[NTLK] Looking for experts on glueing or welding polyprophylen (PP)

[Andrei Chichak]

Frank,

You have stumbled upon an issue that a lot of people have gotten hung up on, low surface energy plastics.

Adhesion depends on texture, porosity, contamination, flexibility of the surface and adhesive, and surface energy (which I’m not going to explain because it’s hard and I’d have to figure it out myself).

Anyway, low surface energy stuff is really hard to bond to, these include polyethylene, nylon, and silicone. High surface energy plastics like ABS and polycarbonate are easier to bond.

You have to have an adhesive that has a lower surface energy than the thing that you are trying to bond.

So for polypropylene you could plasma etch the surface (hah, not likely), use silicone as an adhesive, Scotch-weld DP-8005 adhesive, or there is this stuff that I use for making kites; 3M 9472LE tape.

9472 is a double sided acrylic tape that sticks and doesn’t want to let go. I’ve tried removing it from coated nylon and polyester, with isopropanol, varsol, gasoline, goo gone, and it doesn’t want to move. Apparently it can be broken down with MEK, but that is a controlled substance in a lot of countries. It’s very thin, flexible, expensive, sticks better as time goes on and as temperatures increases.


Andrei from The Great White North