Mining cable sheathing compound
 This series of product is produced according to requirements of national standard GB7594.7-87 and complies with the provisions of the coal industry standard MT818-2009.
Indicator requirements and measured performance
| No. |
Test item |
Unit |
Requirements |
Results |
| Before aging |
Tensile strength |
Mpa |
≥11.0 |
12.9 |
| Elongation at break |
％ |
≥250 |
460 |
| Air oven aging test |
Ageing condition |
Temperature |
ºC |
75±2 |
75±2 |
| Time |
h |
10×24 |
10×24 |
| Tensile strength after aging |
/ |
Mpa |
/ |
13.1 |
| Change rate |
％ |
≤-15 |
2 |
| Elongation at break after aging |
/ |
％ |
≥200 |
421 |
| Change rate |
％ |
≤-25 |
-8 |
| Thermal extension test |
Test conditions |
Air temperature |
ºC |
200±3 |
200±3 |
| Load time |
min |
15 |
15 |
| Mechanical stress |
N/cm2 |
20 |
20 |
| Elongation under load |
％ |
≤175 |
38 |
| Permanent deformation after cooling |
％ |
≤25 |
7 |
| Oil immersion test |
Test conditions |
Oil temperature |
ºC |
100±2 |
100±2 |
| Oil immersion time |
h |
24 |
24 |
| Tensile strength change rate |
％ |
≤-40 |
-8 |
| Change rate of elongation at break |
％ |
≤-40 |
-3 |
| Tear test |
Tearing strength |
N/mm |
≥5.0 |
8.5 |
|
