Metodologia para avaliação do desempenho de tintas para decoração digital de revestimentos cerâmicos
Abstract
Brazil plays an important role in the consumption and production of
ceramic tiles nowadays. The decoration of tiles by digital inkjet printing, due to
its technical and aesthetic advantages, is a spreading technology and has
already been adopted in the national industry. Ink sets acquired from different
manufacturers differ in their extension behavior on the ceramic surface, in the
definition of the printed pattern, in the range of printable colors, and in the ink
yield, square meters of a same decoration that can be printed for unit volume of
ink. Due to the peculiarities of this technology, there is still no methodology for
evaluating the performance of the inks and there is very little published on this
topic. This paper proposes a methodology for a comparative evaluation of the
performance of industrial inks, aiming to help in the selection of these inputs by
ceramic tiles producers. Drops of the evaluated inks were applied on a defined
ceramic substrate. The colorimetric behavior and the extension of the ink were
assessed as indicative parameters of the image quality and yield of the inks.
The colorimetric characteristics and the size of the points produced with inks
from different suppliers were significantly different for all the four colors of the
inks evaluated. For all these colors, the results point to similar conclusions,
demonstrating the validity of the method. Some technical characteristics of the
inks were studied to identify the reasons for the different behaviors observed.
The color differences between inks of different suppliers are explained by the
different pigment phases in each composition of ink. The extension of the inks
were greatly influenced by its viscosities. The more viscous inks, due to greater
difficulty in penetrating the ceramic substrate, expanded more over it.