Systems and methods are disclosed for making a moldable polymer mixture containing long reinforcing fibers that suffered no significant damage during plastication. The system and method produces a mixture in which the long fibers are longer and have encountered less damage than moldable mixtures made in previous plasticators. The plasticator system has a single screw, but with multiple zones for treating the materials differently. The long fibers, wet or dry, are fed into a downstream zone, distributed over a large port in a low density concentration, and heated and dispersed with low shear to separate the long fibers and surround them with polymer for protection before subjecting them to medium to high shear to finalize the dispersion of the long fibers.