Experimental device and method for measuring curing time of polyurethane material for coal mine

Abstract

The invention relates to the field of material testing. The invention discloses an experimental device and method for measuring curing time of a polyurethane material for a coal mine. The experimental device comprises a base, a force measuring device and a container, and is characterized in that the force measuring device is placed on the base, the container is placed on the force measuring device, a support stand column is arranged on the base, a support cross rod capable of adjusting the position is sleeved on the support stand column, a sliding device is installed at the front end of the support cross rod, and the sliding device is arranged on the base. The lower end of the sliding device is connected with the test rod. The method comprises the following steps: checking the testing device, adjusting the temperature of the components of the polyurethane material, mixing the components, stirring and starting timing, reading the reading of the force measuring device, stopping timing and carrying out parallel test. According to the device and the method disclosed by the invention, a more accurate detection result of the curing time of the polyurethane material for the coal mine can be obtained, and the manual subjective influence can be remarkably reduced.

Description

Technical Field

[0001] This invention relates to the field of materials testing, and in particular to an experimental apparatus and method for measuring the curing time of polyurethane materials used in coal mines. Background Technology

[0002] With the development of the national economy and technology, the demand for energy has increased dramatically. Coal, as a major energy resource, has seen its mining intensity increase accordingly. However, the coal mining process still faces many safety issues such as roof falls, collapses, and floods. These safety problems seriously affect production efficiency. Polyurethane materials for coal mines, due to their unique soft and hard chain segment structure, possess numerous advantages such as high strength, low density, low thermal conductivity, wear resistance, waterproofing, sound insulation, and convenient construction. Their application in coal mine production is becoming increasingly widespread, greatly improving production efficiency and coal mine safety. Among them, polyurethane materials for reinforcing coal and rock masses and silicate-modified polyurethane materials for reinforcing coal and rock masses in coal mines have many advantages such as high strength, low density, low thermal conductivity, wear resistance, waterproofing, sound insulation, and convenient construction. Injected into fractured rock strata, they can strongly lock the coal and rock mass together, preventing relative movement between the locked rock blocks, ultimately achieving the purpose of coal and rock reinforcement, improving the physical and mechanical properties of the coal and rock mass, and enhancing its integrity and strength. In addition, polyurethane materials for coal mine water plugging, as a water-insoluble gel-solidified material with extremely strong adhesion to the surface of coal and rock strata pores, can be used to quickly address water seepage in mine roadways. For the aforementioned reactive polymer materials used in mining, their various performance indicators are closely related to the safety control of coal mine construction; therefore, the Safety Standards Center has put forward management requirements for the performance of such materials. The curing time of polyurethane materials for coal mines is an important performance indicator, which determines the extent to which the coal and rock mass can be reinforced and whether it can respond promptly to sudden water leakage disasters.

[0003] Currently, according to industry standards AQ / T 1087-2020 and AQ / T 1089-2020, the testing methods for curing time and the judgment of the curing time endpoint are basically based on the ease with which the experimenter inserts and removes the stirring rod. These testing methods introduce significant errors and have a substantial subjective influence on the curing endpoint of polyurethane materials, resulting in large differences in performance indicator test results. To obtain more accurate curing time test results, there is an urgent need for a precise method for measuring the curing time of polyurethane materials used in coal mines that is not affected by human subjectivity. Summary of the Invention

[0004] The purpose of this invention is to design and develop an apparatus and method for accurately measuring the curing time of polyurethane materials for coal mines without being affected by human subjective factors, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0005] To achieve the aforementioned objective, according to a first aspect of the present invention, an experimental apparatus for measuring the curing time of polyurethane materials for coal mines is provided, comprising a base, a force measuring device, and a container. The force measuring device is placed on the base, and the container is placed on the force measuring device. A support column is provided on the base, and a support crossbar that can be adjusted in both horizontal and vertical directions is fitted onto the support column. A sliding device is installed at the front end of the support crossbar, and the sliding device can move up and down in the vertical direction. The lower end of the sliding device is connected to a test rod, and the sliding device can drive the test rod to move up and down, and the sliding speed of the sliding device can be adjusted.

