define the slot width w in the range of about 0 10 inch to about 0 50 inch the height h of the faces 65 define the height h of the attenuating slot 64 which is in the range of about 0 25 inch to about 2 5 inches from the extruder 2 the molten polymer 40 is extruded through the nozzles 38 forming the filaments 28 having a diameter as they leave the nozzle in the range of about 0 01 to 0 02 inch the attenuating forces both axial and shear generated by the attenuating air flow applied to the filaments 28 within the attenuating slot 64 attenuate the diameter of the filaments 28 at least in a range of approximately 50 1 before the filament exits the attenuating slot 64 and is gathered on a collection belt 10 molten polymer is supplied at a suitably elevated temperature to the nozzles 38 and filaments 28 are discharged uniformly vertically downward by a suitable pressurized supply system air gas streams are introduced laterally from both sides these gas streams are deflected into the spin line direction by means of two dimensional coanda bends 90 u00b0 as shown the curved free jet surface at the outer edge of the coanda bend entrains and accelerates the individual cylindrical filaments 28 discharged vertically above it once the air gas streams are deflected into a direction parallel to the filaments 39 downward movement the flow provides further important axial acceleration to the fluid filaments as the streams merge to.