Glueing Polypropylene

[Pusser]

If you go to the pascofix website make sure you read the bottom of the page.

[Evan Pavlidis]

Bunnings sell a CA glue specifically for difficult to glue plasitcs. It comes with a primer which you apply to both surfaces, let it dry, then apply CA glue to one surface and hold or clamp the parts together until the glue sets. Loctite make it and it set me back ~$7 for a small tube.
Well worth it after I noticed a fellow at the WWW show flogging a similar product in the same size containers with epoxy and a very minute amount of epoxy filler in the package for over $60.

Cheers, Evan

[sumu]

This topic is always hot.

I have found two glues that hold polyolefins (PE, PP), silicone rubber and even PTFE at least up to some point.

The first one is 3M DP 8005, used on well cleaned surfaces and dosed with that 3M EPX dispenser pistol with the adhesive designated mixing nozzle. You need the dispenser and the nozzle for it, because if the mixing ratio is off even slightly, it does not even cure properly. If the cured seam is exposed to high frequency vibration, you should check it out first by testing.

The second one is Permabond POP primer used with Permabond 105 acrylate. I have used these products mostly for silicone foils and vacuum sealing rings. POP primer swells the silicone quite much, but after that it really has a hold on 105. POP primer is pretty expensive everywhere in the world. Do not breathe the fumes.

Other methods that work are melting the base plastic with soldering iron or with a small gas flame, or ultrasonic welding. Hot melts do not really work unless they are applied so hot they melt the base plastic as well.

Or mechanical fasteners, but do not overtighten them, PP and PE (and PTFE) will creep and deform.

sumu

[echnidna]

after a while they let go.