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.
A reference density chart for common recycling plastics — PP, PE, PET, PVC, PS, ABS, and more — with each resin's density in g/cm³ and whether it floats or sinks in water. Includes how fillers shift density, why some resins overlap, and how recyclers use the chart to sort plastic by sink-float.
Every plastic sorting method works on one physical property — density, weight, surface charge, conductivity, or polymer fingerprint. This guide compares sink-float, air classification, electrostatic, eddy-current, and NIR sorting, shows what each one separates, and gives a decision framework for matching the method to your contamination.