[0006] The test rod is moved through the test sample by a sliding device. The reading of the force measuring device will change with the degree and state of curing of the test sample. When a certain pressure reading is reached, it can be determined as the curing endpoint. The reading of the timing device can be read to measure the curing time of the test sample.

[0007] Optionally, the container is a polytetrafluoroethylene cylindrical container.

[0008] Optionally, the container has a bottom diameter of 50 mm and a height of 100 mm.

[0009] Optionally, the force measuring device is a pressure gauge with a detection range of 0-100 N and an indication resolution of 0.01 N.

[0010] Optionally, the sliding device is an electric slider, the sliding speed of which is adjustable, and the sliding stroke is 100 mm.

[0011] Optionally, the test rod is 70 mm long and has a diameter of 5 ± 0.05 mm.

[0012] According to a second aspect of the present invention, an experimental method for measuring the curing time of polyurethane materials for coal mines is provided, the method utilizing the experimental apparatus described above, the method comprising: Step 1: Check the integrity of the experimental apparatus for measuring the curing time of polyurethane materials for coal mines as described above, and check that the sliding device can slide freely within the maximum sliding stroke range and that the sliding speed can be adjusted. Step 2: Place the container at the center of the force measuring device and extend the test rod into the container so that the lower end of the test rod is at the center of the container; Step 3: Adjust the temperature of components A and B of the polyurethane material for coal mines to maintain at 20±1℃; Step 4: Weigh the test sample according to the volume ratio of components A and B, stir it under a stirrer, and start timing while stirring. After observing that the two components are mixed evenly, stop stirring and then quickly pour the stirred test sample into a container. Step 5: After the mixed sample is poured into the container, read the reading of the force measuring device. At the same time, turn on the sliding device to move the test rod upward. Observe the force measuring device reading gradually decrease. When the pressure reading changes to a certain value, stop the timing device. The time recorded by the timing device is the curing time of the polyurethane material for coal mines. Step 6: Perform three parallel tests and take the average value as the final curing time for the polyurethane material used in coal mines.

[0013] Optionally, the total volume of the test sample is 200 mL, and the volume ratio of components A and B is 1:1.

[0014] Optionally, the stirring speed is 800-1000 rpm, and the test sample is stirred under the stirring for 15-30 seconds.

[0015] Optionally, the timing stops when the pressure reading changes by 3N.

[0016] The device and method for accurately measuring the curing time of polyurethane materials used in coal mines provided by this invention use a sliding device to move a test rod within the test sample. The reading of the force measuring device changes with the degree and state of curing of the test sample. When the reading of the force measuring device reaches a certain value, it can be determined as the curing endpoint. By obtaining more accurate curing time detection results through the real-time changes in the force measuring device reading, the influence of human subjectivity can be significantly reduced.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram of one embodiment of the experimental apparatus for measuring the curing time of polyurethane materials for coal mines provided by the present invention.

[0020] The annotations in the diagram are as follows: 1-Base; 2-Force measuring device; 3-Container; 4-Support column; 5-Support crossbar; 6-Sliding device; 7-Test rod. Detailed Implementation

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0022] In this application, the terms "comprising" and "including" cover situations where other elements not explicitly mentioned are also included, as well as situations where the mentioned elements constitute the entirety of the application.

[0023] Unless otherwise specified, 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. In the event of any discrepancy between the definitions of terms in this specification and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0024] The following will further illustrate the concept, specific structure, and technical effects of the present invention with reference to embodiments, so as to enable those skilled in the art to fully understand the purpose, features, and effects of the present invention. It will be readily understood by those skilled in the art that the embodiments described herein are merely illustrative, and the scope of the present invention is not limited thereto.

