A polyethylene environmental stress cracking determination sample preparation device and a preparation method thereof

Abstract

The application discloses a polyethylene environmental stress cracking determination sample preparation device and a preparation method thereof, relates to the polyolefin technical field, and comprises a solution preparation box, the lower end of the right side of the solution preparation box is fixedly connected with the lower end of the left side of a numerical control milling machine, the middle part of the front side of the right end of the numerical control milling machine is fixedly connected with the rear side of a controller, and the right side of the numerical control milling machine is fixedly connected with the left side of a simply supported beam impact instrument. The lifting mechanism is arranged, so that the operator can operate conveniently. The cleaning mechanism is arranged, so that the desktop for polyethylene environmental stress cracking determination can be kept clean, the influence of external factors on the polyethylene environmental stress cracking determination experiment is reduced, the lifting mechanism is arranged, so that the solution or dust on the top plate is more easily collected into the collecting drawer, and the cleaning is more convenient. The stress correction determination mechanism is arranged, so that the test time of the polyethylene environmental stress cracking determination can be greatly shortened.

Description

Technical Field

[0001] This invention relates to the field of polyolefins, specifically to a sample preparation device and method for measuring the environmental stress cracking of polyethylene. Background Technology

[0002] Industrially, it also includes copolymers of ethylene and small amounts of α-olefins. Polyethylene is odorless, non-toxic, and has a waxy feel. It has excellent low-temperature resistance (minimum operating temperature can reach -100 to -70℃), good chemical stability, and can withstand the corrosion of most acids and alkalis (but not oxidizing acids). It is insoluble in common solvents at room temperature, has low water absorption, and excellent electrical insulation. The traditional determination of environmental stress cracking (ESC) of polyethylene uses full-notch creep (FNCT) testing. Traditional testing methods are generally time-consuming, and for pipe materials, the testing time can reach thousands of hours.

[0003] When optimizing existing polyethylene measuring devices, most of the optimization focuses on avoiding measurement errors. For example, Chinese utility model patent CN109374668B discloses "A method for determining the density of polyethylene". (1) Multiple polyethylene standard samples with different densities are pretreated and then analyzed on a nuclear magnetic resonance spectrometer to obtain the corresponding nuclear magnetic signals; (2) A standard working curve of polyethylene density and nuclear magnetic signal is established; (3) The polyethylene sample to be tested is analyzed on a nuclear magnetic resonance spectrometer to obtain the corresponding nuclear magnetic signal; (4) The nuclear magnetic signal of the polyethylene sample to be tested is substituted into the standard working curve to determine the density value of the polyethylene sample to be tested.

[0004] While the aforementioned polyethylene testing device has certain advantages in avoiding measurement errors, it still has some drawbacks:

[0005] 1. For example Figure 10 As shown, by obtaining the corresponding NMR (relaxation time) signal of a polyethylene standard sample with a known density on a nuclear magnetic resonance (NMR) instrument, a standard working curve of polyethylene density versus NMR (relaxation time) signal is obtained. Then, by comparing the NMR signal obtained from the polyethylene sample to be tested with this standard working curve, the density of the polyethylene sample to be tested can be obtained. This method can measure density without damaging the polyethylene resin sample and avoids the errors caused by bubbles generated during melting and cutting of the resin, which are common in gradient tube methods. However, the polyethylene measuring device described above is difficult to adjust the operating table, making it inconvenient for operators.

[0006] 2. The polyethylene measuring device described above is not convenient for automatic cleaning of the operating table, which makes it easy for dust or solution on the table to affect the experimental data, making it difficult to improve the accuracy of the experiment.

[0007] 3. The above-mentioned polyethylene testing device is prone to damage during manual cleaning, which may affect its normal operation. Summary of the Invention

[0008] Therefore, in order to overcome the above-mentioned shortcomings, the present invention provides a sample preparation device and preparation method for measuring the environmental stress cracking of polyethylene.

[0009] The present invention is implemented as follows: a sample preparation device and preparation method for measuring the environmental stress cracking of polyethylene are constructed. The device includes a solution preparation tank, the lower right end of the solution preparation tank is fixedly connected to the lower left end of a CNC milling machine, the middle right front end of the CNC milling machine is fixedly connected to the rear side of the controller, the right side of the CNC milling machine is fixedly connected to the left side of a simply supported beam impactor, and the upper right side of the simply supported beam impactor is fixedly connected to the left side of a monitoring camera.

[0010] Its characteristic is that it also includes:

[0011] A lifting mechanism, wherein the lower left end of the lifting mechanism is fixedly connected to the lower right end of the simply supported beam impactor;

[0012] The cleaning mechanism is fixedly connected to the lower rear end of the front side of the lifting mechanism.

[0013] The lifting mechanism has its bottom surface at the top in contact with the top middle surface of the lifting mechanism.

[0014] A stress correction measuring mechanism, wherein the bottom of the stress correction measuring mechanism is fixedly connected to the top of the lifting mechanism.

[0015] Preferably, the lifting mechanism includes:

[0016] A connecting rectangular block is provided at the lower left end of the lifting mechanism;

[0017] Side panel compartment block, the lower left end of which is fixedly connected to the right side of the connecting rectangular block;

[0018] A connecting base block is fixedly connected to the lower inner end of the side plate compartment block at both its left and right ends.

