Once the ceramic cup body is disturbed by external force, it will crack. Some ceramic cup blanks and utensils are easier to crack than other varieties, but even the worst strength clay will not crack as long as its shape design, drying and firing method are suitable for this kind of clay. When should we consider cracking?
1. Cracking is usually caused by some defects or local stresses.
2. Uneven drying is also one of the most common causes of ceramic cup cracking. The first dry part of the green body also shrinks the earliest, which will form a tensile force on the adjacent non dry area. If the UN dried part is soft enough, this tension will be temporarily offset.
3. Uneven thickness of ceramic cup blank and unreasonable setting of needle are another important reason for pressure. If the bottom is thick, the wall is too thin, the mud net shape is not enough, and the mud used is too delicate, the green body will crack.
4. Improper blank repair. The trimming tool must be very sharp. It can't be cut or scraped until the blank is half dry. When the blank is too dry, its strength is very weak. In this case, the blank is easily cracked by the trimming tool.