Static tensile testing device for round bottom bag production

Abstract

This utility model discloses a static tensile testing device for the production of round bottom bags, including a base plate, a placement platform on the base plate, a top plate on the placement platform, a lifting mechanism between the top plate and the placement platform, a fixed clamping assembly on the placement platform, and a movable clamping assembly on the lifting mechanism. The fixed clamping assembly and the movable clamping assembly have the same structure, and the fixed clamping assembly is equipped with a squeezing and discharging mechanism. This utility model, through the lifting mechanism and the squeezing and discharging mechanism, can easily expel the internal air of the round bottom bag before tensile testing, thereby avoiding uneven tensile force caused by the presence of internal air, which would affect the accurate assessment of the overall tensile performance of the round bottom bag. It also ensures the flatness of the round bottom bag during the testing process, preserving the accuracy of the test results.

Description

Technical Field

[0001] This utility model relates to the field of round bottom bag testing technology, specifically a static tensile testing device for the production of round bottom bags. Background Technology

[0002] Round-bottom bags, a common type of flexible packaging container, effectively disperse the gravitational stress of their contents due to their unique rounded bottom design. They are widely used in the food, chemical, and pharmaceutical industries for encapsulating liquids, powders, and granular substances. These bags are typically made of polyethylene (PE), polypropylene (PP), or other plastic films or composite materials, offering lightweight, strong sealing, and puncture resistance. Their mechanical properties (such as tensile strength and elongation at break) directly affect the sealing reliability and transportation safety of the packaging and require rigorous evaluation through static tensile testing.

[0003] Traditional round-bottom bag tensile testing devices often use simple clamps to hold both ends of the bag for unidirectional stretching, which has certain drawbacks. During the clamping process, the air inside the bag cannot be effectively expelled. The air inside the round-bottom bag is compressible and fluid. During the stretching process, the air will redistribute inside the bag, resulting in uneven tensile force on different parts of the round-bottom bag. This may cause some areas to bear excessive tensile force while other areas bear relatively less, thus affecting the accurate assessment of the overall tensile performance of the round-bottom bag. Local expansion or contraction may occur during stretching, which will interfere with the measurement of the actual deformation of the round-bottom bag. Utility Model Content

[0004] The purpose of this invention is to provide a static tensile testing device for the production of round bottom bags, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a static tensile testing device for the production of round bottom bags, comprising a base plate, a placement platform on the base plate, a top plate on the placement platform, a lifting mechanism between the top plate and the placement platform, a fixed clamping assembly on the placement platform, a movable clamping assembly on the lifting mechanism, the fixed clamping assembly and the movable clamping assembly having the same structure, and the fixed clamping assembly having a squeezing and discharging mechanism.

[0006] Preferably, in order to facilitate the up-and-down movement of the movable clamping assembly and the extrusion discharge mechanism, the internal air can be discharged before the test, and the subsequent tensile test can be facilitated. The lifting mechanism includes a main screw and a driven screw arranged sequentially between the top plate and the placement platform. The top of the main screw and the driven screw are provided with synchronous pulleys. The two synchronous pulleys are located below the top plate and are connected to each other by a synchronous belt. The top of the main screw passes through the top plate and is fixedly connected to the motor output end. The main screw and the driven screw are both threaded with lifting blocks, and the lifting blocks are fixedly connected to the movable clamping assembly.

[0007] Preferably, in order to facilitate the clamping and fixing of the round bottom bag and facilitate subsequent tensile testing, the clamping assembly includes vertical plates symmetrically arranged on the placement platform. The side walls of the vertical plates are provided with clamping plates via electric push rods, and the side walls of the two clamping plates that are close to each other are provided with anti-slip pads.

[0008] Preferably, in order to improve the contact friction, ensure the clamping effect, and prevent slippage, anti-slip protrusions are provided at equal intervals on the side wall of the anti-slip pad, and the moving clamping assembly includes vertical plates symmetrically arranged between the two lifting blocks. The structure of the vertical plate in the moving clamping assembly is the same as the structure of the vertical plate in the fixed clamping assembly.

