Silicone raw material identification method

- Mar 14, 2018-

1. Measure the weight, take out the sample, use the electronic scale or analytical balance, accurate to 0.01 grams can be, to identify the fluorine rubber is the easiest because fluorine plastic weight is the largest, more than 1.8, CR ECO also more than 1.3 in the proportion of obvious bias Large can be considered these glues.

2. The combustion method, first to take out a small amount of product, after burning. Fluorine rubber is generally burned and the effect is general, but CR, CSM is extinguished without the support of fire, and NR and EPDM are burning more flames. In addition, you can also carefully observe the state of combustion, color, and odor. If NBR/PVC is used with glue, there is a fire splash when there is a fire source, it will extinguish after leaving the fire, and the smoke is sour and sour.

3. Hot air aging, remove the sample, put it in an aging box for aging one day, observe the phenomenon after aging. Graded aging gradually warmed up. CR, NR, and SBR will be brittle at 150 degrees, and NBR EPDM will have elasticity. Normal NBR rises to 180 degrees and it will be brittle; HNBR will also be brittle at 230 degrees, and fluoroelastane and silicone still have good elasticity.

4. Resistant to medium weight gain, can be sampled from the finished product, soaked in one or several selected media, weighed after a certain temperature time, and inferred the type of material according to the rate of change in weight change rate of hardness. When immersed in 100-degree oil for 24 hours, the change rates of NBR, fluoroelastomer, ECO, CR quality and hardness were very small, while those of NR, EPDM and SBR were more than doubled and the hardness changed greatly. The volume expansion was obvious.

5. Cryogenic method, remove the sample and place it in a suitable low temperature environment. The sample was soaked in a low temperature environment for 2-5 minutes, feeling soft and hard at the selected temperature. For example, at -40 degrees Celsius, the same high temperature and oil resistance is good for silica gel and fluorine rubber, silica gel is relatively soft.