A. Water based inks contain a class of chemicals called amines. These amines are necessary to maintain resin solubility in an aqueous environment. Over time, the ink loses valuable amines by evaporation which must be replenished at regular intervals. If the amines are not replaced, the resin in the ink will eventually "kick out" of solution, raising the viscosity of the ink and causing dirty printing.

Q. Why is it often necessary to add more defoamer to an ink, once it is on press?

A. There are two primary reasons for this. Over time, defoamers gradually become solubilized in the ink, and therefore become ineffective at defoaming the ink. Secondly, the defoamer may become absorbed onto pigment surfaces thereby removing it from contact with the bubbles in the ink vehicle. Other questions you might want to consider are:

Q. I use solvent inks at the moment. Is it possible to switch to using water based inks?

A. A transition to water based inks must be done carefully and with a lot of consideration. Pemla will work closely with your company to help you in your transition to water based inks, by carrying out a complete technical analysis of your requirements.

Q. What are the advantages to using water based inks?

A. Water based inks have many advantages over solvent inks: lower V.O.C.'s and H.A.P's (Hazardous air pollutants), more environmentally safe, less odor, and reduced fire hazard.