[0025] Example 1 like Figure 1 As shown, Example 1 provides a specific embodiment of an experimental apparatus for measuring the curing time of polyurethane material for coal mines. The apparatus includes a base 1, a force measuring device 2, and a container 3. In optional embodiments, the type of container is not limited. In this embodiment, the container 3 is a polytetrafluoroethylene (PTFE) cylindrical container with a bottom diameter of 50 mm and a height of 100 mm. The advantage of this embodiment is that the PTFE cylindrical container has strong corrosion resistance and stability, preventing corrosion from certain chemicals that may be generated during the curing process of the polyurethane material for coal mines. Furthermore, the cylindrical shape facilitates necessary operations during the curing process. The force measuring device 2 can be a pressure gauge. The pressure gauge has a detection range of 0-100 N and a resolution of 0.01 N. In optional embodiments, the type of force measuring device 2 is not limited; any other instrument capable of measuring the pressure changes that occur in the container during the reaction falls within the scope of this invention. The base has a support column 4, on which a support crossbar 5, adjustable in both horizontal and vertical directions, is fitted. A sliding device 6 is installed at the front end of the support crossbar 5. In some embodiments, the sliding device 6 can be an electric slider, which can move vertically up and down with an adjustable sliding speed and a sliding stroke of 100 mm. In optional embodiments, other sliding devices such as electric push rods that can move vertically up and down and have adjustable speeds, besides electric sliders, are also within the scope of protection of this invention. The lower end of the sliding device 6 is connected to the test rod 7, and the test rod 7 moves by moving up and down the sliding device 6. In optional embodiments, the test rod 7 is 70 mm long and 5 ± 0.05 mm in diameter. Before measuring the curing time, the lower end of the test rod 7 is located at the center of the container 3. It is understood that the experimental apparatus of this invention should be placed vertically and stably, and should not be operated in an environment with significant vibration.

[0026] Example 2 Example 2 provides a specific embodiment of an experimental method for measuring the curing time of polyurethane materials used in coal mines, which utilizes the experimental apparatus shown in Example 1, including: Step 1: Check the integrity of the experimental apparatus for measuring the curing time of polyurethane materials for coal mines, and check that the sliding device can slide freely within the maximum sliding stroke range and that the sliding speed can be adjusted. Step 2: Place the container at the center of the force measuring device and extend the test rod into the container so that the lower end of the test rod is at the center of the container; Step 3: Adjust the temperature of components A and B of the polyurethane material for coal mines to maintain at 20±1℃; Step 4: Weigh the test sample according to the volume ratio of components A and B, stir it under a stirrer, and start timing while stirring. After observing that the two components are mixed evenly, stop stirring and then quickly pour the stirred test sample into a container. Step 5: After the mixed sample is poured into the container, read the reading of the force measuring device. At the same time, turn on the sliding device to move the test rod upward. Observe the force measuring device reading gradually decrease. When the pressure reading changes to a certain value, stop the timing device. The time recorded by the timing device is the curing time of the polyurethane material for coal mines. Step 6: Perform three parallel tests and take the average value as the final curing time for the polyurethane material used in coal mines.

[0027] In optional embodiments, the change in the force measuring device reading can be determined based on testing, requiring multiple trials and adjustments to ensure the accuracy and reliability of the results. In some embodiments, a test sample with a total volume of 200 mL can be weighed according to the 1:1 volume ratio of components A and B. The sample is stirred for 15-30 seconds using a stirrer at a speed of 800-1000 rpm. A timing device is used to start the stirring process. After observing that the two components are evenly mixed, the stirring is stopped, and the stirred test sample is quickly poured into a container. After the container is filled with the mixed sample, the force measuring device reading is read. At the same time, the sliding device is activated, causing the sliding device to move the test rod upward. The change in the force measuring device reading is observed to gradually decrease. When the pressure reading changes by 3 N, the timing device is stopped. The time recorded by the timing device is the curing time of the polyurethane material for coal mines.

