The influence of O-ring vulcanization on rubber properties is mainly evaluated through the following testing methods:
Determination of vulcanization performance
Mooney viscometer method: To determine the Mooney viscosity, thixotropic effect, elastic recovery, scorch characteristics and vulcanization index and other properties of rubber compounds. These indicators can be used to evaluate the rheological properties and scorch risk of the rubber compound during the vulcanization process.
Vulcanization instrument method: Use a vulcanization instrument to continuously and intuitively depict the curve of the entire vulcanization process, and obtain the main parameters of the rubber compound vulcanization process, such as optimum vulcanization time and vulcanization rate.
Hardness test
The hardness of O-rings is measured using a Shore hardness tester. The hardness change of rubber after vulcanization reflects the change in crosslinking density, which directly affects the sealing performance and wear resistance of O-rings.
Tensile property test
Tensile strength: The load per unit area that a specimen can bear when it breaks, reflecting the strength of rubber.
Elongation at break: The elongation of the specimen when it breaks, reflecting the elasticity of the rubber.
Fixed elongation stress: The stress required at a specified elongation rate, reflecting the rigidity of rubber.
Compression permanent set test
After holding the O-ring in the compressed state for a certain period of time, measure the degree of its deformation. This test assesses the sealing effect of rubber after long-term use, and the degree of vulcanization directly affects the permanent compression set rate.
Hot air aging test
Place the O-ring in a hot air aging chamber at a specified temperature. After a certain period of time, measure the changes in its physical and mechanical properties. This test assesses the thermal stability of rubber and the performance of antioxidants.
Low-temperature performance test
Temperature shrinkage method (TR test) : Measures the shrinkage characteristics of rubber at low temperatures to evaluate its low-temperature performance. The degree of vulcanization affects the glass transition temperature and low-temperature flexibility of rubber.
Medium resistance performance test
Place the O-ring in various media such as oils, organic solvents, acid and alkali solutions, etc., and measure the changes in its performance. This test assesses the corrosion resistance and stability of rubber in different media.
Fatigue performance test
Compression fatigue test: Repeatedly compress the specimen at a certain frequency and with a certain deformation amplitude, and measure its temperature rise and deformation.
Flexing and cracking test: To determine the extended length of the cracks produced in rubber after multiple flexing. The degree of vulcanization affects the fatigue resistance of rubber.
Friction and wear performance test
Abrasion test: Use Akron abrasion tester, DIN abrasion tester, etc., to evaluate the abrasion resistance of rubber. The degree of vulcanization affects the surface hardness and wear resistance of rubber.