Method and device for detecting tensile strength of paper-plastic bag

Abstract

The invention discloses a method and device for detecting the tensile strength of a paper-plastic bag, and the method comprises the following steps: 1, sampling the paper-plastic bag, conveying the cut paper-plastic bag through a main conveying belt, randomly selecting a sample from the conveyed paper-plastic bag, and pushing the selected sample into an auxiliary conveying belt to be separated from the main conveying belt; the paper-plastic bags are conveyed into a clamping mechanism through an auxiliary conveying belt, when the device is used, participation of workers is not needed, the labor cost is reduced, in the implementation process, the paper-plastic bags can be conveniently sampled, the positions of the paper-plastic bags can be shifted through the clamping mechanism, and the paper-plastic bags can be conveniently taken out. According to the paper-plastic bag detection device, the paper-plastic bags can be preliminarily positioned through the pre-positioning mechanism, the paper-plastic bags can be prevented from sliding when being detected through the locking mechanism, and then the accuracy of the detection result is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of paper-plastic bag detection, and specifically relates to a method and device for detecting the tensile strength of paper-plastic bags. Background Art

[0002] When processing paper-plastic bags, it is necessary to detect the tensile strength of the paper-plastic bags to ensure that the manufactured products can meet the needs of customers. In the prior art, when detecting paper-plastic bags, most of them are carried out according to the following steps: First step, cut the paper-plastic bag; second step, the staff take samples of the cut products; third step, put the sampled samples into the detection equipment for detection and obtain the detection conclusion. The sampling work is simple and repetitive, and does not require any technical means. Therefore, the method of manual sampling not only wastes labor costs, but also needs to be sent to specific detection equipment after sampling, which is rather troublesome. Summary of the Invention

[0003] To solve the problems raised in the above background art, the present invention provides the following technical solution: A method for detecting the tensile strength of paper-plastic bags, including the following steps

[0004] Step 1, sampling of the paper-plastic bag: The cut paper-plastic bag is conveyed by the main conveyor belt, samples are randomly selected from the conveyed paper-plastic bags, and the selected samples are pushed into the secondary conveyor belt to be separated from the main conveyor belt;

[0005] Step 2, straightening of the paper-plastic bag: The paper-plastic bag is conveyed to the clamping mechanism by the secondary conveyor belt, and during the conveyance of the secondary conveyor belt, the position of the paper-plastic bag is adjusted so that it is in the middle position, and the paper-plastic bag enters the clamping mechanism in this form;

[0006] Step 3, positioning of the paper-plastic bag: A pre-positioning mechanism is arranged at a position close to one side above the clamping mechanism, and the pre-positioning mechanism can press and fix two opposite sides of the paper-plastic bag;

[0007] Step 4, locking of the paper-plastic bag: A locking mechanism is arranged on one side of the pre-positioning mechanism. After the paper-plastic bag is pressed and fixed by the pre-positioning mechanism, the locking mechanism can lock and fix the edge of the paper-plastic bag;

[0008] Step 5, detection of the paper-plastic bag: After the edge of the paper-plastic bag is fixed, the pre-positioning mechanism can separate and pull the paper-plastic bag to both sides until a predetermined tensile force is reached;

[0009] Step 6, completion of detection: According to whether the paper-plastic bag is damaged by pulling in Step 5, judge the tensile strength of the paper-plastic bag, that is, when the paper-plastic bag is damaged or broken by pulling, it means that the tensile strength of the paper-plastic bag is unqualified, and when the paper-plastic bag is not damaged after being pulled, it means that the tensile strength of the paper-plastic bag is qualified.

[0010] Preferably, the pre-positioning mechanism has two identical units, each unit fixes one of the side edges of the paper-plastic bag, and the two units can be separated from each other, and each unit has an upper fixing module and a lower fixing module.

[0011] Preferably, after the side of the paper-plastic bag is clamped by the upper fixing module and the lower fixing module, the side of the paper-plastic bag extends out of the upper fixing module and the lower fixing module, and the length of the extended paper-plastic bag is greater than the height of the upper fixing module.

[0012] A paper-plastic bag tensile strength testing device comprises an auxiliary conveyor belt, a clamping mechanism, a pre-positioning mechanism, and a locking mechanism.