[0028] In optional embodiments, the type of timing device is not limited; any other instrument capable of measuring time intervals falls within the scope of protection of this invention. In this embodiment, the timing device can be an electronic stopwatch. The advantage of an electronic stopwatch is that, compared to a traditional mechanical stopwatch, it is more accurate, can provide smaller time measurement units, such as milliseconds or microseconds, and the start and stop of an electronic stopwatch can be completed in a short time, reducing errors caused by human reaction time.

[0029] The foregoing descriptions are merely exemplary embodiments or examples of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention are included within the scope of this application.

Claims

1. An experimental apparatus for measuring the curing time of polyurethane materials used in coal mines, characterized in that, The device includes a base, a force measuring device, and a container. The force measuring device is placed on the base, and the container is placed on the force measuring device. A support column is provided on the base, and a support crossbar that can be adjusted in both horizontal and vertical directions is fitted on the support column. A sliding device is installed at the front end of the support crossbar, and the lower end of the sliding device is connected to a test rod. The sliding device can drive the test rod to move up and down, and the sliding speed of the sliding device can be adjusted.

2. The experimental apparatus for measuring the curing time of polyurethane materials for coal mines according to claim 1, characterized in that, The container is a cylindrical container made of polytetrafluoroethylene.

3. The experimental apparatus for measuring the curing time of polyurethane materials for coal mines according to claim 2, characterized in that, The container has a bottom diameter of 50 mm and a height of 100 mm.

4. The experimental apparatus for measuring the curing time of polyurethane materials for coal mines according to claim 1, characterized in that, The force measuring device is a pressure gauge with a detection range of 0-100 N and an indication resolution of 0.01 N.

5. The experimental apparatus for measuring the curing time of polyurethane materials for coal mines according to claim 1, characterized in that, The sliding device is an electric slider, the sliding speed of which is adjustable, and the sliding stroke is 100 mm.

6. The experimental apparatus for measuring the curing time of polyurethane materials for coal mines according to claim 1, characterized in that, The test rod is 70 mm long and has a diameter of 5 ± 0.05 mm.

7. An experimental method for measuring the curing time of polyurethane materials for coal mines, said method utilizing the experimental apparatus according to any one of claims 1-6, characterized in that, The method includes: Step 1: Check the integrity of the experimental apparatus for measuring the curing time of polyurethane materials for coal mines as described in any one of claims 1-6, and check that the sliding device can slide freely within the maximum sliding stroke range and that the sliding speed can be adjusted; Step 2: Place the container at the center of the force measuring device and extend the test rod into the container so that the lower end of the test rod is at the center of the container; Step 3: Adjust the temperature of components A and B of the polyurethane material for coal mines to maintain at 20±1℃. Step 4: Weigh the test sample according to the volume ratio of components A and B, stir it under a stirrer, and start timing while stirring. After observing that the two components are mixed evenly, stop stirring and then quickly pour the stirred test sample into a container. Step 5: After the mixed sample is poured into the container, read the reading of the force measuring device. At the same time, turn on the sliding device to move the test rod upward. Observe the force measuring device reading gradually decrease. When the pressure reading changes to a certain value, stop the timing device. The time recorded by the timing device is the curing time of the polyurethane material for coal mines. Step 6: Perform three parallel tests and take the average value as the final curing time for the polyurethane material used in coal mines.

8. The experimental method for measuring the curing time of polyurethane materials for coal mines as described in claim 7, characterized in that, Weigh out a total volume of 200 mL for the test sample, with the volume ratio of components A and B being 1:

1.

9. The experimental method for measuring the curing time of polyurethane materials for coal mines as described in claim 7, characterized in that, The stirring speed is 800-1000 rpm, and the test sample is stirred under the stirring for 15-30 seconds.

10. The experimental method for measuring the curing time of polyurethane materials for coal mines as described in claim 7, characterized in that, The timing stops when the force measuring device reading changes by 3N.

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