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.”