[0013] The auxiliary conveyor belt mounting seat is on the first support frame, and a connecting plate is arranged on one side of the auxiliary conveyor belt. A driving wheel and a first driven wheel are arranged in the auxiliary conveyor belt, and a rotating shaft is arranged inside the first driven wheel, and a bearing is arranged on the rotating shaft outer cover. An arc groove is provided on the first support frame, and the bearing extends into the arc groove. A positioning frame capable of moving up and down is provided inside the first support frame, and a horizontally arranged slide groove is provided in the positioning frame, and the bearing extends into the slide groove. When the positioning frame slides up and down, the bearing can slide in the arc groove to rotate the auxiliary conveyor belt, and the connecting plate is installed on the bearing through the first fixing frame.

[0014] The clamping mechanism includes a second fixed frame, which is fixedly connected to the upper end of the first supporting frame. A movable plate is arranged on the second fixed frame. There are two movable plates, which are symmetrically arranged at the upper end of the auxiliary conveyor belt. The upper end of the movable plate is inserted into the second fixed frame. A rotatable toggle gear is arranged in the second fixed frame. Toggle racks are arranged on both sides of the toggle gear. Each toggle rack is fixedly connected to a movable plate, so that when the toggle rack rotates, the two movable plates can approach / move away from each other. The toggle gear is driven by a motor.

[0015] The pre-positioning mechanism includes an upper fixing module and a lower fixing module, and is located on a side of the auxiliary conveyor belt away from the connecting plate. The upper fixing module is driven by a first driving member so that the upper fixing module can move up and down. A mounting block is fixedly connected to the side of the lower fixing module, and an extension rod that can move up and down is installed inside the mounting block. The extension rod can move upward and extend to one side of the upper fixing module.

[0016] The locking mechanism includes a pressing block, which is located on one side of the upper fixed module. The pressing block can slide toward / away from the upper fixed module, and when the upper fixed module is pressed on the upper end of the lower fixed module, the pressing block can slide and press on the upper surface of the upper fixed module.

[0017] Preferably, a second threaded rod passes through the inside of the positioning frame. The second threaded rod is vertically arranged, and is in threaded cooperation with the positioning frame, and is driven by a motor.

[0018] Preferably, the upper fixing module includes a first upper module, a second upper module and an upper cross plate. The first upper module is fixedly connected to one end of the upper cross plate, and the second upper module is inserted into the other end of the upper cross plate; the lower fixing module includes a first lower module, a second lower module and a lower cross plate. The first lower module is fixedly connected to one end of the lower cross plate, and the second lower module is inserted into the other end of the lower cross plate, and the first lower module is located below the first upper module.

[0019] Preferably, the first lower module is fixedly connected to the second support frame. An outer frame is fixedly connected inside the second support frame. A first threaded rod is rotatably arranged inside the outer frame. A bracket is fixedly connected to the pressing block. The lower end of the bracket is inserted into the outer frame and is in threaded cooperation with the first threaded rod. A rack is also threadedly connected to the outside of the first threaded rod. A rotating gear is rotatably installed on the mounting block. The rack cooperates with the rotating gear so that when the first threaded rod rotates, the rack and the bracket can slide.

[0020] Preferably, the first threaded rod includes two thread units with opposite threads. A plugging rod is fixedly connected to one end of one of the thread units. A plugging groove is formed in the other thread unit. Both the plugging rod and the plugging groove are rectangular structures.

[0021] Preferably, a positioning block is fixedly connected to the upper end of the second lower module. A positioning groove is formed in the lower end of the second upper module. The positioning block cooperates with the positioning groove. A third fixing frame is fixedly connected to one side of the second lower module. The third fixing frame can drive the structure to drive so that the second lower module slides in a direction close to / away from the first lower module.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] When the device is used, it does not require the participation of staff, reducing labor costs. Moreover, during implementation, it is also convenient to sample the paper-plastic bag. By using the clamping mechanism, the position of the paper-plastic bag can be toggled so that it is in the middle position of the auxiliary conveyor belt. By using the pre-positioning mechanism, the paper-plastic bag can be preliminarily positioned. By using the locking mechanism, it can be avoided that the paper-plastic bag slides during the detection of the paper-plastic bag, thereby ensuring the accuracy of the detection result. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0025] Figure 1A step diagram of a method for testing the tensile strength of a paper-plastic bag according to the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of one side of a device for detecting the tensile strength of a paper-plastic bag according to the present invention;

