Needle punched filter are mainly used for liquid filtration ,air filtration and dust collection .compared with ordinary filter material ,needle-punched felt has many advantages:1,High hole rate and good air permeability can increase the loading ability of the equipment and reduce loss and energy construction .2, High efficiency of cleaning and low density of gas ,gas density can be greatly lower than the country standard stipulation.3,after heating ,singeing and coating treatment ,the surface should be smooth ,difficult to stop up and out of shape ,easily –dedusting and long using-life usually 1 to 5 times longer than mechanical filter cloth.