People usually refer to pottery cups and bone china cups as "ceramic cups", not because they are the same item, but because both pottery cups and bone china cups are art produced by the interweaving of earth and fire. Taste. How to judge whether a piece of ceramic is pottery or bone china mug? It is wrong for many people to judge whether it is pottery or bone china cup based on whether there is glaze on the surface, because some pottery has a layer of glaze on the surface, such as Tang Sancai, while some bone china cups have no glaze on the surface, such as plain white porcelain. device. So what is the difference between pottery and bone china cups?
1. The production methods of pottery and bone china cups are different
Pottery is a product that is first made by hand-kneading the raw materials, making them into a regular shape, and then molding them. After they are dried, they are fired in a kiln to become a finished product. The bone china cup is a relatively gorgeous item that is made of regular shaped raw materials and then calcined, and finally painted on the surface.
2. Pottery and bone china cups use different raw materials
The raw material used in pottery is generally clay, which is first made into a blank and then fired directly. Generally, the clay used for firing pottery will become glassy when the temperature reaches over 1,200 degrees, so it is impossible to make a bone china cup. ?There are relatively many raw materials that can be used in bone china cups, such as kaolin, clay, talc, feldspar, quartz and so on.
3. The firing temperature of pottery and bone china cups is different
Generally speaking, bone china mugs are fired at a higher temperature than pottery. The firing temperature of pottery is relatively low, generally between 700 and 1000 degrees. The carcass is basically sintered and will not decompose when exposed to water, but the porosity and water absorption rate are relatively high. The sintering temperature of the bone china cup is relatively high, generally between 1100-1300 degrees.
4. The glazes of pottery and bone china cups are different
Pottery is divided into two types: hanging glaze and non-hanging glaze. Hanging glaze is to melt the glaze at low temperature, so as to directly glaze the body. There are also two forms of bone china cups: glazed and unglazed, and usually glazed. There are two ways to hang the glaze on the bone china cup. The first is to directly fire the glaze with the carcass at high temperature; the second is to hang the glaze again on the carcass that has been hung with high-temperature glaze. The second is low-temperature glaze, which is fired at low temperature.
5. The hardness of pottery and bone china cups is different
The hardness of pottery is generally not as strong as that of bone china cups, because the temperature of firing pottery is low, and the body of pottery is not completely sintered, so it is easy to be scratched by hard objects, and the sound when knocked is dull. The temperature of the bone china mug is high when it is fired, and the green body has basically been sintered. Even with a steel knife, it is not easy to scratch the surface, and the sound is crisp and loud when knocked.
6. The transparency of pottery and bone china cups is different
Pottery is generally opaque, and even very thin pieces have no translucent properties. Generally speaking, bone china cups have a translucent appearance, and the surface has strong reflective ability, and there is a feeling of glowing in places with sufficient light.
After these differences and comparisons between pottery and bone china cups, do you have a certain understanding of pottery and bone china cups? Although bone china cups and pottery are two different substances, there are many internal connections, so people often call them ceramics together. Bone china cups are developed from pottery. It can be said that without the invention and development of pottery, there would be no bone china cups. After the appearance of bone china cups, pottery continued to be produced. Pottery and bone china cups developed independently, and gradually changed from daily necessities to collections of art.