With special singed or glazed finish treatment, the needle felt can avoid the pollution of falling fiber, at the same time, it also avoid the excessive clogging and shortening the lifetime caused by traditional calendaring. The needle felt method leads the three-dimensional filtration, adopts the in-depth filtration. It has high ability of catching to the solid or the gluey particle. The precision is among 1-200 microns, the material is mainly polypropylene or polyester.