When extruding filament to purge the nozzle i have begun to notice that the extruded filament is coming out with imperfections in it. By imperfections I mean that the extruded filament is not perfectly tubular. It had notches or bumps in the filament. I honestly can not remember if this was always the case from when i first got the Mini. I have been printing for about 6 months now. It happens with all the filaments i use and i cant help but think this affects print quality. I have done basic cleaning of wiping the nozzle down with extra cleaning strip as well as heated head up and extruding to clear the nozzle. Is this normal or should the extrusion be smooth. See picture please.
Could be the filament has absorbed water from the air… Bake the spool in the oven to dry out water, and store in a dry box with silica. A de-humidifier in the room helps also.
Have you tried cold pulls to see if there’s some dirt in the heater/nozzle?
I currently keep the filament in a sealed container with dry pack. I have done a hot pull but not a cold pull. I will try that next and see if i pull anything out.