During start up of my Lulzbot Mini according the guideline, when pulling out the filament rest out of the extruder
the cooling fan directly sucked in the resulting remainder thread from the filament.
This slowed down the fan with an awful and shocking noise! So this has been my first experience!
To prevent this for the future I added a Tesa Clean air filter which is usually for the “exhaust” of a laser printer.
It comes with a velcro glue strip. I am sure there are other printer accessories suppliers offering similar filters.
See pictures enclosed!
I hope it may help other users facing the same problem (in past or maybe future)!