The special firing process of the ceramic bone china cup is the core of its porcelain, which makes it both thin and tough, and also presents a warm and jade-like texture. This process is not a single high-temperature treatment, but a combination of multiple fine links, from raw material ratio to temperature control, each step affects the final porcelain characteristics and forms a unique quality.
In the raw material preparation stage, the precise ratio of bone powder and porcelain clay lays the foundation for the subsequent firing. The addition of bone powder is not a simple mixture, but a special treatment to remove impurities so that it can be fully integrated with the porcelain clay particles. This fusion changes the molecular structure of traditional ceramics, allowing the fired porcelain to form a tighter bond inside, providing a material basis for the balance between thinness and toughness, and also laying the groundwork for a warm texture.
Temperature control during the first firing is particularly critical. The temperature in the kiln will slowly rise to a specific range, allowing the moisture and organic components in the raw materials to gradually evaporate, avoiding cracking of the porcelain blank due to excessive heating. The low-temperature slow firing at this stage allows the molecules of bone powder and porcelain clay to initially combine to form a stable basic structure, so that the porcelain blank remains light and thin while having a certain strength and is not easily damaged in subsequent processing.
The secondary firing focuses on improving the density and toughness of the porcelain. The porcelain blank has been formed after the first firing, and the temperature will be raised to a higher level during the second firing, which will cause the molecules to further shrink and aggregate, making the porcelain structure denser. This densification treatment allows the ceramic bone china cup to maintain sufficient toughness even when the thickness is reduced, and it is not easy to break due to collision. At the same time, it also allows light to penetrate better, creating conditions for a transparent texture.
The application and firing of glaze are key steps to give bone china a warm and jade-like texture. The glaze formula has been carefully formulated to match the composition of the bone china blank, and can fully blend with the surface of the blank when fired at high temperature to form a smooth and delicate glaze. This layer of glaze not only fills the tiny pores on the surface of the porcelain blank, but also changes the way light is reflected, allowing light to form a soft diffuse reflection on the porcelain surface, thus presenting a warm luster similar to jade.
The heat preservation and cooling links during the firing process have a significant impact on the stability of the porcelain. Maintaining a constant temperature for a certain period of time in the high temperature section allows the molecules to have enough time to complete the reorganization and ensure the uniformity of the structure; while the slow cooling process can reduce the generation of internal stress, avoid cracks in the porcelain due to uneven shrinkage, and allow the thin porcelain body to maintain its overall toughness while maintaining a stable shape, and not easy to become brittle.
Special kiln atmosphere control also helps to present the texture. During the firing process, the oxidation and reduction atmosphere in the kiln will be adjusted according to different stages, and this adjustment can affect the color and transparency of the porcelain. The appropriate reduction atmosphere can make the bone porcelain present a soft milky white tone, avoiding the harsh feeling of being too pale, while the oxidation atmosphere can enhance the gloss of the glaze, making the warm texture more prominent, and closer to the visual effect of jade.
The synergistic effect of various links allows the ceramic bone china cup to achieve both lightness and toughness under the special firing process. At the same time, through the optimization of structure and glaze, it presents a unique texture as warm and smooth as jade, which not only meets practical needs but also has ornamental value.
