Soft Touch coating doesn't adhere / set

[jotterpinky]

We're new to using this type of coating (soft-touch), usually running only gloss aqueous coat. New job today requires soft-touch so we purchased some from our vendor and are finding that it's not setting up correctly over top the ink. It's a big solid heavy rich black (approx 50,30,30,100 CMYK) and the coating seems fine on the unprinted area of the sheet, however on the areas with ink the coating just rubs off even after several hours and the ink below seems to be set pretty good. Any ideas or things to check?

 

[MacTwidget]

What press are you running it on?
It the coating unit anilox?

 

[chevalier]

With the soft-touch coatings I have worked with (UV and AQ) the blooming agent takes ~24 hours typically to set. You don't heat it, dry it, fan it or otherwise mess with it. You let it bloom and set up. Your inks (assuming conventional inks) have to degas through the coating barrier as well. If you are in a hot high humidity environment it may take much longer than 24 hours.

NOTE: I am not a coatings, inks or press expert. This is purely from my experience of similar issues. The same logic applies to "strike-though" coatings.

 

[jotterpinky]

printing on SM-52 with anilox coater

 

[MacTwidget]

printing on SM-52 with anilox coater

What is the line screen and cell depth on your anilox roller?

Soft Touch AQ requires a roller with deeper cells than Gloss, Satin or Matte AQ.

Most AQs are good with 8.0-8.5 BCM.
Soft Touch likes 10.0-10.5 BCM.

 

[REYES1377]

Soft touch sometimes requires a cross linker that helps set up faster. Ask your vendor for this. This cross link does cut back the soft feel a bit but will help lock up faster on heavy ink coverage jobs. They do not manufacture the coating with this in it because it will ruin the coating in a few days. It is best to only make 5gal at a time.

 

[jotterpinky]

Reyes1377, we found the cross linker and added it. We also ended up letting it set for a full day before finishing and it's pretty scuff resistant, better than I had hoped. Thanks for everyone's input.

 

[chevalier]

Excellent!

 

[Chasfinch]

My lead pressman says to run a second hit and it should dry. Even if it feels "soft" it will smooth out and cure.