1. The shape design of the bone china advertising cup is unreasonable in structure or does not meet the requirements of the ceramic materials and techniques used
① The position of the center of gravity is improperly handled, and the top is heavy and the bottom is light;
②The body shape is too tall and too long; the thickness and size of each part are inappropriate and uneven; the mud storage is improper, etc.
2. Improper formula of the bone china advertising cup blank makes the sintering and shrinkage unbalanced
①The amount of highly plastic clay in the blank is too large, the loss on ignition is too large, and the drying shrinkage and firing shrinkage are too large;
②The amount of flux in the billet is too large. The green body has too much liquid phase and low viscosity at high temperature;
③ Improper coordination of the expansion coefficients of the billet and glaze.
3. The preparation process of bone china advertising cup blank is not strict
① The billet contains air or impurities; the mixing, stirring and refining are not sufficient, and the aging time is short;
② The moisture content of the billet is too high or uneven;
③ The billet is too fine or the particle gradation is unreasonable, and the particles are oriented.
4. Improper forming process of bone china advertising cup
①The forming pressure is too small or too large;
② The pottery equipment used is not sophisticated and vibrates greatly;
③ Improper casting of mud during rolling, spinning, and plastic molding, improper operations such as forming, trimming, and glazing;
④ The grout particles used for grouting are too fine; the density is not suitable; the stability is poor;
⑤ The model is unevenly dried and wet; the drying temperature of the belt mold is not uniform; forced demoulding or demoulding is too late; improper demoulding operation.
5. Improper drying of bone china advertising cups
① The drying system is improperly controlled and the drying speed is too fast;
② Uneven drying of various parts of the green body;
③The green body is not placed flat or placed in an improper way.
6. Improper filling process of bone china advertising cups and kilns
① The water content of the green body entering the kiln is too high;
② Use kiln furniture such as saggers and shed boards with high temperature and low structural strength; the inner bottom of the saggers used is not flat, cracked, and no cake is used; the cake that is uneven or has impurities is used;
③ Improper loading of the billet or vibration during moving, so that the bottom foot of the billet escapes from the pad cake, and the displacement is lower, and the billet tilts to one side due to uneven shrinkage during firing;
④ The sagger column was not kept flat, stable and upright.
7. Improper firing process of bone china advertising cup
① The temperature difference in the kiln is too large (on the one hand, the problem of the kiln itself; on the other hand, the problem of installing the kiln);
②The temperature rises too quickly during firing; the firing temperature is too high; the high-fire holding time is too long.
8. The plaster mold of the bone china advertising cup is of poor quality
①The structure of the plaster mold is unreasonable; the manufacture does not meet the requirements; the specifications are not uniform; the density is inconsistent;
② The moisture content of the plaster mold is uneven; too dry, too wet, too old; the model is deformed or worn;
③The fit between the plaster mold and the mold base is poor, and they are not concentric.