15 display bone China defects

( 6) Bone China fuel sulfur content is too high. To overcome the way: ( 1) Choose the crystallization agent. Crystallization of bone porcelain glaze materials generally divided into three categories, namely into crystalline material, flux, and coloring. Table 6 - Listed in 1 zinc silicate and silicon zinc titanium crystal glaze of commonly used formula: 1 # and 2 # the crystal flower for Zn3RO4 bone porcelain glaze, 3 # bone porcelain crystal flower for titanium silicate in the glaze, and therefore, Zn0, SiO2 and TiO2 of bone porcelain glaze into crystalline material, glass powder, feldspar, borax red lead to form a glaze flux of vitreous material and the formation of crystals and adjust the glaze of melting temperature, viscosity and crystallization condition: Ni0, Fe2O3, TiO2 as colorant, made of glass and coloring, bone porcelain glaze formula can only make the bone porcelain glaze has the ability of crystallization, practice has proved that constitutes the bone porcelain glaze acid with high atomic weight yes crystallization agent such as titanium silicon phosphorus. Manufacturing large crystal oxides have Zn0 commonly used, TiO2, Fe2O3, including lobster Zn0 can form a large crystal. ( 2) Improve bone porcelain glaze formula, appropriate chooses high temperature viscosity lower glaze, because the more bone porcelain glaze high temperature viscosity, more conducive to the crystal, crystal grew up is hard, bone porcelain glaze of high alumina and silica refractory and high temperature viscosity. Crystallization is usually not containing alumina or content in bone porcelain glaze are rare. Appropriate to reduce the content of SiO2, change the SiO2 and RO the molecular ratio of SiO2, RO is more than 3, prevent crystallization devitrification, if and at the same time there is the phenomenon of brightness and luster, can cover a low-temperature glaze calcined again, can be polished surface. If the bone porcelain glaze dull sluggish light is due to containing tin oxide and zinc oxide, can add a small amount of SO2 and A12O3 to eliminate them. ( 3) Bone porcelain glazing, pay attention to the bone porcelain glaze slurry concentration, make the appropriate glaze layer thickness ( 4) Pay attention to the loading operation, first will play a layer of sagger wall coating and billet, according to the bone porcelain glaze firing temperature of billet, should according to the condition of temperature distribution in seting ( 5) Strictly control the bone porcelain firing system and the cooling time, to ensure the bone porcelain crystal glaze, and the formula has the ability of crystallization, reasonable firing system, to strictly grasp the sintering temperature. The correct selection of above 1000 ℃, temperature Temperature between 1000 ℃ to check the fire temperature speed is generally believed to a 130 - It is advisable to the speed at 180 ℃ / heating) Analysis product heat preservation temperature and cooling stage. Using oxidizing flame burning fast, sharp cooling high temperature cooling stage. Check the fire temperature is related to whether the choice of crystalline glaze, check the fire temperature high crystal nucleus is little, but because of bone porcelain glaze viscosity is low, the crystal grew up easily, often large, less crystal flower. Once check HuoWen through high, due to the particle itself or the formation of crystal nucleus all melt, even in the extension of the melt crystallization temperatures of heat preservation time, also cannot obtain the brilliant flowers, but check the fire temperature too low lest make bone porcelain glaze is not fully molten and subcooling. Subcooling products due to poor liquidity glaze, crystal grew up, crystal fine and dense and light even not crystallization. Bone China crystalline glaze firing range 5 - 10 ℃ so strict operation, to be very uniform crystal size of furnace temperature and heat preservation time cooling speed, cooling fast, such as crystal is very small, it is the appearance of the glaze; Crystallization and cooling slowly the son is bulky, bone porcelain glaze surface is rough. For without general bone porcelain glaze of crystallization, fast cooling, through crystallization area as soon as possible. ( 6) Choose better quality bone China fuel, sulfur content less than 0. 8%. — Bone China gift furnishing articles to be continued. 。 。 。 。 。