Method for testing thermal stabilization time of PVC (polyvinyl chloride) material

Abstract

The invention discloses a method for testing thermal stabilization time of a PVC (polyvinyl chloride) material. The method sequentially comprises the following steps: weighing all components of a PVC material according to a formula proportion, mixing, performing open milling to prepare a PVC material sample, cutting the PVC material sample into a plurality of PVC sample units with consistent shapes and sizes, folding or curling the plurality of PVC sample units, filling the PVC sample units into a test tube (the test paper is embedded and suspended at the upper end in the test tube after being rolled into a barrel shape), and performing vacuum packaging. And testing the thermal stability time of the PVC sample sheet unit, recording the color changing time of the test paper in each test tube, and calculating an average value, wherein the average value is the thermal stability time of the PVC material. According to the method for testing the thermal stability time of the PVC material, the quality of each test sample (PVC sample unit) is kept within a very small fluctuation range, so that a foundation is laid for the reliability of a thermal stability time test result of the PVC material; and the thermal stability time of the PVC material is obtained by averaging the thermal stability time corresponding to each test sample (PVC sample unit), and the reliability of the thermal stability time test result is good. Compared with a traditional sample filling mode that a PVC material sample is cut into small fragments and then the small fragments are filled at the bottom of a test tube, the manufacturing and processing efficiency of the PVC sample sheet unit and the filling efficiency of the PVC sample sheet unit in the test tube are remarkably improved, the filling difficulty of the PVC sample sheet unit in the test tube after the PVC sample sheet unit is folded or curled is greatly reduced, the requirement for operators is low, and the cost is low. And the overall testing efficiency of the thermal stabilization time of the PVC material can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material testing, and in particular to a method for testing the thermal stability time of PVC materials. Background Art

[0002] Thermal stability time is one of the main performance indicators of PVC materials. The thermal stability time of PVC materials can also reflect the quality of other performances of subsequent corresponding PVC products, such as static color, aging performance, etc. Therefore, there are very high requirements for the reliability of the thermal stability time test results of PVC materials.

[0003] At present, the general test method for the thermal stability time of PVC materials is to use the national standard thermal stability time test equipment for testing, that is, to heat the glycerin inside the national standard thermal stability time test equipment to a specified temperature, and then place the test tube containing the PVC sample in the glycerin inside the national standard thermal stability time test equipment, and use the glycerin to conduct heat conduction heating on the PVC sample in the test tube to test the thermal stability time of the PVC sample.

[0004] In the above-mentioned test method for the thermal stability time of PVC materials, the specific process of making PVC samples is as follows: the PVC material sample to be tested is cut into small pieces, and then the pieces are filled into a test tube, and the bottom of the test tube is gently shaken a few times on the laboratory table to make the pieces densely filled in the test tube. Finally, the test tube filled with PVC material fragments is placed in the glycerin inside the national standard thermal stability time test equipment, and the glycerin liquid level is not higher than the upper end surface of the PVC material fragments in the test tube. In order to ensure the objectivity and reliability of the test results, when multiple PVC samples are tested simultaneously, it is necessary to ensure that the filling height of the PVC sample pieces in the test tube remains consistent. The problems existing in the PVC sample making process are: (1) it is greatly affected by human filling factors. While ensuring that the filling height of the PVC material sample fragments in several test tubes is consistent, it cannot ensure that the density of the PVC material sample fragments filled in each test tube is consistent. The total weight of the PVC material sample fluctuates greatly, resulting in poor reliability of the thermal stability time test results of the PVC material; (2) the PVC sample making process has complicated operation steps, is difficult, and takes a long time overall, which seriously restricts the test efficiency of the thermal stability time of the PVC material. To this end, the present invention proposes a testing method for the thermal stability time of PVC materials in order to solve the above technical problems. Summary of the Invention

[0005] The present invention aims to overcome the defects in the prior art and provide a method for testing the thermal stability time of PVC materials. The method comprises weighing the components of the PVC material according to a specified formula, stirring and mixing them in sequence, and refining them to form a PVC material sample of uniform thickness. The PVC material sample is then cut into a plurality of PVC sample units of uniform shape and size, thereby ensuring that the quality of each test sample remains within a very small fluctuation range, laying a foundation for the reliability of the thermal stability time test results of the PVC material. The thermal stability time of the PVC material is obtained by averaging the thermal stability times corresponding to the various test samples (PVC sample units), thereby improving the reliability of the thermal stability time test results. Compared with the traditional sample filling method of cutting the PVC material sample into small pieces and filling them at the bottom of a test tube, the method significantly improves the production and processing efficiency of the PVC sample units and the filling efficiency of the PVC sample units in the test tube. The difficulty of filling the PVC sample units in the test tube after folding or curling is greatly reduced, and the operator requirements are low, which helps to improve the overall testing efficiency of the thermal stability time of the PVC material.