[0027] Figure 3 It is a schematic structural diagram of one side of a secondary conveyor belt of a device for detecting the tensile strength of a paper-plastic bag according to the present invention;

[0028] Figure 4 A paper-plastic bag tensile strength testing device according to the present invention Figure 1 A schematic diagram of a top view structure;

[0029] Figure 5 It is a structural schematic diagram of one side of a positioning frame of a device for detecting the tensile strength of a paper-plastic bag according to the present invention;

[0030] Figure 6 It is a top view structural schematic diagram of a pre-positioning mechanism of a paper-plastic bag tensile strength testing device of the present invention;

[0031] Figure 7 A paper-plastic bag tensile strength testing device according to the present invention Figure 6 A schematic diagram of the structure on one side;

[0032] Figure 8 This is a schematic diagram of the internal structure of a mounting block of a device for detecting the tensile strength of a paper-plastic bag according to the present invention;

[0033] Figure 9 This is a schematic diagram of the internal structure of an outer frame of a device for testing the tensile strength of a paper-plastic bag according to the present invention;

[0034] Figure 10 It is a schematic diagram of the matching structure of a movable plate, a shifting gear and a shifting rack of a paper-plastic bag tensile strength testing device of the present invention;

[0035] Figure 11 It is a schematic diagram of the matching structure of a pre-positioning mechanism of a paper-plastic bag tensile strength testing device and a paper-plastic bag according to the present invention;

[0036] In the figure: 1, first support frame; 2, auxiliary conveyor belt; 3, driving wheel; 4, first driven wheel; 5, rotating shaft; 6, arc groove; 7, connecting plate; 8, first fixed frame; 9, second fixed frame; 10, movable plate; 11, second driven wheel; 12, first upper module; 13, first lower module; 14, first driving member; 15, second support frame; 16, bracket; 17, guide rail; 18, first threaded rod; 19, bearing; 20. Positioning frame; 21. Slide groove; 22. Second threaded rod; 23. Second upper module; 24. Upper horizontal plate; 25. Second lower module; 26. Lower horizontal plate; 27. Positioning block; 28. Positioning groove; 29. ​​Mounting block; 30. Rotating gear; 31. Rack; 32. External frame; 33. Extension rod; 34. Plug rod; 35. Plug groove; 36. Fixed frame; 37. Toggle gear; 38. Toggle rack; 39. Press block. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] Depend on Figure 1 The present invention discloses a method for detecting the tensile strength of a paper-plastic bag, comprising the following steps:

[0039] Step 1: sampling of paper-plastic bags. The cut paper-plastic bags are conveyed by the main conveyor belt. The auxiliary conveyor belt can rotate, and samples are randomly selected from the conveyed paper-plastic bags. The selected samples are pushed into the auxiliary conveyor belt and separated from the main conveyor belt. Then the auxiliary conveyor belt rotates in the opposite direction and resets. After that, the paper-plastic bags cannot enter the auxiliary conveyor belt.

[0040] Step 2: Straightening the paper-plastic bag. The paper-plastic bag is conveyed to the clamping mechanism through the auxiliary conveyor belt (the paper-plastic bag passes through the clamping mechanism). During the conveying process of the auxiliary conveyor belt, the clamping mechanism shifts the position of the paper-plastic bag to the middle position, and the paper-plastic bag enters the clamping mechanism in this way (in the middle position of the auxiliary conveyor belt);

[0041] Step 3: Positioning the paper-plastic bag. A pre-positioning mechanism is provided above the clamping mechanism and near one side. The pre-positioning mechanism can press and fix two opposite sides of the paper-plastic bag, and the two sides of the paper-plastic bag extend outside the pre-positioning mechanism, and then the edge of the extended paper-plastic bag is lifted up close to the side of the pre-positioning mechanism;

[0042] Step 4, locking of the paper-plastic bag. A locking mechanism is provided on one side of the pre-positioning mechanism. After the paper-plastic bag is pressed and fixed by the pre-positioning mechanism, the side edge of the paper-plastic bag that is in contact with the pre-positioning mechanism has a height higher than the upper surface of the pre-positioning mechanism. The locking mechanism can push and press the edge of the paper-plastic bag onto the upper surface of the pre-positioning mechanism to lock and fix the paper-plastic bag.

