Nonwoven fabric having improved air permeability and manufacturing method thereof

The method for producing nonwoven fabric having improved air permeability, the method comprising the steps of:

• drying polyester having intrinsic viscosity of 0.6 to 0.8 and melting point of 260° C. and polytrimethylene terephthalate having viscosity of intrinsic viscosity of 0.8 to 1.2 and melting point of 225° C. in each dryer to moisture contents of below 100 ppm, and crystallizing and then providing it with an extruder;
• spinning to sheath/core shape with using each spinneret pack which can spin filaments having different denier each other and is arranged in parallel with each other, wherein a filament is formed such that the spun polytrimethylene terephthalate is to 10-50% by weight with respect to total weight;
• cooling the filament with cooled air, and consolidating it to prevent welding among the filament;
• elongating and dispersing the filament by crashing it to an impinging plate with certain velocity and angle to form a web;
• stacking the prepared filament uniformly on the moving conveyer belt successively to form a web by using a suction device at below;
• and
• thermally bonding the said stacked filament web by using the calendar which has the upper roll set at temperature of 180-210° C. and the lower roll set at temperature of 188-208° C., and nip pressure of 30-100 kg/cm, and whose bonding rate is 10-30%.