there is disclosed a novel apparatus and process for melt - blowing from fiberforming thermoplastic molten polymers to form fine fibers by extruding through orifices in nozzles the molten polymer at low melt viscosity at high temperatures where the molten fibers are accelerated to near sonic velocity by gas being blown in parallel flow through small orifices surrounding each nozzle . the extruded molten polymer is passed to the nozzles through a first heating zone at low incremental increases in temperature and thence rapidly through said nozzles at high incremental increases in temperature to reach the low melt viscosity necessary for high fiber acceleration at short residence time to minimize or prevent excessive polymer degradation .