Airbag Fabric

Airbag Fabric Porosity & Calendering Pressure Modeler

Each further halving of permeability costs the same load increment as the last. That is why the final decade needs hundreds of tonnes.

Calibration Two-point trial
L/dm²/min
N/mm
L/dm²/min
Working Point Calender
N/mm
L/dm²/min
mm

Line Load for Target

— N/mm

Extrapolated from the calibration trial

Calendering Duty

Permeability at Working Load
— L/dm²/min
Reduction Achieved
— %
Load Shortfall to Target
— N/mm
Total Nip Force for Target
— kN
Permeability Decay Constant
— per N/mm

Exponential decay is a fit, not a law: real fabric reaches a floor where the yarns are fully flattened and further load only damages filaments. Extrapolating far past the calibration points will predict loads no calender can apply and no fabric would survive. Airbag fabric is life-safety hardware — permeability must be measured on production cloth, never inferred.

Airbag Fabric Porosity & Calendering Pressure Modeler — free, with the formula and a worked example, at Textile School.