Extrusion
Extrusive means to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. This is opposed to intrusive rock formation, in which magma does not reach the surface.
Extruded when talking about an artificial material like soft metals like aluminium, plastic or glass means that it is pushed out of a nozzle when the material is in a soft state. The shape of the nozzle will vary depending on the shape required in the finished product
Extrusion Media
Clay body being extruded from a de-airing pug
HDPE pipe during extrusion. The HDPE material is coming from the heater, into the die, then into the cooling tank. This Acu-Power conduit pipe is co-extruded - black inside with a thin orange jacket, to designate power cables.
Two-piece aluminium extrusion die set (parts shown separated.) The male part (at right) is for forming the internal cavity in the resulting round tube extrusion.
Plot of forces required by various extrusion processes
Sectional view of a plastic extruder showing the components
Sectional view of how a caterpillar haul-off provides line tension
Elbow macaroni is an extruded hollow pasta.
