From a technological perspective, the porcelain tile polishing process is divided into two types:
(1) Dry method: secondary cloth (thin material on the brick) - pressing - Drying - surface decoration (inkjet bleeding, effect glaze, etc.) - firing - polishing - anti-fouling treatment
(2) Wet method: cloth - pressing - drying - spraying ——Drying——Surface decoration (inkjet bleeding, effect glaze, etc.)——Firing——Polishing——Anti-fouling treatment
Glazed tile process: cloth——pressing——drying—— Applying surface (bottom) glaze - surface decoration (inkjet, screen, roller) - applying transparent glaze (effect glaze) - firing - polishing - anti-fouling treatment
From the ceramic tile structure Look at porcelain polished tiles: body + fine powder, penetrating ink (effect glaze), penetration aid
Glazed tiles: body + surface (bottom) glaze + ink, color glaze + transparent glaze (Effect glaze)
So in the polishing stage, the fired porcelain layer is polished for porcelain tiles, and the transparent glaze is polished for glazed tiles.
From the perspective of raw material structure
The porcelain layer is fine powder after surface decoration: the porcelain layer uses refined powder that is finer than ordinary powder. Penetrating ink is a direct ionization of natural color-producing elements such as cobalt, nickel, titanium, copper, iron, etc., and is chemically combined with an organic solvent (color-developing agent) to become a colored solution, and then in the firing process Oxidized hair color. Among them, porous nano-SiO2 is used as the color agent. Penetration aids help overcome surface tension and help the ink penetrate downward into the fine powder layer.
The glaze layer is a transparent glaze: the glaze is mainly composed of feldspar flux, frit and flux. The flux can promote high-temperature differentiation reaction and adjust the physical and chemical properties of the glaze layer.
From a microstructure perspective
Porcelain layer: After inkjet infiltration, the surface of the porcelain polished tiles becomes a three-dimensional infiltration porcelain layer. The porcelain layer is dense after sintering, and the microstructure shows mullite, glass phases, quartz and pores. Both the clay and glass phases in the porcelain layer will form mullite. Compared with the glass phase, the mullite phase has higher mechanical strength, especially the network-shaped mullite with the highest strength. Mullite forms the skeleton of the glass phase in the porcelain layer, significantly changing the strength of the porcelain layer.
Glaze layer: The surface of the glazed tile product is flat printed (or inkjet printed) and then a transparent glaze layer is applied. The microstructure of the glaze layer after firing consists of a large amount of glass phase, a small amount of residual and precipitated crystals, and bubbles. Oxides (such as SiO2) are combined with each other in the form of tetrahedrons in the glaze layer to form an irregular network structure.
Both have high mechanical strength and anti-fouling properties, but there are differences in wear resistance and chemical corrosion resistance:
(1) Color: From the color type Look at it: the current color of inkjet bleedout is not rich and complete enough. The color variety of polished glazed tile products is more than that of inkjet bleedout, and the texture will be more delicate.
But from the visual effect of the design and color: the inkjet bleed-through process develops color inside the porcelain layer, making the design and color more three-dimensional. However, because the ink spreads to a certain extent after penetrating into the fine material layer, there will be certain changes in the details after polishing. Therefore, there is still a certain gap in the expression of details compared with superfine pink ink stacked on top of each other. So, both have their advantages.
(2) Wear resistance: The surface of glazed tile products is glassy transparent glaze, with low hardness (below Mohs 5 degrees) and low wear resistance. The surface of porcelain polished tiles is a dense porcelain layer with good wear resistance and Mohs hardness of 5.5~6. Can be applied to all occasions including commercial places. Wear resistance: Porcelain polished tiles>Glazed tiles
(3) Glossiness: The principle of transparent glaze is that after the light hits the body through the glaze layer, part of it is reflected back to the eyes, which is a specular reflection of light. Usually 100%. With porcelain polished tiles, light diffusely reflects back to the eyes when it hits the porcelain layer, ensuring aesthetic viewing without irritating the eyeballs. When the gloss measured by instruments is the same, the human body feels that porcelain polished tiles are better than glazed tiles.
(4) Chemical corrosion resistance: When the glaze layer comes into contact with water, acid, and alkali, it will undergo ion exchange, dissolution, or adsorption reactions with these media to varying degrees. Its corrosion mechanism is similar to that of glass. It is carried out between the ions on the network nodes and the ions in the solution, and then extracts the cations from the glaze, destroying its silicon-oxygen bonds, etc., so the transparent glaze glass has slightly poor chemical corrosion resistance. The fine powder forms a dense porcelain layer after high-temperature sintering, which has good chemical corrosion resistance.
Chemical corrosion resistance: Porcelain glazed tiles>Glazed tiles
Through the above comparison, we can find that porcelain glazed tiles perform better than glazed tiles in all aspects. With rich colors and textures that surpass natural stone, tiles highly cater to the ultimate pursuit of simplicity and nature among high-quality home life people. The full, warm and thick texture, noble and elegant colors, coupled with better three-dimensional workability, realize the superposition of practicality and decoration of porcelain polished tiles, giving designers more advantages in material selection.