Hey guys, this is probably a noob question:
I just got a roll of adhesive vinyl from 3M (IJ15-20) and noticed the manufactured date is from 2 years ago, I'm just worried about it because of "shelf life" I've already had problems with other media which were apparently bad because of not being used in a long time, should I worry about it or is this a "normal" that the roll has been stored for this long.
I was told this is a monomeric calendered roll, I'll be testing it for stickers and decals printed with HP Latex.
Thanks!
It isn't bad question.
Sorry, I already wrote it once, but I erased the content. I had problems with the nomenclature in english
now it should be better.
The biggest problem is not in the adhesive or aging of the polymer itself, but in the surface tension. Therefore, all of the polymer should be processed in a year, and therefore the warranty for printability is only one year.
All polymer material in roll (PVC/PP/PET/PE) have in last step of production process surface treatment by corona. It is a high-voltage arc that emits ions and ozone, disrupts the surface and thus forms reactive centers.
This reactive centers is very important for ink adhesion on the polymer. If you have technology with ink that have low polar components (especiality ink on water base (old latex without optimizer) or bad formulated ink....older version of some UV LED inks and many more) you may have problems.
After 6 to 12 months, reactive centers are deactivated. (adsorption of the impurity atoms). The surface tension of the polymer drops, thereby changing the polar components and the number of bonds and changing the contact angle of the ink droplet and Ink will be have weak adhesion.
Deactivation speed is dependent on temperature, ambient and storage conditions. But the material can be considered deactivated after one year. The biggest problems with deactivated surface is in PE / PP / PET polymers, in PVC are not so big problems - polar Chlorine (PolyVinylCHlorid).
I had same trouble maybe one months later. Before 8 months I choise new UV varnish for our UV liquid coating machine. But i make mistake, I tested new liquid varnish at new supply of polymer(PVC)... last month problems started with adhesion on this materials
I had to change the varnish and start modifying by the adhesion promoter.
Return it.