Fiber-loaded rubber compound useful in pdm stators

A stator, comprising:

• a rubber compound formed into a stator;
• the rubber compound including 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;
• and
• the fiber reinforcement including a fiber loading of greater than 1.5 phr of fibers, and the rubber compound having 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.

A stator, comprising:

• a rubber compound formed into a stator;
• the rubber compound including 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”, herein 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;
• and
• the fiber reinforcement including a fiber loading of greater than 2.0 phr of fibers, and the rubber compound having 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.

A stator, comprising:

• a rubber compound formed into a stator;
• the rubber compound including 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;
• and
• the fiber reinforcement including a fiber loading of greater than 2.5 phr of fibers, and the rubber compound having 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.