I'm definitely going to look into the moisture issue. I understand that HDPE is normally insensitive to moisture content but this is an abnormal molding application (a living hinge made from HDPE instead of PP). It seems possible that moisture in the mix could end up in the hinge area.
Keep...
Thank You Insideman, patprimmer, sean, plasgears, and usjbh. You have given me a lot to think about and do. So far we have no definitive answer, but we are exploring a lot of directions simultaneously.
We are using HDPE instead of PP because the hinge is required to break under strain. A PP hinge would require significantly more strain to break it. (Yeah, I know it's a tough application; we want the hinge to be strong, but not too strong.)
There is NO regrind allowed in the mix.
As far as I...
I have a problem with a HDPE living hinge. When I bend the hinge it breaks.
It's a tiny hinge, only 0.005" thick and 0.030" wide. I have made it for years without a problem, but now the molders give me parts that crack and they can't seem to figure out why.
I am NOT a polymer...
