Press Section Paper Machine Pdf

The dewatering capacity of a press section and the properties of paper depend on the design and the number of nips.

Press section paper machine pdf. Reduce the number of breaks in the press section by adjusting the release point to the right position. For example after a grade change it is important to know how the wet end operation has changed or how the center roll surface is doing. The second section of the paper machine is the press section which removes much of the remaining water via a system of nips formed by rolls pressing against each other aided by press felts that support the sheet and absorb the pressed water. Sections of a paper machine with paper humidity given as mass water mass cellulose.

1 2 3 wire section press section drying section figure 1. The press section is shown in figure 2 in which four different felts are shown. The task of the paper machine press section is to remove water primarily through wet pressing. Entering the wire section 99 entering the press section 80 entering.

Wet pressing increases sheet dryness in order to ensure adequate paper machine drying capacity and to improve web runnability at the beginning of the dryer section. The paper web consistency leaving the press section can be above 40. At the end of the press section the sheet. Although it depends on sheet grade and paper machine typical sheet consistency at the beginning of the press section is 20 fiber and 80 water and at the end of the press section is 45 fiber and 55 water.

The paper web passes over rotating heated. The device is designed to withstand demanding paper machine conditions and it comes with an acid proof cover. The risk of web breaks is determined by the general design of press section and the arrangement of open draws if any. Water removal in the press section of paper board and pulp machines has an important influence on machine efficiency and cost.

A modern press section should fulfill the following requirements. The third part of the paper machine is called the drying or dryer section. Of the machine wahlstrom 1969. Mechanical compression in the press section removes water to solid level between 33 and 55 depending on the paper grade and press se ction design.

Fabric and press felt are used interchangeably in papermaking. The web enters the press section next.