Method of Making Fine Spunbond Fiber Nonwoven Fabrics at high Through-Puts

A method of making spunbond fiber nonwoven fabrics comprising:

• providing a spinneret having a length, a width and a thickness and further having a plurality of conduits extending through the thickness of the spinneret, said conduits having an inlet opening in an upper surface of the spinneret and an exit orifice in a lower surface of the spinneret and further having a capillary in fluid communication with said inlet opening and exit orifice, and wherein said exit orifices have an average diameter of between about 0.2 and about 0.45 mm, and wherein the spinneret has at least 5000 exit orifices per meter length of the extrusion area in the cross-direction;
• melting an extrudate composition having a polymeric portion and wherein the polymeric portion comprises at least 65% of an olefin polymer;
• directing a pressurized molten stream of the extrudate composition into the inlet openings of the spinneret and through the capillaries,
• extruding said molten stream of the extrudate composition out of said exit orifices at a rate of at least 0.3 g/orifice/minute and forming a bundle of molten filaments;
• directing a stream of quench air onto said bundle of molten filaments thereby at least partially solidifying said molten filaments to form a bundle of quenched filaments;
• pneumatically drawing said quenched filaments;
• and
• suctioning said bundle of drawn filaments onto a foraminous forming surface to form a nonwoven batt, wherein the drawn filaments deposited on the forming surface forming the nonwoven batt have an average fiber diameter of about 15 microns or less.

A method of making spunbond fiber nonwoven fabrics comprising:

• providing a spinneret having a length, a width and a thickness and further having a plurality of conduits extending through the thickness of the spinneret, said conduits having an inlet opening in an upper surface of the spinneret and an exit orifice in a lower surface of the spinneret and further having a capillary between and in fluid communication with said inlet opening and exit orifice, and wherein said exit orifices have an average diameter of between about 0.2 and about 0.45 mm, and wherein the capillaries have a length, and wherein the capillary length divided by the exit orifice diameter is between 5 and 9;
• melting an extrudate composition having a polymeric portion and wherein the polymeric portion comprises at least about 65% of an olefin polymer;
• directing a pressurized molten stream of the extrudate composition into the inlet openings of the spinneret and through the capillaries,
• extruding said molten stream of the extrudate composition out of said exit orifices at a rate of at least about 0.4 g/orifice/minute and forming a bundle of molten filaments;
• directing a stream of quench air onto said bundle of molten filaments thereby at least partially solidifying said molten filaments to form a bundle of quenched filaments;
• pneumatically drawing said quenched filaments downwardly through a drawing channel and forming a bundle of drawn filaments, said drawing channel having an upper opening and lower opening;
• providing a foraminous forming surface below the lower opening of the drawing channel and suctioning air exiting from the lower opening of the drawing channel through said forming surface;
• suctioning said bundle of drawn filaments onto the foraminous forming surface to form a nonwoven batt, wherein the drawn filaments deposited on the forming surface forming the nonwoven batt have an average fiber diameter less than about 16 microns;
• and
• bonding said nonwoven batt thereby forming a nonwoven fabric.