Grading of tiles and ceramics indicates the level of quality and desirability of the product. Understanding the difference between grade and quality in ceramics and how to identify the grade of ceramics before purchase is very important. Recognizing and identifying the grading of tiles and ceramics before buying prevents loss and saves time.
Therefore, for those who intend to buy porcelain floor or wall ceramics, we have prepared and presented this article. In this article, you can easily distinguish between first, second, third, and fourth-grade ceramics and have an ideal purchase experience.
You might think that first-grade ceramics are high-selling products due to their higher quality and desirability. However, you might be surprised to learn that your assumption contradicts reality. In the following, we will become more familiar with how to identify the grade of ceramics and the various grading types of tiles and ceramics.
Methods for Grading Tiles and Ceramics
Tiles and ceramics are made by mixing completely natural raw materials like clay, kaolin, quartz, feldspar, and stone powder in specific proportions and then baking them in high-temperature kilns.
After mixing, these compounds undergo a pressing process to become biscuits. They are preheated and baked at a minimum temperature of 1100 degrees. Since these products are made using completely natural materials, they pose no health risks.
The main reason for using clay in these products is its high moldability and relatively low baking temperature. Today, ceramic products are divided into different grades based on the quality of raw materials, type of baking, and surface design because most manufacturers pay special attention to maintaining the quality of their products.
In general, the grading of tiles and ceramics indicates the level of desirability, integrity, and quality of the product. Tile and ceramic grading is divided into four levels based solely on surface quality, as follows, and manufacturers are not allowed to package and offer tiles and ceramics outside of this classification.
Identifying First-Grade Tiles
When a sample tile and ceramic are tested according to Iran's national standard number 2-9169, none of the 13 surface quality defects (except body cracks, glaze cracks, and corner chips visible on the surface) listed in section 8 of the standard should be observed from a one-meter distance.
Identifying Second-Grade Tiles
When a sample tile is tested according to Iran's national standard number 2-9169, no more than 3 of the 13 surface quality defects (except body cracks, glaze cracks, and corner chips visible on the surface) listed in section 8 of the standard should be observed from a one-meter distance, provided that these defects are not visible from a two-meter distance.
Identifying Third-Grade Tiles
When a sample tile is tested according to Iran's national standard number 2-9169, no more than 3 of the 13 surface quality defects (except body cracks, glaze cracks, and corner chips visible on the surface) listed in section 8 of the standard should be observed from a two-meter distance.
Identifying Fourth-Grade Tiles
Tiles that do not fall into any of the first, second, or third-grade categories based on surface quality are considered fourth-grade tiles.
Note 1 – In evaluating surface quality for grading, the number of each of the 13 defects listed in section 8 of Iran's national standard number 2-9169 should be counted and then considered regardless of type.
Note 2 – In evaluating surface quality, effects and defects intentionally created for decoration are not considered defects.
Tiles that can be graded in levels 1, 2, 3, and 4 according to this standard should not have body cracks, glaze cracks, corner chips, or visible surface chips.
The test sample according to section 8-3 of Iran's national standard number 2-9169 in each of the grades 1, 2, 3, and 4 can include up to 5% of tiles of the next lower grade.
Identifying the Difference Between Grade and Quality in Ceramics and Tiles from the Carton
In this method of identifying the grading of tiles and ceramics, you should pay attention to the specifications listed on the packaging or carton of the manufacturing company. Generally, specifications such as tile grading, production date, wear class, etc., are printed on the carton.
Grading of Tiles and Ceramics in the Factory
After coming off the production line, tiles and ceramics are placed in the pallets section for 4 to 5 hours; then, using TGV or LGV machines, they are transferred to the grading line to determine the grade. The method of identifying the grade of ceramics in the factory is based on three important factors: appearance, curvature, and size. This process has six stages, which we will explain below so you can fully understand the grading of tiles and ceramics in the factory.
- Appearance Grading by Operators
- Passing the Curvature (Planar) Stage
- Going Through the Calibration (Sizer) Section
- Completing the Grading
- Sorting and Arranging
- Transferring Separated Tiles for Cartoning
Stage One
In the first stage, the operator grades and identifies the visible surface of the products based on the presence of chips, glaze skips, cracks, welds, and printing quality issues. In subsequent stages, this is evaluated by intelligent sensors.
Stage Two
The second stage pertains to curvature (planar). This machine has 5 sensors, each with two electronic eyes that grade the curvature of the tiles based on predefined information.
Stage Three
This stage of tile and ceramic grading relates to calibration or size inspection. Here, intelligent sensors check the size of the tiles and compare them with the predefined sample tile size, which has normal and ideal dimensions.
Stage Four
In stage four, the overall grading of the products is done by two infrared sensors. These sensors generally consider the largest size. For example, if a ceramic has a third-grade appearance, first-grade curvature, and second-grade size, the sensors will grade the tile as third-grade because a defect in one area indicates the overall lower quality of the product.
Stages Five and Six
Stage five is the sorting stage, where tiles of different grades are stacked and separated. This stage is essentially the final inspection for grading. In the sixth stage of tile and ceramic grading, products are packed into cartons. Information such as production date, product code, and grade is printed on the tile and ceramic cartons using a printer.
Final Word
Increasing knowledge and awareness about the grading of tiles and ceramics will help you select the best and most ideal type of tile and ceramic for each part of your building. Therefore, in addition to increasing your knowledge in this area, try to inquire about the defects of non-first-grade tiles from the seller when buying. This will help you make a better decision and save time. It is also advisable to take photos of the product code, grading, and brand when purchasing to avoid mistakes upon delivery.