Forming section of Paper machine

The forming section of paper machine is composed of head box, breast roll, forming wire, suction box and flat roll. The headbox spreader evenly sprays the slurry sent by the flow system to the forming wire, and the slurry speed should match the wire speed. Controlling the pulp speed and wire speed is the main factor in selecting the headbox type. The fully enclosed hydraulic headbox adjusts the pulp speed by adjusting the feeding pressure of the pulp pump, which is suitable for high-speed paper machines; the air cushion headbox adjusts the speed by adjusting the air cushion pressure, while the open high headbox The speed is adjusted by adjusting the height of the pulp level in the box, which is suitable for medium-speed paper machines; the open compartment headbox is suitable for low-speed paper machines. The forming wire is an endless loop web. Between the breast roll and the flat roll, it forms a horizontal or slightly inclined flat web surface. As the working section of pulp dewatering, it is customary to call it a screen, so it is called a long network. If the endless forming net is placed on a circular net cage, it becomes an arc-shaped dehydration forming working section, which is called a circular net. If a steel mesh drum drilled with holes is used to draw a vacuum from the shaft end to accelerate the dehydration of the pulp on the surface of the forming wire, it is called a vacuum cylinder or vacuum forming wire. If the pulp is clamped between two Fourdrinier wires and the two wires are simultaneously dehydrated and formed, it is called a sandwich former (Figure 2). These formers use different forms of dewatering elements to accelerate the dewatering of the pulp on the web. Components are classified into three categories: stationary, rotating and both. Static components such as dewatering plates, arc vacuum boxes, etc., rotating components such as table rolls, vacuum forming rolls, etc. In addition to using a single-form former to form Fourdrinier paper machine, cylinder paper machine, and sandwich paper machine, there is also a forming section that combines multi-fourdrinier, multi-cylinder, multi-cylinder, and multi-form fourdrinier hybrid formers..