Process for preparing a continuous fiber filament, continuous fiber filament and use thereof

A process for preparing a continuous fiber filament comprising:

• a polymeric matrix comprising a polymeric component, optionally reinforcing agents, and optionally at least one additive selected from the group consisting of colorants, lubricants, plasticizers, flame retardants, nucleating agents, flow enhancers and stabilizers, wherein the polymeric component comprises at least one poly(aryl ether ketone) (PAEK) polymer or copolymer, and
• at least one fiber tow, which is embedded into the polymer matrix,
• wherein the process comprises the steps of:
• a) spreading the fiber tow,
• b) impregnating the fiber tow in a liquid medium, comprising the polymeric component in the shape of polymer powder particles, at least an aqueous solvent and from 0.01 to 3 wt. %, based on the total weight of the liquid medium, of at least one alkylphenoxy poly(ethyleneoxy) ethanol surfactant, wherein the polymer powder particles have a d50 varying between 1 and 20 μm, as measured as measured by laser scattering in isopropanol,
• c) heating the impregnated fiber above the melting temperature of the polymeric component, and
• d) calendering the filament using at least one die of cylindrical geometry.