The rolling forming mud is subjected to the calendering force, the forming pressure is large, and the forming speed is fast. The extensional deformation of plastic mud increases with the increase of water content. If the plasticity of the mud is too poor, due to the lack of water, the extensional deformation is also small, and it is easy to crack during rolling and the model is easy to be damaged. If a strong plastic material is used, since it is suitable for high moisture content during rolling, its yield value is correspondingly low, and it is easy to stick to the rolling head during rolling, and the green body is also easy to deform. Therefore, roll forming requires the mud to have proper plasticity and to control the moisture content. In the production of porcelain factory, after determining the composition of raw material blanks, the plasticity of the mud is generally adjusted by controlling the water content to meet the needs of rolling. Therefore, the water content of the mud should be strictly controlled during rolling.
The requirements of rolling forming for mud are also related to the use of male or female mold rolling, hot rolling or cold rolling. When the male mold is rolled, the mud is outside the model, and the water in the mud is less so that it will not be thrown away from the model. At the same time, when the male mold is rolled, the ductility of the mud is required to be better (that is, the amount of deformation must be larger) to adapt to the male mold. Roll forming characteristics. Therefore, the mud suitable for male die rolling should have good plasticity and less moisture. When the female mold is rolled, the moisture can be slightly more, and the plasticity of the mud can be slightly worse. When cold rolling, the mud has less moisture and better plasticity; when hot rolling, the plasticity and moisture requirements of the mud are not strict. In addition, the molding moisture is also related to the shape and size of the product. When molding large products, the moisture should be lower, and when molding small products, the moisture should be higher. The mud moisture is also related to the rotation speed. When the rotation speed of the roller head is small, the mud moisture can be higher. If the rotating speed of the roller head is fast, the moisture of the mud should not be too much, otherwise it is easy to stick to the roller head and even fly mud. The moisture content also depends on the origin and processing method of the mud itself.