The needle punching and thermal bonding combination process is a useful method for manufacturing of bag filter media. We prepared needle punched and thermal bonded nonwovens using a nonwoven pilot plant in KITECH, and studied the various manufacturing conditions to prepare the bag filter media. The differential pressure of the bag filter media was decreased, and the collection efficiency was increased with increasing main-needling strokes, respectively. The most of made filter media were perfectly filtrated to standard test dust having above 2 mu m diameter. The increase in needling strokes resulted in the increase of average pore size, and the average value of all the samples was about 40 mu m. In the result of the mechanical properties test, the web formation was randomized with increase the main-needling strokes. Finally, we evaluated the lifetime durability of the products according to the reliability assessment standard RS K 0001. The arriving time up to 100 cycle of the prepared media with 1200 main-needling was longer than that of the other media. It revealed that many needling strokes resulted in lower differential pressure and longer lifetime of filter. (c) 2005 Springer Science+ Business Media, Inc.