What drives eddy current separator price, why quotes for the same belt width differ by a factor of five, how to size between small and full-scale units, which manufacturer claims you can actually verify, and when a used machine is worth the risk.
The Precious Plastic shredder is the open-source design that started thousands of small recycling workshops. This guide compares building one from the plans against buying a finished desktop shredder — real component costs, build time, safety and CE questions, and when each route makes sense.
An air classifier separates recycled material by weight in a stream of air — film from flake, dust from regrind, labels from bottle chips. This guide compares the main types (zig-zag, cross-flow, drum wind sifter, vertical column), shows which feed each one suits, and explains how to specify one with its dust collection system.
Single-shaft shredders cut against a screen for defined flake; double-shaft shredders tear at low speed for coarse volume reduction. This guide compares the two designs by output size, feed tolerance, wear cost, and energy use — and explains why the feeding system matters as much as the shaft count.
Compressed film bales, extruder purge lumps, and full rolls are the three feeds that damage shredders most in plastic recycling. This guide explains how a hydraulic bale cutter works, how much cutting force each material needs, when pre-cutting pays for itself, and how to size a guillotine to your shredder's feed opening.
Density separation sorts mixed plastics by whether they float or sink in a liquid, and it is the cheapest way to split polyolefins from heavier resins. This guide explains how a sink-float tank works, which plastics float and which sink, what density separation can and cannot do, and how it compares with electrostatic and eddy-current sorting.