[0019] The first rotating rod has its lower outer end rotatably connected to the inner left end of the connecting base block.

[0020] Preferably, the lifting mechanism further includes:

[0021] The second rotating rod has its outer end mid-end rotatably connected to the inner end mid-end of the first rotating rod, and the lower right end surface of the second rotating rod is in contact with the inner bottom end surface of the connecting base block.

[0022] A connector, the inner middle end of which is rotatably connected to the upper ends of the front and rear sides of the second rotating rod;

[0023] The top plate has its front and rear ends on the left side of the bottom of the top plate fixedly connected to the top of the connector, and the right side surface of the bottom of the top plate is in contact with the upper right side surface of the first rotating rod.

[0024] The left side of the connecting rectangular block is fixedly connected to the lower right side of the simply supported beam impactor.

[0025] Preferably, the cleaning mechanism includes:

[0026] An air pump is located at the lower middle part of the cleaning mechanism;

[0027] The connecting pipe has its inner end fixedly connected to the middle of the left and right sides of the air pump, and its outer end is fixedly connected to the inner surface of the holes at the lower middle of the left and right sides of the side plate compartment.

[0028] A cylinder connecting pipe, wherein the bottom of the cylinder connecting pipe is fixedly connected to the middle and outer ends of the top of the connecting pipe;

[0029] An electric valve is located at the outer end of the connecting pipe and the middle end of the cylinder connecting pipe.

[0030] The cylinder has its bottom middle end fixedly connected to the top of the cylinder connecting pipe, and its outer lower end fixedly connected to the inner surface of the top hole of the side plate compartment block.

[0031] Preferably, the cleaning mechanism further includes:

[0032] An elastic tube, the lower end of which is fixedly connected to the outer end of a connecting tube;

[0033] The air chamber frame has its bottom fixedly connected to the outer end of the top of the top plate, and its lower ends on the left and right sides fixedly connected to the upper ends of the elastic tubes.

[0034] The jet head is fixedly connected to the inner end of the outer surface of the jet head and the inner surface of the holes at both ends of the inner side of the air chamber frame.

[0035] A limiting slide bar, the top of which is fixedly connected to the left and right sides of the bottom of the top plate;

[0036] The collection drawer has its left and right ends on the upper surface of its outer side slidably connected to the inner surface of the groove at the inner end of the limiting slide strip.

[0037] The rear side of the air pump is fixedly connected to the middle of the front side of the connecting base block.

[0038] Preferably, the lifting mechanism includes:

[0039] A connecting block, wherein the top left and right ends of the connecting block are fixedly connected to the bottom left and right ends of the top plate;

[0040] A transverse air tube, the top middle end of which is fixedly connected to the bottom middle end of the connecting block;

[0041] The upper end of the hose is fixedly connected to the middle of the bottom of the transverse air tube, and the lower end of the hose is fixedly connected to the middle of the top of the air pump.

[0042] A small cylinder, wherein the lower end of the outer surface of the small cylinder is fixedly connected to the inner surface of the holes on the left and right sides of the top of the connecting block, the middle end of the bottom of the small cylinder is fixedly connected to the upper ends of the left and right sides of the horizontal air pipe, and the middle end of the outer surface of the small cylinder is fixedly connected to the inner surface of the holes on the left and right sides of the top plate.

[0043] Preferably, the lifting mechanism further includes:

[0044] The lifting plate has its bottom left and right ends fixedly connected to the top of a small cylinder;

[0045] The grooves are formed on the left and right sides of the bottom of the lifting plate;

[0046] Rotate the baffle, and the outer ends of the front and rear sides of the rotating baffle are rotatably connected to the outer ends of the front and rear ends of the inner side of the groove;

[0047] The inner surface of the groove at the top of the connecting block is slidably connected to the lower end of the outer surface of the collection drawer.

[0048] Preferably, the stress correction measuring mechanism includes:

[0049] A base, which is disposed at the lower end of the stress correction and measurement mechanism;

[0050] The lever arm is rotatably connected to the middle inner end of the upper end of the base on both the front and rear sides of the left and right sides.

[0051] A stress corrector, the bottom of which is fixedly connected to the top left side of the lever arm;

[0052] Weights, which are set on the lever arm.

[0053] Preferably, the stress correction measuring mechanism further includes:

[0054] An annular retaining frame, the bottom of which is fixedly connected to the outer top end of the stress corrector;

[0055] The clamp is fixedly connected at the bottom middle end to the top middle end of the stress corrector;

[0056] The lower end of the outer surface of the lifting block is fixedly connected to the lower end of the inner side of the holes on the left and right sides of the top of the clamp;

[0057] The bottom of the base is fixedly connected to the top of the lifting plate.

[0058] The present invention has the following advantages: The present invention provides an improved method for preparing a sample preparation device for measuring the environmental stress cracking of polyethylene, which, compared with similar equipment, has the following improvements:

[0059] The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. By setting up a lifting mechanism, the top plate of the lifting mechanism can move up and down, so that the operator can raise and lower the table during the measurement of the environmental stress cracking of polyethylene, making the operation more convenient and easier for the operator.

