Extrusion / Bag making
The extrusion process
The extruder is used to make film and liners.
The plastic pellets are poured into the inlet hopper of the extruder that feeds the extrusion screw. The plastic is heated and softened inside the extruder by a worm screw inside a heated tube in order to make the plastic more malleable. The screw conveys the plastic to the outlet.
At the outlet of the vertical head of the extruder, compressed air is blown into the molten material, which inflates and rises vertically to form a long bubble of film. Once the plastic is cool, it is flattened by rollers into a flat sheet that is wound round reels mounted on mandrels.