Ceramic Tiles - Methods of the test, Sampling and Basis of Acceptance, Part 8: Determination of chemical resistance - Glazed tiles (see IS 13630: Parts 1 to 15)
2006 الطبعة

As per IS 13630 Part 8 (2006) referencing ISO 10545-13:1995, the chemical resistance evaluation entails exposing the glazed tile surface to specific substances such as common household chemicals (like detergents and bleach), swimming pool salts (including sodium chloride and calcium chloride), and citric acid for a duration of six hours at room temperature. Following the exposure, a visual inspection is conducted to detect any changes in color, surface deterioration, or gloss loss, ensuring the tile's suitability for environments like kitchens, bathrooms, and pools.

The pencil test, described in IS 13630 Part 8 Clause 7.2.3, is used to verify the applicability of assessing glazed tiles after chemical exposure. The test involves drawing lines with an HB pencil on a completely dry, untreated glazed surface, then attempting to remove these marks with a dry cloth. If the pencil lines cannot be removed, the test is deemed inapplicable, and only visual evaluation is performed without using the classification scheme. If the marks are removable, the pencil test proceeds, and the surface's resistance is classified based on the pencil mark and reflection tests.

While IS 13630 Part 8 primarily focuses on testing procedures at room temperature and does not explicitly provide a classification system, chemical resistance is generally categorized based on the type of chemical exposure, concentration, duration, and visible effects on the tile surface. Typical classifications range from Class A (no visible change, excellent resistance) to Class D (severe surface damage, poor resistance), reflecting increasing levels of surface alteration such as gloss reduction, etching, or discoloration.

The standard mandates the use of five test specimens per chemical test solution to ensure dependable and reproducible outcomes. These specimens must be intact, either full tiles or tile fragments, cleaned thoroughly with an appropriate solvent like methanol before testing, and free from any surface defects, as outlined in Clauses 6.1 through 6.3.

According to IS 13630 Part 8, glazed ceramic tiles are accepted if after exposure to various chemicals at room temperature they display no visible damage or only minor, non-detrimental changes such as slight gloss or color variation. Tiles exhibiting notable surface etching, discoloration, staining, or corrosion fail the acceptance criteria. Typical chemicals tested include acids, alkalis, salts, and solvents, with the goal of ensuring the tile's suitability for chemically exposed environments.