The principle and advantages and disadvantages of dry pressing of wear-resistant ceramic tiles
In the production process of wear-resistant ceramics, forming is a very important link, and the more commonly used forming methods are dry pressing and isostatic pressing. Today we will talk about the principle, advantages and disadvantages of dry pressing.
Dry pressing, also known as compression molding, is one of the most commonly used molding methods. In the production process of wear-resistant ceramics, dry press molding is to put the powder with good fluidity and suitable particle size after granulation into the metal mold cavity, apply pressure through the pressure head, and the pressure head is displaced in the mold cavity. The pressure is transmitted, so that the powder particles in the mold cavity are rearranged and deformed to be compacted, forming a ceramic green body with a certain strength and shape.
The essence of dry pressing is that under the action of external force, the particles are close to each other in the mold, and the particles are firmly connected by internal friction to maintain a certain shape. This internal friction acts on the thin layer of binder surrounding the particles that are close to each other.
As the pressure increases, the blanks will change shape, slide against each other, the gap will decrease, gradually increase the contact, and stick to each other. As the particles get closer, the force between the colloid molecules and the particles is strengthened, so the green body has a certain mechanical strength.
Features of dry pressing:
advantage
The dry pressing process is simple, easy to operate, short in cycle, high in efficiency, and convenient for automatic production. The embryo body made by dry pressing also has the characteristics of high density, precise size, small shrinkage, high mechanical strength, and good electrical performance.
shortcoming
Dry press molding is difficult to apply to the production of large embryos, and the mold wears a lot, the processing is complicated, the cost is high, and the direction of pressure is relatively single. It can only be pressed up and down, and the pressure distribution is uneven, resulting in uneven density and uneven shrinkage of the embryo body. , cracking and delamination will occur.
Dry pressing has distinct characteristics and a wide range of applications. According to the principle and characteristics of dry pressing, we can improve the process in the production process, and we can also use more advanced isostatic pressing instead of dry pressing to improve wear-resistant ceramics embryo body quality.