[0043] Step 5, detection of the paper-plastic bag. After the edge of the paper-plastic bag is fixed, the pre-positioning mechanism can separate and pull the paper-plastic bag to both sides until a predetermined pulling force is reached.

[0044] Step 6, completion of detection. According to whether the paper-plastic bag is damaged by pulling in Step 5, the tensile strength of the paper-plastic bag is judged. That is, when the paper-plastic bag is damaged or broken by pulling, it indicates that the tensile strength of the paper-plastic bag is unqualified, and when there is no damage to the paper-plastic bag after pulling, it indicates that the tensile strength of the paper-plastic bag is qualified.

[0045] The pre-positioning mechanism has two identical units. Each unit fixes one side edge of the paper-plastic bag, and the two units can be separated from each other. Each unit has an upper fixing module and a lower fixing module.

[0046] After the side edge of the paper-plastic bag is clamped between the upper fixing module and the lower fixing module, the side surface of the paper-plastic bag extends out of the upper fixing module and the lower fixing module, and the extending length of the paper-plastic bag is greater than the height of the upper fixing module.

[0047] As Figures 2 - 11 shown, a device for detecting the tensile strength of a paper-plastic bag includes a secondary conveyor belt 2, a clamping mechanism, a pre-positioning mechanism, and a locking mechanism.

[0048] The secondary conveyor belt 2 is mounted on the first support frame 1. A connecting plate 7 is provided on one side of the secondary conveyor belt 2. When the secondary conveyor belt 2 is inclined, the connecting plate 7 can contact the surface of the main conveyor belt, so that the paper-plastic bag conveyed by the main conveyor belt enters the secondary conveyor belt 2 along the connecting plate 7. An active wheel 3 and a first driven wheel 4 are arranged inside the secondary conveyor belt 2. The active wheel 3 is driven by a motor to drive the secondary conveyor belt 2 to run. A rotating shaft 5 is arranged inside the first driven wheel 4, and the first driven wheel 4 rotates on the rotating shaft 5. A bearing 19 is sleeved outside the rotating shaft 5. An arc-shaped groove 6 is formed on the first support frame 1, and the bearing 19 extends into the arc-shaped groove 6. A positioning frame 20 that can move up and down is arranged inside the first support frame 1. A horizontally arranged sliding groove 21 is formed inside the positioning frame 20. The bearing 19 extends into the sliding groove 21. When the positioning frame 20 slides up and down, the bearing 19 can slide in the arc-shaped groove 6 to make the secondary conveyor belt 2 rotate. The connecting plate 7 is installed on the bearing 19 through a first fixing frame 8.

[0049] The clamping mechanism includes a second fixing frame 9, which is fixedly connected to the upper end of the first support frame 1. An activity plate 10 is arranged on the second fixing frame 9. There are two activity plates 10, which are symmetrically arranged at the upper end of the auxiliary conveyor belt 2. The upper end of the activity plate 10 is inserted into the second fixing frame 9. A rotatable toggle gear 37 is arranged in the second fixing frame 9. Toggle racks 38 are arranged on both sides of the toggle gear 37. Each toggle rack 38 is fixedly connected to an activity plate 10, so that when the toggle rack 38 rotates, the two activity plates 10 can approach / separate from each other, thereby toggling the paper-plastic bag passing through the activity plate 10 towards the middle position, so that the position of the paper-plastic bag is located in the exact middle of the auxiliary conveyor belt 2. The toggle gear 37 is driven by a motor.

[0050] The pre-positioning mechanism includes an upper fixing module and a lower fixing module, and it is located on the side of the auxiliary conveyor belt 2 away from the connecting plate 7. The upper fixing module is driven by a first driving member 14, so that the upper fixing module can move up and down. An installation block 29 is fixedly connected to the side surface of the lower fixing module. An elongating rod 33 that can move up and down is installed inside the installation block 29. The elongating rod 33 can move upward and extend to one side of the upper fixing module. After the paper-plastic bag is conveyed between the upper fixing module and the lower fixing module, the driving member 14 can press down the upper fixing module to fix the position of the paper-plastic bag.

