Welding EVOH to HDPE

[fletch71]

Is it possible to heat weld EVOH to HDPE

 

[stookeyfpe]

Anything is possible.

 

[europipe]

Just curiosity;
What is EVOH ?

 

[StoneCold]

europipe
Google says EVOH is a type of Pex tubing.

Personally I avoid joining disimilar materials by welding. I prefer a bolted or threaded joint. Even on threaded joints I try to take into consideration differences in thermal expansion, to decide which side should be male and which side should be female.
My two cents.

Regards
StoneCold

 

[europipe]

Stone,

You are right about the material,
but when I google for fittings or pipe I get the weirdest sites.
Or is there a respected vendor somewhere?

 

[moltenmetal]

EVOH is ethylene-vinyl alcohol copolymer, which is used as an oxygen barrier coating on PEX tubing amongst numerous other uses.

No, I don't believe it's possible to weld truly dissimilar polymers together. Depending on the polymers you may get an adhesive joint, but that's not quite the same as true weld as far as I understand it.

No, it's not possible to truly weld cross-linked polyethylene material to any other material or to itself, post-crosslinking, for fairly obvious reasons. You need a mechanical joint to connect the two.

 

[Murec]

I worked a lot with PEX pipe (

http://www.pexgol.com)

and it can be welded. For connecting to a different material,however, I would use a mechanical joint - thread, flange or other, depending on pipe type and size.