JB/T 6236.2-1992 Test methods for resin-impregnated glass fiber non-weft lashing tapes for electrical use
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Test Method for Resin-impregnated Glass Fiber Lashing Tape for Electrical Use
1 Subject Content and Scope of Application
JB/T6236.2—92
This standard specifies the test method for resin-impregnated glass fiber lashing tape for electrical use (hereinafter referred to as lashing tape). This standard is applicable to semi-cured lashing tape made of alkali-free glass fiber yarn impregnated with thermosetting resin after merging. 2 Reference standards
GB1408
GB1411
Test method for power frequency electrical strength of solid insulating materialsTest method for high voltage and low current intermittent arc resistance of solid electrical insulating materialsGB11026.1
Guidelines for determining the heat resistance of electrical insulating materialsGeneral procedures for formulating aging test methods and evaluating test results3 Test preparation and test conditions
3.1 Preparation for performance test before curing
3.1:1 Sampling
Take out the sample of the weftless tape reel (hereinafter referred to as the reel) or weftless tape roll (hereinafter referred to as the roll) from the cold wearing box, place it under the environmental conditions of temperature 23±2℃ and relative humidity (50±5)% (hereinafter referred to as standard conditions), and unseal and sample it after 24 hours. Before sampling, at least the outermost two layers of the sample should be removed. After sampling, the sample should be tested immediately. The remaining samples should be immediately placed in the original packaging and stored in a refrigerator.
3.1.2 Cleaning of test equipment
Before and after the test, the parts of the test equipment that come into contact with the sample must be wiped clean with a cotton ball dipped in solvent and kept ready for use after the solvent evaporates. 3.2 Preparation of performance test after curing
3.2.1 Sample preparation
Take samples according to 3.1.1, and then prepare the samples according to the requirements of each performance test (see Part 3). The sample surface should be flat, free of bubbles, delamination, resin accumulation or lack, wrinkles, warping, and damage. 3.2.2 Cleaning of sample surface
Before pretreatment, wipe the sample with a silk cloth dipped in anhydrous ethanol. Before the test, wipe the sample with a clean silk cloth. 3.2.3 Sample pretreatment conditions
The sample is pretreated under standard conditions for 24 hours.
3.3 Test conditions
Unless otherwise specified in the product standard, the test is carried out under standard conditions. 4 Width
4.1 Test equipment
Steel ruler, graduation value 0.5mm, length 300mm. 4.2 Test procedure
Approved by the Ministry of Machinery and Electronics Industry on June 16, 199232
Implemented on January 1, 1993
JB/T6236.2--92
Unwind the reel (coil), place the sample naturally on a smooth platform, and measure the width with a steel ruler at five locations about 300mm apart from the end, starting from about 150mm away from the end, with an accuracy of 0.5mm. 4.3 Test results
Take the median of the five measured values as the test result. 5 Thickness
5.1. Test equipment
a. Outside micrometer, graduation value 0.01mm, measuring range 0~25mm, measuring surface diameter 6.5mm; b. Polyester film, nominal thickness 50μm, width 20mm, length about 1200mm, appearance without defects. 5.2 Test procedure
Evenly distribute the thickness of the polyester film at ten locations, and take the median of the ten measured values as the thickness d1 of the polyester film. Cut the polyester film into small pieces with a length not less than the width of the non-weft tape. After unwinding the tape reel (roll), place the sample on a smooth platform, and cover the sample surface symmetrically from top to bottom at ten locations about 150mm away from the end and about 300mm apart. Use an outside micrometer to measure the thickness d at the center of the ten locations. 5.3 Test results
Thickness is calculated according to formula (1):
d = d, - 2d,
Where: d -. Thickness of sample, mm;
d, thickness of polyester film, mm
d, - total thickness of sample and two layers of polyester film, mm Take the median of ten calculated values as the test result, and round to two significant figures. 6 Length
Estimate the length of the flat tape of the reel (reel) according to the net mass, width and quantitative quantity of the flat tape of the tested reel (reel). (1)
Three reels (reels) are randomly selected from the same batch of reels (reels). The net mass of the flat tape of each reel (reel) is provided by the manufacturer, and the width is measured according to Chapter 4. The quantitative quantity is provided by the manufacturer after measurement according to Appendix A. The length of the non-warp tape of the inspected reel (roll) is calculated according to formula (2): 1
×10°
Wherein: 1—the length of the non-warp tape of the inspected reel (roll), m; m—the net mass of the non-warp tape of the inspected reel (roll); kgG—the basis weight of the batch of non-warp tape, g/m;
b—the width of the non-warp tape of the inspected reel (roll), mm. The median of the three calculated values is taken as the test result, accurate to 1m. 7 Volatile content and resin content
7.1 Test equipment
High temperature furnace, temperature control accuracy ±20℃;
Drying box, maximum temperature not less than 250℃, temperature control accuracy ±2℃; analytical balance, graduation value 0.001gt
Mercury thermometer or other suitable temperature measuring device, graduation value 1℃; porcelain, capacity not less than 30ml;
Dryer;
JB/T 6236.2-92
Steel ruler, graduation value 1mm, length not less than 300mm. 7.2 Test specimen
Test specimen is about 300mm long; quantity three.
