Yellowing Nylon

[brentb]

The guys left the dryer on over the weekend and a bunch of Zytel 101F natural resin, yellowed. Temp was good time not. Is this resin oxidized as I suspect? Parts made with this resin look to have the same impact resistance as non-yellow parts, but I would like some opinions.

Thanks and "Keep on Molding!"

brent

[rickbatey]

Brent-I saw this once as well. Our parts tested and seemed fine. I don't remember there being any customer complaints either. As long as it doesn't affect the color, Keep the molds a Slammin'!
Rick.

[Suhas]

As far as I know the yellowing has not been detrimental to the properties. None of the material people seem to know the answer. I am sure it is some sort of additive. If you cut a pellet (be careful - don't try this at home :) ) do you see the yellow on the inside?
By the way, do not 'Overdry' Nylon if you want good consistency.
Suhas

[brentb]

Next time, I will try to cut, we tossed the resin. I've noticed that fill differs with nylon dryness (easier fill with increased "wetness") this change in viscosity is more apparent in parts with complex geometries. For a consistent process, dry consistently. Suhas is a champion of that principle, I believe.

Keep on Molding!

brent