Time: 2021-03-18 View: 192
Regarding the material properties, it is more complicated, so here is only a brief introduction.
The most commonly used is nitrile rubber, which is suitable for most occasions and has good oil resistance. The temperature planning is generally -30~100℃.
The physical and chemical functions of fluorine rubber are higher than those of nitrile butadiene rubber. The temperature planning is generally -20~200℃. It has strong acid and alkali resistance and excellent vacuum sealing function.
The high temperature resistance of PTFE gaskets is the same as that of silicone rubber, which can be said to be the best among elastomers at present. 26-41 fluorine rubber can be used for a long time at 250°C and short-term use at 300°C; 246 fluorine rubber has better heat resistance than 26-41. The physical properties of 26-41 after air heat aging at 300℃×100 hours are equivalent to those of type 246 after air aging at 300℃×100 hours. The elongation at break can be maintained at about 100%, and the hardness is 90 to 95 degrees. . Type 246 maintains good elasticity after aging in hot air at 350°C for 16 hours, and maintains good elasticity after aging in hot air at 400°C for 110 minutes. After aging in hot air at 400°C for 110 minutes, it contains spray carbon black, thermal black or carbon fiber. The elongation of the rubber compound increases by about 1/2 to 1/3, and the strength decreases by about 1/2, while still maintaining good elasticity. The 23-11 type fluorine rubber can be used for a long time at 200°C and for a short time at 250°C.
Good aging resistance
PTFE gasket has excellent weather resistance and ozone resistance. According to reports, the performance of VitonA developed by DuPont is still satisfactory after ten years of natural storage, and there is no obvious cracking after 45 days of action in the air with an ozone concentration of 0.01%. The 23-type PTFE gasket has excellent weathering resistance and ozone resistance.