7.3 Test procedure
7.3.1 Determination of porcelain mass
Place the porcelain crucible in a high-temperature furnace and burn it at 625±20℃ for 20min. Take it out and put it in a desiccator. After cooling to room temperature, weigh it to the accuracy of 0.001g. Repeat the above procedure until the mass change between two consecutive times is no more than 0.001g. Place it in a desiccator for use. Weigh it again before use to the accuracy of 0.001g.
7.3.2 Determination of sample mass before and after drying
Roll the sample into a loose small roll, put it into the weighed porcelain crucible, weigh it immediately, and calculate the sample mass m1 before drying to the accuracy of 0.001-g. Then put it in a drying oven and dry it at the temperature specified in the product standard for 1h. Take it out and put it in a desiccator. After cooling to room temperature, weigh it and calculate the sample mass mz after drying to the accuracy of 0.001g. Place it in a desiccator for use. 7.3.3 Determination of the mass of the residue after ignition
Put the porcelain crucible containing the sample dried according to 7.3.2 into a high-temperature furnace and ignite at 625±20℃ for at least 30min until all the carbon disappears. Take it out of the high-temperature furnace and put it into a desiccator. After cooling to room temperature, weigh it and calculate the mass of the residue after ignition m, accurate to 0.001g.
7.4 Test results
The volatile matter content and resin content are calculated according to formula (3) and (4) respectively: S = m yuan m × 100 c
Where, S, volatile matter content, %;
S. Resin content; %;
The mass of the sample before drying, g:
m—The mass of the sample after drying, gt
m:——The mass of the residue after ignition, g. Take the arithmetic mean of the three calculated values as the test result, rounding to two significant figures. 8. Soluble resin content
Test equipment
Drying oven, the highest temperature is not less than 200℃, the temperature control accuracy is ±2℃; analytical balance, graduation value 0.001g;
mercury thermometer or other suitable temperature measuring device, graduation value 1℃;: solvent, as specified in the product standard or agreed upon by the supply and demand parties; beaker, 600~1000ml;
porcelain plate:
dryer;
filter paper;
polyester film, nominal thickness not less than 40μm; steel ruler, graduation value 1mm, length not less than 300mm. 8.2 Test sample
Same as Article 7.2. The sampling point should be as close as possible to the sampling point of the volatile content and resin content samples. 8.3 Test procedure
JB/T6236.292
Roll the sample into a loose (not to be scattered) small roll, place it on the weighed polyester film, and weigh it. Calculate the mass of the sample before immersion in the solvent, mi, accurate to 0.001g.
Prepare six beakers, each containing about 500ml of solvent, for the first and second immersion of three samples. Immerse each sample in two beakers for 10 minutes, take it out and place it on filter paper. After the sample is slightly dry, place it on a porcelain plate lined with clean filter paper, and then put it in a drying oven. Bake it at the temperature specified in the product standard for 1h, take out the sample, put it in a desiccator, cool it to room temperature, and weigh it. Calculate the mass of the sample after immersion in the solvent, mz, accurate to 0.001g. 8.4 Test results
The soluble resin content is calculated according to formula (5):
Where; S, soluble resin content, %
S,a. Volatile content, %
S. Resin content, %
S, = m) - m, - m, · Si
m—Sample mass before immersion in solvent, g;
mz—Sample mass after immersion in solvent, g.
Take the arithmetic mean of the three calculated values as the test result, and take two significant figures. 9 Curability
Test equipment
Drying oven, the maximum temperature is not less than 250℃, the temperature control accuracy is ±2℃; b.
Mercury thermometer or other suitable temperature measuring device, the graduation value is 1℃; (5)
Mold, composed of two 120mm×80mm×20mm steel plates. The surface roughness of the upper and lower surfaces of each steel plate c.
parameter Ra value is 0.8μm, and the edge is blunt; d. Heavy object;
Polytetrafluoroethylene film.
9.2 Test specimen
The test specimen is about 100 mm long and one in number.
