How do you make a plastic bag?

Answer 1

A polypropylene bag for use in an automatic bag filling process including a sheet of polypropylene material foA polypropylene bag for use in an automatic bag filling process including a sheet of polypropylene material formed as a tube having first and second sides or expanses sealed at one transverse end and open at the other transverse end to assume an unfilled, substantially flat profile wherein spaced-apart openings or notches are arranged on the transverse open edge portion of the first expanse. In a bag filling process, horizontally stacked bags are arranged on a bag opening unit and two projecting tabs or fingers of a clamping device are inserted through the notches of the uppermost stacked bag for contact against the second or lower side. A partial vacuum producing device applies suction to the upper or first surface and pulls same upwardly. The fingers maintain the lower side substantially flat. The bag is then fully opened and positioning arms of the unit are inserted into the bag which move it into a vertical position for placement under a filling spout.

Answer 2

A2. Commercially, plastic bags are made as an extruded tube which then cools quietly, and with slight air pressure in the tube to keep its shape. A nicely balanced process.

In the interim this may be wound on a roll, and later this stock material is fed into another machine that cuts the (now flat) tube at regular intervals, and seals one end at the same time.

If the bag has to be printed, this is done before the 'cut and seal' process. A mark will be made as part of the printing process, that is then recognized by the 'cut and seal' machine.

A1. in order to make a plastic bag you need a gallon jug and a heating gun. take the jug and heat one spot . then blow into it and there you go