This method is applicable to the determination of thermal conductivity of glass fiber reinforced plastics by the plate steady-state method. GB/T 3139-1982 Test method for thermal conductivity of glass fiber reinforced plastics GB/T3139-1982 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T3139-1982
Test method for thermal conductivity of glass fiber reinforced plastics
National Bureau of Standards
1983—05—01
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Test method for thermal conductivity of glass fiber reinforced plastics
3139-1982
1 Test specimen
2 Test conditionswwW.bzxz.Net
3 Test equipment
4 Test steps
6 Test report
Additional remarks Description:
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Test method for thermal conductivity of FRP
This method is applicable to the determination of thermal conductivity of FRP by the plate steady-state method.
Thermal conductivity of FRP
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1 Sample
1.1 Preparation
The sample is prepared in accordance with the provisions of GB1446 "General Principles for Test Methods for Performance of FRP" or directly made into W according to product requirements
1.2 Size
The size of the sample should meet the following requirements:
a. The side length or diameter of the sample should be equal to that of the heating plate. b. The thickness of the sample is at least 5 mm and the maximum is not more than 1/10 of its side length or diameter. 1.3 Surface
The surface of the sample should be flat, the surface unevenness should not be greater than 0.5 mm/m, and the two sides of the sample should be parallel. 1.4 Pretreatment
The sample should be dried to constant weight at a temperature that does not cause deterioration or deformation (but the maximum should not exceed 105℃) or treated according to the product "Glass
Fiberglass
Thermal Coefficient
Technical requirements. The so-called constant weight means that the weight change of the sample at the treatment temperature is not more than 0.2% after 2 hours. 1.5 Quantity
Each group of samples shall not be less than 3 pieces.
3139-1982
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2 Test conditions
2. 1 Test environment
The test environment conditions shall comply with the provisions of GB1446WW
2.2 Test temperature and temperature difference
The maximum temperature of the hot plate shall not exceed 250℃, the temperature of the cold plate shall be from room temperature to the required temperature, and the temperature difference between the two sides of the sample shall not be less than 10sin
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a. The side length or diameter of the heating plate is generally 100 mm, and the width of the heating plate is 1/4 of the side length or diameter of the heating plate, and appropriate insulation measures shall be taken. If there are special measures, and the error of the measured value of thermal conductivity is guaranteed to be within 8%, this heating plate consists of a main heating plate and a protective heating plate that surrounds the main heating plate and has a certain gap. The requirements are: M
b. The temperature difference of each point on the surface of the main heating plate is not greater than 2% of the temperature difference between the two sides of the sample in a stable state, but the maximum shall not exceed 3 test equipment
0.5℃. The temperature difference of each point on the surface of the protective heating plate is not greater than 5% of the temperature difference between the two sides of the sample in a stable state, and the maximum shall not exceed 1. The main technical parameters of the test instrument and equipment shall meet the following requirements. b. The size of the cooling plate and the surface state of the contact sample are the same as those of the heating plate, but the cooling plate is not spaced. The temperature measurement should be accurate to 1% of the temperature difference between the two sides of the sample in a stable state, but the maximum shall not exceed 0.5℃. C. The surface unevenness of the heating plate should not exceed 0.25 mm/m. 3.1 Heating plate
a. The cooling plate should have a threaded two-way liquid circuit, and the value can also be appropriately changed.
3.2 Cooling plate
3.3 Measurement accuracy
The power of the main heating plate should be measured accurately to 1%. 3.3.1 Temperature
3.3.2 Power
GRP conductivity
Thermal coefficient
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4 Test steps
4.1 Sample appearance inspection
The sample shall be inspected in accordance with the provisions of GB1446. W
4.2 Sample thickness measurement
Measure the sample thickness at least 4 times with an accuracy of 0.05 mm and take the arithmetic mean. 4.3 Install the sample for testing
When installing the sample, pay attention to eliminating the air interlayer. 4.4 Adjust the balance
Adjust the temperature difference between the main heating plate and the protective heating plate, as well as the temperature difference between the main heating plate and the bottom heating plate to achieve balance. The thermal conductivity test error caused by imbalance shall not be greater than 1%. 4.5 Measure
Testing
The thermal conductivity of the FRP
After reaching a stable state, measure the power of the main heating plate and the temperature difference between the two sides of the sample. The test is over. The so-called stable state means that when the power of the main heating plate remains unchanged, the temperature fluctuation on the surface of the sample within 30 minutes is not greater than 1% of the temperature difference between the two sides of the sample, but the maximum shall not be greater than 1°C. 3139-1982 Page 7 5 Calculation of thermal conductivity (cal/cm·sec·C) is calculated as follows: 0.239W·d Where: W--power of the main heating plate when it is stable, W; d--thickness of the sample, cm; S--calculated area of ​​the main heating plate, cm [2]; △t--temperature difference between the two sides of the sample, °C. Page 8 6 Test report The test report shall comply with the requirements of GB1446, but the test results only need to give the thermal conductivity value and arithmetic mean of each sample. FRP thermal conductivity Page 9 Additional remarks: This standard is proposed by the State Building Materials Industry Bureau and is under the jurisdiction of the FRP standardization technical management unit of the State Building Materials Industry Bureau.
This standard was drafted by the Beijing FRP Research Institute of the State Building Materials Industry Bureau. W
The main drafters of this standard are Yu Changgen and Lei Guodongec.
FRP Guide
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