Core Structure & Working Principle

1. Integrated Structure

   A cylinder vat consists of two key parts:

   • The rotating cylinder mould (the core mesh component): a hollow, perforated cylinder wrapped in fine metal or synthetic wire mesh, equipped with internal drainage channels.
   • The vat trough: a stationary container that holds the pulp slurry, with the cylinder mould partially submerged (typically 1/3–1/2 of its diameter) in the slurry during operation.

2. Forming Process

   As the cylinder vat’s mesh cylinder rotates slowly, the pulp slurry in the trough comes into contact with the submerged mesh surface. Under the action of gravity and internal vacuum (in advanced models), water in the slurry passes through the mesh and is discharged via the internal drainage system, while cellulose fibers are retained on the mesh surface. As the cylinder continues to rotate out of the slurry, a thin, uniform layer of wet paper web accumulates on the mesh. This web is then transferred to a felt belt and sent to subsequent pressing and drying processes for further refinement into finished paper.

Key Functions & Application Scenarios

• Fiber Retention & Wet Web Formation: It is the core unit for initial paper shaping, ensuring fibers are evenly distributed to form a consistent wet web, which determines the basic thickness and texture of the final paper.
• Preliminary Dehydration: Reduces the water content of the pulp at the forming stage (from over 99% water content in slurry to around 80–85% in wet web), alleviating the load on downstream dewatering equipment.
• Application Scope: Widely used in small-to-medium cylinder paper machines for producing low-to-medium grade paper such as corrugated base paper, wrapping paper, and household paper, due to its simple structure, low cost, and easy maintenance.