Press Section Rebuilds
Additional water is removed from the newly formed sheet in the press section, where, under high pressure, water is squeezed from the sheet into a press fabric.
The press section is at the heart of all paper machines and is designed to maximise water removal, whilst efficiently transferring the web from the forming section to the dry part.
The press section influences product quality - both strength and surface properties of the sheet are effected - as well as having a major bearing on a machine's production capability. A poorly designed press section can be a contributor to poor machine efficiencies and a major source of paper machine breaks
Reasons of Rebuilds
- Rebuilds for Production: Modifications to the press section of a paper machine can also give benefits in terms of ex-press dryness. This results in either a production capacity increase or, in cases where speed is limited by other factors, the opportunity to reduce steam usage in the dry part can be realised. Rebuilds gave even more production capability and at the same time, resulted in a reduced open draw length at the press to dryer transfer.
Rebuilds for Efficiency: Knowledge gained from experience of modern high-speed press sections can be applied to older machines, resulting in efficiency improvements for relatively low capital cost. Repositioning of the paper rolls and felt rolls, after both the cluster press and the third press, significantly reduced the length of the open draws. Modifications to the third press area, including the installation of an anti-blow box before the nip and a press to dryer transfer box inside the first dryer section fabric loop, considerably improve sheet stability and control.