impinging directly on the fiber and assists in preserving the continuity of the fiber without breaking it this configuration provides four air jets per die hole while it is not shown it is clear from the above that a juxtaposed series of only primary plates would provide a slit die that could be used for film forming consequently the instant invention presents the ability to extend the air and melt nozzle matrix a virtually unlimited distance in the lateral and axial directions it will be apparent to one versed in the art how to provide the polymer and air inlet systems to best accommodate the particular system being constructed the modular die construction in this particular embodiment provides a total of 4 air nozzles for blowing adjacent to each die hole although it is possible to incorporate up to 8 nozzles adjacent to each die hole the air which may be at temperatures of up to 900 u00b0 f provides a frictional drag on the fiber and attenuates it the degree of attenuation and reduction in fiber diameter is dependent on the melt temperature die pressure air pressure air temperature and the distance from the die hole exit to the surface of the collector screen it is well known in the art that very high air velocities will elongate fibers to a greater degree than lower velocities fluid dynamics considerations limit slot produced air velocities to sonic velocity although it is known how to produce supersonic flows with convergent divergent nozzles this has not been successfully accomplished in meltblown or spunbond technology it is believed that this is due to the considerable difficulty or impossibility of producing a large number of convergent divergent nozzles in.