Rubber compound with fiber reinforcement
A rubber compound for use in a stator. The rubber compound includes a fiber reinforcement, which may include fibrillated fibers in some embodiments, and short chop fibers in others. Fibers in the fiber reinforcement create a grain direction. In some embodiments, the rubber compound has a first value for 25% tensile Modulus across the grain and a second value for 25% tensile Modulus with the grain, wherein the first value is at least 10% lower than the second value. In embodiments, the fiber reinforcement may include a fiber loading of greater than 1.0 phr of fibers. In embodiments, the rubber compound may have a 25% tensile Modulus of greater than 400 psi across the grain and a 50% tensile Modulus of greater than 700 psi across the grain. In embodiments, at least some of the fibers may have a Modulus greater than 2.0 GPa.
1. A rubber compound for use in a stator, the rubber compound comprising:
a fiber reinforcement, the fiber reinforcement including a plurality of fibers, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”, wherein the rubber compound has a first value for 25% tensile Modulus “across the grain” and a second value for 25% tensile Modulus “with the grain”, wherein the first value is at least 10% lower than the second value;
wherein the fiber reinforcement includes a fiber loading of greater than 1.0 phr of fibers;
wherein the rubber compound has a 25% tensile Modulus of greater than 400 psi “across the grain” and a 50% tensile Modulus of greater than 700 psi “across the grain”; and
wherein the fiber reinforcement includes fibrillated fibers.
2. The rubber compound of claim 1 , in which the fibrillated fibers have surface areas in a range of 2 m 2 /g to 20 m 2 /g.
3. The rubber compound of claim 1 , in which the fibrillated fibers have surface areas in a range of 7 m 2 /g to 11 m 2 /g.
4. The rubber compound of claim 1 , in which at least some of the fibers have a Modulus greater than 2.0 GPa.
5. The rubber compound of claim 1 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 4.0 GPa.
6. The rubber compound of claim 1 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 14.0 GPa.
7. The rubber compound of claim 1 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 20.0 phr of fibers.
8. The rubber compound of claim 1 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 6.0 phr of fibers.
9. A rubber compound for use in a stator, the rubber compound comprising:
a fiber reinforcement, the fiber reinforcement including a plurality of fibers, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”, wherein the rubber compound has a first value for 25% tensile Modulus “across the grain” and a second value for 25% tensile Modulus “with the grain”, wherein the first value is at least 10% lower than the second value;
wherein the fiber reinforcement includes a fiber loading of greater than 1.0 phr of fibers;
wherein the rubber compound has a 25% tensile Modulus of greater than 400 psi “across the grain” and a 50% tensile Modulus of greater than 700 psi “across the grain”; and
wherein the fiber reinforcement includes short chop fibers.
10. The rubber compound of claim 9 , in which the short chop fibers have lengths in a range of 0.1 mm to 10.0 mm.
11. The rubber compound of claim 9 , in which at least some of the fibers have a Modulus greater than 2.0 GPa.
12. The rubber compound of claim 9 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 4.0 GPa.
13. The rubber compound of claim 9 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 14.0 GPa.
14. The rubber compound of claim 9 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 20.0 phr of fibers.
15. The rubber compound of claim 9 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 6.0 phr of fibers.
16. A rubber compound for use in a stator, the rubber compound comprising:
a fiber reinforcement, the fiber reinforcement including a plurality of fibers, wherein fibers in the fiber reinforcement create a grain direction in which “with the grain” is generally orthogonal to “across the grain”, wherein the rubber compound has a first value for 25% tensile Modulus “across the grain” and a second value for 25% tensile Modulus “with the grain”, wherein the first value is at least 10% lower than the second value;
wherein the fiber reinforcement includes a fiber loading of greater than 1.0 phr of fibers;
wherein the rubber compound has a 25% tensile Modulus of greater than 400 psi “across the grain” and a 50% tensile Modulus of greater than 700 psi “across the grain”; and
wherein at least some of the fibers have a Modulus greater than 2.0 GPa.
17. The rubber compound of claim 16 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 4.0 GPa.
18. The rubber compound of claim 16 , in which at least some of the fibers have a Modulus in a range between 2.0 GPa and 14.0 GPa.
19. The rubber compound of claim 16 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 20.0 phr of fibers.
20. The rubber compound of claim 16 , in which the fiber reinforcement includes the fiber loading in a range from 1.0 phr of fibers to 6.0 phr of fibers.