Plastic extruder machines are like that, but six hours is more of a *minimum* figure in those cases; it takes that long just to fresh start or change material and spec. An outage is worse. You have to separate the whole line into quadrants on the track it sits on, disassemble the die- which can be held together with hundreds of bolts, cut all the shit out of it, reassemble the die and machine line, restart the line, and wait for it to achieve consistency (5+hrs of wasted material). I used to do lab work and maintenance in one of those factories, and have seen extruding lines take two full days to become operational again after a mishap.