 52 and the second fixing plate 51. The anti-slip textures also help to increase the stability of the film clamping by the first clamping plate 43, the first fixing plate 42, the second clamping plate 52, and the second fixing plate 51.
[0029] In summary: the unwinding mechanism 6 facilitates the release of the film, allowing it to pass through the first clamping member 4 and fall into the second clamping member 5. The electric push rod 3 controls the movement of the first clamping member 4, and the guide groove 8 controls the retraction of the first clamping member 4 to clamp and fix the film. At the same time, the telescopic rod 9 controls the retraction of the second clamping member 5 to clamp and fix the lower end of the film. Therefore, clamping and fixing the film is more convenient. As the first clamping member 4 moves upward, the film is stretched, thereby enabling the tensile strength test of the film. When the first clamping member 4 is reset, it causes the first clamping member 4 to open with the second clamping member 5, and releases a new film through the operation of the unwinding mechanism 6, thereby facilitating continuous testing of the film through the device and increasing the accuracy of film testing.
[0030] To better demonstrate a device for testing the strength and quality of finished plastic films, this embodiment proposes a method for testing the strength and quality of finished plastic films, including the following steps: Step 1: First, the motor 66 drives the guide roller 64 to rotate, and the two gears 65 cooperate to control the rotation of the two guide rollers 64 to convey the film downward, and cause the film to pass through the first clamping member 4 and then insert into the second clamping member 5. Step 2: The first clamping member 4 is moved by the electric push rod 3. At this time, the first clamping plate 43 of the first clamping member 4 is moved by the round rod 44, the guide ball 45 and the guide groove 8. The film is cut by the cutting blade 46. At the same time, the second clamping plate 52 of the second clamping member 5 is moved by the telescopic rod 9. Thus, the first clamping plate 43 and the second clamping plate 52 are used to clamp and fix both ends of the film. Step 3: When the first clamping member 4 moves, it pulls one end of the film upward to continuously stretch the film. At the same time, the tensile strength of the film is detected by the force sensor and displacement sensor inside the housing 2. Step 4: Simultaneously, when the first clamping member 4 moves, the control ring 7 moves synchronously. At this time, the control ring 7 drives the unwinding mechanism 6 to rotate, so as to cause the unwinding mechanism 6 to drive the film to rotate, thereby reducing the possibility of the film remaining above the first clamping member 4 and affecting the movement of the first clamping member 4. Step 5: After the film test is completed, the first clamping member 4 is reset by the electric push rod 3. At this time, the first clamping plate 43 of the first clamping member 4 is opened by the cooperation of the guide groove 8, guide ball 45, and round rod 44. At the same time, the second clamping plate 52 of the second clamping member 5 is opened by the telescopic rod 9, so that the broken film loses its limit. Then, the unwinding mechanism 6 releases the new film for continuous testing to increase the accuracy of film testing.
[0031] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A plastic film finished product strength quality detection device, comprising a control console (1) and a machine shell (2), characterized in that: The shell (2) is fixedly installed on the top of the console (1), the electric push rod (3) is fixedly inserted in the shell (2), the first clamping piece (4) is fixedly inserted on the extending end of the electric push rod (3), the second clamping piece (5) is fixedly connected to the side wall of the shell (2), the unwinding mechanism (6) is rotatably inserted on the top of the shell (2), the control ring (7) is fixedly connected to the extending end of the electric push rod (3), the control ring (7) is movably sleeved on one end of the unwinding mechanism (6) inserted into the shell (2) and is used for controlling the rotation of the unwinding mechanism (6), the guide groove (8) is formed in the side wall of the shell (2) and is used for controlling the contraction of the first clamping piece (4), and the movable end of the first clamping piece (4) and the second clamping piece (5) are connected through the telescopic rod (9).
2. The device for testing the strength and quality of finished plastic film according to claim 1, characterized in that: The first clamping piece (4) comprises the movable plate (41) and the first fixed plate (42), one end of the movable plate (41) is fixedly connected to the extending end of the electric push rod (3), the other end of the movable plate (41) extends out of the shell (2) and is fixedly connected to the first fixed plate (42), and the side wall of the first fixed plate (42) movably inserts the first clamping plate (43).
3. The device for testing the strength and quality of finished plastic film according to claim 2, characterized in that: The two ends of the first clamping plate (43) towards the side of the shell (2) are fixedly connected with the round rods (44), the end of the round rod (44) is inserted into the guide groove (8) and is fixedly connected with the guide ball (45), the diameter of the guide ball (45) is larger than that of the round rod (44), and the guide ball (45) is in sliding fit with the inner wall of the guide groove (8).
