SJ/T 11038-1996 Test method for softening point of electronic glass SJ/T11038-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for softening
point of electronic glass
This standard is applicable to the softening point of electronic glass. 1 Summary of the methodbzxz.net
GB9622.4-88
Reduced to SJ/T11038-96
Glass fiber samples of the specified size are vertically suspended in a furnace for heating. Under the action of their own gravity, the elongation speed and temperature of the sample are measured. The temperature when the elongation speed of the sample reaches a certain value is the softening point (for glass with a density of 2.5g/cm, the temperature corresponding to the viscosity of 10Pa·s is the softening point).
2 Equipment and Instruments
2.1 Vertical Tubular Furnace
See Figure 1, height 155mm, outer diameter 102mm, inner diameter 6mm, uniform temperature area 25mm, furnace temperature can be raised to 1000℃, and the furnace temperature is adjusted by automatic control device.
Figure 1 Vertical Tubular Furnace
Approved by the Ministry of Electronics Industry of the People's Republic of China on March 21, 1988TTTKKAca
Implementation on February 1, 1989
GB9622.4-88
1—Insulation material furnace top, 2 Insulation material spacing diagram; 3—Insulation material positioning sheet, 4—Steel furnace core; 5—Mica insulation medium; 6 Electric heating wire: 7—Insulation layer 8— Diatomaceous earth filler: 9-insulating material furnace bottom: 10 bracket top plate: 11-sample wire: 12-bracket 13-glass window: 14-bracket bottom plate, 15-insulating material tube, 16-pull rod, 17-furnace light: 18-thermocouple guide tube; 19-sample wire fixture 2.2 Temperature measurement device
It consists of a calibrated platinum-platinum thermocouple (see GB1578 "Standard Thermocouple Platinum-Platinum Couple Wire") and a standard potentiometer. The cold end of the thermocouple is kept at 0℃. The measured millivolt value is converted into temperature value (℃) according to the appendix of GB1578. 2.3 Glass wire elongation measurement device
Use a reading microscope or telescope and a scale assembly, etc., and the measurement error is required to be no more than 0.02mm. 2.4 The timer
The accuracy is 1s.
3 Sample preparation
Select the glass to be tested without defects such as stones, bubbles and stripes, and draw it into a glass fiber with a diameter of 0.65±0.10mm. The diameter difference of each part of the glass fiber is no more than 0.02mm, and it does not contain bubbles and spots. The end of the glass fiber is sintered into a round bead with a diameter of 2mm, and a length of 235±1mm (excluding the round bead) is cut as the sample.
4 Test steps
4.1 Turn on the power to heat the tubular furnace to about 30℃ higher than the predetermined softening point of the sample, and then reduce the furnace temperature to about 20℃ lower than the predetermined softening point.
4.2 Pass the sample wire through the small hole of the fixture and hang it freely in the center of the furnace. Check that the sample does not touch the furnace wall. If necessary, adjust the horizontal screw on the bottom plate.
4.3 Heat the tubular furnace at a rate of 5±1℃/min, and adjust the measuring device to clearly observe the lower end of the sample wire. When the sample wire stretches at 0.1mm/min, start recording, and record the sample elongation value every 1min. In the interval, record the millivolt reading of the potentiometer once at 0.5min. Until the elongation rate of the sample wire reaches 1.20mm/min. Other interval times can also be selected arbitrarily. 4.4 Take out the sample and lower the furnace temperature to prepare for the test of the next sample. 5 Calculate
Make a temperature (converted from millivolts)-elongation rate relationship diagram on semi-logarithmic coordinate paper with the measured data. The equally divided coordinates represent the temperature, and the logarithmic coordinates represent the elongation rate. Obtain the corresponding points and connect the points into a straight line. This straight line intersects with the straight line with an elongation rate of 1.0mm/min. The temperature corresponding to the intersection is the softening point, see Figure 2. Elongation
mm/min
6Test results and accuracy
Figure 2 Temperature-elongation rate relationship
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Softening point
Temperature ℃
GB9622.4—88
This method allows a measurement error of ±1.0℃. When the difference between the data of two parallel measurements of the same batch of samples is within this range, the average value is taken as the test result. In order to ensure the accuracy of the test results, the test device should be calibrated regularly using standard samples. The softening point and density of the selected standard sample should be close to the values ​​of the test sample. Calculate the correction value of the test device and correct the results of the test sample. Additional notes:
This standard was drafted by Factory 4404, Factory 4400 and the Standardization Research Institute of the Ministry of Electronics Industry. The main drafters of this standard are: Luo Shenghua, Bai Yixiang, Pang Shuqin and Liu Chengjun. YYKAoNrkAca
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