[0051] The locking mechanism includes a pressing block 39. The pressing block 39 is located on one side of the upper fixing module. The pressing block 39 can slide in the direction of approaching / separating from the upper fixing module, and when the upper fixing module presses on the upper end of the lower fixing module, the pressing block 39 can slide and press on the upper surface of the upper fixing module.

[0052] When the device is in use, when it is necessary to detect the paper-plastic bag, one end of the auxiliary conveyor belt 2 is rotated downward to be in an inclined state. The paper-plastic bag enters the auxiliary conveyor belt 2 through the connecting plate 7, and then the position of the paper-plastic bag is toggled by the clamping mechanism so that the paper-plastic bag is located at the center of the auxiliary conveyor belt 2. Then the paper-plastic bag enters the pre-positioning mechanism. After the pre-positioning mechanism fixes the paper-plastic bag, the locking mechanism can lock and fix the paper-plastic bag to prevent the paper-plastic bag from sliding during detection. Finally, when the paper-plastic bag is locked, the paper-plastic bag is detected.

[0053] When the device is in use, it does not require the participation of staff, reducing labor costs. Moreover, during implementation, it is also convenient to sample the paper-plastic bag. By using the clamping mechanism, the position of the paper-plastic bag can be toggled so that it is in the middle of the auxiliary conveyor belt 2. By using the pre-positioning mechanism, the paper-plastic bag can be preliminarily positioned. By using the locking mechanism, it can prevent the paper-plastic bag from sliding during the detection of the paper-plastic bag, thereby ensuring the accuracy of the detection result.

[0054] A second threaded rod 22 runs through the interior of the positioning frame 20. The second threaded rod 22 is arranged vertically, and the second threaded rod 22 and the positioning frame 20 are threadedly matched. The second threaded rod 22 is driven by a motor, and the output end of the motor is connected to the second threaded rod 22. Then, the rotation of the second threaded rod 22 can drive the positioning frame 20 to move up and down, thereby causing one end of the auxiliary conveyor belt 2 to rotate.

[0055] The second threaded rod 22 may be driven by a motor.

[0056] The upper fixed module includes a first upper module 12, a second upper module 23 and an upper cross plate 24, the first upper module 12 is fixedly connected to one end of the upper cross plate 24, and the second upper module 23 is plugged into the other end of the upper cross plate 24; the lower fixed module includes a first lower module 13, a second lower module 25 and a lower cross plate 26, the first lower module 13 is fixedly connected to one end of the lower cross plate 26, the second lower module 25 is plugged into the other end of the lower cross plate 26, and the first lower module 13 is located below the first upper module 12.

[0057] The second upper module 23 and the second lower module 25 can slide toward one side, and then after locking the edge of the paper-plastic bag, the paper-plastic bag can be stretched to be tested.

[0058] The first lower module 13 is fixedly connected to the second support frame 15, and an outer frame 32 is fixedly connected inside the second support frame 15. A first threaded rod 18 is rotatably provided inside the outer frame 32. A bracket 16 is fixedly connected to the pressing block 39. The lower end of the bracket 16 is inserted into the outer frame 32 and threadedly cooperates with the first threaded rod 18. A rack 31 is also threadedly connected to the outside of the first threaded rod 18. A rotating gear 30 is rotatably installed on the mounting block 29, and the rack 31 cooperates with the rotating gear 30 so that when the first threaded rod 18 rotates, the rack 31 and the bracket 16 can slide.

[0059] When the device is implemented, by using the first threaded rod 18, the rack 31 can slide along the first threaded rod 18 to clamp and fix the edge of the paper-plastic bag, and then the pressing block 39 moves the edge of the paper-plastic bag so that it is pressed on the upper surface of the pre-positioning mechanism, thereby locking the position of the paper-plastic bag, which facilitates subsequent detection.

[0060] The first threaded rod 18 includes two threaded units with opposite threads. A plug-in rod 34 is fixedly connected to one end of one of the threaded units, and a plug-in slot 35 is provided in the other threaded unit. Both the plug-in rod 34 and the plug-in slot 35 are rectangular structures.

