Troubleshooting Guide - Pressroom UV
On Press Issue: Scumming After Clean Press Start Up
Potential Causes
Dyne level (surface energy) is too low, can adversely affect transfer
Solution: Corona or flame treat the stock or select a substrate with a higher dyne level 38+.
A plasticizer and/or contaminate is on the surface of the stock
Solution: Select another stock or possibly apply a primer.
The treatment/coating on the stock is faulty
Solution: Select another stock or possibly apply a primer.
Ink and/or coating crosslink density is too high = brittle
Solution: Use a lower crosslink density formulation.
Ink is not properly cured; crosslink density is too low
Solution: Check the UV lampor EB unit settings, increase if possible. Check press speeds, if possible lower the speed. Lower the density of the ink. For UV inks add photoinitiator 1% at a time up to 3%.
Insufficient slip agent/surfactant in the coating
Solution: Adjust slip agent/surfactant.