[0009] Preferably, in order to facilitate the expulsion of internal air before testing, the expulsion mechanism includes scrapers symmetrically arranged in the moving clamping assembly with two clamping plates close to each other on the bottom of their side walls, and rubber pads are provided on the side walls of the scrapers that are close to each other.

[0010] Preferably, in order not to affect the subsequent clamping and fixing test operation after air is discharged, guide rods are provided at equal intervals on the side wall of the scraper away from the rubber pad, and a movable plate is fixedly provided at the end of the guide rod. The bottom end of the clamping plate in the movable clamping assembly is provided with sliding cavities that slide with the movable plate at equal intervals, and the movable plate and the sliding cavity are connected by a spring.

[0011] Preferably, in order to facilitate the installation of the whole unit, mounting holes are provided at equal intervals on the base plate.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] The lifting mechanism combined with the extrusion mechanism allows for the convenient removal of internal air from the round bottom bag before tensile testing. This prevents uneven tensile force caused by internal air, which could affect the accurate assessment of the overall tensile performance of the round bottom bag. It also ensures the flatness of the round bottom bag during testing and preserves the accuracy of the test results.

[0014] The movable clamping component, in conjunction with the fixed clamping component, allows for convenient clamping of the top and bottom of the round bottom bag during tensile testing, facilitating subsequent tensile testing. The anti-slip pads and protrusions ensure a secure clamping, preventing slippage and ensuring proper contact. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a static tensile testing device for the production of round bottom bags proposed in this utility model;

[0016] Figure 2 This is a schematic diagram of the lifting mechanism and dynamic clamping assembly in a static tensile testing device for the production of round bottom bags proposed in this utility model.

[0017] Figure 3 This is a schematic diagram of the bottom plate and the placement platform in a static tensile testing device for the production of round bottom bags proposed in this utility model;

[0018] Figure 4 This is a partial structural diagram of the dynamic clamping component in a static tensile testing device for the production of round bottom bags proposed in this utility model.

[0019] Figure 5 This is a schematic diagram of the internal structure of the dynamic clamping component in a static tensile testing device for the production of round bottom bags proposed in this utility model.

[0020] In the diagram: 1. Base plate; 2. Placement platform; 3. Top plate; 4. Main screw; 5. Driven screw; 6. Vertical plate; 7. Lifting block; 8. Mounting hole; 9. Synchronous pulley; 10. Synchronous belt; 11. Electric push rod; 12. Clamping plate; 13. Anti-slip pad; 14. Anti-slip protrusion; 15. Scraper; 16. Rubber pad; 17. Guide rod; 18. Sliding cavity; 19. Moving plate; 20. Spring; 21. Motor. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figures 1-5This utility model provides an embodiment of a static tensile testing device for the production of round-bottom bags, comprising a base plate 1, with mounting holes 8 at each of the four corners of the base plate 1. These mounting holes 8 can be threaded holes, allowing for screw-based installation and facilitating the overall installation and fixation of the base plate 1. A placement platform 2 (which can be fixed by welding or screws) is fixedly mounted at the top center of the base plate 1. The placement platform 2 is connected to a top plate 3 via a lifting mechanism. A fixed clamping assembly is mounted on the placement platform 2, and a movable clamping assembly is mounted on the lifting mechanism, facilitating static tensile testing of the round-bottom bags. The main body of the device also includes a load sensor (using a high-precision force sensor, combined with an analog-to-digital converter to convert analog signals into digital signals, recording tensile data in real time; setting upper limits for force and displacement to prevent damage to the equipment or sample due to overload during testing). Before testing, the tensile testing machine needs to be zero-point calibrated to ensure the accuracy of the sensor and displacement encoder. The lifting mechanism includes components sequentially mounted on the top plate 3 and the placement platform 2. The main screw 4 and driven screw 5 are connected by a synchronous pulley 9 at the top of both screws 4 and 5. Both synchronous pulleys 9 are located below the top plate 3 and are connected by a synchronous belt 10. The synchronous pulleys 9 and the synchronous belt 10 can also be sprockets or chains, as long as they can achieve synchronous rotation. The top of the main screw 4 extends out of the top plate 3 and is fixedly connected to the output end of the motor 21 through a coupling. The motor 21 is fixedly mounted to the top plate 3 by a fixing bracket (not shown in the figure) to ensure the stability of the motor 21. Both the main screw 4 and the driven screw 5 have lifting blocks 7 engaged by threads. The lifting blocks 7 are fixedly connected to the moving clamping assembly. The motor 21 can be a servo motor or a stepper motor, which can achieve multi-level speed regulation through programming. With the help of a screw transmission mechanism (such as a lead screw + guide rail), the rotational motion of the motor can be converted into linear motion. With the help of a ball screw, friction is reduced and the test repeatability is improved. Other drives such as hydraulic cylinders can also be used to achieve up and down movement and lifting, which is convenient for static tensile testing.

