Printing on Nylon Flags... What kind of Ink ??

I've used Nylabond on nylon. Add it to the plastisol by the ratio it says and it acts as an adhesion promoter.

Yea, flags sound tricky in the dryer...

What don't you subcontract sublimation polyester flag, that could be cheaper at the end

+1 on dyesub poly flags.

Dye sub is the way to go. Contact @skdave. With screen printing the problem would be putting the flag in the right place.

Nylon curing with a conveyor requires it have circulating air. Not tricky with proper equipment.

Nylobond at 10-15% by weight. Print through a 305. Lots and lots of pallet adhesive - nylon is slick. Keep your dryer temp around 315 or so. Wash out the screen and your squeegee right after printing. Throw away the leftover mixed ink because it will harden after a few hours.