9.3 Test procedure
9.3.1 Place the die and weight in a drying oven and preheat to the test temperature specified in the product standard. 9.3.2 Place the test specimen with the upper and lower surfaces covered with polytetrafluoroethylene film flatly between the upper and lower die. If necessary, press with a weight so that the test specimen is subjected to a pressure of about 0.02 MPa. After heating at the test temperature for 2 h, take out the test specimen with the film and lay it flat. After cooling to room temperature, peel off the film and take out the test specimen. The die and weight are still preheated in the drying oven. 9.3.3 Cut the test specimen into two sections of approximately equal length and overlap them (with the ends staggered by 2 to 3 mm). Repeat 9.3.2 so that the overlapped test specimen is subjected to a pressure of about 0.4 MPa. Peel the overlapped test specimens between layers to observe whether they are easy to peel and non-sticky. After the test, remove the die and weight.
9.4 Test results
The superimposed specimens are easy to peel off and do not stick together, which is qualified. 10 Tensile strength and elongation at break
Test equipment and instruments
Testing machine, with a suitable load range, the relative error of the load indication does not exceed 1%; 8.
Steel ruler, graduation value 0.5mm, length not less than 300mm; b.
Cardboard, nominal thickness 0.5~1.0mm;
d. Heavy objects;
e. Adhesive cured at room temperature.
10.2 Specimens
10.2.1 Specimen size and quantity
JB/T6236.292
The specimen size is shown in Figure 1, and the specimen width is the original width of the non-weft belt and is not more than 30mm. The quantity is not less than five. 10.2.2 Preparation of the specimen
Fix one end of the flat tape and hang a weight on the other end so that the flat tape bears a tensile force of 1N per millimeter of width. Stick a cardboard reinforcement sheet with adhesive evenly coated on one side on the flat tape according to Figure 1. After curing, remove the weight and cut the specimen according to Figure 1. 10.2.3 Measurement of specimen size
Measure the width of the specimen at three locations in the middle of the specimen with an accuracy of 0.5mm using a steel ruler. Take the median value as the width of the specimen. 10.3 Test procedure
Adjust the gap between the jaws of the test machine fixture to 200mm, clamp the specimen so that the longitudinal axis of the specimen coincides with the longitudinal axis of the upper and lower fixtures. The test speed is 10mm/min, and the load is applied to the specimen evenly and continuously until the specimen fails. Record the failure load and the increment of the gap between jaws. If failure occurs in the reinforcement sheet or at the overlap, the test is invalid. Supplementary tests are performed until the number of valid tests is five. 50
10.4 Test results
1-Weftless tape;
Figure 1 Specimen dimensions
2-Reinforcement sheet;
b-Weftless tape original
Tensile strength is calculated as the breaking load of each 10mm wide specimen, in N/10mm width. Elongation at break is calculated as the relative increment of the gap spacing and expressed as a percentage.
Take the arithmetic mean of five valid test calculation values as the test result. Take three significant figures for tensile strength and two significant figures for elongation at break. Take the median of the widths of five valid test specimens as the specimen width and indicate it in the test report. 11 Electrical Strength
11.1 Test Equipment and Apparatus
Electrical Strength Test Equipment, according to Chapter 5 of GB1408; Electrode System, upper and lower electrodes with diameters of 6mm, edges with radius of 1mm, electrode material of brass, total mass of upper electrode of 500±10g: To ensure good contact between electrode and specimen, a suitable electrode holder can be used; c.
Constant pressure thickness gauge, graduation value of 0.01mm, measuring surface diameter of about 6mm, pressure applied to specimen of 7±0.7MPa; d.
Polytetrafluoroethylene film;
Polyester pressure-sensitive adhesive tape.
11.2 Specimens
After overlapping two 150mm long non-weft tapes, sandwich them between clean polytetrafluoroethylene films, and cure them under a pressure of 0.05MPa (curing conditions are in accordance with product standards) to make strip specimens, three in number. 11.3 Test procedure
Perform according to GB1408.
JB/T6236.2—92
The test is carried out in air with continuous pressure rise. For samples with a width of less than 25 mm, polyester pressure-sensitive adhesive tape is attached along the length edge to prevent arcing. The distance between the test point and the end (except for the process burrs) is not less than 25 mm, and the interval between adjacent test points is not less than 30 mm. A total of ten points are punctured. Measure the thickness of the sample at each puncture point with an accuracy of 0.01 mm. 11.4 Test results
Take the median of the ten calculated values as the test result, and take two significant figures. The test report should indicate the nominal width and nominal thickness of the non-weft belt sample. 12 Arc resistance
12.1 Test equipment and instruments
High-voltage and low-current intermittent arc resistance test equipment, according to Chapter 5 of GB1411; constant pressure thickness gauge, same as 11.1 c;
Polytetrafluoroethylene film.
12.2 Test specimen
The strip test specimen is made by overlapping four non-weft strips of about 150 mm in length, and the rest is the same as 11.2. The thickness of each test specimen is measured at five locations evenly distributed, and the distance between the measuring location and the end (excluding the process burrs) is not less than 25 mm. The median value of the 15 measured values is taken as the thickness of the test specimen, accurate to 0.01 mm. 12.3'Test procedure
Perform according to GB1411.
