Abstract: A process for producing a mass of entangled solvent swollen polymer filaments which can be converted into paper-making fibrils by subsequent refining. An olefin polymer such as polyethylene having an inherent viscosity of at least 3.5 is dissolved in a hot solvent. The hot polymer solution is subjected to timed sequential steps in which the polymer solution first is sheared and attenuated into fine polymer streams. The hot polymer streams then are cooled to precipitate the polymer which is recovered as a mass of entangled solvent swollen filaments. These filaments can be beaten in a non-solvent liquid such as isopropanol to prepare fibrils having diameters on the order of about 5 to 30 microns and lengths of about 1 to 15 millimeters.