Round bottom bags, using glass fiber filter bag because of its good heat resistance, high tensile strength, cleaning and good governance in the dust, etc. are widely used, but in the coal-fired boilers, waste incinerators produce acidic flue gas filter, since the acid invasion caused a significant reduction in strength, influence the life of the filter, limiting the glass fiber filter in the field of application. Our filter material research and development center developed the use of acid-resistant glass fiber filter acid formulation process, the formulations of the acid polymer cladding on the glass fiber surface, to generate a protective barrier, making it from chemical attack.