The present invention relates to a method for recirculating non-hygroscopic polymers from rigid plastic food containers or industrial post-consumption and a system for carrying out said method. The method of the invention allows for low-speed grinding of the containers to be recirculated, keeping the contaminants on the surface of the flakes generated by the cutting of the hooked blades on different levels of a shredder, while helping to eliminate contaminants by scrubbing, which is done in pools specifically designed for this purpose, provided with a worm screw and perforated fins that extend from the same. Advantageously, the high-speed shredding of the flakes is done as one of the final steps of the method.