Patent ID: 6892767

Claim:
A method of producing a woven uncoated air bag fabric comprising: (a) providing an original yarn of a thermoplastic fiber that has a single yarn size of 8 d or lower, a total yarn size of 100 to 700 d, and a boiling water shrinkage percentage of 5 to 15%, (b) weaving the thermoplastic fiber to form a woven fabric, and (c) subjecting the woven fabric to a shrinkage treatment under adjustment of an overfeeding percentage in order to provide the woven uncoated air bag fabric with a pore distribution value (PD) expressed by equation (1) of pores formed in the thermoplastic fiber is 2.0 or smaller, and air permeability at differential pressure of 20 kPa is 2.5 (L/cm 2 /min) or lower, wherein PD =( FDmax−FDmin )/ FDave (Equation 1) FDmax: maximum pore size (μm) FDmin: minimum pore size (μm) FDave: average flow rate pore size (μm).