Field of Invention
The invention relates to development of nitrile rubber compound HA1824.
BACKGROUND
The supply of imported rubber compound is not consistent due to high lead time & less shelf life of rubber compound (i. e. 3 months). In order to meet the production requirement the nitrile rubber compound HA1824 was developed in-house. The rubber compound HA1824 is used for manufacture of rubber seals and rubber bonded valves of Brake units of fighter aircraft.
SUMMARY OF INVENTION
i) The ingredients were used for manufacture of nitrile rubber compound HA 1824 as per
Table - 1 below:
Table- 1

SI. No. Ingredient Quantity
1. Polymer Perbunan (18% nitrile content) 2500 gm
2. Sulphur ( Rubber Grade) 6.25 gm
3. Nonox B 37.5 gm
4. Vulcanox ZMBT 37.5 gm
5. Zinc Oxide 375 gm
6. Carbon Black HAF 1875 gm
7. Stearic Acid 12.5 gm
8. Plasticator FH 125 gm
9. Vulcanol 88 250 gm
10. Sulphasan R 47.5 gm
11. Vulcacit CBS (CZ) 37.5 gm
12. Vulcacit TMTD 37.5 gm
ii) After successful manufacturing of nitrile rubber compound HA 1824 it was evaluated for physic-mechanical properties & the results are listed in Table -2.
Table-2

SI. No. Test carried out Results obtained
1 Tensile strength, Kg/cm 142
2 Relative Elongation at break, % 260
3 Residual Elongation at break, % 4
4 Hardness Shore 77-78

5. Brittleness Temperature, °C Passes at-55 °C
6 Relative residual deformation at 20% compression in oil AMG-10 for 24 hours at 150 °C, % 4.5
7. Volumetric swelling in oil AMG-10 at 150°C for 24 hours,% 38.4
8. Ageing coefficient 0.80
9. Density, gm/cc 1.26
10. Endurance Test as per para of 6.6 of Test Schedule TS/1ND/55/48 Satisfactory
11. Shelf life 3 months
12. Shrinkage, % 1.29-2.0
13. Vulcanization details 143±luCfor40 min
iii) The developed rubber compound is subjected to functional test on the Brake unit assembly as per Test Schedule TS/IND/55/48 & found satisfactory.
OBJECT OF INVENTION
(i) To develop rubber compound in-house
(ii) To provide permanent solution for availability of rubber compound for manufacturing shop

CLAIMS
1. We claim the procedure for manufacture of rubber compound HA 1824 for airborne applications as per Flow chart for Rubber HA 1824. (Annexure -I)
2. We claim the physico-mechanical properties of rubber compound HA 1824 obtained during testing of rubber compound as per Table-2.