How long do screens need to dry?
A newly coated screen needs to be bone dry before you expose it. You do not want any moisture left in the emulsion before exposing.
How long it takes to completely dry a screen is 100% dependent on the dryness of your room/space the screens are drying in. If you are in a space with fans, 80°F, and 30% humidity, you can have a single screen done in under 30 minutes. If your space is 80°F, no fans, 60%+ humidity, you may never have a screen that is dry enough to expose.
To learn more about the drying process, please watch this video.