PTFE Brown Staple Fiber contains a very small amount of carbon because of special production process,which makes the fiber dark brown. It is the small amount of carbon that reduces the static of PTFE fibers without damaging its chemical properties. Such an improvement has mitigated the weakness of PTFE fiber's tendency to pill during carding process. The fineness of PTFE Brown Staple Fiber is more unifom than that of white fiber,which improves the filrtion effectiveness of fine dust. The circular cross section of PTFE Brown Staple Fiber also makes the friction coefficient of the fiber surface lower.