Paper machine can be roughly divided into main part and auxiliary system part.

　　The main engine is roughly divided into wet parts, cadres, and curls. The wet part can be understood as a part of the paper with a relatively large amount of water; the cadre is the dry part of the paper with little water; the curling is the organization where the paper is rolled up.

　　Referring to the content of the picture, headbox, net part and pressing part can be counted as wet part, drying cadres, sizing, coating and calendering cadres, and then curling. Since it does not involve academia, please do not delve into the concept of classification.

　　Auxiliary system is the literal meaning of the auxiliary host to achieve its functions.

　　For modern high-speed paper machines, each system complements each other, and there is no division of primary and secondary functions or functions. Auxiliary system is just a title. Just like mobile phones, besides phone calls and short messages, they also have various functions, such as photography, social networking, wallet and so on, to meet people's demand for quality of life and efficiency. Paper machine is also a need to pursue high efficiency, so-called auxiliary system is also indispensable.