Describing the manufacturing processes of plastic bag?

Question

Can you describe the manufacturing processes of plastic bag?
thank you very much!

Answer 1

Look in the textbook of the class you are asking this for.

Answer 2

Pellets of polyethylene plastic are poured into the hopper (big funnel) of an extruder. They drop onto a a screw (worm gear) of the extruder enclosed in a barrel of metal. Electric heaters outside the barrel melt the plastic. The shearing action of the plastic against the coils of the screw and the inside barrel wall also contribute heat. The molten plastic, about the consistency of a thick syrup, is extruded through a die. The die is an extremely narrow circle cut in metal at the exit. So the molten plastic exits the extruder to the air in the form of a thin endless tube that is pulled upwards. At intervals, hot cutters close off individual bags. The bags are compressed into flat sheets. This is the reason that you have to shake plastic bags on first opening them to let air in so you can fill them with other things.