[0060] The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. By incorporating a cleaning mechanism, an air pump in the cleaning mechanism fills the air chamber frame with external gas, which is then ejected from the air nozzle. This facilitates the blowing of solution or dust on the top plate into a hole at the center of the top plate. The solution or dust on the top plate then falls into the collection drawer through this hole, keeping the tabletop for measuring the environmental stress cracking of polyethylene clean. This reduces the influence of external factors on the polyethylene environmental stress cracking test and improves the accuracy of the test.

[0061] The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. By setting up a lifting mechanism, a small cylinder in the lifting mechanism can drive the lifting plate to move up and down, avoiding the gas blowing onto the stress correction measuring mechanism and affecting its operation. When the gas blows onto the top plate, it can be guided by the lifting plate, making it easier for the solution or dust on the top plate to enter the collection drawer, making cleaning more convenient.

[0062] The present invention discloses a sample preparation device and method for measuring environmental stress cracking of polyethylene. By setting up a stress correction and measurement mechanism, the test time for measuring environmental stress cracking of polyethylene can be significantly shortened. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the structure of the present invention;

[0064] Figure 2 This is a front view of the present invention;

[0065] Figure 3 This is an isometric structural diagram of the lifting mechanism and cleaning mechanism of the present invention;

[0066] Figure 4 This is a right-side sectional view of the lifting mechanism of the present invention;

[0067] Figure 5 This is an isometric structural diagram of the lifting mechanism of the present invention;

[0068] Figure 6 This is the present invention. Figure 4 Enlarged view of point A in the middle;

[0069] Figure 7 This is a partial cross-sectional view of the right end of the lifting mechanism of the present invention;

[0070] Figure 8 This is the present invention. Figure 7 Enlarged view of point B in the middle;

[0071] Figure 9 This is a schematic diagram of the stress correction and measurement mechanism of the present invention;

[0072] Figure 10 This is a schematic diagram of existing technology.

[0073] The components include: solution preparation tank-1, CNC milling machine-2, controller-3, simply supported beam impactor-4, monitoring camera-5, lifting mechanism-6, connecting rectangular block-61, side plate compartment block-62, connecting bottom block-63, first rotating rod-64, second rotating rod-65, connector-66, top plate-67, cleaning mechanism-7, air pump-71, connecting pipe-72, cylinder connecting pipe-73, electric valve-74, cylinder-75, elastic tube- 76. Air chamber frame - 77. Jet nozzle - 78. Limiting slide bar - 79. Collection drawer - 710. Lifting mechanism - 8. Connecting block - 81. Horizontal air pipe - 82. Hose - 83. Small cylinder - 84. Lifting plate - 85. Groove - 86. Rotating baffle - 87. Stress correction and measurement mechanism - 9. Base - 91. Lever arm - 92. Stress corrector - 93. Weight - 94. Annular baffle frame - 95. Clamp - 96. Lifting block - 97. Detailed Implementation

[0074] The following will be combined with the appendix Figure 1-9 This invention will be described in detail, and the technical solutions in the embodiments of this invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0075] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0077] Example 1:

[0078] Please see Figures 1-5 The present invention provides a sample preparation device and preparation method for measuring the environmental stress cracking of polyethylene, comprising a solution preparation box 1, the lower right end of the solution preparation box 1 being fixedly connected to the lower left end of the CNC milling machine 2, the middle of the right front end of the CNC milling machine 2 being fixedly connected to the rear side of the controller 3, the right side of the CNC milling machine 2 being fixedly connected to the left side of the simply supported beam impactor 4, and the upper right side of the simply supported beam impactor 4 being fixedly connected to the left side of the monitoring camera 5.

[0079] The lower left end of the lifting mechanism 6 is fixedly connected to the lower right end of the simply supported beam impactor 4, thus fixing the lifting mechanism 6 in place.

[0080] The rear end of the front lower side of the cleaning mechanism 7 is fixedly connected to the middle of the front lower end of the lifting mechanism 6, so that the cleaning mechanism 7 is fixed.

[0081] The bottom surface of the upper end of the lifting mechanism 8 is in contact with the middle surface of the top of the lifting mechanism 6, and the bottom of the stress correction and measuring mechanism 9 is fixedly connected to the top of the lifting mechanism 8, so that the stress correction and measuring mechanism 9 is fixed.

[0082] The connecting rectangular block 61 is located at the lower left end of the lifting mechanism 6, and the lower left end of the side plate compartment block 62 is fixedly connected to the right side of the connecting rectangular block 61, so that the side plate compartment block 62 is fixed.

[0083] The left and right ends of the connecting base block 63 are fixedly connected to the lower end of the inner side of the side plate block 62, so that the connecting base block 63 is fixed.

[0084] The lower end of the outer side of the first rotating rod 64 is rotatably connected to the left inner side of the connecting base block 63, so that the first rotating rod 64 can rotate.

[0085] The middle of the outer end of the second rotating rod 65 is rotatably connected to the middle of the inner end of the first rotating rod 64, and the lower right end surface of the second rotating rod 65 is in contact with the inner bottom end surface of the connecting base block 63, so that the second rotating rod 65 can rotate.

