Abstract: The process of this invention for making strong, discontinuous fibers from a polyolefin includes feeding a solution of polyolefin dissolved in an organic solvent at a pressure that is at least autogenous pressure to a spinneret. Plexifilamentary film-fibril strands are formed by flash spinning, by passing said solution through the exit of the spinneret and into a tunnel at a lower pressure and temperature than the solution, the temperature being greater than the boiling point of the organic solvent. At or subsequent to the exit from the spinneret but inside the tunnel, the strands and solvent are contacted in the tunnel with an inert fluid that has a liquid and a vapor phase, the amount of inert fluid being such that the ratio of the total volumetric flow rate of solvent vapor plus inert fluid vapor to the mass flow rate of the polymer is greater than 4.5 m.sup.3 /kg in the tunnel. The temperature of the inert fluid in the tunnel is 2.degree.-40.degree. C. lower than the melting point of the polymer.