PTFE Thermal Stability ? 2

[QT]

Can anyone advise on the thermal and mechanical stability of PTFE at temperatures above 300C. Data sheets that I have seen, give the upper working temperature of the material to be 260C with a (Theoretical??) melting point of 327C. Dose the material melt? And does it give off any toxic fumes above the recommended upper working temperature.

Thanks in advance

Q

 

[BLN]

The generic PTFE has a melt point of 327°C according to the literature, but you need to be more specific. Look at DuPont's website to see how many variations of "Teflon" there are. Most of theirs have a melt temp of 302°C. I used some PTFE (or FEP) sheeting to make some cylindrical alignment collars a few years ago, and I got the material to flow at 150°F. It didn't take much to soften.

You need specific info on the PTFE (in particular manufacturer and their designation) to find the elevated temperature properties. Literature list hydrogen fluoride as a decomposition product of fire.

 

[wmv]

You anwser is that Teflon (PTFE) has a 90% declination of mechanical properties at 260 C. The modified PTFE (TFM) has a slightly better declination rate about 83 % at 260 C. The material doe not flow at elavated temperature like a typical thermoplastic,
howver any load will cause cold flow or extrusion of the material.

Good Luck,

WMV