SJ/T 11039-1996 Test method for annealing point and strain point of electronic glass SJ/T11039-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for annealing point and strain point of electronic glass This standard is applicable to testing the annealing point and strain point of electronic glass. 1 Method Summary
GB9622.5--88
decreases to SJ/T11039-96
The glass fiber sample is suspended in a heating furnace, and gravity is applied to the lower end. When it is cooled at a certain speed, the relationship between the viscous elongation rate and the viscosity of the sample conforms to the following formula:
33 yuan d2.dL/d
-viscosity of the sample, Pa·S,
where:
the mass added to the sample, kg;
g——gravitational acceleration, m/s,
L-—sample length, m,
d-sample diameter, m,
dL/dt—sample elongation rate, m/s.
According to the definition, the temperature corresponding to n=101\Pa·s is the annealing point. At this time, the sample elongates by AL, = 2. 5 × 10-10 m·LF
Where: F—magnification of the optical lever system. The rest is the same as (1).
When n=191s.5Pa·s, the corresponding temperature is the strain point. At this time, the sample elongates by ALg=7.9×1012×m·4.F
The temperatures corresponding to AL, and △L are the annealing point and strain point of the sample, respectively. 2 Instruments and Equipment
2.1 Vertical Tubular Furnace
The outer diameter is 114mm and the height is 368mm. The outer diameter of the central furnace core is 29mm and the height is 305mm. There are two holes with a diameter of 8mm in the center of the furnace core, 4mm apart, where thermocouples and samples are placed respectively. The furnace temperature is adjusted by an automatic control device. During the test, the furnace temperature can be controlled at the set temperature ±2℃, as shown in Figure 1.
Approved by the Ministry of Electronics Industry of the People's Republic of China on March 21, 1988TTKNTKAa
Implemented on February 1, 1989
2.2 Temperature measurement device
GB9622.5-88
It consists of a calibrated platinum-platinum thermocouple (GB1578 "Platinum 10-Platinum Couple Wire for Standard Thermocouple") and a standard potentiometer. The cold end of the thermocouple is kept at 0℃. The measured millivolt value is converted into a temperature value (℃) according to the appendix of GB1578. 2.3 Glass filament elongation measurement device
It can accurately measure the change of glass filament length within a range of 6mm, and the measurement deviation is ±0.01mm. Usually, an optical reflector and a telescope with a scale are used, as shown in Figure 1. The fulcrum of the reflector 13 should be placed on a rigid bracket that is not subject to vibration and can be adjusted up and down, and the arm of the reflector is placed on a heavy hammer. When not testing, place it flat on a bracket that can be adjusted up and down. The length of the lever arm is, and the distance between the mirror and the scale is, then the optical lever magnification F (usually 50-100) can be calculated using the following formula. F=2g/zbZxz.net
2.4 Quartz fixture
See Figure 1.
Figure 1 Schematic diagram of test loading and sample fixture
1 Upper quartz glass fixture, 2-furnace core, 3-platinum energy-platinum thermocouple, 4-sample rack, 5-insulating material tube, 6-electric heating wire: 7-silica filler: 8-sample wire: 9-adjusting level screw, 10-lower quartz glass fixture! 11-scale, 12-telescope: 13-optical reflector 14-horizontal platform, 15 heavy hammer (1kg magnetic code) 2.5 timer
The accuracy is 1s.
3 Sample preparation
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GB9622.5-88
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 on the glass fiber is not more than 0.02mm, and it does not contain bubbles and spots. The two ends are sintered into round beads with a diameter of 2mm. The length of the wire between the round beads is 120±1mm. This is the sample. Note that the center of the two round beads on the sample and the center line of the wire should be kept in a straight line. Measure the length and diameter of the sample wire (excluding the two round beads). The diameter should be the average value of the two ends and the middle of the wire. 4 Test steps
4.1 Turn on the electric excitation to heat the tubular furnace to about 30℃ higher than the predetermined annealing point of the sample, and keep it warm for 30 minutes. 4.2, as shown in Figure 1, place the sample on the quartz fixture, carefully put it into the furnace, and hang the upper quartz fixture on the sample rack. At this time, the quartz fixture and the sample should be located in the center of the furnace and should not touch the furnace wall. If necessary, the horizontal adjustment screw on the furnace chassis can be adjusted. 4.3 The tubular furnace is cooled at a rate of 4 ± 1 ° C / min. When the sample is 20 ° C above the predetermined annealing point, the weight is hung on the lower quartz fixture with a chain, and the optical lever arm is placed on the weight. Adjust the position of the reflector fulcrum until the reflector can be seen in the field of view of the telescope. And there is a clear scale reflected by the scale on the mirror surface. 4.4 Measure the elongation value of the sample every 1 minute. During the interval, measure the potentiometer reading once at 0.5 minutes. When the sample no longer elongates, stop measuring, put down the weight, take out the quartz fixture and sample, and the test is completed. 5 Calculation
The measured data of each point are plotted on semi-logarithmic coordinate paper to form a temperature (converted from millivolts)-elongation rate relationship curve (equally divided coordinates represent temperature, and logarithmic coordinates represent elongation rate). This line intersects with the calculated elongation rate AL and the AL straight line. The temperatures corresponding to the intersection points are the annealing point and the strain point, respectively, as shown in Figure 2.
6 Test results and accuracy
Strain point
Fire point
Temperature ℃
Figure 2 Temperature-elongation rate relationship diagram
The allowable measurement error of this method is ±1℃ for annealing point and ±2℃ for strain point. When the difference between the two parallel measurement data 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, standard samples should be used regularly to perform calibration tests according to the above steps to calculate the correction value, which should be added when calculating the test results of the samples. The annealing point and expansion coefficient of the selected standard sample should be close to the annealing point and expansion coefficient of the test sample. Additional note: This standard was drafted by Factory 4400 of the Ministry of Electronics Industry. The main drafters of this standard are Bai Yixiang, Pang Shuqin and Liu Chenggou. 3
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