Plastic bags are light and easy to shape. They are widely used in soft, hard, wet, dry, airtight,
breathable, one-time use and long-term use.Since its inception, plastics have been studied to replace
metals, wood, glass and other materials, in order to reduce weight, facilitate use, storage,
transportation or reduce fuel consumption. Plastic bags can also be used to protect goods, keep food
fresh, carry liquids and wrap air. In the supermarket, most of the goods are all plastic packaging.