GB/T 15047-1994 Test method for torsional rigidity of plastics

This standard specifies the test method for the torsional rigidity of plastics as a function of temperature. This standard applies to thermoplastics. GB/T 15047-1994 Test method for torsional rigidity of plastics GB/T15047-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for stiffness proporties in torsion of plastics
1 Subject and scope of application
This standard specifies the test method for torsion stiffness of plastics as a function of temperature. This standard applies to thermoplastics.
2 Referenced standards
GB2918 Standard environment for conditioning and testing of plastic specimens 3 Terminology
The apparent modulus of rigidityGB/T 15047—94
Due to the distortion of the specimen beyond the elastic limit and the influence of the creep characteristics of the material, the modulus of rigidity different from that within the elastic limit is formed, expressed in G.
4 Principle
At a set temperature, a torque is applied to the specimen within a specified time, and the apparent modulus of rigidity is calculated by measuring the torsion angle. 5 Equipment
5.1 Testing machine
It can apply enough torque to twist the specimen by 5° to 100°. And the ratio of span to width is 6 to 8. As shown in Figure 1. Approved by the State Administration of Technical Supervision on April 12, 1994 and implemented on December 1, 1994bZxz.net
The accuracy is 1g.
5.3 Thermos bottle
Capacity 1 000 mL.
5.4 Thermometer
GB/T15047-94
Figure 1 Torsion tester
1-reset knob; 2-torque wheel; 3---scale wheel; 4--pointer; 5-temperature sensor, 6-upper clamp, 7-sample, 8-lower clamp; 9-heater; 10-thermos bottle; 11-stop rod; 12-yard; 13-span; 14-load rope; 15-thermometer accuracy is 1℃ and has the required measurement range. 5.5 Timer
The accuracy is 0.1s.
5.6 Heat transfer medium
Material that is liquid within the test temperature range and has no softening or other effects on the sample. Commonly used liquid media include water, ethanol, butanol, acetone, n-hexane, silicone oil, and a mixture of methyl phosphate and water in a volume ratio of 87:13. In addition, a mixture of 50 parts ethanol, 30 parts ethylene glycol and 20 parts water is suitable for low-temperature tests at -70°C. 5.7 Refrigeration
According to the required temperature, a refrigerator or dry ice is used. 600
Heater
Use an immersion electric heater.
5.9 Micrometer
The accuracy is 0.01mm.
5.10 Vernier caliper
The accuracy is 0.02mm.
6 Sample
6.1 Preparation
Use pressing or machining methods.
6.2 Shape and size
GB/T 15047---94
The shape of the specimen is rectangular, with a length of 63.50±0.02mm, a width of 6.35±0.02mm, and a thickness of 1~~3mm, see Figure 2. -$3.73
6.3 Quantity
50.80±0.02
63.50±0.02
Two specimens shall be taken from each group. For non-homogeneous materials, two specimens shall be taken from the longitudinal and transverse directions. 7 Conditioning
6. 35±0.02
The test shall be carried out in accordance with the standard environment and normal deviation range specified in GB2918. The conditioning time shall be at least 40h. For hygroscopic plastics, the test shall be carried out immediately after conditioning.
8 Test Procedure
8.1 Measure the width and thickness of the specimen.
8.2 Fix the specimen on the fixture.
8.3 Apply the required weight to the load rope.
8.4 Place the thermometer in the positioning device of the test machine, and the temperature-sensing bulb should be as close to the specimen as possible. 8.5 Fill the thermos bottle with heat transfer medium. The medium temperature should be slightly lower than the lowest temperature to be tested. 8.6 Place the thermos bottle in a fixed position on the test machine. 8.7 Turn on the immersion heater and stirrer to allow the medium to reach the required test temperature evenly. 8.8 After the specimen has been balanced at this temperature for 180+15s, release the torque wheel, record the torsion angle of the torque wheel after 5s, and then return the torque wheel to "0". If the reading does not fall within the range of 5° to 100°, change the applied torque and continue the test in the above manner until a suitable reading is produced.
9 Calculation and expression of test results
GB/T 15047—94
9.1 The apparent rigidity modulus at a certain temperature is calculated by formula (1), 2) and (3): G
±= 5.33 - 3.36 Number (
wherein: G
apparent rigid modulus, Pa;
applied torque, Nm;
L span, m;
b/8 ratio
b/8 ratio
6/8 ratio
specimen width, m;
specimen thickness, m
-depends on 6/ratio [see table or calculate using formula (3)); torsion angle, (°);
dimensional constant;
total weight of the code used to apply the torque wheel, N; sum of the radius of the torque wheel and the radius of the load rope, m. b
Draw a graph of the logarithm of the average value of the apparent rigid modulus of the two specimens versus temperature. If necessary, read the temperature corresponding to the specified apparent rigid modulus from the graph. 9.3
Test report
The test report shall include the following contents:
Code of this standard;
Sample name and specification;
Sample state adjustment;
The relationship between the logarithm of the average value of the apparent rigidity modulus and temperature; The temperature corresponding to the specified apparent rigidity modulus; Test personnel and date.
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Additional remarks:
This standard is proposed by China Light Industry General Association.
GB/T15047—94
This standard is under the jurisdiction of the National Technical Committee for Standardization of Plastic Products. This standard was drafted by the Plastic Processing and Applied Science Research Institute of the Ministry of Light Industry. The main drafters of this standard are Cao Tongzhang and Yuan Liqun. This standard refers to the American Society for Testing and Materials standard ASTMD1043-87 "Standard test method for torsional rigidity of plastics as a function of temperature".
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