[0006] To achieve the above object, the technical solution of the present invention is to design a test method for the thermal stability time of PVC materials, comprising the following steps:

[0007] S1: Weigh PVC resin powder, heat stabilizer and other raw materials according to the formula ratio;

[0008] S2: The weighed PVC resin powder, filler, processing aid and heat stabilizer are stirred and mixed uniformly in a high-speed mixer to obtain a mixed material;

[0009] S3: Start the double-roll mill: Turn on the power of the double-roll mill, set the refining temperature, refining time, and sample thickness range, add the mixed material into the hopper of the double-roll mill, start the double-roll mill working button, perform the triangle bagging operation to process the mixed material into PVC material samples, remove the prepared PVC material samples from the double-roll mill, and cool them to room temperature for use;

[0010] S4: cutting the PVC material sample into a number of PVC sample units with the same shape and size;

[0011] S5: Take a number of equal test tubes and cut PVC sample units, fold or roll the PVC sample units into a certain shape and insert them one by one into the bottom of the test tubes, roll the test paper into a tube shape and insert it into the upper end of the test tube, leaving a distance between it and the upper end of the PVC sample unit at the bottom of the test tube, and cover the upper end of the test tube with a lid;

[0012] S6: Place several test tubes containing PVC sample units in the heat-conducting solvent inside the national standard thermal stability time testing equipment to test the thermal stability time of the PVC sample units. Record the color change time of the test paper in each test tube and calculate the average value to obtain the thermal stability time of the PVC material.

[0013] A preferred technical solution is that in step S3, the refining temperature is the plasticizing temperature of the mixed material, the refining time is 3 to 5 minutes, and the sample thickness ranges from 0.3 to 0.6 mm.

[0014] A further preferred technical solution is that in step S4, the PVC material sample is cut into a plurality of rectangular PVC sample units of uniform size.

[0015] A further preferred technical solution is that in step S5, the PVC sample units are rolled into a columnar structure, and then the columnar PVC sample units are loaded one by one into the bottom of the test tube.

[0016] A further preferred technical solution is that in step S6, the heat-conducting solvent used is methyl silicone oil.

[0017] The advantages and beneficial effects of the present invention are:

[0018] 1. A method for testing the thermal stability time of PVC materials of the present invention comprises weighing the components of the PVC material according to a specified formula, stirring and mixing them in sequence, and refining them to form a PVC material sample of uniform thickness. The PVC material sample is then cut into a plurality of PVC sample units of uniform shape and size, thereby ensuring that the quality of each test sample remains within a very small fluctuation range, laying a foundation for the reliability of the thermal stability time test results of the PVC material. In addition, the thermal stability time of the PVC material is obtained by averaging the thermal stability times corresponding to the various test samples (PVC sample units), and the thermal stability time test results are highly reliable.

[0019] 2. Compared with the traditional sample filling method of cutting the PVC material sample into small pieces and then filling them at the bottom of the test tube, the present invention significantly improves the production and processing efficiency of the PVC sample unit and the filling efficiency of the PVC sample unit in the test tube. The difficulty of filling the PVC sample unit in the test tube after folding or curling is greatly reduced, and the requirements for the operator are low, which helps to improve the overall test efficiency of the thermal stability time of the PVC material.

[0020] 3. In the test method for the thermal stability time of PVC materials of the present invention, methyl silicone oil is used as the heat-conducting solvent to replace the glycerin in the traditional test method. Since methyl silicone oil has good temperature stability and is not easy to volatilize, it eliminates the slippery phenomenon of the ground caused by the large-scale volatilization of glycerin, ensuring the safety of the experimental operators during walking.

[0021] 4. The present invention provides a method for testing the thermal stability time of PVC materials. The overall operation steps are simple, fast, safe, practical, and instructive, and it provides a new idea for testing the thermal stability time of PVC materials. DETAILED DESCRIPTION

[0022] The following examples are only used to illustrate the technical solution of the present invention more clearly, and are not intended to limit the scope of protection of the present invention.

[0023] The instrument used in Examples 1 to 3 is a K-WRWD thermal stability tester (Suzhou Keitel Instrument Equipment Co., Ltd.), wherein the thermal stabilizers are all commercially available products of Baerloch New Material Technology Co., Ltd. Specifically, the thermal stabilizer model used in Example 1 is MC 91660KA / 1, the thermal stabilizer model used in Example 2 is MC 92730KA / 1, and the thermal stabilizer model used in Example 3 is MC 92538KA. The plasticizer used in Examples 1 to 3 is commercially available dioctyl terephthalate (DOTP), and PVC resin powder and calcium powder are both commercially available products.

