Plastic Recycling Industry Terms Guide

Feedstock sources for a Plastic Recycling Facility

Post-industrial waste (factory waste)	Waste generated by factories or other industrial facilities during manufacturing, typically including scrap, off-spec material, and defective parts produced in processes such as injection-moulding and extrusion. Within the trade it is also called purge, first-grade regrind, sprue/runner scrap, edge-trim scrap, or reprocessed material.
Pre-consumer waste (also factory waste)	Like post-industrial waste, but refers to products made in excess or that cannot be sold.

Both categories are generally called plastic scrap and have the highest recycling priority.
Plastics that fail to meet finished-product specifications—whether pellets, semi-finished pieces, or trimming scrap—may, depending on contamination and degradation, be re-ground for reuse, sold, or discarded.

Common collection and supply channels

Material Recovery Facility (MRF)	Uses manual and mechanical processes to sort recyclables, remove contaminants, and process them (usually baling) for sale into various markets.
Secondary MRF	Receives the low-volume or low-value fractions from primary MRFs and performs finer sorting, cleaning, and aggregation, upgrading them to saleable grades. (Availability depends on the city.)
Mixed Waste Facility	An MRF that accepts mixed municipal solid waste (MSW) together with recyclables, separates and bales the recyclables, and sends the remaining MSW for disposal. (City-specific.)
Deposit Return Scheme (DRS)	Generates material with very high recovery rates and purity; though slightly higher-priced, it contains fewer impurities and has more stable IV, making it suitable for high-end applications.
Import broker	When domestic supply is insufficient and national regulations permit, compliant waste plastics can be imported under HS Code 3915—subject to Basel Convention rules and local solid-waste laws.

Equipment and Processes a PET Bottle Recycling Facility Should Know

Materials

PET bottle bales	MRF-sorted bottles, baled for handling; bale quality determines bottle-to-bottle viability, loss rate, overall yield and line design.
Regrind	Flat flakes after size-reduction; best washing & pelletising size ≈ 12 mm ± 0.5 mm.
Washed flakes	Water-cleaned flakes, further purified; sold as fibre-, filament- or food-grade.
Preforms	Injection-moulded blanks later reheated, stretched and blown into final bottles; key downstream product in bottle-to-bottle loops.
PET pellets	Washed flakes extruded and pelletised; high bulk density, good feedability; typically made on parallel twin-screw extruders with optional homogenising / additive silos.

Equipment / Process Step

Bale breaker	Opens compressed bales, loosening bottles for downstream flow.
Trommel screen	Rotating perforated drum removes non-target items by size.
De-labeller	Strips labels; PVC ppm in flakes is a key quality metric.
Whole-bottle pre-wash	Pre-cleans bottles and aids secondary label removal.
Whole-bottle optical sorter	Colour / resin sorting (common on food-grade lines).
Manual picking station	Final hand removal of residual contaminants (≈ 0.5 – 1 %).
Granulator	Cuts bottles into flakes; screen sets final flake size.
Sink–float tank	Light fractions (caps, label chips) float; PET sinks and advances.
Cold wash	Ambient-water rinse; basic soil removal.
Hot wash	Heated wash (≥ 1 tank) removes glue & oils; mandatory for bottle-to-bottle.
Centrifugal dryer + hot-air pipe	Lowers flake moisture to < 1.5 %.
Elutriator (Z-shaped air classifier)	Airflow lifts fines / label dust, leaving heavier PET.
Flake optical sorter	High-precision colour / polymer sorting (e.g. TOMRA units).
Eddy-current separator	Removes non-ferrous metals (e.g. aluminium shards).
Water-treatment loops	Recirculate rinse water; chemical-return loop for hot wash.

Bottle-to-Bottle Key Terms

Intrinsic viscosity (IV)	Indicates PET molecular weight; governs suitability for bottle-grade use.
Solid-state polycondensation (SSP)	Post-pellet process to raise IV when needed.
Compounding	Blending high-quality masterbatch with food-grade flakes to meet preform specs without SSP.
Clumping	Agglomeration during drying; avoided via homogenising silos or pre-crystallisation.
*Colour values (L a* b)*	Colour metrics; bottle-grade product must be clear or blue within spec.
ppm	Parts per million; expresses contaminant concentration in recyclate.

Equipment and Processes a Soft Plastics Recycling Facility Should Know

Soft plastics — a broad category of plastics whose density is lower than water — include, but are not limited to: PE film types (agricultural mulch film, greenhouse film, clean factory off-cut film, municipal solid-waste garbage film); PP woven-sack types (cement bags, chemical raw-material bags, grain bags); and PP/PE jumbo (FIBC) bags, among others.

Materials

MRF curbside film bales	HDPE / LDPE / LLDPE film vacuum-collected at an MRF; no non-PE film allowed; bales must be emptied and rinsed.
PE clear film bales	≥ 95 % clear or natural-colour HDPE / LDPE / LLDPE mix; must be emptied and rinsed.
Agricultural PE film bales (incl. mulch)	Field-cover / greenhouse PE film; must be thoroughly washed.
Washed film	Dirty film after water washing and further cleaning; dewatering + pipe drying leaves 4 – 8 % moisture. Claims of 1 % moisture from this system are unreliable—if true, a squeeze-dryer would be redundant.
Semi-plasticised pellets	Film washed, cleaned, then passed through a squeeze-dryer; final moisture 1 – 1.5 %.

Equipment / Process Step

Shredder (for bales / lumps)	First-stage size reduction when whole bales are fed; handles embedded metal. Usually screen-less, produces large strips.
Granulator (fine size-reduction)	Cuts film to final size; screen mesh sets flake dimensions.
Cold wash	Ambient-water cleaning; removes basic dirt. Hot wash can be added for higher cleanliness.
Float-sink tank	Film & woven-bag flakes float; heavy contaminants sink and are screw-discharged.
Drying – option 1	Centrifugal dewaterer + pipe dryer; film moisture remains relatively high (bags down to ≈ 3 %); lower cost.
Drying – option 2	Squeeze dryer; achieves very low moisture, product feeds directly to pelletising; higher cost.

Notes
Except for factory off-cuts and specially sorted film bales from an MRF, other post-consumer film feedstocks typically contain 20 %–70 % contaminants. When purchasing a PP/PE film washing line, users should focus closely on capacity.

The throughput figures quoted by recycling-line manufacturers always refer to the input rate. If your feedstock contains ≥ 30 % contaminants, we recommend specifying a line rated for at least 1,500 kg/h. For ease of calculation, assume a normal loss rate of about 30 % for film scrap.

If woven sacks or FIBC (jumbo) bags have previously held chemical raw materials, take special care: these plastic containers are classified as hazardous waste. If your country permits in-plant recycling, see our “Hazardous Waste Packaging Container Solution.”