1. The waste porcelain chip itself does not contain organic matter, adsorbed water and crystal water, and the gas content is also very small. Its drying shrinkage and firing shrinkage are extremely small, so it can reduce the bending deformation of the green body after firing and the product size tolerance is small. It is also more suitable for rapid firing.
Note: a. If you want to get porcelain with good transparency, you should not add waste porcelain pieces to the green body, otherwise it will reduce its light transmittance due to the formation of more mullite (mullite has a greater influence on light transmittance) Big).
b. Attention should be paid to the influence of the added waste porcelain pieces on the plasticity of the clay. Add an appropriate amount of waste porcelain pieces according to the plasticity of the blank, or increase the plasticity of the paste while adding the waste porcelain pieces, so as to maintain the plasticity of the clay. The plasticity of the mud is affected by adding too much waste porcelain
c. When adding waste porcelain pieces, the shrinkage of the mud should be fully considered to prevent inconsistent shrinkage of the mud before and after.
2. Introduce 2% – 40% waste porcelain chips into the glaze to replace part of fluxes such as feldspar, calcined clay and quartz in the glaze to save raw material costs.
3. The waste porcelain pieces have been fired at high temperature, the physical and chemical reactions of each component are basically completed, and the gas content is very small. Therefore, if a large amount of waste porcelain pieces are introduced into the glaze, the gas content in the glaze will be greatly reduced, thereby reducing the pinholes on the glaze surface. and glaze blisters and other defects
4. The waste porcelain pieces themselves contain very little gas, which increases the density of the glaze layer and the reflectivity of the glaze surface accordingly. Therefore, introducing a large number of waste porcelain pieces into the glaze can easily form a smooth and bright glaze surface, which is helpful for improving the gloss of the glaze surface. degree plays an important role.
5. The various reactions between the components in the waste porcelain are relatively thorough, so its activity is poor, and the reaction between the waste porcelain and other materials is relatively slow, so the initial melting temperature of the glaze is increased, which is beneficial to the physical and chemical reactions in the glaze. The gas generated by the reaction is quickly eliminated, thereby reducing defects such as glaze pinholes and glaze bubbles, and widening the firing temperature range of the glaze.
6. The introduction of a large number of waste porcelain pieces into the glaze reduces the amount of fluxes such as feldspar accordingly, thus reducing the damage to the glaze network structure caused by fluxes such as potassium oxide and sodium oxide in the glaze, and reducing the expansion coefficient of the glaze. It also helps to form a thicker intermediate layer of the glaze, which improves the adaptability of the glaze, thereby improving the thermal stability of the product.
7. If calcium oxide is introduced from waste porcelain pieces, it can not only prevent the phenomenon of high feldspar low calcium glaze from inhaling “yellow smoke” during heavy oil reduction firing, but also solve the problem of low feldspar high calcium glaze firing in a narrow temperature range. Tunnel kiln and drawer kiln and other kiln firing problems; in addition, the calcium oxide in the waste porcelain has the effect of rapidly reducing the high-temperature viscosity of the glaze at high temperature, so the high-temperature fluidity of the glaze increases, thereby solving the problem of glaze needles. Holes, glaze bubbles, back glazes, etc. are all very beneficial.
Post time: Dec-23-2022