Film Transfer Sizing Machine for Paper Machines
What is a Film Transfer Sizing Machine for Paper Machines?
A film transfer sizing machine is a core piece of equipment in the surface sizing and coating processes of modern papermaking machines. It functions much like a high-precision "coating machine"—first, a uniform film is pre-coated onto the sizing roll, and then this film is completely transferred to the paper surface. This technology replaces the traditional immersion sizing press, solving the problems of uneven sizing and paper breaks in high-speed paper machines.
What are the applications of film transfer sizing machines for paper machines?
In papermaking, film transfer sizing machines primarily undertake the task of surface modification and functionalization of paper sheets. Specifically, they are used in the following stages:
Surface Sizing: For cultural paper, packaging paper, and paperboard, surface sizing is applied to form a continuous film on the paper surface, improving the paper's water resistance, surface strength, and smoothness, while reducing lint and dust.
Pigment-based sizing and coating: Suitable for lightweight coating or pigment-based sizing, applying pigment-containing coatings to the paper surface to improve whiteness, opacity, and printability. The sizing/coating amount can be adjusted within the double-sided range of 0.5-12 g/m², adaptable to various paper types.
Specialty paper processing: In specialty paper production, it allows for the use of the same raw material on both sides, different raw materials on both sides simultaneously, or even sizing only one side of the paper, offering high flexibility.
Its working process can be summarized as three consecutive steps: "predicted amount - film formation - transfer," achieving precise and controllable transfer of the sizing compound:
Predicted amount: The sizing liquid or coating is fed to the sizing beam device via a feeding system. Before reaching the sizing roller, the sizing compound passes through a precision metering element—usually a metering rod (or metering roller). This metering element precisely scrapes the sizing compound into a uniformly thick film, with excess sizing compound recycled.
Film Formation: After the expected amount of sizing compound has passed through, a continuous, uniform, and sealed sizing film forms on the surface of the sizing rolls. The thickness of this film directly determines the final amount of sizing compound transferred onto the paper sheet.
Transfer: The paper web enters the pressure zone, which consists of two counter-rotating sizing rolls (top roll and bottom roll). As the paper web passes through the pressure zone, the sizing film on the roll surface is completely transferred to the paper web surface under pressure. Because the sizing film has passed through the expected amount, the hydraulic pressure experienced by the paper web in the pressure zone is very small.
What are the advantages of a film transfer sizing machine for paper machines?
Compared to traditional immersion sizing presses, film transfer sizing machines offer the following significant advantages, making them the preferred choice for modern high-speed paper machines:
| Advantage Dimension | Description |
| Excellent Operating Performance | Completely solves the problems of uneven coating, adhesive splashing, and paper web breakage or wrinkling that often occur with traditional size press machines at high speeds (especially above 600–800 m/min). It greatly improves the operating efficiency and stability of the paper machine. |
| High Sizing Precision | The coating amount is precisely controlled by metering rods and is not affected by factors such as machine speed fluctuations, changes in coating solid content, paper absorbency, or moisture content, ensuring accurate and consistent coating application. |
| Better Paper Quality | Due to the lower pressure in the press zone, the impact force on the paper web during sizing is reduced, making it less likely to crush or break the sheet while maintaining paper strength. The formed coating film is more uniform with better surface coverage. |
| Energy Saving and Cost Reduction | After sizing, the paper web has lower moisture content, which reduces steam consumption in the drying section and saves energy. At the same time, the coating amount can be accurately controlled to avoid waste and reduce production costs. |
| Strong Operational Flexibility | The sizing amount can be adjusted within a wide range, suitable for different process requirements from surface sizing to light coating. It also allows flexible production with different coating amounts or different coating materials on both sides of the paper to meet diverse product requirements. |