Plastics Engineering general discussion

Forming PTFE tubing

Forming PTFE tubing

boottmills

(Mechanical)

(OP)

29 Apr 14 15:11

thanks!

So I am not very familiar with PTFE tubing, but I have an application that requires the use of PTFE tubing and since it is not very flexible, I was wondering if anyone could recommend a way to possibly form it using heat (bath vs heat gun) and what to possibly look out for (besides Teflon Flu).thanks!

~Boottmills

RE: Forming PTFE tubing

Demon3

(Materials)

30 Apr 14 09:54

Teflon is a tradename for more than one polymer from DuPont but assuming you mean the PTFE kind you can heat it up and it will become transparent at I think 220C. As a complete guess that could be a good temperature to form it.

Dr. Chris DeArmitt

Plastics consultant to the Fortune 500: www.phantomplastics.com

Webinars on plastics, fillers & impact modification: www.plastictraining.com

RE: Forming PTFE tubing

MikeHalloran

(Mechanical)

30 Apr 14 10:16

Better to buy it with a heavy wall, wrestle it into the shape you want, and mechanically restrain it there.

PTFE tube can be heat formed, but it's slow and skill-intensive.Better to buy it with a heavy wall, wrestle it into the shape you want, and mechanically restrain it there.

Mike Halloran
Pembroke Pines, FL, USA

RE: Forming PTFE tubing

btrueblood

(Mechanical)

30 Apr 14 12:06

Chris,

Are you thinking of PFA tubing, which is translucent, but becomes nearly transparent near its softening point? I've made useful objects from such tubing using a hot air gun and glass-blowing techniques.

For PTFE (white, opaque) tubing, Mike has the right idea. Heat in boiling water and then drop it onto a forming jig, clamp in place and let it sit for a day. Or put the whole jig into a 250 deg. F oven. Usually it will spring back a bit, so you have to over-bend a little.

RE: Forming PTFE tubing

Demon3

(Materials)

30 Apr 14 15:25

There's a reference to that behaviour here:

"It attains what is referred to as a "gel state" - where the material goes from being opaque-white to transparent, but retains its shape even in this state. While in gel state, PTFE is soft, but still not completely pliable - making it very difficult to handle."

I'm thinking of PTFE. It's white but when heated to around 220C it becomes transparent. Found that out in my PhD days when friends heated their stirrer bars in a super hot oven to dry off water (to make polymers by GTP).There's a reference to that behaviour here: http://polyfluoroltd.blogspot.se/2011/04/ptfe-myth... "It attains what is referred to as a "gel state" - where the material goes from being opaque-white to transparent, but retains its shape even in this state. While in gel state, PTFE is soft, but still not completely pliable - making it very difficult to handle."

Dr. Chris DeArmitt

Plastics consultant to the Fortune 500: www.phantomplastics.com

Webinars on plastics, fillers & impact modification: www.plastictraining.com

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