| 摘要 |
<p>The present invention provides a method for manufacturing polypropylene spun-bonded fabrics, which method involves preparing a polypropylene melt at a temperature of about 240 DEG to 280 DEG C. and forming polypropylene filaments by extruding this melt through a spinning nozzle at an extrusion velocity of about 0.02 meter/second to 0.2 meter/second. The spinning nozzle, or spinneret, has holes with a diameter less than 0.8 millimeter. The filaments thus formed are subsequently quenched by transversely blowing air at a temperature between about 20 DEG to 40 DEG C. The filaments are also aerodynamically withdrawn by means sufficient to create a filament withdrawal velocity between about 20 meters/second and 60 meters/second. The ratio of the extrusion velocity to the withdrawal velocity (herein defined as the deformation ratio) is between about 1:200 and 1:1000. These aerodynamically withdrawn filaments are then deposited onto a moving porous support in order to form a continuous web. This web is then bonded by suitable means, forming a finished spun-bonded nonwoven fabric.</p> |