Electrodes are arranged along the length direction of the test specimen, and the distance between the test point and the end (excluding the process burrs) is not less than 25 mm, and the interval between the centers of adjacent test points is not less than 20 mm, with a total of nine test points. After each test point, exhaust is required, and the electrode tip is wiped with a silk cloth dipped in anhydrous ethanol. A blank test is performed and then exhaust is performed again.
12.4 Test results
Take the median of the nine test values as the test result, accurate to 1s. The test report shall indicate the nominal width, nominal thickness and specimen thickness of the non-wefted tape sample. 13 Tensile strength and elongation at break of annular specimens 13.1 Test equipment and instruments
Testing machine, same as Article 10.1 a. A circulating blast heating furnace shall be provided for hot tensile testing, with a temperature control accuracy of ±2°C; b.
A dial indicator or other suitable deformation meter, the relative error of the indicated value shall not exceed ±1%; the tensile test fixture consists of two symmetrical parts, upper and lower, as shown in Figure 2. The fixture is equipped with a device for installing a strain gauge, a drying oven with a maximum temperature of not less than 250°C and a temperature control accuracy of ±2°C; a heating oil bath with a temperature control accuracy of ±2°C; a
mercury thermometer or other suitable temperature measuring device with a graduation value of 1°C; a vernier caliper with a vernier reading of 0.02mm; a sample holder for oil immersion test, made of metal, as shown in Figure 3; insulating oil, the model shall be in accordance with the product standards or agreed upon by the supply and demand parties. 37Www.bzxZ.net
13.2 Test specimen
13.2.1 Preparation of annular test specimen
JB/T6236.2—92
Figure 2 Schematic diagram of tensile test fixture
1—Fixture body;
2—Blocking ring cam;
3—Locate pin
Slots are evenly distributed
Figure 3, Schematic diagram of test specimen holder for oil immersion test A
Evenly coat the mold for preparing annular test specimen (as shown in Figure 4) with a release agent, heat it to 80-100℃, and wrap the non-weft tape with a width of 10mm flatly around the mold according to the binding tension specified in the product standard. The winding thickness should make the size of the cured test specimen meet the requirements of Article 13.2.2.
JB/T6236.2—92
Put the mold wrapped with the non-weft tape into a drying oven for curing. The curing conditions are in accordance with the product standards. After curing, take out the mold, cool it to room temperature and demould it. Use sandpaper to wipe off the resin burrs and resin deposits on the surface of the sample. 1os
Figure 4 Schematic diagram of the mold for preparing annular specimens 1-mandrel;
13.2.2 Dimensions and number of specimens
2-partition;
3-specimen,
4-core disk,
5-oyster shell
The dimensions of the specimens are shown in Figure 5. The number of specimens tested in normal state, hot state and after oil immersion is not less than five. 0
Figure 5 Dimensions of annular specimens
13.2.3 Measurement of specimen dimensions
Measure with a vernier caliper. Measure the width and thickness of five points evenly distributed along the circumference of the annular specimen to an accuracy of 0.02mm. The arithmetic mean of the five-point measurement values is used as the width and thickness of the specimen, respectively, and is taken to 0.02mm. Measure the inner diameter of the specimen from two mutually perpendicular directions to an accuracy of 0.02mm. The arithmetic mean of the two measurement values is used as the inner diameter of the specimen, and is taken to 0.02mm. The sum of the inner diameter and thickness of the specimen is the median diameter of the specimen, and is taken to 0.1mm.
13.3 Test procedure
13.3.1 Normal tensile strength and elongation at break Accurately align the part of the tensile fixture that contacts the specimen, mount the specimen on the fixture, and tighten the cover or retaining ring cam. Install the strain gauge on both sides of the fixture as shown in Figure 6), adjust its zero point. 39
JB/T6236.292
The test speed is 5mm/min. Apply the load evenly and continuously until the specimen fails. Record the failure load and the deformation increment of the specimen on both sides of the fixture. If the specimen fails intermittently or is not completely destroyed, the test is invalid. Supplementary tests are performed until the number of valid tests is five. Figure 6 Schematic diagram of the installation position of the device for measuring deformation 1-Tensile test fixture;
13.3.2. Hot tensile strength
2-Specimen;
3-Strain gauge;
4-Deformometer
Install the specimen according to Article 13.3.1. Preheat for 30 minutes according to the test temperature specified in the product standard, and perform the tensile test according to Article 13.3.1 at this test temperature, and record the failure load. 13.3.3 Tensile strength after oil immersion
Put the specimen on the specimen holder for oil immersion test, immerse it in insulating oil at 105±2℃, take it out after 24 hours, cool it to room temperature, and check whether the specimen is delaminated or cracked.
