NOVELTY - Gel-spinning of high tensile strength ultra high molecular weight polyethylene (UHMWPE) yarns comprising ultra-low dtex filaments, involves a) preparing a solution of an UHMWPE in a solvent; b) spinning through a spinneret and into an air gap the solution of step (a) to form fluid filaments; c) drawing the fluid filaments with a fluid draw ratio as given in specification; and d) cooling the fluid filaments to form solvent-containing gel filaments; and e) removing at least partly the remaining solvent from the gel filaments to form solid filaments.    USE - For gel-spinning of high tensile strength UHMWPE yarns useful in fabric, medical suture, cable, implantable valve, vascular graft or mesh, composite articles, antiballistic articles (claimed), fishing lines and fishing nets, kite lines, dental floss, tennis racquet strings, canvas e.g. tent canvas, webbings, battery separators, capacitors, pressure vessels, hoses, automotive equipment, power transmission belts, building construction materials, cut and stab resistant and incision resistant and abrasion resistant articles, protective gloves, composite sports equipment such as skis, helmets, kayaks, canoes, bicycles and boat hulls and spars, speaker cones, high performance electrical insulation.    ADVANTAGE - The process provides UHMWPE multifilament yarn having a tensile strength of at least 3.5 GPa and modulus of at least 100 GPa, and has good productivity. The filament has a dtex of at most 0.5.    DETAILED DESCRIPTION - Gel-spinning of high tensile strength ultra high molecular weight polyethylene (UHMWPE) yarns comprising ultra-low dtex filaments, involves a) preparing a solution of an UHMWPE in a solvent; b) spinning through a spinneret and into an air gap the solution of step (a) to form fluid filaments, the spinneret containing multiple spinholes and where each spinhole comprises at least one zone with a gradual decrease in diameter and where the downstream diameter of the spinhole from which the solution is issued in the air gap is 0.1-1.5 mm; c) drawing the fluid filaments with a fluid draw ratio as given in specification; and d) cooling the fluid filaments to form solvent-containing gel filaments; and e) removing at least partly the remaining solvent from the gel filaments to form solid filaments, before, during or after drawing the solid filaments with a draw ratio of at least 4.