Foam Acrylic Coating

Foam coating mechanically whips acrylic dispersion to blow ratios of 1:3 to 1:8 (wet foam density 0.10–0.25 g/cm³) before application via knife or rotary screen at 20–60 g/m² dry add-on. The cellular foam structure collapses during drying at 120–150°C, leaving open-cell or closed-cell morphology that controls air permeability (50–500 cm³/cm²/s, ISO 9237) and water vapor transmission. Foam coating reduces chemical consumption by 30–50% versus conventional coating at equivalent add-on. Used for softback carpet underlay, interlinings, and acoustic panel fabrics. Machine speeds of 30–60 m/min are achievable with foam coating versus 10–20 m/min for knife coating.