1. Secondary firing process Bone china cup is a typical representative of soft porcelain. The secondary firing process of high-temperature biscuit firing and low-temperature glaze firing is its most notable technological feature. The secondary firing process of bone china cups is different from the traditional ceramic low-temperature biscuit firing and high-temperature glaze firing process, which better solves the problems of high-temperature deformation and glaze gloss. The Japanese call the green body that cannot be glazed at low temperature (about 900°C) “biscuit firing”, the green body that cannot be glazed at high temperature (about 1300°C) is called “associated firing”, and firing the green body and glaze together is called “biscuit firing”. This burn”.
2. Forming process Bone china uses 40%-50% non-plastic bone powder, and the total amount of clay in the green body formula is relatively low. Compared with ordinary ceramics, the plasticity is poorer, and forming is more difficult. Generally, the following methods are used to increase plasticity or improve yield:
① Use high plasticity clay;
② Use organic plasticizers, such as CMC, etc.;
③Increase the fineness of the particles and practice the mud several times;
④Use a hot roll forming machine.
3. The firing process using imitation sagger is the most representative process in the bone china firing process, because the bone china firing range is narrow, the shrinkage is large, and it is easy to be soft and deformed during firing. Support mouth burning or buried burning and other processes to solve the problem of deformation.
4. Kiln furniture materials The kiln furniture materials used in bone china have higher requirements than ordinary ceramics. Most of the kiln furniture should match the products. Generally, there are matching kiln furniture for each type of product. It is also a place where bone china production is more cumbersome than general ceramic production. The bone china production team has a large demand for kiln furniture materials, and the requirements for the working surface of kiln furniture products are quite high.
5. Mold material Bone china has a high production cost and is generally suitable for making high-grade porcelain. The matrix is thinner, so the requirements for molds are more stringent. High-quality gypsum needs to be used for fine processing, and the number of times the mold is used must be strictly controlled. The mold cannot be used for a long time.
6. Production management The material of bone china is white and delicate, and any small dirty spots are particularly dazzling. To produce high-grade bone china, strict and meticulous production management is required to ensure product quality.
Post time: Mar-20-2023