Working Principle of Paper Machine

According to the different structure of the wire section of the paper machine, the paper machine can be divided into fourdrinier wire type, cylinder wire type, nip type, stacked wire type and facing roller type. The paper machine can be regarded as a kind of linkage composed of multiple equipments, which can usually be divided into two parts: the wet end and the dry end. The wet part includes the slurry flow equipment, the wire part and the press part: the dry part includes the dryer part, calender and reel.
After pulping, sizing, filling and purification, the pulp suitable for papermaking performance enters the pulp flow equipment of the paper machine at a concentration of 0.3%-1.3%, and the paper material passes through the pulp flow distributor and After the distribution and leveling of the slurry flow by the headbox, the uniform and stable flow is sent to the mesh surface of the moving forming mesh. After the pulp flows on the net near the center line of the breast roll on the screen, it is gradually filtered and dehydrated to form a continuous wet paper web. Forming-dewatering elements such as table rolls, vacuum suction boxes, and flat rolls are usually arranged on the net bank. When the wet paper web is dehydrated to a certain degree of dryness (usually about 20%), it can be peeled from the wire surface and sent to the press section to continue dehydration.
The press section of the paper machine is composed of several roll presses. The wet paper web is supported by a press felt and dewatered by mechanical squeezing between the press rolls. In order to maintain the good dewatering performance of the press felt, the upper press roll is equipped with a felt washing device. After the press section, the dryness of the wet paper web can generally reach about 40%.
The wet paper web is further dehydrated on the paper machine, usually by heating and evaporation drying. The drying section of a paper machine usually consists of a number of drying cylinders heated from the inside with steam. The drying cylinder is covered with dry blanket (or canvas, dry net), the purpose is to press the paper web to the cylinder surface to improve the heat transfer efficiency and improve the surface quality of the paper web.
After drying, a calender consisting of 6-8 rolls is usually used to improve the surface quality of the paper web.

Finally, it is rolled into a paper tube with a paper reel for further processing in the whole decoration section.