In the industry, there is a washable primary filter, also known as a sub mother frame primary filter. It is a type of filter material made of non-woven fabric, glass fiber, etc., with a wedge-shaped folding shape to increase the filtering area. It is supported by a metal dragon skeleton and matched with a metal frame to form a plate structure. It has the characteristics of low resistance, long service life, washable, economical and durable.

At present, in the front-end filtration section of various large purification air conditioning units,Cleanable primary filter - Mother frame primary filterIt is widely used.