The role of paper machine forming device

The forming device of the paper machine is also called the wire section. It is the most important part of the paper machine. The paper stock suspension forms paper sheets on it. The quality of the paper and the normal production of the paper machine are closely related to the operation of the forming device. Once the wet paper web is formed in the forming device, the interweaving state of the fibers in the paper is basically set, and the basic physical properties of the paper are also determined. The subsequent pressing, drying and calendering processes of the paper machine can only improve the formed shape to a limited extent. The nature of the paper web. The forming device is usually the most complicated part of the paper machine. In operation, the power consumption and maintenance cost of the forming device occupy a considerable proportion of the entire paper machine.

The main functions of the paper machine forming device are as follows:

1. Obtain a well-organized wet paper web

The forming of the paper web is a complicated process, which can usually be simply regarded as the result of the fibers gradually being deposited on the surface of the forming wire and interwoven into a thin layer. In order to obtain a uniformly structured paper web, in addition to a good-performance streaming device, it is also necessary to make the paper material undergo a reasonable dewatering process on the forming wire surface. Generally, it is possible to control the difference between the wire speed and the online pulp speed, the shaking of the screen and the selection of appropriate dewatering elements, so that the fiber suspension is relatively calm and has a certain turbulence during the forming process of the paper web. Disperse the deposited fibers evenly, without flocculation, and at the same time avoid inappropriate excessive dehydration, which will cause excessive loss of sizing material, fillers and fine fibers in the paper material, resulting in the difference in the properties of the two sides of the paper web.

2. Dehydrate the formed paper web to a certain degree of dryness

After the wet paper web is initially formed, it is generally required to achieve a certain dryness or wet strength by means of forced dehydration (vacuum suction, pressing, etc.), so that it can be peeled off from the forming wire surface.

The commonly used paper machine forming devices now include Fourdrinier wire formers, rotary screen formers, sandwich formers, composite formers, high-concentration forming devices and dry forming devices.