[0023] Please see Figures 1-5To facilitate clamping and fixing the round-bottom bag, and to allow for the removal of internal air before testing, thus facilitating subsequent tensile testing, ensuring measurement accuracy, and reducing errors, two sets of positioning clamping components are symmetrically welded onto the placement platform 2. Clamping plates 12 are mounted on the side walls of the vertical plates 6 via electric push rods 11. Anti-slip pads 13 are adhered to the side walls of the two adjacent clamping plates 12. Anti-slip protrusions 14 (which can be adhered to or integrally formed with the anti-slip pads 13) are equidistantly located on the side walls of the anti-slip pads 13. The movable clamping component includes vertical plates 6 symmetrically arranged between two lifting blocks 7. The structure of the vertical plates 6 in the movable clamping component is the same as that in the fixed clamping component. The fixed clamping component facilitates clamping and fixing the bottom of the round-bottom bag, while the movable clamping component clamps and fixes the top (open end) of the round-bottom bag. Before clamping the top, to improve the accuracy of the test, scrapers 15 for extrusion and discharge mechanisms are provided on the bottom of the side walls of the two clamping plates 12 of the moving clamping assembly that are close to each other. Rubber pads 16 are glued to the side walls of the scrapers 15 that are close to each other to avoid hard contact with the round bottom bag and to prevent scratches. In order not to affect the subsequent clamping and fixing, guide rods 17 are welded at equal intervals on the side wall of the scraper 15 away from the rubber pads 16. A movable plate 19 is fixedly welded to the end of the guide rod 17. The bottom end of the clamping plate 12 in the moving clamping assembly has sliding cavities 18 that slide with the movable plate 19 at equal intervals. The movable plate 19 and the sliding cavity 18 are also connected by a spring 20, which can facilitate the reciprocating movement of the movable plate 19 in the sliding cavity 18, facilitate the movement and reset, and do not affect the subsequent clamping and fixing operation.