[0086] The inner middle end of the connector 66 is rotatably connected to the upper ends of the front and rear sides of the second rotating rod 65, so that the connector 66 is fixed.

[0087] The front and rear ends of the bottom left side of the top plate 67 are fixedly connected to the top of the connector 66. The bottom right surface of the top plate 67 is in contact with the upper right surface of the first rotating rod 64. The left side of the connecting rectangular block 61 is fixedly connected to the lower right side of the simply supported beam impactor 4, so that the top plate 67 can be raised and lowered.

[0088] The working principle of the polyethylene environmental stress cracking test sample preparation device and preparation method based on Example 1 is as follows: 60L of deionized water is added into the solution preparation tank 1, and then 2% Arkopal N100 and 5% Genapol LRO are added into the solution preparation tank 1. Then, the internal temperature of the solution preparation tank 1 is set to 90℃ by the controller 3. The prepared solution should be aged for 2 weeks before it can be used. During the aging period, Na2CO3 is used to adjust the pH value of the solution to between 9 and 10. The sign that the solution is properly aged is that the pH value no longer fluctuates.

[0089] Then, a certain amount of polyethylene granule samples were taken, and a 10mm thick sample was prepared by compression molding. The compression temperature was 200℃, the compression pressure was 10MPa, the compression time was 30min, and the cooling time was 15min. The pressed sample was then milled into 5 10*10*100mm strips using a CNC milling machine 2. The milled strips were then conditioned for at least 48h in an environment with a temperature of 23℃±2℃ and a humidity of 50%±10%. After the conditioning was completed, the strips were cut with notches on all four sides using a coplanar cutter. The notch depth was 1.6mm±0.1mm. Then, any strip with an annular notch was taken, and its actual width and thickness were measured with an accuracy of 0.01mm. Then, it was broken using a simply supported beam impactor 4, and the actual cross-sectional area of ​​the fracture surface was measured. This area was used as the cross-sectional area of ​​all strips in this batch.

[0090] Then, the controller 3 controls the operation of the air pump 71 and the opening of the electric valve 74 in the cylinder connecting pipe 73, so that the air pump 71 can charge and depress the cylinder 75. When the cylinder 75 is charged, it will drive the top plate 67 to move upward. The movement of the top plate 67 will drive the connector 66 to move. The movement of the connector 66 will drive the upper end of the second rotating rod 65 to move. The movement of the upper end of the second rotating rod 65 will cause the second rotating rod 65 to rotate. The rotation of the second rotating rod 65 will drive the first rotating rod 64 to rotate, so that the top plate 67 can be raised and lowered. This allows the operator to raise and lower the table during the polyethylene environmental stress cracking test, making the operation more convenient and easier.

[0091] Example 2:

[0092] Please see Figure 4 and Figure 6 The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. Compared with Embodiment 1, this embodiment further includes a cleaning mechanism 7: the cleaning mechanism 7 includes an air pump 71.

[0093] Air pump 71 is located at the lower middle of cleaning mechanism 7. The inner end of connecting pipe 72 is fixedly connected to the middle of left and right sides of air pump 71. The outer end of the outer surface of connecting pipe 72 is fixedly connected to the inner surface of the holes at the lower middle of left and right sides of side plate block 62, so that connecting pipe 72 is fixed.

[0094] The bottom of the cylinder connecting pipe 73 is fixedly connected to the middle and outer ends of the top of the connecting pipe 72, so that the cylinder connecting pipe 73 is fixed in place.

[0095] The electric valve 74 is located at the outer end of the connecting pipe 72 and the middle end of the cylinder connecting pipe 73, so that the electric valve 74 can control the air supply of the connecting pipe 72 and the cylinder connecting pipe 73.

[0096] The bottom middle of cylinder 75 is fixedly connected to the top of cylinder connecting pipe 73, and the lower end of the outer surface of cylinder 75 is fixedly connected to the inner surface of the top hole of side plate compartment 62. There are two cylinders 75 in total, and the two cylinders 75 are internally connected to each other.

[0097] The lower end of the elastic tube 76 is fixedly connected to the outer end of the connecting tube 72, so that the elastic tube 76 is fixed.

[0098] The bottom of the gas chamber frame 77 is fixedly connected to the outer top of the top plate 67, and the lower ends of the left and right sides of the gas chamber frame 77 are fixedly connected to the upper ends of the elastic tube 76, so that the gas chamber frame 77 is fixed.

[0099] The inner end of the outer surface of the jet head 78 is fixedly connected to the inner surface of the holes at both ends of the inner side of the air chamber frame 77, so that the jet head 78 is fixed.

[0100] The top of the limiting slide bar 79 is fixedly connected to the left and right sides of the bottom of the top plate 67, so that the limiting slide bar 79 is fixed.

[0101] The left and right ends of the upper part of the outer surface of the collection drawer 710 are slidably connected to the inner surface of the groove at the inner end of the limiting slide strip 79, and the rear side of the air pump 71 is fixedly connected to the middle of the front side of the connecting base block 63, so that the collection drawer 710 can slide.