If there is no delamination or cracking, perform the tensile test according to Article 13.3.1, and record the failure load. 13.4 Test results
The tensile strength is calculated according to formula (6):
Where:. -
-Tensile strength, MPa
-Failure load, N;
6-Specimen width, mm;
dSpecimen thickness. mm.
Elongation at break is calculated according to formula (7):
In the formula, e-
-Elongation at break, %
JB/T6236.2—92
is the deformation increment of the specimen on both sides of the fixture at the time of failure, mm; ALAL
D-Medium diameter of the specimen, mm.
Take the arithmetic mean of five valid test calculation values as the test result. The tensile strength is taken to three significant figures, and the elongation at break is taken to two significant figures.
14Tensile elastic modulus of annular specimen
The tensile elastic modulus of annular specimen is measured by strain gauge method or deformation meter method. The strain gauge method is used in arbitration test. 14.1 Test equipment and instruments
a. Testing machine, same as in 10.1a;
·b. Instruments and meters for measuring deformation, strain gauge method uses strain gauge and resistance strain gauge, and strain gauge method uses dial indicator or other suitable strain gauge, the relative error of the indicated value shall not exceed 1%; c. Tensile test fixture, same as in 13.1c, d. Vernier caliper, vernier reading value 0.02mm; e. Adhesive.
14.2 Test specimen
Same as in 13.2.
14.3. Test procedure
Install the specimen and the instruments and meters for measuring deformation according to 13.3.1, as shown in Figure 6. When using the strain gauge method, the strain gauge shall be pasted on the specimen in advance according to the strain gauge manual and the position shown in Figure 6, and the seam end of the specimen shall be avoided when pasting. The test speed shall be selected according to the convenience of measuring and reading deformation. Apply initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters used to measure deformation, and add load continuously or step by step until 50% of the failure load is reached. Record the load and the corresponding stress or deformation. Draw a load-strain curve (strain gauge method) or a load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
DAF
E = 26.d(2L + △L)
Where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by strain gauge method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, rounding to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of the 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105 ± 2 ° C for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
Perform according to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and apparatus
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 4202mm. Measure the inner diameter of the specimen from two mutually perpendicular directions to the nearest 0.02mm. Take the arithmetic mean of the two measured values as the inner diameter of the specimen to the nearest 0.02mm. The sum of the inner diameter and thickness of the specimen is the median diameter of the specimen to the nearest 0.1mm.
13.3 Test procedure
13.3.1 Normal tensile strength and elongation at break Accurately align the part of the tensile fixture that contacts the specimen, mount the specimen on the fixture, and tighten the cover or retaining ring cam. Install the strain gauge on both sides of the fixture as shown in Figure 6), and adjust its zero point. 39
JB/T6236.292
The test speed is 5mm/min. Apply the load evenly and continuously until the specimen fails. Record the failure load and the deformation increment of the specimen on both sides of the fixture. If the specimen fails intermittently or is not completely destroyed, the test is invalid. Supplementary tests are performed until the number of valid tests is five. Figure 6 Schematic diagram of the installation position of the device for measuring deformation 1-Tensile test fixture;
13.3.2. Hot tensile strength
2-Specimen;
3-Strain gauge;
4-Deformometer
Install the specimen according to Article 13.3.1. Preheat for 30 minutes according to the test temperature specified in the product standard, and perform the tensile test according to Article 13.3.1 at this test temperature, and record the failure load. 13.3.3 Tensile strength after oil immersion
Put the specimen on the specimen holder for oil immersion test, immerse it in insulating oil at 105±2℃, take it out after 24 hours, cool it to room temperature, and check whether the specimen is delaminated or cracked.
If there is no delamination or cracking, perform the tensile test according to Article 13.3.1 and record the failure load. 13.4 Test results
The tensile strength is calculated according to formula (6):
Where:. -
-Tensile strength, MPa
-Failure load, N;
6-Specimen width, mm;
dSpecimen thickness. mm.
Elongation at break is calculated according to formula (7):
In the formula, e-
-Elongation at break, %
JB/T6236.2—92
is the deformation increment of the specimen on both sides of the fixture at the time of failure, mm; ALAL
D-Medium diameter of the specimen, mm.
Take the arithmetic mean of five valid test calculation values as the test result. The tensile strength is taken to three significant figures, and the elongation at break is taken to two significant figures.
14Tensile elastic modulus of annular specimen
The tensile elastic modulus of annular specimen is measured by strain gauge method or deformation meter method. The strain gauge method is used in arbitration test. 14.1 Test equipment and instruments
a. Testing machine, same as in 10.1a;
·b. Instruments and meters for measuring deformation, strain gauge method uses strain gauge and resistance strain gauge, and strain gauge method uses dial indicator or other suitable strain gauge, the relative error of the indicated value shall not exceed 1%; c. Tensile test fixture, same as in 13.1c, d. Vernier caliper, vernier reading value 0.02mm; e. Adhesive.
