Synthetic fiber filter cotton: In the general filtration environment, it can completely replace the non-woven fabric and glass fiber cover coarse, medium and high efficiency full range of filtration products. It is an emerging filter material and the main development direction of the filter material in the future. Compared with other filter media of the same grade, it has the advantages of small resistance, light weight, large capacity, environmental protection (burnable), and moderate price. The main raw material is (polyester fibre), abbreviated as: PET, polyester fiber is made of polyethylene terephthalate, also known as synthetic fiber or polyester. The specific gravity of the polyester fiber is 1.38; the melting point is 255 to 260°C; the bonding starts at 205°C; the safe ironing temperature is 135°C; the water absorption is poor, only 0.4%; the breaking strength of the filament is 4.5 to 5.5 g/den ,Short fiber is 3.5-5.5 g/denier; filament elongation at break is 15-25%, short fiber is 25-40%; high strength fiber strength is 7-8 g/d, elongation is 7.5- 12.5%. Polyester has excellent wrinkle resistance, elasticity and dimensional stability, good electrical insulation properties, resistance to sunlight, abrasion resistance, no mildew, good chemical resistance, resistance to weak acids and weak bases. The industry name is: chemical fiber, chemical fiber has a large chemical fiber and small chemical fiber, large chemical fiber refers to the use of high-quality PET chip production of polyester fiber. Small chemical fiber refers to the fiber produced by some small and medium-sized manufacturers using recycled PET chips with poor quality recycled content.