You can get problems when switching from a high temperature resin – like glass-filled nylon 66 – to one that moulds at lower temperature, such as EVA.
If you're not careful, you'll see lumpy parts with horrible surface quality. These are chunks of unmelted nylon turning up in your EVA mouldings.
So make sure you shift all that high temperature resin and then process the EVA at a gentler temperature.
Once you've finished the nylon, run Barrel Blitz Universal through at those temperatures until it's totally clean. Then, drop the temperature to the EVA processing temperature, run through a bit more Barrel Blitz Universal, and move to the EVA.
If you just want to pull the screw after running glass-filled nylon 66, that's easy: purge with Barrel Blitz Universal, cut the heat to 200C, purge with some more Barrel Blitz Universal, then dismantle the equipment and remove the Barrel Blitz Universal while it's hot.
