The invention relates to a process for the simultaneous preconcentration and preselection of at least one group of used polymer materials of various compositions, as a mixture with one another and with contaminant materials, originating from the destruction, by grinding, of durable consumer goods that have reached the end of life, which can be recycled in the fields of plastics processing. The universal controller is capable of controlling the power converter in any quadrant of the PQ domain. The hinge panels may have laterally spaced apart the adjacent folding panels from one another such that a compartment is formed upon retraction or folding of the sheets of folding panels. Memory may be accessed to obtain at least one transformation audio from a number of stored transformation audio. The length of need section may include portions of each of the respective cables running in between the plurality of intermediate support posts.