Polyamide Fabrics Series, which made of polyamide fiber (PA), can be divided into PA staple fabrics and PA long thread fabrics. These products possess the properties of weak acid-resistance, alkali-resistance, high mightiness, specific gravity of 1014g/squ.mt, melting point of 215-250 degree, and operating temperature maximum 130. They can also be divided into PA6 series and PA66 series, and the later performance is better than the former. They are mainly used in the chemical, coal mine, building materials, melting industrial, for the equipment in the strong alkali operating conditions, such as frame press filter, disc filter, and centrifuge filter. The filtering precision can reach less than 5 microns.