Friction-fit filament filter

thingiverse

This is an adjustable friction-fit plastic fiber filter. If it's too snug, file down or widen the fit. If it's too sloppy, add electrical tape to the inside, or narrow the fit. The slot allows you to put it on or take it off without spilling the fiber, but if you don't want a slot, simply set the slot size to nothing. No supports required, very simple to print.