A device and method for testing the underwater displacement of a thin film material
By applying a constant tension in the water displacement test device of the thin film material, the problem of insufficient measurement accuracy in the prior art is solved, and high-precision measurement of underwater displacement is achieved, and the accuracy of the test results is improved.
Patent Information
- Application Number
- CN201711438773.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2017-12-26
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2037-12-26
AI Technical Summary
The existing in-water displacement testing devices of thin film materials have insufficient accuracy and cost. The ultrasonic measurement accuracy is not high enough and the structure is complex. Laser measurement is limited in application in underwater, and grating measurement has not been found, making it difficult to meet high-precision underwater displacement measurement. need.
A film material in-water displacement testing device including a test box, a tension mechanism and a fixture is designed to achieve precise control of the tension by applying a constant downward tension at the bottom end of the film material, and by pulling ropes, pulleys and scales. Forges the buoyancy influence of water and improves measurement accuracy.
By applying a constant tension, the accuracy of underwater measurement is effectively improved, the impact of buoyancy on the measurement results is reduced, and the accuracy of the test results is improved.
Smart Images
Figure CN107907451B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of underwater displacement testing of thin film materials, and in particular to an underwater displacement testing device and a testing method for thin film materials. Background Art
[0002] At present, the swelling performance of film materials in water is generally tested by detecting the displacement of film materials in water. Take the swelling performance test of PVA (polyvinyl alcohol) film, one of the raw materials of polarizer, in water as an example. The PVA film material test requires a constant tensile force of 7.8g to be applied to the 40mm wide PVA film, and the PVA film is placed in 32℃ constant temperature water, the water temperature fluctuation must be within 0.3℃, and the swelling change of the PVA film is tracked and measured.
[0003] There are many displacement measurement devices on the market, the most common ones are ultrasonic measurement, laser measurement and grating measurement.
[0004] Ultrasonic measurement can be used for underwater distance measurement. The accuracy of ordinary ultrasonic distance measurement is 2%-3%, which does not meet the requirements of this test device. In addition, the structure of high-precision ultrasonic measuring instruments is complex and the cost is high. The speed of sound is greatly affected by temperature, and the propagation speed of ultrasound at different temperatures needs to be considered. Since ultrasonic measurement requires a sufficiently large reflection surface, its scope of use is limited and cannot meet the use requirements.
[0005] When laser measurement encounters a material with a high laser absorption rate, the distance and accuracy of the distance measurement will decrease. This test device has limited underwater space, many devices, and high accuracy requirements. Laser ranging is not applicable. In addition, the laser generation device is relatively complex and large in size, and the application range is more demanding.
[0006] Grating displacement measurement There are currently no products available for underwater displacement measurement. Summary of the invention
[0007] In order to overcome the deficiencies of the prior art, one of the objects of the present invention is to provide an underwater displacement testing device for thin film materials, which can provide a constant pulling force to the tested object in water, offset the influence of the buoyancy of water on the measurement results, and improve the accuracy of the test results.
[0008] A second object of the present invention is to provide a method for testing the underwater displacement of a thin film material, which can improve the accuracy of the test results.
[0009] One of the purposes of the present invention is achieved by the following technical solution:
[0010] A device for testing the displacement of a thin film material in water comprises a test box, a tension mechanism and a clamp; the top of the test box is provided with a fixed base plate for fixing the top of the thin film material; the clamp is used to fix the bottom of the thin film material and to apply a constant downward tension F1 to the bottom of the thin film material; the tension mechanism is used to apply a constant upward tension F2 to the top of the clamp; F1-F -F2=m*g, g is the acceleration of gravity, and m=7.8g.
[0011] Preferably, the pulling mechanism includes a pull rope, a pulley, a tray and a scale; a pointer is provided at the bottom end of the tray; the pulley is pivotally connected to the top of the test box; one end of the pull rope passes around the pulley and is fixed to the top of the clamp; the other end of the pull rope is fixed to the tray; the scale is arranged along the height direction of the test box; the pointer is used to indicate one of the scale lines of the scale.
[0012] Preferably, the drawstring is made of bulletproof fiber material.
[0013] Preferably, a heating mechanism is provided in the test box.
[0014] Preferably, the heating mechanism includes a heating tube and a heating wire; the heating tube is arranged at the bottom end of the test box; and the heating wire is attached to the inner wall of the test box.
[0015] Preferably, a water pump and a water pipe are provided in the test box; the water pipe includes a first section and a second section, the first section extends along the height direction of the test box; the bottom end of the first section extends to the bottom end of the test box and is connected to the water pump; the second section is connected to the top end of the first section and extends along the inner wall of the test box; a plurality of water outlet holes are provided on the second section.
