With the development of the times, ceramic cups have become an indispensable part of human life. The dazzling patterns of ceramic cups are dazzling, but it is not difficult to find that there are some small bubbles on some ceramic cups. So how do these small bubbles happen? Today, our Borui ceramics editor will give us a popular science about the small bubbles on the ceramic cup.
Bubbles are small bubbles formed by gases in porcelain body or glaze. The reason for its formation is that the water and space gas in the glaze and tire move through the high-temperature firing process and are obstructed by the glaze. In this bubble layer, the size, number and hierarchical layout of bubbles; Due to the changes of porcelain making material, kiln temperature, fuel and firing skills in various periods.
The life of bubbles is protected by the embryo and glaze. In the history of porcelain, the life of bubbles is also different due to the different conditions of the glaze. In normal space storage, the life of porcelain bubbles has the change of self extinction.
Like a barometer, it is very helpful for us to identify ancient porcelain, which is also a scientific break on the basis of traditional methods to identify porcelain. Bubbles are divided into green bubbles and glaze bubbles.
Green bubble, also known as tire bubble, is a hollow bubble of different sizes raised by the green body under the glaze, which can not be cut with nails. The glaze bubbles – generally are very fine, and the drum is on the surface of the glaze layer. This kind of glaze bubble is gathered at the mouth edge or corner of the product, commonly known as blister edge. Such defects are common in ancient porcelain. The main reason for the occurrence of tire bubbles is that the blank contains too many harmful magazines such as organic matter, carbonate and sulfide. Perhaps the mud is kneaded unevenly, mixed with gas, or the firing operation is improper, so that the gas released by the decomposition of harmful impurities can not be discharged in time before the glaze melting. The primary reason for glaze bubbles is that the initial melting temperature of glaze is low and vitrification is premature. Perhaps the firing is improper, the deposited carbon or decomposition products are not burned out or discharged before the glaze melts, so the generated gas is wrapped by the glaze and cannot escape. Perhaps the raw materials contain too many soluble salts. When drying the transpiration water, bring it to the edge or corner, and melt early during roasting to prevent the gas from escaping and form bubbles.