4. The device for testing the strength and quality of finished plastic film according to claim 2, characterized in that: The side of the first clamping plate (43) towards the first fixed plate (42) is fixedly connected with the cutting knife (46), the first fixed plate (42) is provided with the knife groove corresponding to the cutting knife (46), the top surface and the bottom surface of the movable plate (41) are fixedly connected with the folding dust cover (47), and the folding dust cover (47) is used for sealing the opening of the shell (2).
5. The apparatus for testing strength and quality of finished plastic film according to claim 2, characterized in that: The second clamping piece (5) comprises the second fixed plate (51), the second fixed plate (51) is fixedly connected to the side wall of the shell (2), the side wall of the second fixed plate (51) movably inserts the second clamping plate (52), the lower end of the telescopic rod (9) is fixedly connected to the second clamping plate (52), and the upper end of the telescopic rod (9) is fixedly connected to the first clamping plate (43).
6. The apparatus for testing strength and quality of finished plastic film according to claim 5, characterized in that: The top surface and the bottom surface of the first fixed plate (42) and the second fixed plate (51) are fixedly connected with the material guide plates (53), the material guide plates (53) are in the shape of a circular arc, and the surfaces of the first fixed plate (42), the second fixed plate (51), the first clamping plate (43) and the second clamping plate (52) are provided with anti-skid lines.
7. The apparatus for testing strength and quality of finished plastic film according to claim 1, characterized in that: The unwinding mechanism (6) comprises a disc (61) and a vertical rod (62), the vertical rod (62) is rotatably inserted into the inner top wall of the shell (2), the upper end of the vertical rod (62) extends out of the shell (2) and is fixedly connected with the disc (61), the side wall of the disc (61) is fixedly connected with a U-shaped frame (63), two material guide rollers (64) are rotatably inserted into the U-shaped frame (63), the ends of the two material guide rollers (64) are inserted into the U-shaped frame (63) and are fixedly sleeved with gears (65), the two gears (65) are engaged, the side wall of the U-shaped frame (63) is fixedly installed with a motor (66), the rotating shaft of the motor (66) is fixedly connected with the end of one of the material guide rollers (64), the top surface of the U-shaped frame (63) is fixedly connected with two supporting plates (67), recesses (68) are formed in the two supporting plates (67), film rollers (69) are rotatably installed in the recesses (68), a spiral groove (610) is formed in the lower end of the outer wall of the vertical rod (62), and a vertical groove (611) is formed in the upper end of the outer wall of the vertical rod (62).
8. The apparatus for testing strength and quality of finished plastic film according to claim 7, characterized in that: The control ring (7) comprises a circular ring (71) and a semicircular block (72), the outer wall of the circular ring (71) is fixedly connected with the extending end of the electric push rod (3), the circular ring (71) is movably sleeved on the vertical rod (62), and the semicircular block (72) is fixedly connected to the inner wall of the circular ring (71); the semicircular block (72) is in sliding fit with the inner walls of the spiral groove (610) and the vertical groove (611).
9. The apparatus for testing strength and quality of finished plastic film according to claim 1, characterized in that: The outer contour shape of the inner wall section of the guide groove (8) is L-shaped.
10. A detection method for detecting the strength quality of a plastic film product, comprising the plastic film product strength quality detection device according to any one of claims 1-9, characterized in that, Further comprising the following steps: S101: first, drive the material guide roller (64) to rotate by the motor (66), and control the two material guide rollers (64) to rotate by the two gears (65) to downwardly convey the film, and make the film pass through the first clamping piece (4) and then be inserted into the second clamping piece (5); S102: control the first clamping piece (4) to move by the electric push rod (3), at this time, control the first clamping plate (43) of the first clamping piece (4) to move by the circular rod (44), the guide ball (45) and the guide groove (8), and cut the film by the cutting knife (46), and at the same time, drive the second clamping plate (52) of the second clamping piece (5) to move by the telescopic rod (9), so that the two ends of the film are clamped and fixed by the first clamping plate (43) and the second clamping plate (52); S103: when the first clamping piece (4) moves, pull one end of the film to move upward, so as to continuously stretch the film, and at the same time, detect the tensile strength of the film by the force sensor and the displacement sensor in the shell (2); S104: at the same time, drive the control ring (7) to move synchronously when the first clamping piece (4) moves, at this time, drive the unwinding mechanism (6) to rotate by the control ring (7), so as to drive the film to rotate by the unwinding mechanism (6), so as to reduce the possibility that the film stays above the first clamping piece (4) and affects the movement of the first clamping piece (4). S105: when the film test is completed, the first clamping part (4) is reset by the electric push rod (3), at this time the first clamping part (4) is opened by the cooperation of the guide groove (8) and the guide ball (45), the round rod (44) and the first clamping plate (43), and the second clamping plate (52) of the second clamping part (5) is opened by the telescopic rod (9) at the same time, so as to make the broken film lose the limit, and then the new film is released by the unwinding mechanism (6) for continuous detection, so as to increase the accuracy of film detection.