High heat and oil resistant conveyor belt
Conveyor belts having a reinforcement layer, a carry cover layer above the reinforcement layer, and a pulley cover layer disposed beneath the reinforcement layer, where the carry cover layer includes least one hydrogenated nitrile butadiene rubber (HNBR) material. The HNBR material(s) may have a percentage of hydrogenation of from about 90% to about 96%, from about 92% to about 95%, or even about 94%. The carry cover layer may be from about 4 mm to about 6 mm thick, or even from about 4 mm to about 5 mm thick. In some cases, the reinforcement layer includes a rubber matrix, which may be formed of a nitrile rubber (NBR), or mixture of nitrile NBR and natural rubber blended in a NBR:NR weight ratio of from 3:1 to 9:1. In some aspects, the reinforcement layer includes a plurality of reinforcement plies embedded in the rubber matrix.
1. A conveyor belt comprising a reinforcement layer, a carry cover layer above the reinforcement layer, and a pulley cover layer beneath the reinforcement layer, wherein the carry cover layer comprises at least one hydrogenated nitrile butadiene rubber (HNBR) material, and wherein the carry cover layer has an original tensile strength value of greater than 3000 psi.
2. The conveyor belt as claimed in claim 1 , wherein the carry cover layer is from 4 mm to 6 mm thick.
3. The conveyor belt as claimed in claim 2 , wherein the carry cover layer is from 4 mm to 5 mm thick.
4. The conveyor belt as claimed in claim 1 , wherein the reinforcement layer comprises a reinforcement rubber matrix.
5. The conveyor belt as claimed in claim 4 , wherein the reinforcement rubber matrix comprises a nitrile rubber (NBR).
6. The conveyor belt as claimed in claim 5 , wherein the reinforcement rubber matrix further comprises a natural rubber (NR), and wherein the nitrile rubber (NBR) and natural rubber are blended in an NBR:NR weight ratio of from 3:1 to 9:1.
7. The conveyor belt as claimed in claim 6 , wherein the nitrile rubber (NBR) and natural rubber are blended in an NBR:NR weight ratio of from 5:1 to 9:1.
8. The conveyor belt as claimed in claim 1 , wherein the reinforcement layer comprises a plurality of reinforcement plies embedded in a reinforcement rubber matrix.
9. The conveyor belt as claimed in claim 8 , wherein the reinforcement layer comprises three reinforcement plies embedded in the reinforcement rubber matrix.
10. The conveyor belt as claimed in claim 1 , wherein the reinforcement layer comprises a plurality of steel cables embedded in a reinforcement rubber matrix.
11. The conveyor belt as claimed in claim 1 , wherein the carry cover layer has an oven aged (after 168 hours @ 302 deg F.) tensile strength value of greater than 2600 psi.
12. The conveyor belt as claimed in claim 1 , wherein the carry cover layer has a fluid immersion volume % swelling of less than 11.0% after immersion IRM903 oil for 168 hours at a temperature of 302 deg F.
13. The conveyor belt as claimed in claim 1 , wherein the carry cover layer has an oven aged (after 168 hours @ 302 deg F.) Shore A hardness of less than 90.
14. A conveyor belt comprising a reinforcement layer, a carry cover layer above the reinforcement layer, and a pulley cover layer beneath the reinforcement layer, wherein the carry cover layer comprises a hydrogenated nitrile butadiene rubber (HNBR) material having a percentage of hydrogenation of from 92% to 95%, wherein the reinforcement layer comprises nitrile rubber (NBR) blended with natural rubber and a plurality of reinforcement plies embedded in the nitrile rubber (NBR) blended with natural rubber, and wherein the conveyor belt transports materials having a temperature in excess of 150° C.
15. The conveyor belt as claimed in claim 14 , wherein the nitrile rubber (NBR) and natural rubber are blended in an NBR:NR weight ratio of from 3:1 to 9:1.
16. The conveyor belt as claimed in claim 15 , wherein the nitrile rubber (NBR) and natural rubber are blended in an NBR:NR weight ratio of from 5:1 to 9:1.
17. The conveyor belt as claimed in claim 14 , wherein the carry cover layer has an original tensile strength value of greater than 3000 psi.
18. The conveyor belt as claimed in claim 14 , wherein the carry cover layer has an oven aged (after 168 hours @ 302 deg F.) tensile strength value of greater than 2600 psi.
19. The conveyor belt as claimed in claim 14 , wherein the carry cover layer has a fluid immersion volume % swelling of less than 11.0% after immersion IRM903 oil for 168 hours at a temperature of 302 deg F. and an oven aged (after 168 hours @ 302 deg F.) Shore A hardness of less than 90.