ABSTRACT
This chapter describes the fundamentals of kneading and plastic forming processes. In industrial applications, kneading is usually combined with the plastic forming processes. Compounds for plastic forming in a narrow sense should be prepared to a capillary state where the voids among particles are saturated with liquid. The powder concentration corresponding to a capillary state is called a critical powder volume concentration. Plastic forming methods among a variety of forming methods include wet pressing, jiggering, extrusion, and injection molding. Plastic bodies prepared by kneading processes are treated in these forming methods. Compared with the dry feed, the wet feed deforms plastically during compression. Wet pressing is similar to dry pressing and is often called semidry pressing, or dust pressing. Jiggering is one of the oldest plastic-forming techniques, where a skilled hand-worker can make any hollowware from plastic clay supported on a rotating wheel. A compound adjusted to a capillary state will show a plastic flow necessary for extrusion.
