Buying Guides

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.

A 3D printer filament recycler is a two-stage system — a shredder that turns failed prints into regrind, and an extruder that turns regrind into new filament. This guide explains how the system works, realistic costs from DIY to lab-grade, what output quality to expect from PLA, PETG, and ABS, and how to match a setup to your monthly waste volume.

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.