This standard outlines the procedure for assessing the crazing resistance of glazed ceramic tiles, excluding those designed with intentional crazing. It involves exposing tiles to high-pressure steam in an autoclave followed by staining to reveal fine surface cracks, serving as a quality assessment for manufacturers and testers.
Overview
This standard outlines the procedure for assessing the crazing resistance of glazed ceramic tiles, excluding those designed with intentional crazing. It involves exposing tiles to high-pressure steam in an autoclave followed by staining to reveal fine surface cracks, serving as a quality assessment for manufacturers and testers.
Audience
Contents
Structure
This section defines the extent and limitations of the standard, focusing on test methods for crazing resistance in glazed tiles, excluding those with intentional crazing features. It also specifies the rules for rounding numerical values as per IS 2:1960, ensuring consistency in test result reporting. The section references related Indian Standards for methodology alignment.
Key terms are aligned with ISO 13006:1998 standards pertinent to ceramic tiles, including classifications and marking. The section emphasizes adherence to IS 2:1960 for rounding numerical data to maintain uniformity in reporting and interpretation of test results.
This part lists applicable Indian Standards referenced within the document and reiterates the importance of rounding off test values according to IS 2:1960 guidelines. It provides examples illustrating how to round values to the appropriate number of significant figures.
Details the specifications and requirements for the autoclave apparatus used in testing, including pressure range (typically 1.2 to 1.5 MPa), temperature control (around 180°C ± 2°C), material construction, and safety features. It also reiterates the rounding rules for reporting test data.
Describes the selection criteria for test specimens, ensuring they are free from pre-existing defects or crazing. Specifies the autoclave test procedure involving gradual pressurization to 750 ± 20 kPa over one hour, maintaining pressure for two hours, followed by controlled decompression and cooling stages both inside the autoclave and in ambient conditions.
Though no dedicated procedure clause exists, this section consolidates instructions on preparing specimens, autoclave usage, and rounding off results per IS 2:1960. It highlights the importance of consistent specimen preparation and testing conditions for reliable assessment.
Specifies that final test results must be rounded according to IS 2:1960 rules to match the significant figures of the referenced values. It provides a summary of rounding rules and practical examples to ensure consistency across reports.
Outlines the mandatory contents of the test report, including tile description, number of specimens tested, count of specimens exhibiting crazing, and descriptive documentation of crazing via text, sketches, or photos. It also cautions against confusing crazing with scratches or cracks, ensuring accurate reporting.
Frequently Asked
The crazing resistance test involves selecting appropriate glazed tile specimens (excluding those with intentional crazing), exposing them to high-pressure steam in an autoclave at 750 ± 20 kPa and about 168 ± 1°C for two hours, followed by rapid decompression and controlled cooling. After the treatment, tiles are stained and inspected visually to detect fine surface cracks. The number of specimens tested and those showing crazing are recorded and reported.
Specimens must be free from visible defects and pre-existing crazes before testing. Selection involves a visual inspection under normal conditions, allowing spectacles if routinely used. Multiple specimens from a batch are tested to ensure reliability. Post-test, specimens are examined carefully to distinguish crazing from scratches or cracks, and detailed documentation is maintained.
A steam autoclave with external steam supply is preferred, though a directly heated autoclave is acceptable. It should accommodate at least five tiles spaced to avoid contact. Testing involves gradually increasing pressure to 750 ± 20 kPa over one hour, maintaining it for two hours at approximately 168 ± 1°C, followed by rapid decompression to atmospheric pressure, then cooling specimens inside the autoclave for 30 minutes and subsequently at room temperature for another 30 minutes.
After autoclave exposure, tiles are stained to reveal fine cracks in the glaze surface. Visual inspection distinguishes crazing—network-like fine cracks limited to the glaze—from scratches or structural cracks. The number of specimens exhibiting crazing is recorded along with descriptive documentation such as text, drawings, or photographs.
Acceptance criteria involve recording and reporting the presence and extent of crazing after testing, including detailed descriptions. The standard does not specify numeric thresholds but excludes tiles designed with inherent crazing features. Proper documentation of the number of specimens tested, those with crazing, and the nature of crazing ensures quality control and consistency.
Ask AI about any clause, requirement, or provision in IS 13630 PART 9. Get instant, clause-cited responses powered by our indexed library.
Free tier includes 150 queries (50 AI + 100 Reference) · No credit card required