You can find a piece of fiberboard or plywood, the length is slightly longer than the width of the film, and the width of fiberboard should be half the length of the plastic bag you want to cut. Then the plastic film is wound along the width direction of the fiberboard, and generally 20 to 50 layers are wound according to the thickness of the plastic film. Finally, a sharp knife is inserted along one side of the width of the fiberboard to cut the film and heat it to form a plastic bag. This is the way we used to produce plastic bags.

The thickness of fiberboard is about 3-4 mm, and it can also be replaced by other thin plates.