Characteristics of rubber material

1. High elasticity: low elastic modulus, large elongation deformation, recoverable deformation, and can maintain elasticity in a wide range of temperature (-50~150℃).

2. Viscoelasticity: rubber material has obvious stress relaxation and creep phenomenon under the influence of temperature and time when deformation and deformation recovery occurs, and hysteresis loss occurs under the action of vibration or alternating stress.

3, electrical insulation: rubber and plastic are the same as electrical insulation materials.

4, there is aging phenomenon: such as metal corrosion, wood decay, rock weathering, rubber will also produce aging phenomenon because of the change of environmental conditions, so that the performance is bad, the life is reduced.

5, must be vulcanized to use, except for thermoplastic elastomers.

6. The coordination agent must be added.

Other characteristics such as small specific gravity, low hardness, good softness, good air tightness, etc. belong to the valuable properties of rubber.

Indicators of physical and mechanical properties of rubber:

1, tensile strength: also known as tensile strength, tensile strength, refers to the test piece tensile to fracture unit section load, the unit is MPa (MPa), formerly for kg force/square centimeter (KGF /cm2).

2. Constant elongation stress: formerly called constant elongation strength, refers to the load borne by the unit area of the sample when it is stretched to a certain length. Units of measurement are the same as tensile strength. In common use are 100%, 300% and 500% constant extension stresses. It reflects the ability of rubber to resist external deformation.

3, tear strength: the special test piece (with a cut or rectangular) when the unit thickness of the load, indicating the tear resistance of the material, the unit is kN/m.

4. Elongation: when the test piece is pulled, the ratio of the elongation part to the original length is called elongation; Expressed as a percentage.

5, permanent deformation: after the specimen is stretched to fracture, the percentage of the irrecoverable part of the standard distance elongation deformation to the original length. After the external force is removed and placed for a certain time (generally 3 minutes), expressed in %.

6, resilience: also known as impact elasticity, refers to the ability of rubber to recover after impact, expressed in %.

7, hardness: indicates the ability of rubber to resist external force pressed into, commonly used shore hardness tester. The hardness range of rubber is generally between 20 and 100, and the unit is Shaw A.