Process for the preparation of fibers from polymeric materials

A process for obtaining short, elongated fibers of a polyolefinic material which are useful as produced and without prior cutting thereof, or disintegrating operations, in the manufacture of paper by conventional paper-making methods, which comprises ejecting a homogeneous, one-phase solution of from 50 to 400 grams of a polyolefinic material per liter of a solvent thereof and which is free of liquids immiscible with the solvent at a temperature at least 60.degree. C. higher than the boiling point of the solvent and under antogenous or higher than autogenous pressure, into a zone of lower pressure in which the solution at least partially expands;

• and hitting the at least partially expanded solution with a jet of fluid maintained at a temperature lower than the temperature of the solution, the angle at which the jet of fluid hits the at least partially expanded solution of polyolefinic material being between 30.degree. and 90.degree., the speed at which the solution of polyolefinic material is ejected into the zone of lower pressure being from 1,000 to 200,000 meters per hour, and the impact speed of the hitting fluid being from 200 to 600 meters per second.