Bone porcelain glaze 03

Generally speaking, the softening threshold refers to the glaze temperature of deformation, traditionally called bone porcelain glaze of melt temperature melting temperature limit is mature temperature of the finger bone porcelain glaze, the glaze fully melted, and spread out on the billet into smooth bone porcelain glaze with required performance, usually called the temperature of the melting temperature of the glaze or glaze firing temperature of molten nature directly influence the surface quality of the products. Bone porcelain bone porcelain glaze of melting temperature too low or molten scope too narrow, pinhole, bubble will appear, appear even broken gold color roast. Bone porcelain glaze melting range is wide, bone porcelain glaze is stronger adaptability. General and Al2O3, SiO2 can effectively improve the glaze of melting temperature, and improve, like bone porcelain glaze is fine, melting temperature, the high temperature viscosity. K2O and MgO style on expanding our scope of molten glaze degree is lower. Bone China main oxides in the role of bone porcelain glaze glaze is more commonly used pure mineral raw materials and chemical raw materials preparation, in order to reduce the influence on the effect of impurities on bone porcelain glaze. Glaze of mineral raw materials commonly used in general and bone porcelain body material basic same, namely, quartz, feldspar, kaolin, stalactites, talc, small white dry, etc. , but to demand a higher purity. Bone porcelain glaze of commonly used chemical raw materials with boric acid, borax, zinc oxide, titanium dioxide, soda ash, alumina, etc. Bone China ( 1) SiO2 SiO2 is the main formation of bone porcelain glaze, is the main element of the bone porcelain glaze, it can effectively improve the bone porcelain glaze melting temperature, high temperature, mechanical strength and chemical stability, lower viscosity coefficient of expansion. In general, through the SiO2 / ( R2O+RO) Mole ratio can preliminary judgment glaze melting performance, if SiO2 / ( R2O+RO) The mole ratio of 2. Five to four. 5, the bone porcelain glaze is a fusible glaze; If SiO2 / ( R2O+RO) The mole ratio of greater than 4. 5, it is difficult to melt glaze. Bone porcelain glaze of SiO2 generally introduced by quartz. Bone China ( 2) Al2O3 Al2O3 can form glass network intermediates, can effective improve the chemical stability of the bone porcelain glaze, high temperature melting temperature, viscosity and hardness, etc. , can reduce the expansion coefficient of bone porcelain glaze, which can effectively prevent the crack phenomenon, generally introduced by feldspar, clay and so on. Due to the aluminum hydroxide in the glass forming reaction melt faster, so the use of aluminum hydroxide in the fritted glaze as Al characters. Bone China ( 3) B2O3 B2O3 is bone China ( Bone China) Fritted glaze important component, is not only strong fluxing agent, network formation and glass body, it can be with a mixture of silicate formation of low melting point, reduce the melting temperature of bone porcelain glaze, high low temperature when the melt viscosity, temperature rise, make the bone porcelain glaze melt viscosity reducing body, increase liquidity. Borosilicate glass has good resistance to chemical attack. When using B2O3, attention should be paid to & other; Boron anomaly & throughout; , which refers to the B2O3 content is 12%, the performance of the bone porcelain glaze will change with the addition of boron is obvious. Generally introduced with boric acid, borax etc. Bone China ( 4) CaO at the beginning of the heating, CaO quickly response with the other ingredients in the glaze. At higher temperature, the melting capacity increase, can effectively reduce the high temperature viscosity of glaze. Adding CaO can reduce the expansion coefficient of glaze and improve the hardness and tensile strength of bone porcelain glaze, but too much CaO can increase bone porcelain glaze devitrification tendency, even light. Light calcium carbonate used in practical production, stalactites, calcite, dolomite, etc. Bone China ( 5) MgO style high temperature condition, MgO style can reduce the viscosity of glaze, the associativity between improving bone porcelain glaze. But in some color magnesium may be having an impact. Introduced is commonly used in production of talc, dolomite, etc. — Tangshan bone porcelain cup dish suits to be continued. 。 。 。 。 。