[0016] Preferably, a clip is provided on the fixed base plate.
[0017] The second object of the present invention is achieved by adopting the following technical solution:
[0018] A method for testing the displacement of a thin film material in water comprises the following steps:
[0019] Step 1: Before testing, connect the trays on both sides to the fixtures with a drawstring. After the connection is complete, place the fixture on a fixed base plate to prevent the fixture from sinking to the bottom of the test box due to its heavier weight than the tray.
[0020] Step 2: fix the bottom end of the film material to be tested to the fixture, and fix the top end of the film material to the fixed substrate;
[0021] Step 3: Fill the test box with water so that the highest point of the water level is flush with the lower surface of the fixed base plate;
[0022] Step 4: Turn on the power supply and use the heating mechanism to make the water temperature in the test box reach 32℃±0.5℃;
[0023] Step 5: Put the film material to be tested together with the fixture into the water, record the scale L1 indicated by the pointers on both sides of the tray, and start timing;
[0024] Step 6. When the timing time is up, record the scale L2 indicated on the tray at this time. The displacement of the film material in water = L2-L1.
[0025] Preferably, in step 2, the clamp applies a downward pulling force F1 to the film material of the test object, and the volume of the clamp is calculated to obtain the buoyancy F buoyancy exerted on the clamp; a tray with weights is hung so that the pull rope applies an upward pulling force F2 to the clamp, so that F1-F buoyancy- F2=7.8g*g.
[0026] Preferably, in step four, at the beginning, the heating tube and the heating wire of the heating mechanism work simultaneously; when the heating reaches the set water temperature, the heating tube stops heating, and the heating wire continues to work to maintain the water temperature; when the heating mechanism is working, the water pump draws hot water into the water pipe and sprays it out from the water outlet above the water surface.
[0027] Compared with the prior art, the beneficial effect of the present invention is that it applies a constant tension to the film material to be tested, thereby offsetting the influence of the buoyancy of water on the constant tension applied to the test object, thereby effectively improving the accuracy of the underwater tension and improving the accuracy of the test results. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a schematic diagram of the structure of the testing device of the present invention.
[0029] In the figure: 10, test box; 11, fixed substrate; 20, fixture; 30, film material; 40, tension mechanism; 41, pull rope; 42, scale; 43, tray; 431, pointer; 44, pulley; 50, heating tube; 60, heating wire; 70, water pump; 80, water pipe; 81, first section; 82, second section; 83, water outlet. DETAILED DESCRIPTION
[0030] Below, the present invention is further described in conjunction with the accompanying drawings and specific embodiments:
[0031] like Figure 1The device for testing the displacement of a thin film material in water shown in the figure comprises a test box 10, a tension mechanism 40 and a fixture 20. A fixed base plate 11 is provided at the top of the test box 10, and the fixed base plate 11 is used to fix the top of the thin film material 30. The fixture 20 is used to fix the bottom of the thin film material 30, and the fixture 20 can apply a constant downward tension F1 to the bottom of the thin film material 30; the tension mechanism 40 is used to apply a constant upward tension F2 to the top of the fixture 20, F1-F2=F, and F is greater than 0, so as to offset a part of the downward tension applied to the film by the weight of the fixture.
[0032] On the basis of the above structure, when the underwater displacement test device of the thin film material 30 of the present invention is used, taking the test of PVA film as an example, before the test, the clamp 20 is fixed to the bottom end of the PVA film, and then the top end of the PVA film is fixed on the fixed substrate 11. At this time, the clamp 20 is first placed on the fixed substrate 11, and the tension mechanism 40 is fixed to the clamp 20, so that the tension mechanism 40 gives the clamp 20 an upward tension F1. Thereafter, the clamp 20 is placed in the test box 10, and the clamp 20 gives the test object PVA film a downward tension F2. The volume of the clamp 20 is calculated to obtain the buoyancy F buoyancy of the clamp 20; in this embodiment, F1-F -F2=m*g, where g is the acceleration due to gravity, and m=7.8g, that is, F1-F buoyancy-F2=7.8g*g (it should be noted that in this formula, the g in front is the mass unit gram, and the g behind is the acceleration due to gravity). During the test, the influence of the buoyancy of the fixture 20 on the pulling force can be eliminated. Of course, F1 can be the weight of the fixture.
[0033] After that, the test box 10 is filled with water that meets the test temperature. In this embodiment, water with a temperature of 32°C ± 0.5°C can be added. After a period of time, the PVA film will swell and change in weight and displacement. In this way, according to the displacement change of the front and rear PVA films, a constant tension is applied to the film material 30 to be tested, which offsets the effect of the buoyancy of water on the constant tension applied to the test object, effectively improving the accuracy of the underwater tension and the accuracy of the test results.