[0061] When performing tensile testing on a paper-plastic bag, the second upper module 23 and the second lower module 25 slide towards one side. At this time, the first threaded rod 18 can extend to avoid jamming. And the above structure can enable the first threaded rod 18 to expand and contract, and the entire first threaded rod 18 rotates synchronously.

[0062] The first threaded rod 18 can be driven by a motor.

[0063] A positioning block 27 is fixedly connected to the upper end of the second lower module 25, and a positioning groove 28 is provided at the lower end of the second upper module 23. The positioning block 27 cooperates with the positioning groove 28 so that after the second upper module 23 is pressed downwards, the second upper module 23 and the second lower module 25 can be connected. Then when the second lower module 25 is pulled towards one side, the second lower module 25 can drive the second upper module 23 to be pulled together, thereby performing tensile testing on the paper-plastic bag.

[0064] A third fixing frame 36 is fixedly connected to one side of the second lower module 25. The third fixing frame 36 can drive the driving structure so that the second lower module 25 slides towards the direction close to / away from the first lower module 13.

[0065] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0066] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for testing the tensile strength of a paper-plastic bag, characterized in that: The following steps are included: Step 1: sampling of paper-plastic bags. The cut paper-plastic bags are conveyed through the main conveyor belt. Samples are randomly selected from the conveyed paper-plastic bags, and the selected samples are pushed into the auxiliary conveyor belt and separated from the main conveyor belt. Step 2: Straightening the paper-plastic bag, conveying the paper-plastic bag to the clamping mechanism through the auxiliary conveyor belt, and in the process of conveying by the auxiliary conveyor belt, the position of the paper-plastic bag is adjusted to be in the middle position, and the paper-plastic bag enters the clamping mechanism according to this pattern; Step three, positioning the paper-plastic bag, a pre-positioning mechanism is provided above the clamping mechanism near one side, and the pre-positioning mechanism can press and fix two opposite sides of the paper-plastic bag; Step 4: locking the paper-plastic bag. A locking mechanism is provided on one side of the pre-positioning mechanism. After the paper-plastic bag is pressed and fixed by the pre-positioning mechanism, the locking mechanism can lock and fix the edge of the paper-plastic bag. Step 5: Inspection of the paper-plastic bag. After the edge of the paper-plastic bag is fixed, the pre-positioning mechanism can be separated and the paper-plastic bag is pulled to both sides until a predetermined pulling force is reached; Step six, the test is completed, and the tensile strength of the paper-plastic bag is judged according to whether the paper-plastic bag is pulled and damaged in step five. That is, when the paper-plastic bag is pulled and damaged or broken, it means that the tensile strength of the paper-plastic bag is unqualified, and when the paper-plastic bag is pulled without damage, it means that the tensile strength of the paper-plastic bag is qualified.

2. A method for detecting the tensile strength of a paper-plastic bag according to claim 1, characterized in that: The pre-positioning mechanism has two identical units, each unit fixes one of the side edges of the paper-plastic bag, and the two units can be separated from each other, and each unit has an upper fixing module and a lower fixing module.

3. A method for detecting the tensile strength of a paper-plastic bag according to claim 2, characterized in that: After the side of the paper-plastic bag is clamped by the upper fixing module and the lower fixing module, the side of the paper-plastic bag extends out of the upper fixing module and the lower fixing module, and the extending length of the paper-plastic bag is greater than the height of the upper fixing module.

