Graphite packing strings are made up of a large number of graphite filaments that have been twisted together to form a string. A “yarn” is the graphite packing string that results. The tensile strength and endurance of these yarns are then increased by braiding them. To further boost chemical resistance, manufacturers treat the strands with substances such as PTFE after braiding. Finally, block agents are added to the braided packing to ensure that the filaments are effectively sealed and that the packing’s overall sealability is improved. Graphite packing is commonly employed in businesses that treat acids and oils due to its well-known resilience to chemicals and extremely high temperatures. Its toughness makes it ideal for use in the petroleum, chemical, and gas sectors.