Flexible container bags, also known as ton bags or space bags, are made of polypropylene as the main raw material. A small amount of stabilizing agent is added and evenly mixed. The plastic film is melted and extruded through an extruder, cut into filaments, and then stretched. The PP raw yarn with high strength and low elongation is made through heat setting. The base fabric of the plastic woven cloth is then made by weaving and laminating, and then sewn with accessories such as slings to make ton bags.