How Is Plastic Recycled? A Step-by-Step Process

The recycling process begins with plastic waste being collected separately from other waste — this can be from household separate-collection bins or from industrial/packaging waste arriving at recycling facilities.

Collected waste is sorted by type according to recycling codes (1-7, see the related article). This sorting can be done manually, with optical sensors, or using density-based methods such as float-sink separation — because processing different plastic types together reduces quality.

The sorted plastics are washed to remove labels, adhesives, food residue and other contaminants. This step is critical for the quality of the resulting recycled raw material.

The cleaned plastic pieces are ground into small particles (regrind), then melted and re-formed into pellets. This recycled pellet can be mixed with virgin (primary) raw material at certain ratios, or used on its own, in the production of new products.

Plastic polymer chains undergo a degree of mechanical quality loss with each melt-reprocessing cycle — for this reason mechanical recycling has a practical limit on the number of times it can be repeated (unlike glass). Chemical recycling methods (breaking the polymer back down into its monomers), which aim to overcome this limitation, are a still-developing and more costly field.