A needle punched fabric is made from webs or batts of fibers in which some of the fibers have been driven upward or downward by barbed needles (Figure 1). This needling action interlocks fibers and holds the structure together by friction forces. The phases of needle punching process are shown in figure 2. 

Invention of needle punching technology offered three-dimensional filter media with pore sizes in the range of 10 – 20 microns. Particle emissions are therefore lower in comparison to woven filter media.

The following advantages of needle punched filter media are therefore realized over woven filter media:

Advantages of Needle Punched Filter Media Over Woven Filter Media:

1. Lower Particle Emission Rates

2. Lower Pressure Drops

3. Improved Service Life

4. Higher Filtration Velocities

5. Lower Capital Costs