Packing is also called sealing filler. It is usually made of softer linear fabric. Generally, square or rectangular, circular strips are filled in the sealing chamber, and then the sealing is completed. Packing seal was first used to block the leakage of liquid flow by cotton, hemp and other fiber plugs in the leak passage. It was primarily used as the shaft seal of water-lifting machinery. Because fillers have a wide range of origins, simple processing, low price, reliable sealing, simple operation, so they are still in use today. Nowadays, disk roots are widely used in rotary shaft seals of centrifugal pumps, compressors, vacuum pumps, mixers and ship propellers, piston pumps, reciprocating compressors, reciprocating motion shaft seals of refrigerators, and rotary seals of various valve stems. Wrapping pan-root: Weaving pan-root is made of expanded graphite thread. It is often used in most occasions except strong oxidant. It can be used in boiling water, high temperature, high pressure steam, heat exchange medium, oil, acid, alkali, hydrogen, ammonia, organic solvents, hydrocarbons, cryogenic liquids and other media. It is a unique new seal packing.