With the continuous emergence of production technology, the weaving forms of packing packing have gradually diversified. According to different use conditions and environments, different weaving forms have a direct impact on the performance and service life of the seal. The main weaving forms of packing weaving fillers are: braid weaving, sheath weaving, core weaving, sandwich weaving and so on. The packing format and characteristics are as follows:
1. Braid weaving Braid braiding is knitting with eight spindles running on two tracks. There is no wool core at the four corners and the middle. The section of the braided product is square. It is characterized by loose packing, but it uses a certain compensation effect for shaft vibration and eccentricity. It is used for small-section fillers, but large section size will cause the defects of rough surface pattern, loose structure and poor compactness of the filler.
2. Cover weaving Cover weaving is to use 8, 12, 16, 24, 36, 48, 60 and other spindles to weave on the two tracks. The cover is determined according to the packing specifications. Generally, 1 to 4 layers are woven. There is no wool core in the middle, and the cover is filled. It has good compactness and strong airtightness, but because it is a jacket layer, there is no fiber connection between the layers and it is easy to delamination, so it is mostly used for static sealing or low-speed equipment.
3. Sandwich knitting Sandwich knitting is based on rubber or metal as the core, the fiber is outside, and the number of layers is set according to the needs. It is similar to the sheath knitting. The sandwich knitting has good density, high strength, good bending performance, and sealing. Good performance, but like the jacket structure, the surface layer is easy to fall off after abrasion. It is generally used for pumps and valves, and rarely used for reciprocating equipment.
4. Through the heart knitting Through-the-heart knitting is knitting on three or four tracks with 8, 12, 16, 24, 36, 48, 60 and other spindles. The cross section is square, the surface is flat, the elasticity and wear resistance are good, the strength is high, and the density is high. Good performance, the contact surface with the shaft is larger and more uniform than the braid type, and the gap between the fibers is small, so the sealing performance is good, the entire filler will not be loose after the surface layer is worn, and the service life is long. It is a relatively advanced woven structure.