[0102] The working principle in this embodiment is as follows: When it is necessary to clean the solution or dust on the top of the top plate 67, the controller 3 controls the air pump 71 to work and fill the connecting pipe 72 with external gas. Then, the controller 3 opens the electric valve 74 on the connecting pipe 72, so that the gas in the connecting pipe 72 can enter the elastic tube 76 through the connecting pipe 72. The gas in the elastic tube 76 will enter the air chamber frame 77 through the elastic tube 76. The gas in the air chamber frame 77 will be sprayed onto the top plate 67 through the jet nozzle 78 on the air chamber frame 77.

[0103] This design allows the solution or dust on the top plate 67 to be blown into the hole at the middle of the top of the top plate 67. The solution or dust on the top plate 67 will then fall into the collection drawer 710 through the hole at the middle of the top of the top plate 67, keeping the tabletop for the polyethylene environmental stress cracking test clean, reducing the influence of external factors on the polyethylene environmental stress cracking test, and improving the accuracy of the polyethylene environmental stress cracking test.

[0104] Example 3:

[0105] Please see Figures 7-8 The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. Compared with Embodiment 1, this embodiment further includes a lifting mechanism 8: the lifting mechanism 8 includes a connecting block 81.

[0106] The top left and right ends of the connecting block 81 are fixedly connected to the bottom left and right ends of the top plate 67, so that the connecting block 81 is fixed.

[0107] The top middle of the transverse trachea 82 is fixedly connected to the bottom middle of the connecting block 81, thus fixing the transverse trachea 82.

[0108] The upper end of the hose 83 is fixedly connected to the middle of the bottom of the horizontal air tube 82, and the lower end of the hose 83 is fixedly connected to the middle of the top of the air pump 71, so that the hose 83 is fixed in place.

[0109] The lower end of the outer surface of the small cylinder 84 is fixedly connected to the inner surface of the holes on the left and right sides of the top of the connecting block 81. The middle end of the bottom of the small cylinder 84 is fixedly connected to the upper ends of the left and right sides of the horizontal air pipe 82. The middle end of the outer surface of the small cylinder 84 is fixedly connected to the inner surface of the holes on the left and right sides of the top plate 67, so that the small cylinder 84 is fixed.

[0110] The bottom left and right ends of the lifting plate 85 are fixedly connected to the top of the small cylinder 84, so that the lifting plate 85 is fixed in place;

[0111] The groove 86 is located on the left and right sides of the bottom of the lifting plate 85. The outer ends of the front and rear sides of the rotating baffle 87 are rotatably connected to the outer ends of the front and rear sides of the inner side of the groove 86. The inner surface of the groove at the top of the connecting block 81 is slidably connected to the lower end of the outer surface of the collection drawer 710, so that the rotating baffle 87 can be rotated.

[0112] The working principle in this embodiment is as follows: When cleaning the solution or dust on the top plate 67, the controller 3 controls the air pump 71 to work and draw the external gas into the hose 83. The gas inside the hose 83 will enter the horizontal air pipe 82 along the hose 83. The gas inside the horizontal air pipe 82 will enter the small cylinder 84 along the horizontal air pipe 82. The small cylinder 84 will drive the lifting plate 85 to move upward.

[0113] The movement of the lifting plate 85 will cause the stress correction and measuring mechanism 9 to move. The movement of the lifting plate 85 will cause the rotating baffle 87 to rotate downward under the action of gravity. When cleaning the solution or dust on the top plate 67, the lifting plate 85 can drive the stress correction and measuring mechanism 9 to move upward, preventing gas from blowing onto the stress correction and measuring mechanism 9 and affecting its operation. When the gas blows onto the top plate 67, it can be blocked and guided by the lifting plate 85, making it easier for the solution or dust on the top plate 67 to enter the collection drawer 710, making cleaning more convenient.

[0114] Example 4:

[0115] Please see Figure 9 The present invention discloses a sample preparation device and method for measuring the environmental stress cracking of polyethylene. Compared with Embodiment 1, this embodiment further includes a stress correction measuring mechanism 9: the stress correction measuring mechanism 9 includes a base 91.

[0116] The base 91 is located at the lower end of the stress correction and measurement mechanism 9, and an angle sensor is provided on the base 91.

[0117] The left end of the front and rear sides of the lever arm 92 is rotatably connected to the inner middle end of the upper end of the base 91, so that the lever arm 92 can rotate.

[0118] The bottom of the stress corrector 93 is fixedly connected to the top left side of the lever arm 92, thus fixing the stress corrector 93 in place.

[0119] The weight 94 is set on the lever arm 92, and the bottom of the annular retaining frame 95 is fixedly connected to the outer end of the top of the stress corrector 93, so that the annular retaining frame 95 is fixed.

[0120] The bottom middle of the clamp 96 is fixedly connected to the top middle of the stress corrector 93, so that the clamp 96 is fixed.

[0121] The lower end of the outer surface of the lifting block 97 is fixedly connected to the lower end of the inner side of the holes on the left and right sides of the top of the clamp 96. The bottom of the base 91 is fixedly connected to the top of the lifting plate 85. An electric push rod is provided at the lower end of the lifting block 97.

