1. Test facilities and auxiliary devices:
a) Temperature chamber (drying cabinet), providing temperature maintenance up to 200 ° C;
b) thermometer for measuring air temperature up to 200 °C with a division price of 1 °C;
c) metal ruler according to GOST 427;
f) glass plate;
2. The test is carried out on three samples with a length of (220 ± 5) mm.
3. Before testing, the temperature chamber is heated to (150 ± 3) ° C.
4. Test procedure:
The sample is placed horizontally on a glass plate, previously sprinkled with talc, and placed in a chamber in which it is kept for (30 ± 1) minutes. Then the sample is removed, cooled in air to room temperature and examined.
5. Processing the results:
The sample is considered to have passed the test if there are no damages on its external surfaces, and there are no delaminations and shells on the end surface.
The test result is considered satisfactory if all three samples have passed the test.