Elongation rate E (elongationpercent)
Due to the deformation of the working part caused by stretching the specimen, the value of the increment of elongation and the initial length percent ratio.
Constant stress elongation Eg (elongationatagivenstress)
Elongation of the specimen under a given stress.
Elongation at break Eb (elongationatbreak)
Elongation of the specimen at break.
Tearing permanent deformation (tensilesetatbreak)
The specimen will be stretched to fracture, and then subjected to its state in the self-exit, recovery of a certain time (3min) after the remaining deformation, the value of the working part of the increment of elongation and the initial length percent ratio.
A: tearing elongation and tensile strength related to.
Only with a high tensile strength to ensure that it is not damaged during the deformation process, there will be a high elongation. Generally, with the increase of fixed tensile stress and hardness, the tearing elongation decreases, and the tearing elongation is large if the resilience is large and the permanent deformation is small. The elongation at tear is different for different rubbers. The elongation at tear of natural rubber can reach 1000% when its rubber content is above 80%. In the deformation of rubber easy to produce plastic flow will also have a higher elongation. Such as butyl rubber.
B: elasticity and cross-link density related.
With the increase of cross-linking density, the elasticity of vulcanized rubber increases and appears the maximum, cross-linking density continues to increase the elasticity is under the interesting trend. Manufacture of high tensile products, the degree of vulcanization should not be too high, can be slightly less sulfur or reduce the amount of vulcanizing agent. Increase the amount of filler will reduce the tearing elongation, the higher the structure of the reinforcing agent, the lower the tearing elongation, had increased the amount of softening agent, you can get a larger tearing elongation.