The paper frame primary filter is made of high efficiency and low resistance non-woven material composite wire mesh. The frame is a paper frame, which is light in weight, strong in versatility, compact in structure and high in dust capacity. It is commonly used in commercial heating, ventilation and air conditioning systems, such as the ventilation and air conditioning systems of civil buildings such as office buildings, hospitals, shopping malls, airports, and the centralized ventilation and air conditioning systems of industrial plants.
