There are a number of extrusion techniques available such as co-extrusion, offset extrusion, oriented extrusion, overcoat extrusion, cold extrusion, ram extrusion and much more.
These plastic milk jugs are first separated from the other plastics, cleaned and are then ground into small pieces. There is a feed hopper at one end of the barrel and a specially shaped hole or die at the other, where the product comes out.