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
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