Methodology of discovering and control of clay roofing tile textural inhomogenities

The adjustment of shaping parameters, including vacuum press working ones, is an important factor in the production of ceramic roofing tiles, especially regarding their textural characteristics. This paper is focused on the investigation of the screw conveyer wearing degree of the vacuum press in the period of 13 weeks, with the aim to define its time of replacement. The industrial clayey raw material with a considerable amount of quartz, orthoclase, mica and traces of carbonates presented the composition used in the tile manufacturing process. A control method which correlates the textural characteristics of tile segments with the degree of screw conveyer wearing was set up. This method could be a useful tool in the prevention of tile lamination and small pores appearance regarding the extruded column shaping by a vacuum press.