A paper machine is a machine that makes paper pulp that meets the requirements of papermaking after beating and modulation.

According to this definition, the paper machine should start from the feed header of the headbox or the feed system that must be attached to it, until the winder that unwinds the paper roll.

The main body of the paper machine is divided into a wet section, which is made from pulp into wet paper, and a dry section, which dries the wet paper and rolls it. The light part and the roll paper part are three parts. In addition, there are mechanical transmission parts and the vacuum system, air pressure and hydraulic system, lubrication system, paper threading system, steam system, hot air system, steam hood and its exhaust system, which are indispensable for the operation of these main parts. It also belongs to paper machine the body part.

The body part of the paper machine and its auxiliary and auxiliary systems have different forms and specifications. In engineering design, the form and specification of each part are determined mainly on the basis of pulp type, paper type, and output requirements for papermaking. Different forms have different structures. The formal classification of paper machine is determined by the structural form of its main parts. It is an international common practice to express the general form of paper machine by the structural form of the main part. At present, in order to adapt to the paper machine to select the paper machine according to its own actual process conditions, the main part of the paper machine has many forms according to its structural principle and technical characteristics.

In engineering practice, the formal and structural features of the forming part and the drying part, which play a decisive role in the output and quality of paper machine products, are usually selected as the basis for the basic form classification of paper machine.