Method of increasing the meltblown jet thermal core length via hot air entrainment

The present invention relates to an apparatus and process for forming meltblown fibers. More specifically, the present invention relates to an apparatus and process for forming meltblown fibers utilizing an extended jet thermal core produced by entraining hot air at the point of jet thermal core formation. A method for producing super fine meltblown fibers increases the length of the meltblown jet thermal core to increase the dwell time of the extruded thermoplastic polymer within the jet thermal core. Through use of the method it is practical to use low viscosity resins and further to provide meltblown nonwovens with superior barrier properties to the passage of fluids and particularly gases. The method further provides a useful means for blooming internal additives to the surface of the fibers.