[0122] The working principle in this embodiment is as follows: the strip with the annular notch cut is clamped onto the lifting block 97 on the fixture 96. During the clamping process, the strip cannot be subjected to any external force. At least 3 strips are tested for each batch of samples. Then, stress correction is performed using the stress corrector 93 so that the stress control range that the stress correction measuring mechanism 9 can reach is 0-6.0MPa. The stress corrector 93 is loaded onto the lever arm 92 of the stress correction measuring mechanism 9.

[0123] Then raise the lever arm 92 until the angle sensor displays an angle of 0°±1°, fix the lever arm 92, and then measure the actual cross-sectional area of ​​the strip with the cut annular notch and record it into the controller 3. According to the stress value displayed by the controller 3, adjust the position of the weight 94 on the lever arm 92 until the stress value reaches the desired value. After the calibration is completed, save the calibration result, and then complete the calibration of other stations in the same way.

[0124] Then, the clamp 96 holding the sample is sequentially attached to the lever arm 92 of the stress correction and measurement mechanism 9. The sample is immersed in the solution. At this time, the sample should be in a state of no force, that is, the lever arm is not raised. For tube material samples, the sample is immersed in the solution for 24 hours before the test is started. Then, the lever arm 92 is raised until the angle sensor shows an angle of 0°±1° and the lever arm 92 is fixed.

[0125] Then, click "Start Test" on controller 3 and start each station with a sample in sequence. After the test, record the fracture time of the sample strips through monitoring camera 5. The average fracture time of the three sample strips in each batch is the final result. At the same time, according to the description in GB / T32682, observe the fracture mode of the sample fracture surface. The fracture mode must be brittle fracture. The appearance of ductile fracture means the test fails. This can greatly shorten the test time for determining the environmental stress cracking of polyethylene.

[0126] This invention provides an improved sample preparation device and method for measuring the environmental stress cracking of polyethylene. By incorporating a lifting mechanism 6, the top plate 67 of which can move up and down, the operator can adjust the tabletop during the polyethylene environmental stress cracking measurement operation, making the operation more convenient. A cleaning mechanism 7 is also included. The air pump 71 in the cleaning mechanism 7 fills the air chamber frame 77 with external gas, which is then ejected from the nozzle 78. This facilitates the blowing of solution or dust on the top plate 67 into the hole at the center of the top plate 67. The solution or dust then falls into the collection drawer 710 through the hole, allowing the polyethylene sample to be collected and processed. The tabletop for polyethylene environmental stress cracking testing can be kept clean, reducing the impact of external factors on the polyethylene environmental stress cracking test and improving the accuracy of the test. A lifting mechanism 8 is included, in which a small cylinder 84 drives a lifting plate 85 to move up and down, preventing gas from blowing onto the stress correction testing mechanism 9 and affecting its operation. Furthermore, when gas blows onto the top plate 67, the lifting plate 85 guides the solution or dust on the top plate 67, making cleaning easier. The stress correction testing mechanism 9 significantly shortens the testing time for polyethylene environmental stress cracking.

[0127] The above description shows and illustrates the basic principles, main features, and advantages of the present invention. Standard parts used in the present invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0128] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sample preparation device for measuring the environmental stress cracking of polyethylene, comprising a solution preparation box (1), the lower right end of the solution preparation box (1) being fixedly connected to the lower left end of a CNC milling machine (2), the middle of the right front end of the CNC milling machine (2) being fixedly connected to the rear side of a controller (3), the right side of the CNC milling machine (2) being fixedly connected to the left side of a simply supported beam impactor (4), and the upper right side of the simply supported beam impactor (4) being fixedly connected to the left side of a monitoring camera (5); Its features are: Also includes: The lower left end of the lifting mechanism (6) is fixedly connected to the lower right end of the simply supported beam impactor (4); The cleaning mechanism (7) is fixedly connected to the lower rear end of the front end of the lifting mechanism (6) at the middle of the lower front end. The cleaning mechanism (7) includes: An air pump (71) is located at the lower middle part of the cleaning mechanism (7); Connecting pipe (72), the inner end of the connecting pipe (72) is fixedly connected to the middle of the left and right sides of the air pump (71), and the outer end of the outer surface of the connecting pipe (72) is fixedly connected to the inner surface of the lower middle hole on the left and right sides of the side plate block (62). Cylinder connecting pipe (73), the bottom of the cylinder connecting pipe (73) is fixedly connected to the middle and outer ends of the top of the connecting pipe (72); An electric valve (74) is provided at the outer end of the connecting pipe (72) and the middle end of the cylinder connecting pipe (73); Cylinder (75), the bottom middle of the cylinder (75) is fixedly connected to the top of the cylinder connecting pipe (73), and the lower end of the outer surface of the cylinder (75) is fixedly connected to the inner surface of the top hole of the side plate compartment block (62). The bottom surface of the upper end of the lifting mechanism (8) is in contact with the middle surface of the top of the lifting mechanism (6); The lifting mechanism (8) includes: Connecting block (81), the top left and right ends of the connecting block (81) are fixedly connected to the bottom left and right ends of the top plate (67); A transverse air tube (82) is fixedly connected at the top middle end to the bottom middle end of a connecting block (81); The upper end of the hose (83) is fixedly connected to the middle of the bottom of the transverse air pipe (82), and the lower end of the hose (83) is fixedly connected to the middle of the top of the air pump (71). Small cylinder (84), the lower end of the outer surface of the small cylinder (84) is fixedly connected to the inner surface of the holes on the left and right sides of the top of the connecting block (81), the middle end of the bottom of the small cylinder (84) is fixedly connected to the upper ends of the left and right sides of the horizontal air pipe (82), and the middle end of the outer surface of the small cylinder (84) is fixedly connected to the inner surface of the holes on the left and right sides of the top plate (67). The stress correction measuring mechanism (9) is fixedly connected at the bottom to the top of the lifting mechanism (8).

2. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 1, characterized in that: The lifting mechanism (6) includes: A connecting rectangular block (61) is provided at the lower left end of the lifting mechanism (6); Side plate compartment block (62), the lower left end of the side plate compartment block (62) is fixedly connected to the right side of the connecting rectangular block (61); Connecting bottom block (63), the left and right ends of the connecting bottom block (63) are fixedly connected to the lower end of the inner side of the side plate compartment block (62); The lower end of the outer side of the first rotating rod (64) is rotatably connected to the left side of the inner side of the connecting base block (63).

3. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 2, characterized in that: The lifting mechanism (6) also includes: The second rotating rod (65) has its outer end mid-end rotatably connected to the inner end mid-end of the first rotating rod (64), and the lower right end surface of the second rotating rod (65) is in contact with the inner bottom end surface of the connecting block (63). Connector (66), the inner middle end of the connector (66) is rotatably connected to the upper ends of the front and rear sides of the second rotating rod (65); Top plate (67), the front and rear ends of the bottom left side of the top plate (67) are fixedly connected to the top of the connector (66), and the bottom right side surface of the top plate (67) is in contact with the upper right side surface of the first rotating rod (64); The left side of the connecting rectangular block (61) is fixedly connected to the lower right side of the simply supported beam impactor (4).

4. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 3, characterized in that: The cleaning mechanism (7) also includes: The lower end of the elastic tube (76) is fixedly connected to the outer end of the connecting tube (72); The bottom of the air chamber frame (77) is fixedly connected to the outer end of the top of the top plate (67), and the lower ends of the left and right sides of the air chamber frame (77) are fixedly connected to the upper end of the elastic tube (76). The inner end of the outer surface of the jet head (78) is fixedly connected to the inner surface of the holes at both ends of the inner side of the air chamber frame (77); The top of the limiting slide bar (79) is fixedly connected to the left and right sides of the bottom of the top plate (67); The collection drawer (710) has its left and right ends on the upper side of the outer surface of the collection drawer (710) slidably connected to the inner surface of the groove at the inner end of the limiting slide strip (79); The rear side of the air pump (71) is fixedly connected to the middle of the front side of the connecting base block (63).

5. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 4, characterized in that: The lifting mechanism (8) further includes: The lifting plate (85) is fixedly connected to the top of the small cylinder (84) at its bottom left and right ends; The groove (86) is formed on the left and right sides of the bottom of the lifting plate (85); Rotate the baffle (87), and the outer ends of the front and rear sides of the rotating baffle (87) are rotatably connected to the outer ends of the front and rear ends of the inner side of the groove (86); The inner surface of the groove at the top of the connecting block (81) is slidably connected to the lower end of the outer surface of the collection drawer (710).

6. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 5, characterized in that: The stress correction measuring mechanism (9) includes: The base (91) is located at the lower end of the stress correction measuring mechanism (9); Lever arm (92), the left end of the front and rear sides of the lever arm (92) is rotatably connected to the inner middle end of the upper end of the base (91); Stress corrector (93), the bottom of which is fixedly connected to the top left side of lever arm (92); Weight (94) is disposed on lever arm (92).

7. The sample preparation device for measuring environmental stress cracking of polyethylene according to claim 6, characterized in that: The stress correction measuring mechanism (9) also includes: An annular baffle (95) is fixedly connected at its bottom to the outer top end of the stress corrector (93); The clamp (96) is fixedly connected at the bottom middle end to the top middle end of the stress corrector (93); The lower end of the outer surface of the lifting block (97) is fixedly connected to the lower end of the inner side of the holes on the left and right sides of the top of the clamp (96); The bottom of the base (91) is fixedly connected to the top of the lifting plate (85).

