VISCOSITY-TEMPERATURE BEHAVIOR OF POWDER COATINGS

This paper presents rheological investigations of pigmented and non-pi gmented powder coatings with the oscillation technique. The measured v iscosity-temperature behaviour of the powder coatings exhibits a chara cteristic viscosity minimum which strongly depends on the selected hea ting rate. Here, the viscosity level decreases as the heating rare inc reases, while the temperature at which the minimum occurs is shifted t o higher temperature values. The rheological results are compared with surface structure measurements of the final powder coating film. We f ound that the long waviness of the surface increases at higher viscosi ty levels. (C) 1998 Elsevier Science S.A.