Thanks guys. It was a pretty big deal. By the time I walked in, the plant manager, engineering director et al literally had their heads on the chopping block. The pressure doesn't get much worse.
chemisttree said:
Similar to the way that PET is strain hardened?
I couldn't say. We go to the glass transition temperature and then a little, stretch and expand at precise rates using a specific tension and internal pressure, expand to a certain external pressure, maintain for a fixed time, then cool at a precise rate. The diameter, wall thickness, molecular orientation, roundness etc., all happen in one move. I can tell you that every piece of equipment was running at the absolute limit of precision possible for the technology. We barely made it - about 0.5% error max on any system.
No doubt the crystallinity is much higher after the process. Have they tested it for slow crack growth?
I was not aware of any issues here. Exposure to temps greater than about 130 or 140 something degrees F can cause it to shrink back to the original size. And some chemicals can be a problem...I think acetone was one of them.
The stuff is incredibly hard and strong. One guy took a whack with a hammer expecting to break it like the regular pipe, but the pipe didn't break, and the hammer bounced back so hard that he took it in the head and nearly knocked himself out!
Berkeman, you will likely appreciate this: The system was so tight that we found a math error in the AB processor. It was so small that no one had ever noticed before. There was a firmware revision with my name on it.
One other note: Almost as soon as we got it working, the company, PW Eagle, formerly PW Pipe, was sold to a foreign company.
The expansion process is terribly tricky but we finally nailed it!
No, but I wasn't nearly as popular!