[0034] Specifically, the tension mechanism 40 includes a pull rope 41, a pulley 44, a tray 43 and a scale 42; a pointer 431 is provided at the bottom end of the tray 43; the pulley 44 is pivotally connected to the top of the test box 10; one end of the pull rope 41 passes around the pulley 44 and is fixed to the top of the clamp 20; the other end of the pull rope 41 is fixed to the tray 43; the scale 42 is arranged along the height direction of the test box 10; the pointer 431 is used to indicate one of the scale lines of the scale 42. Thus, during the test, the fixture 20 can be placed in the test box 10, and an appropriate amount of weights can be placed in the tray 43. The scale L1 of the scale 42 indicated by the pointer 431 at the bottom of the tray 43 can be noted. After that, warm water can be added to the test box 10. After a period of time, the film will swell and change its displacement, that is, the fixture 20 will become heavier, driving the stretching downward. At this time, the scale L2 of the scale 42 indicated by the pointer 431 at the bottom of the tray 43 can be noted. The displacement of the film material 30 in water = L2-L1, thereby testing the swelling of the film. In this device, the above F2 = M weights * g. When the tension needs to be adjusted, the tension can be adjusted by adjusting the weight of the weights in the tray.
[0035] Of course, the tension mechanism 40 can also be implemented by a tension meter in the prior art, or other devices that can provide a constant tension.
[0036] Preferably, the drawstring 41 is made of a bulletproof fiber material, which is lightweight, inelastic, and will not stretch during the test, making the test result more accurate.
[0037] Preferably, a heating mechanism is provided in the test box 10, so that normal temperature water can be directly added into the test box 10, and the heating mechanism can be used to heat the water to a suitable temperature before stopping the heating.
[0038] More specifically, the heating mechanism includes a heating tube 50 and a heating wire 60; the heating tube 50 is arranged at the bottom of the test box 10; and the heating wire 60 is attached to the inner wall of the test box 10. In this way, when the initial water temperature of the test box is greatly different from the water temperature required for the test, the two heating elements are used to heat the box at the same time. When the target temperature is heated, the heating tube 50 is disconnected and the heating is stopped, and then the heating wire 60 cooperates to fine-tune the temperature. Specifically, the above-mentioned heating tube 50 can adopt an ordinary heating tube 50, and the outside of the heating wire 60 has a coating with good insulation and thermal conductivity, so that the heating wire 60 can be bent arbitrarily, can fit on the inner wall of the box, and transfer heat evenly, while also meeting the requirements of corrosion resistance, riot resistance, impact resistance, and aging resistance.
[0039] Preferably, a water pump 70 and a water pipe 80 are provided in the test box 10; the water pipe 80 includes a first section 81 and a second section 82, the first section 81 extends along the height direction of the test box 10; the bottom end of the first section 81 extends to the bottom end of the test box 10 and is connected to the water pump 70; the second section 82 is connected to the top end of the first section 81 and extends along the inner wall of the test box 10; a plurality of water outlet holes 83 are provided on the second section 82. In this way, during the test process, in order to ensure that the water temperature of each part of the test box is balanced, the water at the bottom of the test box 10 can be pumped to the first section 81 of the water pipe 80 through the water pump 70, and the water in the first section 81 can enter the second section 82 and be ejected from the water outlet holes 83 above the water surface, which can reduce the temperature on the one hand, and prevent the water circulation from fluctuating too much on the other hand, causing fluctuations to the test object in the water, thereby affecting the test results.
[0040] Preferably, a clip is provided on the fixed substrate 11 to facilitate fixing of the film to the fixed substrate 11 .
[0041] This embodiment also provides a method for testing the displacement of a thin film material in water, comprising the following steps:
[0042] Step 1: Before testing, connect the trays on both sides to the fixtures with a drawstring. After the connection is complete, place the fixture on a fixed base plate to prevent the fixture from sinking to the bottom of the test box due to its heavier weight than the tray.
[0043] Step 2: fix the bottom end of the film material to be tested to the fixture, and fix the top end of the film material to the fixed substrate;
[0044] Step 3: Fill the test box with water so that the highest point of the water level is flush with the lower surface of the fixed base plate;
[0045] Step 4: Turn on the power supply and use the heating mechanism to make the water temperature in the test box reach 32℃±0.5℃;
[0046] Step 5: Put the film material to be tested together with the fixture into the water, record the scale L1 indicated by the pointers on both sides of the tray, and start timing;
[0047] Step 6. When the timing time is up, record the scale L2 indicated on the tray at this time. The displacement of the film material in water = L2-L1.
