Rubber Identification Method
1 Medium resistance weight gain test
You can take samples from the finished product, soak it in one or several selected media, weigh it after a certain temperature and time, and infer the type of material based on the weight change rate and hardness change rate.
For example, after soaking in 100-degree engine oil for 24 hours, the mass and hardness change rates of NBR, fluororubber, ECO, and CR are very small, while NR, EPDM, and SBR gain more than double the weight and change greatly in hardness, and the volume expansion is obvious.
2 Hot air aging test
Take samples from the finished product, put them in an aging box for one day, and observe the phenomenon after aging. You can age them in stages and gradually increase the temperature. For example, at 150 degrees, CR, NR, and SBR will break brittlely, while NBR EPDM still has elasticity. At 180 degrees, ordinary NBR will break brittlely; and at 230 degrees, HNBR will also break brittlely, while fluororubber and silicone still have good elasticity.
3 Combustion method
Take a small amount of sample and burn it in the air. Observe the phenomenon.
Generally speaking, fluorine rubber, CR, and CSM will extinguish themselves when they are away from fire, and even if they are burning, the flames are much smaller than those of general NR and EPDM. Of course, if we observe carefully, the burning state, color, and smell will also provide us with a lot of information. For example, when there is a fire source, the fire of NBR/PVC combined rubber will splash and splash, as if there is water, and it will extinguish itself when it is away from fire, and the smoke is thick and sour. It should be noted that sometimes rubber with flame retardants added but no halogen will also extinguish itself when it is away from fire, which requires further inference by other methods.
4 Measure specific gravity
Use an electronic scale or analytical balance, accurate to 0.01 grams, plus a cup of water and a strand of hair.
Generally speaking, fluorine rubber has the largest specific gravity, above 1.8, and CR ECO is also mostly above 1.3. The specific gravity is obviously larger, which can be considered to be these rubbers.
5 Low temperature method
Take samples from the finished product and create a suitable low temperature environment with dry ice and alcohol. Soak the sample in a low temperature environment for 2-5 minutes, and feel the softness and hardness at the selected temperature. For example, at -40 degrees, compared with silicone and fluororubber, which are both resistant to high temperature and oil, silicone is relatively soft.
You can take samples from the finished product, soak it in one or several selected media, weigh it after a certain temperature and time, and infer the type of material based on the weight change rate and hardness change rate.
For example, after soaking in 100-degree engine oil for 24 hours, the mass and hardness change rates of NBR, fluororubber, ECO, and CR are very small, while NR, EPDM, and SBR gain more than double the weight and change greatly in hardness, and the volume expansion is obvious.
2 Hot air aging test
Take samples from the finished product, put them in an aging box for one day, and observe the phenomenon after aging. You can age them in stages and gradually increase the temperature. For example, at 150 degrees, CR, NR, and SBR will break brittlely, while NBR EPDM still has elasticity. At 180 degrees, ordinary NBR will break brittlely; and at 230 degrees, HNBR will also break brittlely, while fluororubber and silicone still have good elasticity.
3 Combustion method
Take a small amount of sample and burn it in the air. Observe the phenomenon.
Generally speaking, fluorine rubber, CR, and CSM will extinguish themselves when they are away from fire, and even if they are burning, the flames are much smaller than those of general NR and EPDM. Of course, if we observe carefully, the burning state, color, and smell will also provide us with a lot of information. For example, when there is a fire source, the fire of NBR/PVC combined rubber will splash and splash, as if there is water, and it will extinguish itself when it is away from fire, and the smoke is thick and sour. It should be noted that sometimes rubber with flame retardants added but no halogen will also extinguish itself when it is away from fire, which requires further inference by other methods.
4 Measure specific gravity
Use an electronic scale or analytical balance, accurate to 0.01 grams, plus a cup of water and a strand of hair.
Generally speaking, fluorine rubber has the largest specific gravity, above 1.8, and CR ECO is also mostly above 1.3. The specific gravity is obviously larger, which can be considered to be these rubbers.
5 Low temperature method
Take samples from the finished product and create a suitable low temperature environment with dry ice and alcohol. Soak the sample in a low temperature environment for 2-5 minutes, and feel the softness and hardness at the selected temperature. For example, at -40 degrees, compared with silicone and fluororubber, which are both resistant to high temperature and oil, silicone is relatively soft.