14.2 Test specimen
Same as in 13.2.
14.3. Test procedure
Install the specimen and the instruments and meters for measuring deformation according to 13.3.1, as shown in Figure 6. When using the strain gauge method, the strain gauge shall be pasted on the specimen in advance according to the strain gauge manual and the position shown in Figure 6, and the seam end of the specimen shall be avoided when pasting. The test speed shall be selected according to the convenience of measuring and reading deformation. Apply initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters used to measure deformation, and continue or gradually increase the load until 50% of the failure load is reached. Record the load and the corresponding stress or deformation. Draw a load-strain curve (strain gauge method) or a load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
DAF
E = 26.d(2L + △L)
Where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by strain gauge method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, rounding to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of the 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105 ± 2 ° C for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
According to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and instruments
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 4202mm. Measure the inner diameter of the specimen from two mutually perpendicular directions to the nearest 0.02mm. Take the arithmetic mean of the two measured values as the inner diameter of the specimen to the nearest 0.02mm. The sum of the inner diameter and thickness of the specimen is the median diameter of the specimen to the nearest 0.1mm.
13.3 Test procedure
13.3.1 Normal tensile strength and elongation at break Accurately align the part of the tensile fixture that contacts the specimen, mount the specimen on the fixture, and tighten the cover or retaining ring cam. Install the strain gauge on both sides of the fixture as shown in Figure 6), and adjust its zero point. 39
JB/T6236.292
The test speed is 5mm/min. Apply the load evenly and continuously until the specimen fails. Record the failure load and the deformation increment of the specimen on both sides of the fixture. If the specimen fails intermittently or is not completely destroyed, the test is invalid. Supplementary tests are performed until the number of valid tests is five. Figure 6 Schematic diagram of the installation position of the device for measuring deformation 1-Tensile test fixture;
13.3.2. Hot tensile strength
2-Specimen;
3-Strain gauge;
4-Deformometer
Install the specimen according to Article 13.3.1. Preheat for 30 minutes according to the test temperature specified in the product standard, and perform the tensile test according to Article 13.3.1 at this test temperature, and record the failure load. 13.3.3 Tensile strength after oil immersion
Put the specimen on the specimen holder for oil immersion test, immerse it in insulating oil at 105±2℃, take it out after 24 hours, cool it to room temperature, and check whether the specimen is delaminated or cracked.
If there is no delamination or cracking, perform the tensile test according to Article 13.3.1, and record the failure load. 13.4 Test results
The tensile strength is calculated according to formula (6):
Where:. -
-Tensile strength, MPa
-Failure load, N;
6-Specimen width, mm;
dSpecimen thickness. mm.
Elongation at break is calculated according to formula (7):
In the formula, e-
-Elongation at break, %
JB/T6236.2—92
is the deformation increment of the specimen on both sides of the fixture at the time of failure, mm; ALAL
D-Medium diameter of the specimen, mm.
Take the arithmetic mean of five valid test calculation values as the test result. The tensile strength is taken to three significant figures, and the elongation at break is taken to two significant figures.
14Tensile elastic modulus of annular specimen
The tensile elastic modulus of annular specimen is measured by strain gauge method or deformation meter method. The strain gauge method is used in arbitration test. 14.1 Test equipment and instruments
a. Testing machine, same as in 10.1a;
·b. Instruments and meters for measuring deformation, strain gauge method uses strain gauge and resistance strain gauge, and strain gauge method uses dial indicator or other suitable strain gauge, the relative error of the indicated value shall not exceed 1%; c. Tensile test fixture, same as in 13.1c, d. Vernier caliper, vernier reading value 0.02mm; e. Adhesive.
14.2 Test specimen
Same as in 13.2.
14.3. Test procedure
Install the specimen and the instruments and meters for measuring deformation according to 13.3.1, as shown in Figure 6. When using the strain gauge method, the strain gauge shall be pasted on the specimen in advance according to the strain gauge manual and the position shown in Figure 6, and the seam end of the specimen shall be avoided when pasting. The test speed shall be selected according to the convenience of measuring and reading deformation. Apply initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters used to measure deformation, and continue or gradually increase the load until 50% of the failure load is reached. Record the load and the corresponding stress or deformation. Draw a load-strain curve (strain gauge method) or a load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
element DAF
E = 26.d(2L + △L)
where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by strain gauge method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, rounding to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105±2℃ for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
Perform according to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and apparatus
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 421. Install the sample. Preheat for 30 minutes at the test temperature specified in the product standard, and perform a tensile test according to Article 13.3.1 at the test temperature, and record the failure load. 13.3.3 Tensile strength after oil immersion
Place the sample on the sample holder for oil immersion test, immerse it in insulating oil at 105±2℃, take it out after 24 hours, cool it to room temperature, and check whether the sample is delaminated or cracked.
