Process for producing non-woven webs

Abstract

A process for producing a non-woven polymeric fabric web, such as a spunbond web, having filaments of 0.1 to 5 denier with equivalent production rates. A plurality of continuous polymeric filaments is extruded from an extruder and attenuated by a drawing unit that includes a longitudinal elongated slot strategically positioned at an optimum distance very close to the spinneret. A web forming table is positioned below the drawing unit for collecting the filaments and forming the filaments into a non-woven fabric web. At startup, throughput is nominal, air pressure is below 20 psig, and the spinneret is positioned more than 100 cm away from the drawing unit. Gradually, throughput is greatly increased by simultaneously increasing air pressure while reducing the distance between the spinneret and the drawing unit. Coordinating the adjustment of the throughput with air pressure and distance reduction of the spinneret and the drawing unit produces the finest filaments at equivalent production or the same filament size at the highest production rate and lowest cost.

Dependencies are inferred from the claim text.