I. principle of plastic torsional rigidity test:
At the set temperature, a torque is applied to the specimen within the specified time, and the apparent stiffness modulus is calculated by measuring the torsion Angle.
2. Test equipment:
Testing machine
To exert enough torque and the sample 5 ° ~ 100 °. Furthermore, the ratio of span to width is 6~8.
Iii. Test procedures for plastic torsion rigidity:
1. Measure the width and thickness of the sample.
2. Fix the sample on the fixture.
3. Apply the required weight on the load rope.
4. Place the thermometer in the positioning device of the test machine, and the temperature bubble should be as close as possible to the test sample.
5. Fill the heat transfer medium with the thermos flask. The temperature of the medium should be slightly lower than the lowest temperature tested.
6. Put the thermos bottle in the fixed position of the test machine.
7. Operate immersion heaters and agitators to make the medium reach the required test temperature uniformly.
8, sample at the temperature balance after 180 + 15 ° s, loosen the torque wheel, 5 s after record torque wheel torsion Angle, then the wheel torque return to zero." If the reading does not fall within the scope of the 5 ° ~ 100 °, the torque will be expected to change, to continue in this way test, to produce appropriate reading.
Iv. Standards for the implementation of plastic torsion rigidity test:
GB/T 15047-1994 test method for torsional rigidity of plastics