Calendering

Calendering is a finishing process in which a fabric passes through one or more nip rollers under pressure and temperature to modify thickness, surface topography and permeability. For woven monofilament meshes, calendering smooths the surface, improves cake release and reduces initial roughness that can trap fines; it can also lock the weave and stabilise aperture. The trade‑off is lower open area and higher clean‑medium resistance if over‑calendered. Process settings—nip pressure, temperature, line speed and roller hardness—are tuned to achieve target air/water permeability and surface Ra without damaging filaments. In specifications, calendered versus non‑calendered versions of a mesh are treated as distinct grades with separate permeability and retention data. Validation includes porometry, permeability and release tests under application‑specific conditions.