[0024] Working Principle: In use, the round-bottomed bag to be tested is placed between two clamping plates 12 on the placement platform 2. The corresponding electric push rod 11 extends, bringing the two clamping plates 12 closer together. The anti-slip pads 13 and anti-slip protrusions 14 clamp and fix the bottom of the round-bottomed bag. Then, the motor 21 rotates clockwise, causing the main screw 4 to rotate. This, in conjunction with the synchronous pulley 9 and synchronous belt 10, rotates the driven screw 5, moving the lifting block 7 downwards towards the clamping plates 12 on the placement platform 2. At this point, the electric push rod 11 between the lifting blocks 7 extends, bringing the two clamping plates 12 closer together. The two scrapers 15 first contact the round-bottomed bag. As the movement continues, the rubber pads 16 on the two clamping plates 12 contact and press against the round-bottomed bag, simultaneously generating a squeezing force that pushes the guide rod 17 and the moving plate 19 away from each other. This creates a squeezing force in the sliding cavity 18. When the bag slides inward, the spring 20 contracts and stores potential energy. At this time, the motor 21 can rotate counterclockwise, moving the lifting block 7 upward as a whole. The air inside the round bottom bag can then be expelled by the two scrapers 15. When the clamping plate 12 on the lifting block 7 moves to the opening end of the round bottom bag, the electric push rod 11 on the lifting block 7 continues to extend, bringing the two clamping plates 12 closer together. This creates a squeezing force that pushes the guide rod 17 and the moving plate 19 away from each other. The bag slides in the sliding cavity 18, and the spring 20 contracts and stores potential energy. Then, the anti-slip pad 13 and anti-slip protrusion 14 on the clamping plate 12 contact the round bottom bag and clamp it. At this time, the motor 21 can rotate counterclockwise, moving the lifting block 7 upward as a whole. A static tensile test can be performed on the clamped round bottom bag. The air inside the round bottom bag can be expelled before the test to ensure flatness and improve the accuracy of the test results.

[0025] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A static tensile testing device for the production of round-bottom bags, comprising a base plate (1), characterized in that: The base plate (1) is provided with a placement platform (2), the placement platform (2) is provided with a top plate (3), a lifting mechanism is provided between the top plate (3) and the placement platform (2), the placement platform (2) is provided with a fixed clamping component, the lifting mechanism is provided with a movable clamping component, the fixed clamping component and the movable clamping component have the same structure, and the fixed clamping component is provided with a squeezing and discharging mechanism.

2. The static tensile testing device for producing round bottom bags according to claim 1, characterized in that: The lifting mechanism includes a main screw (4) and a driven screw (5) arranged sequentially between the top plate (3) and the placement platform (2). The top of the main screw (4) and the driven screw (5) are provided with synchronous pulleys (9). The two synchronous pulleys (9) are located below the top plate (3) and are connected to each other by a synchronous belt (10). The top of the main screw (4) extends out of the top plate (3) and is fixedly connected to the output end of the motor (21). The main screw (4) and the driven screw (5) are both threaded with lifting blocks (7). The lifting blocks (7) are fixedly connected to the moving clamping assembly.

3. The static tensile testing device for round bottom bag production according to claim 2, characterized in that: The clamping assembly includes vertical plates (6) symmetrically arranged on the placement platform (2). The side walls of the vertical plates (6) are provided with clamping plates (12) via electric push rods (11). Anti-slip pads (13) are provided on the side walls of the two clamping plates (12) that are close to each other.

4. The static tensile testing device for producing round bottom bags according to claim 3, characterized in that: The anti-slip pad (13) has anti-slip protrusions (14) equidistantly arranged on its side wall. The moving clamping assembly includes a vertical plate (6) symmetrically arranged between two lifting blocks (7). The structure on the vertical plate (6) in the moving clamping assembly is the same as the structure on the vertical plate (6) in the fixed clamping assembly.

5. The static tensile testing device for producing round bottom bags according to claim 4, characterized in that: The extrusion and discharge mechanism includes scrapers (15) symmetrically arranged in the dynamic clamping assembly with two clamping plates (12) close to each other on the bottom of the side walls. Each scraper (15) has a rubber pad (16) on its close side wall.

6. The static tensile testing device for producing round bottom bags according to claim 5, characterized in that: The scraper (15) is provided with guide rods (17) at equal intervals on the side wall away from the rubber pad (16). A movable plate (19) is fixedly provided at the end of the guide rod (17). The bottom end of the clamping plate (12) in the moving clamping assembly is provided with sliding cavities (18) that slide with the movable plate (19) at equal intervals. The movable plate (19) and the sliding cavity (18) are also connected by a spring (20).

7. The static tensile testing device for producing round bottom bags according to claim 6, characterized in that: The base plate (1) has mounting holes (8) spaced at equal intervals.

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