GB/T 2572-1981 Test method for average linear expansion coefficient of glass fiber reinforced plastics GB/T2572-1981 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T2572-1981
Test Method for Average Linear Expansion Coefficient of Glass Fiber Reinforced Plastics General Administration of Standardization of the People's Republic of China
1981—10—01
Page 1
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《Test Method for Average Linear Expansion Coefficient of Glass Fiber Reinforced Plastics》Data Compilation
2572-1981
1. Scope of Application
2. Specimen.
3. Test Conditions.
4. Test Procedures
5. Calculation
Page 2
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《Test Method for Average Linear Expansion Coefficient of Glass Fiber Reinforced Plastics》
2-1981
Scope of Application
1. This method is used to determine the average linear expansion coefficient of glass fiber reinforced plastics. sinoaec.com
Glass Fiber Reinforced Plastic Flat
Expansion Coefficient
Test Method
2572-1981
Page 3
II. Sample
2. The sample is cylindrical. The diameter is 610 mm and the length is 50, 100 mm. The cross section of the sample can also be square with a side length of 5 to 7 mmsinoaec.com
3. The end face of the sample must be flat and perpendicular to the long axis of the sample. The non-parallelism of the two end faces should be less than 0.01 mm. Glass Fiber Reinforced Plastic Flat
Expansion Coefficient
Test Method
2572-1981
Page 4
III. Test Conditions
5. The test environment conditions should comply with the provisions of the Glass Fiber Reinforced Plastic Performance Test Method GB1446-78. 6. Test equipment: Any expansion instrument that can heat the sample uniformly, control the sample temperature rise rate, and measure the sample temperature and its relative elongation can be used. The temperature fluctuation in the uniform temperature zone of the heating furnace shall not exceed 0.5°C. The accuracy of the device for measuring the change in sample length shall reach 0.001 mm. The accuracy of the sample temperature measuring device shall reach 0.5. C
7. The heating rate is 1±0.2°C/min.
Glass 4
Test method
Expansion coefficient
2572-1981
Page 5
IV. Test stepsWww.bzxZ.net
8. The sample preparation shall be in accordance with the provisions of the glass fiber reinforced plastic performance test method GB1446-78 or directly pressed in accordance with the product standard. 9. The appearance inspection of the sample shall be in accordance with the provisions of the glass fiber reinforced plastic performance test method GB1446-78. ww.
10. Sample pretreatment: After the sample is treated at the peak temperature of resin curing for 2 hours or treated according to the product technical requirements, it is naturally cooled to room temperature in the oven.
11. Number the samples. Measure the length of each sample three times and take the arithmetic mean. The measurement accuracy is ±0.05 mm. 12. Place the sample so that the central axis of the sample is consistent with the axis of the quartz tube of the expansion meter, and calibrate the zero point to make it stable. 13. Start the heating device and heat the sample at a heating rate of 1±0.2°C/min. Record the temperature T and the corresponding change in the length of the sample △L until the required test temperature.
|Fiberglass Average Linear Expansion Coefficient Test Method
2572-1981
Page 6
V. Calculation
14. Draw the expansion-temperature curve. Calculate the average linear expansion coefficient of the curve or calculate the average linear expansion coefficient within a certain temperature interval as required.
15. The average linear expansion coefficient α (1/°C) is calculated as follows: AL
aT1~T2=
+aquartz
K·LO·△T
Wherein: LO is the length of the sample at room temperature, mm; K is the magnification of the sample elongation measuring device; △T is the temperature difference, C, and △T=T2-T1; △L is the elongation of the sample corresponding to △T, mm; aquartz
is the average linear expansion coefficient of quartz corresponding to the test temperature (T1-T2), generally taken as 0.51×10[-6] (1/°C);
T1, T2 are the lower and upper limits of the temperature interval. 16. The test results are expressed as the arithmetic mean of each group of samples, taking two significant figures. 17. The test report shall comply with the provisions of the glass fiber reinforced plastic performance test method GB1446-78. Page 7
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Glass Fiber Reinforced Plastic Flat
Expansion Coefficient
Test Method
2-1981
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