High Gloss

Gloss is a film property mesure, where we mesure the reflectivity of the surface of the film: the higher the gloss, the more reflective the coating.

A maximum particle size greater than 5 microns is generally considered unacceptable for gloss paint finishes, whilst in high quality gloss coatings, 3 microns is the acceptable limit. Most inks contain particles dispersed to less than 1 micron.

Large particles, present in the coating, may occur either through a failure to disperse effectively or through flocculation or "shock-seeding" during letdown.

Figure 1: Drawdowns of ink on a polythylene film

Hyperdispersants will aid the efficiency of the grinding process, directly through their ability to wet-out newly created pigment surfaces, or indirectly through their ability to increase the dispersion pigment concentration.

Hyperdispersants will also reduce the incidence of large particles due to flocculation effects.