FIELD: paper-and-pulp industry. SUBSTANCE: cellulose-based liquid-crystalline solution is extruded to give cellulose fiber using aqueous coagulation agent containing at least one additive. When agent is brought into contact with solution, kinetics of diffusion and kinetics of coagulation agent-assisted sedimentation of cellulose materials measured on microscope using so-called coagulation test with 20 wt % of additive is determined by following relationship: 0,55<Kp/Kd≤1 wherein Kp and Kd, respectively, are diffusion and sedimentation factors (corresponding angles of slope for Fick's straight line) expressed in mcm/s1/2. Cellulose fibers thus obtained are used to strengthen rubber and plastic products, in particular envelopes for inflatable articles. EFFECT: increased elasticity, stretching modulus, and other physico- mechanical characteristics. 19 cl, 2 dwg, 4 ex
