Slabs in fine porcelain stoneware perfectly fused and compacted. The product must be manufactured by pressing according to the loading technique for raw materials pie-mixed during the preparation stage. The back of the material must show the natural circular saw cutting, the edges and corners are straight. The material
must be completely inert. The production process must be carried out with harmless and non-radioactive raw materials than do not contain heavy metals (cadmium and lead), thus enabling the manufacture of a product in accordance with bio-architectural techniques. The variegation of the product must produce the appearance of the Tuscan sandstones on the surface and throughout the body, with soft and non-repetitive shadings in the body of the product and a guarantee of resistance to wear over time. This material must he classified in the Bla group, in compliance with standard ISO 13006, and meet all the product requirements set forth in standard ISO 30545.
Specifically it must be resistant to frost (ISO 10545/12), thermal shock (ISO 10545/9), and the effects of acids and bases (ISO 10545/13). It must feature a water absorption value (ISO 10545/3) of less than 0.05%. It must achieve a resistance to bending stress (ISO 10343/4) greater than or equal so 58 N/mm2 and achieve a volume of material removed of less than or equal to 115mm3 when the deep abrasion resistance test (ISO 10545/6) is performed on it. In must be resistant to food stains in accordance with CTI-81-7 (Ceramic Tile Institute, USA). In general all the technical specifications must be checked according to testing methods carried out in compliance with the ISO 9001 standards.
The tiles must therefore not contain any micro-cavities. If they are subjected to extreme wear (at least the amount of abrasion obtained with 6000 machine revolutions for the P.E.I. test, they should maintain their features of complete ease of cleaning to such a degree that ink pen stains (such as those resulting from Shachihata Artline
HP ink) can he completely removed.