A plastic recycling line is one of the largest capital purchases a recycling operation will make. It is also one of the easiest to get wrong, because the failure modes are not visible at the quotation stage. A line can arrive with every machine meeting its individual specification and still fail to produce saleable recycled material, because the stages do not work together.

For importers, trading companies, and project developers sourcing a plastic recycling line from overseas suppliers, the procurement process must be a verification process. This guide sets out twelve verification points, organised into four groups: feedstock definition, stage matching, technical specification, and supplier assessment.

The first group of verification points establishes what the line must actually process. Without these, every subsequent quotation is incomparable.

Confirm the polymer composition of the feedstock and the proportions in which each polymer appears. A line configured for PE film behaves differently from one configured for mixed rigid plastics containing PP, HDPE, ABS, and PS. Mixed streams require additional density separation stages and may require different washing chemistry.

Ask the supplier to confirm which polymer streams the proposed line is designed for, and what happens if the mix ratio changes.

Contamination determines the intensity of the washing section. Confirm the expected contamination levels for soil, organic residue, adhesives, printing inks, and incompatible polymers.

Agricultural film carries soil and organic matter. Post-consumer packaging carries food residue and adhesives. Post-industrial scrap may be relatively clean. Each requires a different washing configuration, and specifying a line without this information produces a system that either over-washes clean material or under-washes contaminated material.

Confirm whether the feedstock arrives as bales, loose material, purgings, or film rolls. Confirm the bulk density of each form. This determines the receiving, feeding, and primary reduction configuration.

A line designed for baled material requires de-baling equipment. A line designed for loose material does not. A line handling purgings requires a different primary shredder from one handling film.

Confirm the required pellet or flake specification. This includes particle size, moisture content, contamination limits, colour requirements, and — where applicable — intrinsic viscosity for PET.

The output specification is the input to reverse-specification. Everything upstream should be designed to meet it. Without a defined output specification, the supplier cannot size the stages correctly.

The second group verifies that the stages within the proposed line are matched to each other. This is where most lines fail in practice.

Confirm the particle size distribution the shredder will produce, and confirm the particle size range the washing system is designed to handle. These must overlap.

If the shredder produces a wide distribution containing fines and large chunks, the washing system will lose fines with the wash water and retain contamination inside large chunks. Ask the supplier to state both ranges explicitly and explain how they are matched.

Confirm the moisture content of material leaving the washing and dewatering stage, and confirm the moisture level the drying stage is specified to reduce it to.

This is one of the most frequently mismatched interfaces in a plastic recycling line. Centrifugal dewatering performs differently on rigid flakes and film. If the dryer was specified on the assumption of low incoming moisture and the washer delivers wetter material, the line will not reach the target moisture level, and the extruder will produce inconsistent pellets.

Confirm the rated throughput of every stage and identify the bottleneck. A line's actual capacity is set by its slowest stage, not its fastest.

Ask the supplier to provide a throughput table covering receiving, primary reduction, secondary reduction, washing, dewatering, drying, extrusion, and output handling. If any stage is rated below the others, confirm whether that is intentional and what the resulting line capacity is.

Confirm the contamination level the washing system will achieve, and confirm the filtration fineness the extrusion system is specified for.

If the washer delivers flake with more contamination than the filtration system was designed to handle, screen changes will occur more frequently than planned, and the line will stop more often than the throughput calculation assumes.

The third group verifies the technical detail of individual stages where it affects line performance.

Confirm the screen aperture options available on the secondary shredder and the classification equipment. Confirm how easily screens can be changed, and whether alternative apertures are stocked as spare parts.

A line with limited screen options cannot be adapted if feedstock or output requirements change. This is a common cause of premature line obsolescence.

Confirm whether the washing stage includes hot washing capability, and confirm the temperature control range. Confirm the drying stage's temperature control and residence time.

Hot washing is required for food-grade PET and heavily contaminated film. Without it, the line cannot produce material for higher-value applications. Temperature control throughout determines whether the polymer is protected from thermal degradation.

Confirm the filtration fineness of the extruder screen changer, and confirm whether the extrusion system includes vacuum degassing.

Degassing is essential for PET and for any polymer sensitive to hydrolysis. Without it, moisture remaining in the flake causes intrinsic viscosity loss and inconsistent pellet quality. For food-grade applications, confirm whether solid-state polycondensation is included or available as an add-on.

The fourth group verifies the supplier's capability to deliver and support the line.

Ask for references from installations processing the same polymer type and similar contamination profile. A supplier with experience in rigid HDPE may have no experience with agricultural film.

Ask whether the line, or its individual stages, will be tested before shipment, and whether test data — throughput, moisture content, particle size distribution, and pellet quality — will be provided.

Additional supplier verification points include documentation language, spare parts availability and lead times, installation and commissioning support arrangements, and warranty scope. Confirm which components are covered and for how long, and confirm explicitly that consumables such as screens, blades, and filtration elements are excluded.

Beyond the technical verification, several commercial factors affect the landed cost and long-term viability of a plastic recycling line.

Packing and shipping. A complete line comprises multiple machines, often shipped in multiple containers. Confirm the packing method, container count, and shipping dimensions.

Voltage and configuration. Confirm every stage is configured for the destination market's voltage, phase, and frequency. Mixed configurations across a line create commissioning problems.

Installation sequence. Confirm the recommended installation sequence and the utilities required at each stage — power, water, compressed air, and drainage.

Payment and delivery schedule. Confirm production lead times per stage, the payment schedule, and the inspection arrangement before shipment.

Procurement of a plastic recycling line is a verification process, not a price comparison. Feedstock definition, stage matching, technical specification, and supplier assessment — verify each group, and quotations become comparable. Skip any one, and the commissioning cost after the line arrives may exceed the price difference between suppliers.