4. A paper-plastic bag tensile strength testing device, characterized in that : comprising an auxiliary conveyor belt (2), a clamping mechanism, a pre-positioning mechanism, and a locking mechanism, The auxiliary conveyor belt (2) mounting seat is on the first support frame (1), a connecting plate (7) is arranged on one side of the auxiliary conveyor belt (2), a driving wheel (3) and a first driven wheel (4) are arranged inside the auxiliary conveyor belt (2), a rotating shaft (5) is arranged inside the first driven wheel (4), a bearing (19) is arranged on the outer sleeve of the rotating shaft (5), an arc groove (6) is provided on the first support frame (1), the bearing (19) extends into the arc groove (6), a positioning frame (20) capable of moving up and down is arranged inside the first support frame (1), a horizontally arranged slide groove (21) is provided in the positioning frame (20), the bearing (19) extends into the slide groove (21), when the positioning frame (20) slides up and down, the bearing (19) can slide in the arc groove (6) to rotate the auxiliary conveyor belt (2), the connecting plate (7) is mounted on the bearing (19) through the first fixing frame (8), The clamping mechanism comprises a second fixed frame (9), the second fixed frame (9) is fixedly connected to the upper end of the first support frame (1), a movable plate (10) is arranged on the second fixed frame (9), the movable plates (10) have two and are symmetrically arranged at the upper end of the auxiliary conveyor belt (2), the upper end of the movable plate (10) is inserted into the second fixed frame (9), a rotatable toggle gear (37) is arranged in the second fixed frame (9), toggle racks (38) are arranged on both sides of the toggle gear (37), each toggle rack (38) is fixedly connected to a movable plate (10), so that when the toggle rack (38) rotates, the two movable plates (10) can approach / move away from each other, and the toggle gear (37) is driven by a motor. The pre-positioning mechanism comprises an upper fixing module and a lower fixing module, and is located on a side of the auxiliary conveyor belt (2) away from the connecting plate (7). The upper fixing module is driven by a first driving member (14) so ​​that the upper fixing module can move up and down. A mounting block (29) is fixedly connected to the side of the lower fixing module. An extension rod (33) that can move up and down is installed inside the mounting block (29). The extension rod (33) can move upward and extend to one side of the upper fixing module. The locking mechanism comprises a pressing block (39), which is located on one side of the upper fixed module. The pressing block (39) can slide in a direction approaching or moving away from the upper fixed module, and when the upper fixed module is pressed on the upper end of the lower fixed module, the pressing block (39) can slide and press on the upper surface of the upper fixed module.

5. A paper-plastic bag tensile strength testing device according to claim 4, characterized in that: A second threaded rod (22) runs through the interior of the positioning frame (20); the second threaded rod (22) is arranged vertically, and the second threaded rod (22) and the positioning frame (20) are threadedly matched, and the second threaded rod (22) is driven by a motor.

6. A paper-plastic bag tensile strength testing device according to claim 5, characterized in that: The upper fixed module comprises a first upper module (12), a second upper module (23) and an upper transverse plate (24), wherein the first upper module (12) is fixedly connected to one end of the upper transverse plate (24), and the second upper module (23) is plugged into the other end of the upper transverse plate (24); the lower fixed module comprises a first lower module (13), a second lower module (25) and a lower transverse plate (26), wherein the first lower module (13) is fixedly connected to one end of the lower transverse plate (26), and the second lower module (25) is plugged into the other end of the lower transverse plate (26), and the first lower module (13) is located below the first upper module (12).

7. A paper-plastic bag tensile strength testing device according to claim 6, characterized in that: The first lower module (13) is fixedly connected to the second support frame (15), an outer frame (32) is fixedly connected inside the second support frame (15), a first threaded rod (18) is rotatably arranged inside the outer frame (32), a bracket (16) is fixedly connected to the pressing block (39), the lower end of the bracket (16) is inserted into the outer frame (32) and threadedly matched with the first threaded rod (18), a rack (31) is also threadedly connected to the outside of the first threaded rod (18), a rotating gear (30) is rotatably installed on the mounting block (29), the rack (31) cooperates with the rotating gear (30), so that when the first threaded rod (18) rotates, the rack (31) and the bracket (16) can slide.

8. A paper-plastic bag tensile strength testing device according to claim 7, characterized in that: The first threaded rod (18) comprises two threaded units with opposite threads, a plug-in rod (34) is fixedly connected to one end of one of the threaded units, and a plug-in groove (35) is provided in the other threaded unit, and both the plug-in rod (34) and the plug-in groove (35) are rectangular structures.

9. A paper-plastic bag tensile strength testing device according to claim 8, characterized in that: A positioning block (27) is fixedly connected to the upper end of the second lower module (25), and a positioning groove (28) is opened at the lower end of the second upper module (23). The positioning block (27) cooperates with the positioning groove (28). A third fixing frame (36) is fixedly connected to one side of the second lower module (25). The third fixing frame (36) can be driven by the driving structure to make the second lower module (25) slide in a direction close to / away from the first lower module (13).

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