Extrusion Shaping
The extrusion machines consist of three main parts:
1. The “propulsion” system, which compresses the ceramic mass at high pressure and forces it out through the extrusion mouth.
2. The extrusion mouth, which constitutes the shaped aperture that forms the extruded material.
3. The cutting device: this receives the formed material and sizes it as per requirements by making a cross-cut (and sometimes a longitudinal one).
Upstream from the actual extruder a mixer is normally installed; this is generally schematised as a horizontal-axis rotary propeller, which pushes the body through a holed grating in a de-gassing chamber. De-gassing, essential to attainment of proper body density, is normally affected in a chamber upstream from the propulsion unit by applying low pressure.
To be contd….
