LM Special red not passing a 90 degree rub test.

[lpprc810]

We are having an unusual problem with a LM special red and it not curing. Normally this is never an issue with this red and we let our product sit for 48 hours before further processing.

We figure it must either be a bad batch of ink or coating but it seemes to be thoughtout the entire 200k sheet run.

What do y'all think?

 

[Cornishpastythighs]

What other tests have you done. Ethanol is used for testing the cure of UV inks; while Methyl Ethyl Ketone (M.E.K.) is used to test the curing of UV varnishes. What does the rub test tell you, how many rubs are you getting with a 2lb/4lb weight. Have you done a Sutherland test. You dont say what press or UV system you are running

Some reading material https://www.flintgrp.com/media/3092/uv_offsettsg_2014.pdf

 

[SteveSuffRIT]

Is this a UV cured ink?
Try re-exposing a few sheet to see if they were under cured?