Quality Control
Whiteness Test
A whiteness test for tiles is a method applied to assess that level of whiteness, or lightness, of the surface of the tiles. In the tile manufacturing industry, this is an important quality control measure to maintain consistency and quality of final products. The test is measuring the reflectance of light properties of the tile's surface, this is very close to the perceived whiteness of the tile.
The test is done with the help of a whiteness meter, also called spectrophotometer or colorimeter. The measurements of intensity of light as reflected off the surface of the tile at different wavelengths are measured by this device. The whiteness tests help manufacturers ensure that tiles are of an aesthetically and quality appropriate level. This is especially critical to industries with visual appeal in tiles such as architecture, interior design and construction.
Deviation in Length & Width Test
Deviation in length and width tests for tiles is a quality control process used to assess the dimensional accuracy and consistency of the tiles. They are used to check whether the tiles conform to the required size and to meet standards of the industry. This deviation is defined as allowed variation in size measurements from what is intended.
These tests are done with precision measuring instruments like calipers, micrometers or digital measuring tools. These tools can accurately measure length and width. Running deviation in length and width tests can help manufacturers detect any variation in tile size and rectify to ensure product quality and consistency. This is a way of helping to make sure the tiles are appropriate for their intended use and match with expectations of architects, designers, and end users.
Glossiness Test
The glossiness test for tiles is a quality assessment procedure that determines the reflecting property of the tile surface. The second quality of interest is glossiness as a surface measure which is defined as the amount to which a surface reflects light uniformly and specular (as if by a mirror) to produce the appearance of a shiny, polished surface. This is a test of great importance to assess the aesthetic and functional aspects of tiles.
A gloss meter, also known as a Glossmeter, is used for this test. This is a device that is designed to do the measurement of gloss and shine. It has a light source that shines light on the tile's surface at a certain angle and a receiver measuring the amount of light reflected from the surface. There is no escape from glossiness tests, it is a part of quality control in tile production. It also helps the manufacturer to maintain the visual characteristics of the product and the expected shine level of the tiles.
Stain Test
The stain test for tiles is a way to check how tiles resist the staining by different substances. Porcelain is also often used in areas that may come in contact with liquids, oils and other materials that could stain. This test looks at the rate in which the tile will repel or resist the absorption of these substances and keep the look and cleanliness of the tile surface.
For the test, a range of substances is selected that are likely to be in contact with the tiles’ surface. They can include common household items such as red wine, coffee, ketchup, oil, ink and much more. The goal is to simulate real-life scenarios that might cause stains.
Deviation in Thickness Test
Deviation in thickness means variation or difference in thickness of tiles in the same batch of lot. All tiles are manufactured by standards and specifications including their thickness. Nevertheless, the manufacturer itself cannot ensure that the tiles will have no variance in their thickness, even within the same production run.
Deviation in thickness can be measured and quantified using precision instruments such as calipers or digital thickness gauges. This involves measuring the thickness of multiple tiles from the same batch at different points on each tile and then calculating the range of thicknesses observed.
In most cases, thickness deviations are expressed as tolerances. For example, 9mm thick with a tolerance of ± 0.5mm. What it does mean is that the actual thickness of the tile could range from 8.5mm to 9.5mm by still fitting the required standards. Finally, the deviation in thickness for tiles relates to the deviation in tile thickness that is made during the porcelain manufacturing process.
Flexural Strength Test
The flexural strength test of tiles is one of the major mechanical tests to check their capacity to withstand bending without breaking. It tests the structural integrity of the tile and its suitability for applications under bending forces, i. e. installed on the floor or the wall. The test involves applying a controlled load to a supported tile specimen until it fractures.
Put the tile specimen onto the bending fixture with the glazed surface to be tested. Support points should be located under the tile at fixed distances from each other and a loading point located on the centerline of the span between the support points. A hydraulic or mechanical testing machine is used to apply a force or load at a constant rate from the center of a tile, gradually. Stress is applied to the tile uniformly and the rate of loading is controlled. There is no end to the test until the tile specimen fractures. Also recorded is the point at which the tile breaks and the force at that point. This breaking point gives information on the maximum load that the tile can bear before failure.
The calculated flexural strength value is an indication of the tile's strength to withstand bending forces. It is used to see if the tile provides the needed quality for the thing that it is supposed to be used for. In general, tiles with higher flexural strength values are more durable, allowing them to perform and withstand longer time under high-stress environments and provide longer time in high safety.
Surface Flatness Test
Surface flatness, also known as surface profile or surface evenness, is an important characteristic of tiles, especially when they are used in applications where a smooth and level surface is essential, such as flooring or wall cladding. The tile surface flatness test determines the level, and how uniform the tile’s surface is, to provide a visually and technically pleasing tile installation. The test is usually run in this manner.
The deviations from a perfectly flat plane are measured using a surface flatness testing apparatus. It can be a specialized tool that is made for this purpose or maybe a simpler set-up with a straightedge and a feeler gauge. Place the selected tile on a flat and level surface glazed side up. Make sure that there are no vibrations or shaking of the tile. Set a long and straight tool on the surface of the tile. At that point, employ the feeler gauge to determine the distance between the straightedge and the surface of the tile at different locations. Any disparity from the flat plane is indicated by the feeler gauge.
The advanced methods consist of laser levels or digital scanners for capturing the tile’s surface profile digitally. Provided detailed visual representations of the surface deviations. It is critical to surface flatness test because an installation that lacks visual appeal and is filled with uneven surfaces, lippage (when the edges of adjacent tiles are not level), and difficulties with grout application. Properly assessing and solving surface flatness will have a long-term contribution to the durability and aesthetics of a tile installation.
Rectangularity Test
The rectangularity test for tiles evaluates how closely a tile's edges and corners conform to a true rectangular shape. Installing tiles with correct rectangularity is easier and will generate consistent grout lines and a visually pleasing finished appearance, which makes this test important. It tests to make sure that tiles lie very close to and even similarly to each other so there isn’t too much lippage (uneven edges between adjacent tiles).
It is used to assess the tile conformity to a true rectangular shape with the use of a rectangularity gauge or template. Usually, two arms that are perpendicular to each other and form a right angle make up this template. Put the selected tile on a flat and level surface and glaze the downside facing up. Position the rectangularity gauge or template over the tile in such a way that the arms of the gauge align with the edges of the tile. Compare the edges and corners of the tile to the gauge or template. This is a qualitative assessment of how well the tile's shape matches the right angle formed by the template.
The testing of the tiles against the surface (rectangularity test) guarantees that the tiles both fit tightly together and fit evenly to make a good cohesive surface. This is crucial for applications where very accurate alignment is needed, like large format installations. Manufacturers and users can now assess and categorize tiles according to their rectangularity and accordingly decide how to use the tiles efficiently and get the required aesthetics or practicality while constructing projects with them.
