Conveyor belt
A conveyor belt 10 is formed with a belt core body 14 covered by a cover rubber 12 . The cover rubber 12 is formed with a shock resistance performance evaluation index, i.e., the product of an elongation at break Eb, a tensile strength at break TSb, and a loss tangent tan δ of 6000 or greater. The loss tangent tan δ is the ratio between a storage modulus and a loss modulus calculated from a stress when vibrations of a predetermined frequency are applied to cover rubber 12 . The measurement conditions of the loss tangent tan δ are determined on the basis of a speed of an impact applied under the use conditions of the conveyor belt 10.
1. A conveyor belt, comprising:
a belt core body; and
a cover rubber covering the belt core body;
the cover rubber being formed with a shock resistance performance evaluation index value, which is a product of an elongation at break Eb, a tensile strength at break TSb, and a loss tangent tan δ, which is a ratio between a storage modulus and a loss modulus calculated from stress when vibrations of a selected frequency are applied to the cover rubber, the shock resistance performance evaluation index value being equal to or greater than a selected minimum value;
wherein a measurement condition of the loss tangent tan δ is determined on a basis of a speed of an impact applied under a use condition of the conveyor belt.
2. The conveyor belt according to claim 1 , wherein
the measurement condition is the selected frequency; and
the selected frequency is determined by matching the speed of an impact applied under a use condition of the conveyor belt to a maximum speed of the vibrations.
3. The conveyor belt according to claim 1 , wherein the shock resistance performance evaluation index value calculated using the loss tangent tan δ at a frequency of 10 kHz is 6000 or greater.
4. The conveyor belt according to claim 2 , wherein the shock resistance performance evaluation index value calculated using the loss tangent tan δ at a frequency of 10 kHz is 6000 or greater.