What stage is the burning of Japanese porcelain?
The burning of the billet is a process from quantitative to qualitative change. Physical changes and chemical changes are staggered and complex, and generally can be divided into four stages: 1. Evaporation period; 2. Oxidative decomposition and crystalline transition period; 3. Glass into porcelain period; 4. Cooling period. General household fine porcelain highest firing temperature is between 1250-1350 ℃. However, the specific stages shall be determined according to the formula, the class of raw materials and their characteristics, the temperature, the scope of the fire, the shape of the products, the thickness of the products, and the form of the furnace
What do you mean "one burn" and "two burnt out"?
Both of these methods are methods of porcelain burning. 1. A cooking method. Is to have hang dry green glaze (also have not hanging glaze), into the furnace, a firing (also called the burn), such as fine porcelain of jingdezhen blue and white porcelain, the glaze color (such as ruby red, the red, sharply glaze porcelain), blue and white and exquisite is via a burning. 2. Two ways of cooking. There are two kinds of low - burning and high - burning. The former USES low temperature to burn the dry raw billets, then hangs the glaze, and then the kiln is fired at a high temperature. There is also a biscuit firing is in order to increase the water imbibition of the body and its strength in order to easy to hang glaze without damage (e.g., some thin foetus porcelain body), will only green burn to about 700-960 ℃, also called biscuit firing. After the cooked billet that has been burnt is glazed, then in the kiln, it will be burnt by a cooking method. This method is used for hard and fine daily white porcelain. The latter is to billet temperature biscuit firing (1260-1280 ℃), and then to low temperature glaze to burn (950-1050 ℃), such as daily-use porcelain, and bone China use it more.
What is the function of the vegetable burning?
Most of the foreign ceramics are used for secondary cooking, especially for export porcelain. Our country also has some porcelain factories to use the vegetable, such as jingdezhen's high white glaze thin porcelain and hunan's advanced glazed porcelain, etc. Biscuit firing has the following function: 1, the body after 900 ℃ or so of biscuit firing, under 900 ℃ can be volatile organic matter and moisture, volatile, mostly part of salt decomposition. When the glaze is burned, it is very rare to have the glaze caused by the glaze, which can result in the formation of orange glaze, pinhole, bubble, and hole, etc., which affects the color surface of porcelain, which is an important measure to improve the quality of glaze. 2. The strength of the billet is large and the glaze is damaged and low, which can be made into thin wall products. The water absorption rate is strong, the glaze speed is fast and the glaze is uniform, the glaze is smooth and smooth, and the glaze can be burnt once. 3. A lot of quality defects of semi-finished products can be found after the billet burning, which can be processed or reworked in advance, thus improving the yield of the glaze. 4. The precast of the blank body can not only increase the speed of the loading and loading of the glaze and the loading of the box, but also greatly improve the mechanization degree and save labor in the operation of the billet body.
What main problems should the kiln pay attention to?
1. Kiln, cold kiln too fast porcelain crack; 2. Insufficient oxidation time, the kiln could be bubbling rapidly; 3. When the firing of kiln is not uniform, it is easy to deform; 4. When the temperature in the kiln is not uniform and excessive, the porcelain parts are swelling; 5. When the fire and flame are not suitable, the porcelain face is prone to discoloration and stain. 6. The cold kiln is too slow, the section of porcelain is often rough; 7. When burning and reducing flame, it should not be too heavy or too long. 8. When the heavy wall products are burned, the heating stage should be warmed slowly, oxygen and oxygen should be cleared in the oxidation stage, and the cooling stage should be extended appropriately. 9. The content of free oxygen should be taken care of in addition to the proper time of controlling carbon monoxide and the proper time to recover the colored glaze products. 10. In addition to the proper temperature and heat preservation time, the flame should be burned in the crystal glaze.
What principle does billet, glaze recipe have?
1. The billet formula has the following four principles; 1) according to the use of products, physical and chemical performance requirements, the selection of raw materials. 2) master the chemical composition and performance of raw materials. 3) the ingredients should be adapted to the manufacturing process and can be produced on a large scale. 4) local materials should be made available, rich in mineral resources, stable grade, convenient transportation and low cost. 2. The glaze recipe has the following principles; 1) the expansion coefficient of the glaze should be close to the expansion coefficient of billet, and may be a little bit smaller. 2) the composition of the glaze shall ensure that the intermediate layer of a certain thickness is formed in the process of burning. 3) ensure that the glaze has good elasticity and tensile strength. 4) the addition of regular colorant can have a good color effect. 5) the glaze should have proper process performance. 6) the glaze must have a good melting property, including melt temperature, range, and melt properties. For the glaze of a burnt product, it is required to mature in the sintering range of the billet. Glaze of secondary burning products, general glaze firing temperature is lower than the temperature 60-120 ℃
