Views: 0 Author: Wordfik Vacuum Publish Time: 2026-01-23 Origin: Wordfik Vacuum
In modern paper manufacturing, efficient water removal is essential for improving production speed, paper quality, and energy efficiency. During the papermaking process, the forming and press sections are responsible for removing the majority of water from the pulp slurry before the sheet enters the drying stage.
Industrial vacuum systems and vacuum pumps play a critical role in this process by accelerating dewatering, stabilizing the paper web, and reducing energy consumption in downstream drying operations.
This article explains how vacuum dewatering techniques are applied in the forming and press sections of paper machines and how advanced vacuum systems improve performance in modern paper mills.
Paper production begins with a pulp suspension containing over 99% water. During the forming stage, this slurry is deposited onto a moving wire where water is gradually removed to create a continuous paper web. Mechanical and vacuum-based dewatering techniques are then used to increase sheet dryness before the drying section.
The forming section typically removes the bulk of water, increasing sheet dryness to roughly 18–22%, while subsequent pressing further increases dryness to around 40% before thermal drying.
Vacuum technology accelerates this process by creating a pressure differential that forces water out of the fiber network.
One of the most important components in the forming section is the vacuum suction box, installed beneath the forming wire.
These devices use vacuum pressure to draw water downward through the fiber mat while keeping fibers on the surface of the wire.
Key functions include:
Rapid removal of free water from pulp slurry
Improving fiber distribution and sheet formation
Increasing initial web consistency
Stabilizing the sheet before transfer to the press section
The suction box operates by generating a pressure difference between the top and bottom of the web, forcing water through the wire and into a drainage system connected to a vacuum pump.
Modern paper machines often include multiple suction boxes operating at different vacuum levels, allowing gradual and controlled dewatering across the forming zone.
At the end of the forming section, the vacuum couch roll provides final dewatering before the paper web leaves the wire.
This roll features a perforated shell connected to an internal vacuum chamber that removes additional water from the sheet.
Benefits include:
Higher sheet dryness before pressing
Improved sheet uniformity
Stable sheet transfer to the press section
Vacuum couch rolls are essential for maintaining production stability, especially in high-speed paper machines.
After leaving the forming section, the wet paper web enters the press section, where mechanical pressure and vacuum technology work together to remove additional moisture.
In the press section, vacuum press rolls enhance water removal during the pressing process.
These rolls combine:
mechanical compression from press nips
vacuum suction inside the roll shell
The vacuum inside the roll helps extract water more efficiently and reduces the risk of rewetting, where water flows back into the sheet after pressing.
Advantages include:
Higher sheet dryness
Reduced drying energy consumption
Improved paper strength and formation
Press felts absorb large amounts of water during the pressing process. To maintain performance, the felts must be continuously cleaned and dewatered.
Felt suction boxes remove water, contaminants, and residual pulp fibers from the press felts before the next pressing cycle.
These systems help:
Maintain felt permeability
Prevent contamination buildup
Improve press efficiency
Without effective felt dewatering, the press section would lose its ability to remove water efficiently.
Modern paper machines increasingly rely on high-vacuum suction systems to improve dewatering performance.
High-vacuum zones typically operate at pressures ranging from −15 kPa to −40 kPa, and in high-speed machines vacuum levels can reach −65 kPa or lower.
High-vacuum pulses applied through slotted suction boxes create rapid pressure differences that pull water from the fiber network.
Benefits include:
faster water removal
improved sheet formation
higher production speeds
better energy efficiency
Industrial vacuum systems offer several advantages in paper production.
Efficient water removal allows paper machines to operate at higher speeds without sheet instability.
Improved dryness before the dryer section significantly reduces steam usage.
Uniform dewatering improves fiber bonding, resulting in stronger and more consistent paper.
Vacuum systems stabilize the wet paper web during transfer between forming and pressing stages.
Paper mills require high-capacity industrial vacuum pumps capable of continuous operation.
Common vacuum pump technologies include:
liquid ring vacuum pumps
dry screw vacuum pumps
dry claw vacuum pumps
turbo vacuum systems for large machines
Liquid ring pumps are widely used in papermaking due to their ability to handle large volumes of water vapor and process liquids.
However, newer dry vacuum technologies are increasingly adopted for energy efficiency and lower maintenance requirements.
Vacuum dewatering technology is essential for efficient paper production. By integrating vacuum suction boxes, couch rolls, vacuum press rolls, and felt suction systems, paper mills can significantly improve water removal during the forming and press sections.
These technologies help increase sheet dryness, reduce energy consumption, and enhance production stability in modern high-speed paper machines.
As the paper industry continues to improve efficiency and sustainability, advanced industrial vacuum systems will remain a critical component of paper machine design and operation.
