What Is An Extruder?

An extruder is a machine which is normally used for melting a plastic polymer into molten form and then converts it to certain shape. In today modern world plastic is very much used for a lot of appliances and for all the appliances to be made from plastic extrusion is used. There are different types of extrusion processes like blown film extrusion, cast film extrusion, injection molding etc.

If we see the details of an extruder it is a combination of screw and a barrel with some heating being done from outside through electric or gas heaters. The heat is being used to melt the plastic polymer. All the heat is not being supplied through external heaters in fact a lot of heat is being produced internally due to friction between the polymer granules and the barrel of the extruder. In case of an extruder the plastic granules should slip on the screw and they should stick to the barrel for the effective transport of molten plastic in the forward direction.

Typical screws used for blown film extrusion have feed, transition and metering zones, once the polymer is melted it is passed on to the die for achieving the final shape. After getting the desired shape the polymer is cooled down and desired product is made.