In the production of silicone rubber products, there are occasions when it's necessary to identify silicone rubber materials. What are some common methods used to identify silicone rubber?

1. Weigh the sample using an electronic scale or analytical balance, accurate to 0.01 grams. It's easy to identify fluororubber, as it weighs 1.8 grams or more. CR ECO materials typically weigh above 1.3 grams, and those with significantly higher specific gravity may be these types of rubber.

2. The combustion method involves first taking a small amount of the product and subjecting it to combustion. Generally, fluoroelastomers burn with moderate effectiveness, while CR and CSM extinguish without flame support. NR and EPDM produce larger flames upon combustion. Additionally, you can observe the combustion state, color, and odor closely. For instance, NBR/PVC blended adhesives will sputter and spark when exposed to a flame, self-extinguish after the flame is removed, and produce dense smoke with a sour smell.

3. Heat air aging: Remove the sample, place it in the aging chamber for one day, and observe the phenomena after aging. Gradual aging with increasing temperature. At 150 degrees, CR, NR, and SBR will脆break; NBR and EPDM still have elasticity. At 180 degrees, regular NBR will脆break; while at 230 degrees, HNBR will脆break as well, with fluororubber and silicone still maintaining good elasticity.

4. Material weight increase in medium resistance can be determined by sampling the finished product, soaking it in one or more selected media, and then weighing it after a specific temperature and time period. The type of material can be inferred from the weight change and hardness change rates. After 24 hours of soaking in 100-degree engine oil, the quality and hardness change rates of NBR, fluoro rubber, ECO, and CR were minimal. However, NR, EPDM, and SBR experienced weight increases of more than double and significant hardness changes, with notable volume expansion.

5. The Low-Temperature Method: Extract the sample and place it in an appropriate low-temperature environment. Soak the sample in the low-temperature environment for 2-5 minutes and assess the softness and hardness at the selected temperature. For instance, at -40 degrees Celsius, compare the softness and hardness of silicone and fluororubber, which are both highly resistant to high temperatures and oil. The silicone is relatively soft.

Summary: There are five methods to identify silicone rubber raw materials. However, the actual operation should be judged based on the current situation, such as the configuration and conditions in a silicone product factory. Choosing the appropriate method can quickly identify the materials, saving time and costs, and ensuring the production efficiency of silicone rubber products.