If there is no delamination or cracking, perform a tensile test according to Article 13.3.1, and record the failure load. 13.4 Test results
The tensile strength is calculated according to formula (6):
Where: -
-Tensile strength, MPa
-Failure load, N;
6-Sample width, mm;
dSample thickness. mm.
Elongation at break is calculated according to formula (7):
In the formula, e-
-elongation at break, %
JB/T6236.2-92
respectively are the deformation increments of the specimen on both sides of the fixture at the time of failure, mm; ALAL
D--mid diameter of the specimen, mm.
Take the arithmetic mean of five valid test calculation values as the test result. The tensile strength is taken to three significant figures, and the elongation at break is taken to two significant figures.
14 Tensile elastic modulus of annular specimen
The tensile elastic modulus of annular specimen is measured by the strain gauge method or the strain gauge method. The strain gauge method is used for arbitration test. 14.1 Test equipment and instruments
a. Testing machine, same as Article 10.1a;
·b. Instruments and meters for measuring deformation: strain gauges and resistance strain gauges are used for the strain gauge method, and dial indicators or other suitable strain gauges are used for the strain gauge method. The relative error of the indicated value shall not exceed 1%; c. Tensile test fixture, same as in Article 13.1 c, d. Vernier caliper, vernier reading value 0.02mm; e. Adhesive.
14.2 Specimen
Same as in Article 13.2.
14.3. Test procedure
Install the specimen and instruments and meters for measuring deformation according to Article 13.3.1, as shown in Figure 6. When using the strain gauge method, the strain gauge shall be pasted on the specimen in advance according to the strain gauge manual and the position shown in Figure 6. When pasting, avoid the seam end of the specimen. Select the test speed according to the convenience of measuring deformation. Apply the initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters for measuring deformation, and add the load continuously or step by step until 50% of the failure load is reached. Record the corresponding load or deformation. Draw the load-strain curve (strain gauge method) or load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
Element DAF
E = 26.d(2L + △L)
Where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by deformometer method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, and round to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105±2℃ for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
Perform according to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and apparatus
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 421. Install the sample. Preheat for 30 minutes at the test temperature specified in the product standard, and perform a tensile test at the test temperature according to Article 13.3.1, and record the failure load. 13.3.3 Tensile strength after oil immersion
Put the sample on the sample holder for oil immersion test, immerse it in insulating oil at 105±2℃, take it out after 24 hours, cool it to room temperature, and check whether the sample is delaminated or cracked.
If there is no delamination or cracking, perform a tensile test according to Article 13.3.1, and record the failure load. 13.4 Test results
The tensile strength is calculated according to formula (6):
Where: -
-Tensile strength, MPa
-Failure load, N;
6-Sample width, mm;
dSample thickness. mm.
Elongation at break is calculated according to formula (7):
In the formula, e-
-elongation at break, %
JB/T6236.2-92
respectively are the deformation increments of the specimen on both sides of the fixture at the time of failure, mm; ALAL
D--mid diameter of the specimen, mm.
Take the arithmetic mean of five valid test calculation values as the test result. The tensile strength is taken to three significant figures, and the elongation at break is taken to two significant figures.
14 Tensile elastic modulus of annular specimen
The tensile elastic modulus of annular specimen is measured by the strain gauge method or the strain gauge method. The strain gauge method is used for arbitration test. 14.1 Test equipment and instruments
a. Testing machine, same as Article 10.1a;
·b. Instruments and meters for measuring deformation: strain gauges and resistance strain gauges are used for the strain gauge method, and dial indicators or other suitable strain gauges are used for the strain gauge method. The relative error of the indicated value shall not exceed 1%; c. Tensile test fixture, same as in Article 13.1 c, d. Vernier caliper, vernier reading value 0.02mm; e. Adhesive.
14.2 Specimen
Same as in Article 13.2.
