Efeito da porosidade sobre o manchamento de porcelanato polido

Abstract

Porcelain tile is a type of ceramic tile which has shown the highest worldwide expansion in recent years due to the excellent technical and esthetic qualities of the product, which have augmented the possibilities of its use in a wide variety of applications. Among the various types of porcelain tiles today, polished porcelain tile stands out because consumers greatly appreciate the esthetic effect of its characteristically high gloss. However, polishing exposes part of the material s closed pores and facilitates the impregnation of dirt when the product is in use, which may compromise one of its most important properties, i.e., stain resistance. Staining of polished porcelain tile does not depend only on the occurrence of closed pores on the surface of the product but also on other characteristics such as the size and morphology of the pores. This research work aimed to investigate the characteristics of the pores that most contribute to staining and to ascertain how processing variables act in the formation of the material s porous microstructure. The methodology employed to deal with the theme differs from that of other works reported in the literature, since it is based on the characterization of porosity throughout all the stages of processing (green compact to end product) and on a systematic study of several process variables responsible for pore formation (granulometric distribution and particle size distribution). The main experimental techniques used in the development of this study were scanning electron microscopy, digital optical microscopy, image analysis (software), mercury porosimetry, diffuse reflectance spectrophotometry, X-ray sedimentometry, helium gas pycnometry, and mechanical profilometry. In addition to achieving the initial objectives, the results indicated several viable alternatives for reducing the staining tendency of polished porcelain tile.