An inline method for producing a spring strip profile (1) for a slatted frame that comprises at least one core strand (2) formed by a
fiber-reinforced plastic and at least one
thermoplastic cover layer (3) surrounding the core strand (2), comprises at least the following steps: joining multiple fibers, threads and / or filaments to form a
fiber bundle (2.1); impregnating the
fiber bundle (2.1) with a thermally activatable reaction resin; molding the outer contour of the
fiber bundle (2.1) impregnated with the reaction resin; thermally activating the reaction resin (2.1) to form a cured core strand; introducing the core strand (2) into an extruder head (110); applying
thermoplastic melt in the extruder head (110) to form the cover layer (3) on the spring strip profile (1); and cooling and calibrating the spring strip profile (1) in a cooling and calibrating device (111, 112, 113). The outer contour of the
fiber bundle (2.1) is wrapped around, in a
winding machine (105), by at least one thread or filament (2.2) supplied laterally in relation to the
fiber bundle in at least one position and orientation, and, in a heating section (106), before the core strand (2) is introduced into the extruder head (110), at least a partial curing of the reaction resin is achieved, at least in the wrapped outer layer of the fiber bundle (2.1).