The nature of plastic or clay plasticity is the quality of the relationship between clay particles is determined by the content and the fineness of grain meniral clay. Plasticity serves as a binder in the formation process so that objects do not have cracks formed / broken or deformed.
The plastic properties are key requirements that must be met to achieve the required level of plasticity clay it must be coupled with the plastic materials. Average two adjacent particles will stick together perfectly when lubricated with water and provide quality plastic clay and have the power, because the structure of clay particles formed like bricks then difficult to have cracks, as it is shown in the figure below.
Figure 6.7. Clay particles and the structure of the plastic.
Plasticity clay is influenced by: the fineness of the clay particles form clay particles of organic matter (remains of plants and animals) the amount of water structure (arrangement of particles) clay clay types.
Some kind of pure natural soil, such as soil stoneware is the easiest land to be used directly, although there are also red earth that are as good as the soil Earthenware stoneware. Ball clay is usually too plastic so it is not easily dried and burned without changing shape, ground kaolin was formed ter for the “short”, which is easily deformed not hold the load of its own weight.
Plastic nature of the clay caused among others by:
Power cohesion clay particles are very fine and electrically charged (-) and (+) that bind to one another. Water content of plasticity, when viewed with a microscope instrument magnification of 50,000 times through the structure of clay particles that have a flat plate-shaped flat surface.
Each slab is coated with a very thin water like a movie. The function of water particle coating is smoothed surface plates to each other so that each can slide especially when clay or molded under pressure and bind the particles together and form a solid mass of clay.