[0048] Preferably, in step 2, the clamp applies a downward pulling force F1 to the film material of the test object, and the volume of the clamp is calculated to obtain the buoyancy F buoyancy exerted on the clamp; a tray with weights is hung on it so that the pull rope applies an upward pulling force F2 to the clamp, so that F1-F buoyancy-F2=7.8g*g, thereby offsetting the buoyancy exerted on the clamp during the test.
[0049] Preferably, in step 4, at the beginning, the heating tube and the heating wire of the heating mechanism work simultaneously; when the water temperature reaches the set temperature, the heating tube stops heating, and the heating wire continues to work to maintain the water temperature; when the heating mechanism works, the water pump pumps hot water into the water pipe and sprays it out from the water outlet above the water surface. On the one hand, it can reduce the temperature, and on the other hand, it can avoid excessive fluctuations in the water circulation, which will cause fluctuations in the test object in the water, thereby affecting the test results.
[0050] For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the protection scope of the claims of the present invention.
Claims
1. A device for testing the displacement of a thin film material in water, characterized in that: It includes a test box, a tension mechanism and a clamp; the top of the test box is provided with a fixed base plate for fixing the top of the film material; the clamp is used to fix the bottom of the film material and to apply a constant downward tension F1 to the bottom of the film material; the tension mechanism is used to apply a constant upward tension F2 to the top of the clamp; the buoyancy of the clamp is F; F1-F -F2=m*g, g is the acceleration of gravity, and m=7.8g.
2. The underwater displacement testing device of a thin film material according to claim 1, characterized in that: The pulling mechanism includes a pull rope, a pulley, a tray and a scale; a pointer is provided at the bottom end of the tray; the pulley is pivotally connected to the top of the test box; one end of the pull rope passes around the pulley and is fixed to the top of the clamp; the other end of the pull rope is fixed to the tray; the scale is arranged along the height direction of the test box; the pointer is used to indicate one of the scale lines of the scale.
3. The underwater displacement testing device of a thin film material according to claim 2, characterized in that: The drawstring is made of bulletproof fiber material.
4. The underwater displacement testing device of a thin film material according to claim 1, characterized in that: A heating mechanism is arranged in the test box.
5. The underwater displacement testing device of a thin film material according to claim 4, characterized in that: The heating mechanism comprises a heating tube and a heating wire; the heating tube is arranged at the bottom end of the test box; and the heating wire is attached to the inner wall of the test box.
6. The underwater displacement testing device of a thin film material according to claim 1, characterized in that: A water pump and a water pipe are provided in the test box; the water pipe includes a first section and a second section, the first section extends along the height direction of the test box; the bottom end of the first section extends to the bottom end of the test box and is connected to the water pump; the second section is connected to the top end of the first section and extends along the inner wall of the test box; a plurality of water outlet holes are provided on the second section.
7. The underwater displacement testing device of a thin film material according to claim 1, characterized in that: A clip is arranged on the fixed base plate.
8. A method for testing the displacement of a thin film material in water, characterized in that: The steps include: Step 1: Before testing, connect the trays on both sides to the fixtures with a drawstring. After the connection is complete, place the fixture on a fixed base plate to prevent the fixture from sinking to the bottom of the test box due to its heavier weight than the tray. Step 2: fix the bottom of the film material of the test object to the fixture, and fix the top of the film material to the fixed substrate; in step 2, the fixture gives the film material of the test object a downward pulling force F1, and the volume of the fixture is calculated to obtain the buoyancy F exerted on the fixture; hang a tray with weights on it so that the pull rope gives the fixture an upward pulling force F2, so that F1-F -F2=m*g, where g is the acceleration of gravity, and m=7.8g; Step 3: Fill the test box with water so that the highest point of the water level is flush with the lower surface of the fixed base plate; Step 4: Turn on the power supply and use the heating mechanism to make the water temperature in the test box reach 32℃±0.5℃; Step 5: Put the film material to be tested together with the fixture into the water, record the scale L1 indicated by the pointers on both sides of the tray, and start timing; Step 6. When the timing time is up, record the scale L2 indicated on the tray at this time. The displacement of the film material in water = L2-L1.
9. The method for testing the displacement of a thin film material in water as claimed in claim 8, characterized in that: In step four, at the beginning, the heating tube and the heating wire of the heating mechanism work simultaneously; when the heating reaches the set water temperature, the heating tube stops heating, and the heating wire continues to work to maintain the water temperature; when the heating mechanism is working, the water pump draws hot water into the water pipe and sprays it out from the water outlet above the water surface.