[0024] Table 1 Material formula of PVC materials 1 to 3 in Examples 1 to 3

[0025]

[0026] Example 1

[0027] S1: Weigh PVC resin powder, calcium powder, heat stabilizer, and plasticizer according to the PVC material formula ratio of sequence number 1 in Table 1;

[0028] S2: The weighed PVC resin powder, calcium powder, heat stabilizer, and plasticizer are stirred and mixed uniformly in a high-speed mixer to obtain a mixed material;

[0029] S3: Start the double-roll mill: Turn on the power of the double-roll mill, set the refining temperature to 175° C., the refining time to 5 minutes, and the sample thickness to 0.4 mm, add the mixed material into the hopper of the double-roll mill, activate the double-roll mill working button, perform the triangle bagging operation to process the mixed material into PVC material sample 1, remove the prepared PVC material sample 1 from the double-roll mill, and cool it to room temperature for use;

[0030] S4: Cut the PVC material sample 1 into a number of rectangular PVC sample units 1 with a size of 180 mm × 25 mm;

[0031] S5: Take three test tubes and three cut PVC sample units 1, roll the PVC sample units 1 into a columnar structure, and then install the columnar PVC sample units 1 one by one into the bottom of the test tube. Roll the test paper into a cylindrical shape and then install it in the upper end of the test tube, leaving a distance between it and the upper end surface of the PVC sample unit 1 at the bottom of the test tube. Cover the upper end of the test tube with a cap and number them in sequence as test tube 1, test tube 2, and test tube 3.

[0032] S6: Place three test tubes containing PVC sample unit 1 in methyl silicone oil (heat-conducting solvent) at 200°C inside a K-WRWD thermal stability testing machine to test the thermal stability time of the PVC sample unit 1. Record the color change time of the test paper in each test tube and calculate the average value to obtain the thermal stability time of the PVC material 1. The test results are shown in Table 3.

[0033] Example 2

[0034] The heat stability time test of PVC material 2, number 2 in Table 1, was carried out with reference to the above-mentioned Example 1. The test results are shown in Table 3.

[0035] Example 3

[0036] The heat stability time test of PVC material 3, number 3 in Table 1, was carried out with reference to the above-mentioned Example 1. The test results are shown in Table 3.

[0037] Table 2 Quality details of each PVC sample unit 1 to 3 in Examples 1 to 3

[0038]

[0039] As can be seen from Table 2, the quality of several PVC sample units corresponding to the PVC material samples of the same formula cut and produced by the method of the present invention is not much different, which lays a foundation for the reliability of the subsequent PVC material thermal stability time test results.

[0040] Table 3 Thermal stability time of PVC sample units in test tubes 1 to 3 in Examples 1 to 3

[0041]

[0042] It can be seen from Table 3 that the thermal stability time of the corresponding PVC material 1 in Example 1 is 95 minutes, the thermal stability time of the corresponding PVC material 2 in Example 2 is 135 minutes, and the thermal stability time of the corresponding PVC material 3 in Example 3 is 180 minutes. The method of the present invention can successfully test the thermal stability time of the PVC material, and the production and processing difficulty of the PVC sample unit corresponding to the PVC material is small and the production efficiency is high. The filling efficiency of the PVC sample unit in the test tube is high, and the quality fluctuation of several PVC sample units produced and processed at one time is small, thereby ensuring that the thermal stability time of the PVC material can be quickly and efficiently tested by the method of the present invention, and the test results are reliable, thereby achieving the purpose of the invention.

[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for testing the thermal stability time of PVC materials, characterized in that: The steps are as follows: S1: Weigh PVC resin powder, heat stabilizer and other raw materials according to the formula ratio; S2: The weighed PVC resin powder, filler, processing aid and heat stabilizer are stirred and mixed evenly with a high-speed mixer to obtain a mixed material; S3: Start the double-roll mill: Turn on the power of the double-roll mill, set the refining temperature, refining time, and sample thickness range, add the mixed material into the material bin of the double-roll mill, start the double-roll mill working button, perform the triangle bagging operation to process the mixed material into PVC material samples, remove the prepared PVC material samples from the double-roll mill, and cool them to room temperature for use; S4: cutting the PVC material sample into a number of PVC sample units with the same shape and size; S5: Take a number of equal test tubes and cut PVC sample units, fold or roll the PVC sample units into a certain shape and put them into the bottom of the test tubes one by one, roll the test paper into a tube and hang it on the upper end of the test tube with a distance between it and the upper end surface of the PVC sample unit at the bottom of the test tube, and cover the upper end of the test tube with a lid; S6: Place several test tubes containing PVC sample units in the heat-conducting solvent inside the national standard thermal stability time testing equipment, conduct a thermal stability time test on the PVC sample units, and record the color change time of the test paper in each test tube and then calculate the average value to obtain the thermal stability time of the PVC material.

2. The method for testing the thermal stability time of PVC materials according to claim 1, characterized in that: In the step S3, the refining temperature is the plasticizing temperature of the mixed material, the refining time is 3 to 5 minutes, and the sample thickness ranges from 0.3 to 0.6 mm.

3. The method for testing the thermal stability time of PVC materials as claimed in claim 2, characterized in that: In the step S4, the PVC material sample is cut into a plurality of rectangular PVC sample units of the same size.

4. The method for testing the thermal stability time of PVC materials according to any one of claims 1 to 3, characterized in that: In the step S5, the PVC sample units are rolled into a columnar structure, and then the columnar PVC sample units are loaded into the bottom of the test tube one by one.

5. The method for testing the thermal stability time of PVC material according to any one of claim 1, characterized in that: In the step S6, the heat-conducting solvent used is methyl silicone oil.

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