A self-sealing bag is a type of packaging bag featuring a pressure-activated, automatic sealing mechanism; common varieties include airtight bags, interlocking-track bags, and zipper bags.
These bags-also known as airtight bags, interlocking-track bags, sealable bags, zipper bags, or "bone" bags (English terms include Ziplock bags, reclosable bags, sealing bags, zipper closure bags, and bone bags)-are manufactured using a process that involves blown-film extrusion of Low-Density Polyethylene (LDPE) or Linear Low-Density Polyethylene (LLDPE), followed by heat-sealing and cutting. They are designed to be resealable. Common materials include PE, PO, and EVA, as well as multi-layer composite zipper bag structures.