Improvements in the extrusion of plastic material.

摘要

Food products particularly of meat are extruded cased under pressure. The extrusion pressure, and the energy in the extrudate, makes the circular cross-section the only stable one on emergence from the extrusion head. In accordance with the present invention two unstable shapes, D-shaped (6) as described are extruded each cased (7) from its own extrusion head. The heads are disposed closely adjacent back to back so as to have a generally circular overall profile. An outer casing (8) is fitted over the two heads. On extrusion the two D-shaped pieces abut one another and the outer casing to preserve their shapes until stabilised by freezing.