non-woven filter bag technology is mature, stable and good technical characteristics, the production of crude, in effect plate, bag filter. Process to meltblown, needle, spunlace, spunbond, etc. Compared with other filters with the same level of quality, large capacity dust, moisture and strong, long life, economic and durable and so on. Combined with good air-tightness and strength, its main function is to control the bag when not overly expansive pressure to bear covered with each other, and reduce the effective filtration area and effect.