Printing inks are a fine dispersion of pigments or dye derivatives in a liquid medium of variable viscosity called vehicle or binder (commonly varnish). Its structure and composition are conditional on the following elements: printing system – printing form – type of printing machine – printing support – static requirements – requested resistances of any kind in any position of the form depending on the use to which it will be used : mechanical, physical, chemical.

The printing inks are composed of three fundamental parts, which depending on the measurement or variation thereof, are used for different printing systems, media to be printed, needs in printing, tonalities, etc.

– The first part of the composition of an ink is the vehicle of it. This is a varnish that is prepared at high temperature for a long period of time to define the series of inks to be manufactured. Depending on this cooking we obtain “penetration, viscosity, resistances, etc.” These vehicles or varnishes can be mineral based or vegetable based. In many cases the vehicle is obtained by mixing these mineral oils with the vegetables. At the present time it is the vegetables that are being imposed and in the last generation inks we only talk about vegetable bases.

– The second part is going to tell us tonality. According to the pigment that we choose, we obtain one color or another. In addition we can vary the tonalities in more or less intense depending on the pigments used. We have in line with the Pantone system mono pigmented colors, which are made based on a single pigment (Pantone Bases) and are the “clean” colors but we also have multipigmented, which are all other colors of this internationally known system and which are mixed between mono pigmented bases to achieve the desired shade.

– As a third part we contemplate the additives. These additives are mixed in the manufacture of an ink in a specific measure to achieve the objective of the ink: drying, anchoring, gloss, matt, resistance to rubbing, resistance to temperature, to varnishing, to plasticizing to external agents (alkali, solvents, alcohol etc.). These additives are for example, drying agents, waxes, silicones, and / or specific additives to achieve our purpose.

In recent years, when incorporating more complicated supports to dry like plastics, P.P. P.E.T metallized, etc., drying inks are Ultra Violet Radiation, and this leads us to look for new additives to make this ink dry instantly. These secants that are attached to the Ultraviolet inks are called Photoinitiators since they react instantly with the photosynthesis that these U.V rays give off.

SOURCE: www.interempresas.net