Historical trends via Canary Labs and Axiom trending.  The extruder is running great since the retrofit.  Shown in the chart are two independent sources for extruder speed.  Percent current is also displayed which is proportional to extruder pressure.  The characteristic sawtooth wave of the two gravimetric feeders is also shown.  The key metric is melt flow index but the value can only be obtained at twenty minute intervals due to limitations in the lab process.

The PLC-5 in the previous post was converted to an Automation Direct Productivity system.  I prefer to use Allen Bradley but availability issues forced me to choose another vendor or face major delays due to long lead times.

It's hard to believe that a major manufacturing company is still using PLC-5's in 2022 but we were.  I recently upgraded this entire system to a new controller.  The heart of the process is a Werner & Pfleiderer twin screw extruder (400hp).  The DCS also controls a material vacuum convey system with three independent vacuum pumps.  Resin powder is transferred from bags to various hoppers and then to a third floor mixer.  The mixer prepares batches by dosing an additive via a Coriolis meter.  The batch gets mixed with pure resin with two KTron gravimetric feeders then fed to the extruder inlet.  Twelve heated (and water cooled) zones on the extruder manage the temperature of the reaction with independent PID loops.  The finished material gets flattened with nip rolls, solidified on a water cooled belt cooler and turned into powder through a pin mill and hammer mill.  The final step is vacuum conveyed into finish product on RiceLake weigh scales.