Plastic Injection Molding (2015) [video]
I operated a line like this for seven years before becoming a programmer, except that we extruded continuous paper-thin sheets of plastic for people to print signs on. That was a more skilled process, I guess; injection molders I talked to often had one person monitoring multiple machines.<p>My plant was in Wisconsin but wasn&#x27;t heated during the winter when the lines were running. Melting plastic takes so much heat that we were the main electricity consumer in my town.<p>Because there isn&#x27;t a check ring in place while the screw is turning, plastic is always trying to slip backwards over the flights of the screw. You have not just heater bands around the barrel, but also cooling water, which makes the plastic less melty so the flights can push it forward without slipping back. The more recycled material you use, generally the cooler you need the barrel because those little flakes melt faster and slip more than virgin pellets.<p>The many challenges of fighting reality to get your plastic to come out correctly mixed and without bubbles build a lot more character than similar paying jobs like driving a forklift. Facing the same problems repeatedly helped me develop the quick-access note system I still use for debugging and syntax. I wouldn&#x27;t be half the programmer I am without the life skills from manufacturing. The only problem with being a line operator was that most permanently solvable problems have been engineered out already, so being clever and organized about solving things didn&#x27;t produce nearly as much value for the plastic factory as it does now that I&#x27;m a programmer.