Generally, UV screen printing does not require additional adhesion promoters because there is a hardener agent mixed into the ink just prior to the printing process. This increases adhesion and works well.
Occasionally, we do run into situations where UV screen printers need exceedingly high adhesion and then we recommend an adhesion promoter. Currently, there are only a few adhesion promoters available that can be jetted through a print head, so the most common application methods are brush, wipe-on, and sprayers (either pump or low-pressure, high-volume sprayer).
All application methods work well – it is normally a decision based on volume. Unfortunately, there is no bulletproof process that guarantees perfect results for UV printing.