Fusion welds

Q&A: GMA Techline | October 1, 2014 | By: ATA

Geomembrane patching? Landfill cooling?<br /> Puncture protection?

Geomembrane patching? Landfill cooling?
Puncture protection?

Questions and answers from the GMA Techline

Double-track fusion welds
Can you offer any guidance on the minimum allowable ambient temperature to perform double-track fusion welds of HDPE and LLDPE geomembranes? Thanks.

(Noah | North Carolina)

Noah,
(1) Regarding the seaming window for HDPE (it is really MDPE resin) it is between 100 C and 120 C. The lower bound is your answer but remember that melting just begins at 100 C and you better increase the nip pressure and maybe slow the speed at such a low value.

(2) The seaming window for LDPE is between 90 C and 108 C and its lower bound is the minimum that you need for the beginning of melting. Same comment applies to the nip pressure and speed.