Plastics Extruder

Plastics extrusion is a process in which raw plastic material is melted and formed into a continuous profile.

raw plastic

Extrusion produces items such as pipe/tubing, window frames,plastic films and sheet, thermoplastic coatings, and wire insulation.

A cross section of Plastic Extruder  

Hopper : A conical shape plastic row material feeder, raw plastics are gone in to the screws with support of gravity. 
Screw Drive Motor : A geared motor which can easily bare high level of torque.
Barrel : The raw materials are conveyed by the screw through the barrel. Equally separated heating elements are connected beside of the barrel and required temperature is maintained by controller. 
Die:  The final product is determined by the die, melted plastic pass through the die and coll down to make required product.  

Control Unit
Heart of the machine is the control unit. All of the modern manufacturers are use computer control interfaces to control the machine and real time observations. The working temperature and pressure would be 350 C and 100 - 150 bar. It is necessary to have solid mechanical structure for safety and durable operation. 
  
Double Screw Extruder:

The double or twin screw extruders function similarly like a single screw extruders, but they are more effective due to the presence of two screws that generate and mixed the polymers more efficiently. The screw function in generating heat when it rotates, this heat generation process is achieved by friction between the barrel walls and the screw. In some extruders, the screws rotate in the same direction 
while in others they rotate in opposite direction. The way the twin screw extruder is designed makes it possible to be used for specific operations.