8. A method for preparing a sample preparation device for measuring the environmental stress cracking of polyethylene according to any one of claims 1 to 7, characterized in that: Includes the following steps: S1: Add 60L of deionized water into the solution preparation tank (1), then add 2% Arkopal N100 and 5% Genapol LRO into the solution preparation tank (1), and then set the internal temperature of the solution preparation tank (1) to 90℃ through the controller (3). The prepared solution should be aged for 2 weeks before it can be used. During the aging period, use Na2CO3 to adjust the pH value of the solution to between 9 and 10. The sign that the solution is properly aged is that the pH value no longer fluctuates. S2: Then take a certain amount of polyethylene granule samples and use compression molding to prepare a 10mm thick sample plate. The compression temperature is 200℃, the compression pressure is 10MPa, the compression time is 30min, and the cooling time is 15min. The pressed sample plate is milled into 5 10*10*100mm strips using a CNC milling machine (2). The milled strips are conditioned for at least 48h in an environment with a temperature of 23℃±2℃ and a humidity of 50%±10%. The strips after the condition is conditioned are cut with a coplanar cutter to cut notches on the four sides respectively. The notch depth is 1.6mm±0.1mm. Then take any strip with a cut ring notch and measure its actual width and thickness. The accurate value is 0.01mm. Then use a simple beam impactor (4) to break it and measure the actual cross-sectional area of ​​the fracture surface. This area is used as the cross-sectional area of ​​all strips in this batch. S3: Then, the controller (3) controls the operation of the air pump (71) and the opening of the electric valve (74) in the cylinder connecting pipe (73), so that the air pump (71) works to inflate and evacuate the cylinder (75). When the cylinder (75) is inflated, it will drive the top plate (67) to move upward. The movement of the top plate (67) will drive the connector (66) to move. The movement of the connector (66) will drive the upper end of the second rotating rod (65) to move. The movement of the upper end of the second rotating rod (65) will cause the second rotating rod (65) to rotate. The rotation of the second rotating rod (65) will drive the first rotating rod (64) to rotate, so that the top plate (67) will be raised and lowered. This allows the operator to operate the tabletop during the polyethylene environmental stress cracking test, making it easier for the operator to operate and making the polyethylene environmental stress cracking test more convenient. S4: When it is necessary to clean the solution or dust on the top of the top plate (67), the controller (3) controls the air pump (71) to work to fill the connecting pipe (72) with external gas. Then, the controller (3) opens the electric valve (74) on the connecting pipe (72), so that the gas in the connecting pipe (72) enters the elastic tube (76) along the connecting pipe (72). The gas in the elastic tube (76) will enter the air chamber frame (77) along the elastic tube (76). The gas in the air chamber frame (77) will be sprayed onto the top plate (67) along the jet nozzle (78) on the air chamber frame (77). S5: It is convenient to blow the solution or dust on the top plate (67) into the hole at the middle of the top of the top plate (67). The solution or dust on the top plate (67) will fall into the collection drawer (710) through the hole at the middle of the top of the top plate (67), so that the table of polyethylene environmental stress cracking test is kept clean, reducing the influence of external factors on the polyethylene environmental stress cracking test experiment and improving the accuracy of the polyethylene environmental stress cracking test experiment. S6: When cleaning the solution or dust on the top plate (67), the controller (3) controls the air pump (71) to work and draw the external gas into the hose (83). The gas inside the hose (83) will enter the horizontal air pipe (82) along the hose (83). The gas in the horizontal air pipe (82) will enter the small cylinder (84) along the horizontal air pipe (82). The small cylinder (84) will drive the lifting plate (85) to move upward. S7: The movement of the lifting plate (85) will drive the stress correction measuring mechanism (9) to move. The movement of the lifting plate (85) will cause the rotating baffle (87) to rotate downward due to gravity. When cleaning the solution or dust on the top plate (67), the lifting plate (85) will drive the stress correction measuring mechanism (9) to move upward, preventing gas from blowing onto the stress correction measuring mechanism (9) and affecting its operation. When the gas blows onto the top plate (67), under the blocking and guidance of the lifting plate (85), the solution or dust on the top plate (67) will more easily enter the collection drawer (710), making cleaning more convenient. S8: Clamp the strip with the cut annular notch onto the lifting block (97) on the fixture (96). During the clamping process, the strip must not be subjected to any external force. At least 3 strips are tested for each batch of samples. Then, stress correction is performed using the stress corrector (93) so that the stress control range that the stress correction measuring mechanism (9) can reach is 0-6.0MPa. Load the stress corrector (93) onto the lever arm (92) of the stress correction measuring mechanism (9). S9: Then raise the lever arm (92) until the angle sensor displays an angle of 0°±1°, fix the lever arm (92), then measure the actual cross-sectional area of ​​the cut annular notch in the template and record it in the controller (3). According to the stress value displayed by the controller (3), adjust the position of the weight (94) on the lever arm (92) until the stress value reaches the desired value. After the calibration is completed, save the calibration result, and then complete the calibration of other stations in the same way. S10: Then, the clamp (96) holding the sample is sequentially attached to the lever arm (92) of the stress correction measuring mechanism (9). The sample is immersed in the solution. At this time, the sample should be in a state of no force, that is, the lever arm is not raised. For tube material samples, the sample is immersed in the solution for 24 hours before the test is started. Then, the lever arm (92) is raised until the angle sensor shows an angle of 0°±1° and the lever arm (92) is fixed. S11: Then click Start Test on the controller (3) and start each station with sample in sequence. After the test, record the fracture time of the sample through the monitoring camera (5). The average fracture time of the 3 samples in each batch is the final result. At the same time, according to the description in GB / T32682, observe the fracture mode of the sample fracture surface. The fracture mode must be brittle fracture. If ductile fracture occurs, the experiment will fail. This greatly shortens the test time of polyethylene environmental stress cracking determination.

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