how is a trash bag made?

Answer 1

I believe that a cylinder of plastic film of specified thickness or gage is extruded from a machine (like huge macaroni?) and laid flat on a conveyor where a hot iron melts and seals the strip at intervals and a straight or curved perforated cut is made between seals that will permit the trash bags to be opened (usually with great difficulty?). It may help to wet your fingers (lick your wrist if fingers are dirty and wet fingers on wrist?). Because the extrusion process is not perfect there is often a slight but changing "grain" to the plastic (such as streaks) and forensic scientists can often determine whether a plastic bag found at a crime scene is from the same batch found in the suspect's garage, etc.

Answer 2

All most same way as other bag's made.