14.3. Test procedure
Install the specimen and instruments and meters for measuring deformation according to Article 13.3.1, as shown in Figure 6. When using the strain gauge method, the strain gauge shall be pasted on the specimen in advance according to the strain gauge manual and the position shown in Figure 6. When pasting, avoid the seam end of the specimen. Select the test speed according to the convenience of measuring deformation. Apply the initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters for measuring deformation, and add the load continuously or step by step until 50% of the failure load is reached. Record the corresponding load or deformation. Draw the load-strain curve (strain gauge method) or load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
element DAF
E = 26.d(2L + △L)
where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by deformometer method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, rounding to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of the 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105 ± 2 ° C for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
According to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and instruments
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 421. Install the specimen and the instruments and meters for measuring deformation, as shown in Figure 6. When using the strain gauge method, stick the strain gauge on the specimen in advance according to the strain gauge instructions and the position shown in Figure 6. When sticking, avoid the seam end of the specimen. Select the test speed according to the convenience of measuring deformation. Apply the initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters for measuring deformation, and add continuously or step by step until 50% of the failure load. Record the load and the corresponding strain or deformation. Draw a load-strain curve (strain gauge method) or a load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
element DAF
E = 26.d(2L + △L)
where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by strain gauge method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm;
d specimen thickness, mm
D—sample median diameter, unit;
△e1, △e: are the strain increments on both sides corresponding to the load increment AF; AL1, L—are the deformation increments on both sides corresponding to the linear increment △F, mm. Take the arithmetic mean of the five calculated values as the test result, rounding to three significant figures. 15 Thermal Weight Loss
15.1 Test Equipment
a. Same as 7.1 except that the scale value of analytical balance is 0.0001g; b.
Constant pressure thickness gauge, same as 11.1 c.
Polytetrafluoroethylene film.
15.2 Sample
SJB/T6236T+92
Sample preparation is the same as 12.2. Samples are cut from the middle of the sample, with a length of 5 mm and five small pieces. The thickness of each sample is measured at three locations approximately distributed, with an accuracy of 0.01 mm. The median of 15 measured values is taken as the sample thickness, and the thickness is rounded to 0.01 mm.
15.3 Test procedure
15.3.1 Determine the mass of the dried sample
Determine the mass of the porcelain according to the method in 7.3.1, and burn until the mass change between two consecutive burns is no more than 0.0005 g, and the weight is accurate to 0.0001 g. Put the sample in a porcelain crucible, put it in a drying oven, dry it at 105±2℃ for 30 min, take it out and put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the dried sample m1, accurate to 0.0001 g. 15.3.2 Determine the mass of the baked sample
Put the porcelain crucible containing the dried sample in a drying oven, bake it at the temperature specified in the product standard for 120 h, take it out, put it in a desiccator, cool it to room temperature and weigh it, and calculate the mass of the baked sample ms, accurate to 0.0001 g. 15.3.3 Determine the mass of the residue after burning. Burn and weigh the porcelain crucible containing the baked sample according to the method in 7.3.3, and calculate the mass of the residue after burning, ms, to an accuracy of 0.0001 g.
15.4 Test results
Thermal weight loss is calculated according to formula (10):
Where: The mass of the sample after drying of bottle a
Thermal weight loss (%) =
The mass of the baked sample,
times
The mass of the residue after burning, 8.
m, = me
Take the arithmetic mean of the five calculated values as the test result, and take two significant figures. The test report should indicate the nominal width, nominal thickness and sample thickness of the lathless sample. 16 Long-term heat resistance
Perform according to GB11026:1:
Use the tensile strength method of the ring specimen, and use the tensile strength (MPa) at the time of failure as the diagnostic test performance. Unless otherwise specified in the product standard. Failure standard, tensile strength, 50%. 16.1 Test equipment and apparatus
8. In addition to complying with the provisions of GB11026.1, the heat aging test chamber should also have high and low temperature protection and a timer; tensile testing machine, the same as a in Article 10.1;
c. Tensile test fixture, the same as c in Article 13.1; d. Vernier caliper, vernier reading value 0.02mm; e.
Thermometer, graduation value 0.5℃, maximum indication temperature not less than 300℃, the length inserted into the heat aging box working room should be not less than one third of the working room height,
. For dryer:
g The sample rack for heat aging test is made of seamless steel pipe (galvanized or chrome-plated) or aluminum pipe, as shown in Figure 7. 421. Install the specimen and the instruments and meters for measuring deformation, as shown in Figure 6. When using the strain gauge method, stick the strain gauge on the specimen in advance according to the strain gauge instructions and the position shown in Figure 6. When sticking, avoid the seam end of the specimen. Select the test speed according to the convenience of measuring deformation. Apply the initial load (about 5% of the failure load), check and adjust the zero point of the instruments and meters for measuring deformation, and add continuously or step by step until 50% of the failure load. Record the load and the corresponding strain or deformation. Draw a load-strain curve (strain gauge method) or a load-deformation curve (deformometer method). 14.4 Test results
The tensile elastic modulus is calculated according to formula (8) and (9): AF
E, =.d(+A)
element DAF
E = 26.d(2L + △L)
where: E, tensile elastic modulus by strain gauge method, MPa; E.—tensile elastic modulus by strain gauge method, MPa; △F—load increment of the initial straight line segment on the linear strain or load-deformation curve, N; b specimen width, mm
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