Dewatering Press Felt for Building Roof Sheet Making

Dewatering Press Felt

2026-03-23 17:02

Dewatering Press Felt for Building Roof Making

Dewatering press felt is used in the production of roof sheets (asbestos cement tiles, calcium silicate boards, fiber cement boards, etc.) are the core dehydration and forming felt of the hatschek/flow on forming line. The core requirements are high line pressure tolerance, vertical rapid dehydration, high rebound, no caking, no shedding, and dimensional stability.

roof sheet felt.png

roof sheet felt

Classification of Dewatering Felt According to Production Process

1. Hatschek / Flow on Machine Dewatering Felt : high breathability, high water capacity, and quick dehydration; Single/double-layer bottom mesh, medium weight.

2. Press section Dewatering Felt: high compression resistance, high rebound, low breathability; Three layer/multi axial bottom mesh, high weight.

3. Forming Felt: super flat, high-strength, anti imprint; Full nylon, heat setting.

Main Function of Dewatering Press Felt

1. Forming+Dehydration: Undertaking cement/fiber slurry, rapidly dehydrating under vacuum suction and pressing to form uniform wet slab.

2.Carrying and Conveying: Continuously conveying wet roof sheet to the press/cutting machine to withstand repeated high-pressure impacts.

3.Surface Forming: The flatness of the dewatering felt surface directly determines the surface quality of the roof sheet, and the key is to have no felt marks or shedding.

4.Anti Stain and Easy to Clean: resistant to mud corrosion, easy to backwash, and not easy to block holes.

fiber cement felt

fiber cement board felt

fiber cement felt

Key Parameter for Dewatering Press Felt

Air Permeability	300-800 CFM (high in the forming section and low in the press section), ensuring rapid vertical dehydration
Felt Weight	(higher limit for high line pressure machine)
Line pressure tolerance	≥ 500 kN/m, preferably 800-1200 kN/m (multi axial bottom mesh)
Rebound rate	≥ 90% (rapid recovery after high pressure, no hardening)
Elongation rate	≤ 1.5% (longitudinal), stable size, no deviation
Surface roughness	Ra ≤ 5 μ m, no felt marks, no felt lint
Temperature resistance	≤ 95 ℃ (cement pulp process temperature)