Some industries request the material which can stand for high temperature. First, because the limitation of specific resistance, the electric dust collectors are not suitable, the bags are the only choice. Second, the cost will be very high or because of the space limitation, the temperature is very hard to be lowered to under 150 ℃. Third, because of composition of sulfur in the dust, there will be acid dew point. Therefore, the filtration has to be operated at the temperature above the acid dew point. It requests one type of chemical fiber which can stand for high temperature. We select the Nomex fiber of Du pont. Adopting the international advanced standard, we produce high-temperature needle punched felt