General problems encountered in Casting – Casting Defects:
In dry pressing method, binders are an important element and casting defects can arise due to wrong or incorrect use of binders. Hence it is essential to test and experiment the binder to be used in the process and then make it available for commercial production. Binders with lubricating properties are the preferred ones, as the lubricants prevent the ware from sticking to the die. In casting by means of extrusion, it is important to maintain the plasticity of the clay and the clay has to be in a good flocculated state. To improve the plastic properties of the body, the clay can be mixed with a little quantity of plaster and then filter pressed and used for extrusion. Keeping the clay in flocculated state will help maintain plasticity. Another major factor determining plasticity is the moisture content in the clay. Correct amount of moisture has to be maintained in the clay to have a proper dimensioned product.
To be Contd….
