In modern papermaking, stable sheet transfer between machine sections is essential for maintaining production efficiency, paper quality, and machine reliability. As paper machines operate at increasingly higher speeds, transferring the wet and fragile paper web from one section to another becomes more challenging. To solve this problem, paper machines rely on one of the most important transfer components in the system—the Vacuum Transfer Roll.
A vacuum transfer roll is a specially designed roll used in paper machines to transfer the wet paper web between machine sections, typically from the forming section to the press section or between other critical transfer points. Unlike a conventional support roll, the vacuum transfer roll uses internal vacuum suction to hold the sheet against the roll surface during movement.
This vacuum-assisted transfer is especially important when the paper web is still weak, wet, and highly sensitive to disturbance. By stabilizing the sheet during transfer, the vacuum transfer roll reduces the risk of web breaks, wrinkles, and sheet flutter, making it an essential component in high-speed paper production.
The vacuum transfer roll is specifically designed to support and transfer the paper web under vacuum suction, ensuring that the sheet remains stable, controlled, and securely attached during the transfer process. Its performance directly affects machine runnability, sheet stability, moisture control, and the overall efficiency of the papermaking process.
1. Stable Sheet Transfer
The primary function of the vacuum transfer roll is to ensure smooth and secure transfer of the wet paper web from one section of the paper machine to the next. By holding the sheet firmly to the roll surface with vacuum suction, it prevents instability during transfer and helps maintain continuous operation.
2. Reducing Web Breaks
Wet paper is fragile and easily damaged during section transfer. Vacuum support significantly reduces the chance of web flutter, sheet separation, and transfer failure, especially at high machine speeds.
3. Improving Machine Runnability
A stable transfer process means fewer interruptions, fewer sheet breaks, and less downtime. This directly improves machine runnability and supports higher production efficiency.
4. Supporting Better Moisture and Web Control
Because the vacuum transfer roll helps maintain consistent contact between the web and the roll surface, it also contributes to better web control and more uniform transfer conditions. In some applications, it can support more controlled moisture handling before the press section.
Diameter: 500–1,500 mm
Face Length: 2,000–10,500 mm
Operating Speed: up to 2,000 m/min or higher
Dynamic Balance: ISO 21940 G2.5
Shell Material: stainless steel, carbon steel, or alloy steel
Vacuum Hole Pattern: precision drilled according to transfer requirements
Surface Finish: precision ground or coated depending on application
Runout Tolerance: typically ≤0.02 mm
Vacuum Chamber Design: customized according to machine layout and transfer performance requirements