Extrusion Process

Extrusion is a metal forming process in which metal or work piece is forced to flow through a die to reduce its cross section or convert it into desire shape. This process is extensively used in pipes and steel rods manufacturing. The force used to extrude the work piece is compressive in nature.

This process starts by feeding plastic material (pellets, granules, flakes or powders) from a hopper into the barrel of the extruder. The material is gradually melted by the mechanical energy generated by turning screws and by heaters arranged along the barrel. The molten polymer is then forced into a die, which shapes the polymer into a shape that hardens during cooling

As we already discuss,

The extrusion process will take place from all the Co-extruder and the main extruder. than melt fill reach the die from the melt line passing through the filtration process.

Extrusion System -

The extrusion system contains the following components:
• Silos and Transportation of Resin
• Main extruder and Coextruder(s)
• Filters for the melt stream
• Die
The raw material transport to the main extruder starts from the raw material main silo
via the pneumatic conveyor to the intermediate silo.
From the intermediate silos it proceeds via a dosing unit, where additives and re‐
granulates can be added, to the cyclone.
From the cyclone the raw material and the cut edge trim waste fall into the mixing
hopper.
In the mixing hopper the granulate and the cut edge trim waste is mixed homogene‐
ously to be able to process it in the main extruder.
The extruder is used to melt granules and pressurise melt. The extruder is designed
for processing only those materials that are described in the technical data sheets
and in the procedure manual and may only be operated with these materials.
The raw material transport to the coextruder(s) is effected directly from the mixing
unit to the hopper on top of the extruder.
The melt stream from the main extrusion system passes through the main filter to
the die. The system is connected by adapter pieces.