ABS and Engineering Plastics Recycling: Sources, Sorting, Grades

Engineering plastics such as ABS, polycarbonate, nylon, POM and PMMA are used where commodity plastics are not strong, stiff or heat-resistant enough. They are found in appliances, electronics, automotive parts and industrial components. Their scrap is generally worth recovering, but it is also harder to sort and process well.

This article covers where engineering plastic scrap comes from, why sorting is difficult and what grades buyers can expect. HIPS is included because it often turns up alongside ABS in the same waste streams.

Where the scrap comes from

• E-waste: housings of televisions, monitors, printers, computers and small appliances, often ABS, HIPS, PC and PC/ABS blends.
• Appliances: refrigerator liners, washing machine parts, air conditioner panels and kitchen appliances, using ABS, HIPS, PP and others.
• Automotive: dashboards, trims, light covers, grilles and under-bonnet parts, which may be ABS, PC, PMMA, nylon or PP compounds.
• Post-industrial scrap: runners, sprues, rejects and purgings from moulders. Usually the cleanest and most consistent source.
• Other sources: PC sheets and water jars, PMMA sheet offcuts, and nylon from textiles and engineering parts.

The polymers at a glance

Polymer	Key traits	Common recycled uses
ABS	Rigid, tough, good surface finish	Appliance parts, housings, automotive interior parts
HIPS	Impact-modified polystyrene, easy to mould	Household goods, hangers, stationery, refrigerator parts
PC	High impact strength, transparent, heat resistant	Technical parts, sheets, blends with ABS
PA / Nylon	Strong, wear resistant, often glass-filled	Engineering components, automotive parts
POM	Stiff, low friction, dimensionally stable	Gears, clips, fasteners
PMMA	Clear, rigid, good weathering	Signage, light covers, regranulated sheet

Why sorting is difficult

Unlike PET bottles or PP raffia, engineering plastic scrap is rarely a single, clean stream:

• Similar appearance: ABS, HIPS and PC/ABS can look almost identical, especially when painted or textured.
• Overlapping densities: most engineering plastics sink in water, so simple float-sink separation cannot separate them from each other.
• Blends and fillers: PC/ABS blends, glass-filled nylon and mineral-filled grades behave differently from unfilled resin.
• Additives: flame retardants are common in electronic housings, and some additives are restricted. Material from e-waste should be handled by authorised dismantlers and recyclers in line with the applicable e-waste rules.
• Attachments: metal inserts, screws, labels, foam and paint must be removed.

Larger recyclers use techniques such as spectroscopic identification (near-infrared or FTIR), density separation in liquids other than water, and electrostatic separation. Smaller units rely on careful manual sorting by part type and source. Our guide on how to identify plastic types covers the basic methods.

Grades buyers will find

• Post-industrial regrind: single polymer, often single colour, from moulding scrap. The most predictable option.
• Sorted post-consumer regrind: sorted by polymer and colour from appliance or e-waste parts; quality depends on how well it was sorted.
• Recycled granules: extruded and filtered, sometimes colour-matched, such as recycled ABS granules and recycled nylon granules.
• Compounds: recycled material upgraded with impact modifiers, glass fibre, stabilisers or flame retardants to meet a target specification.

When comparing offers, check exactly which of these forms is being quoted. A regrind of mixed appliance parts and a filtered, colour-matched granule may both be described as recycled ABS, but they suit very different applications. Ask about the source of the scrap, whether parts were sorted by type before grinding, and whether any blends or filled grades are present. Suppliers who keep each source separate can usually give more reliable answers.

Processing tips for buyers

ABS, PC, nylon and PMMA are hygroscopic and need drying before moulding or extrusion; see our moisture and drying guide. POM must be kept away from PVC and other halogen-containing materials, and should not be overheated, because it degrades and releases harmful gases.

Ask suppliers for MFI, density, ash content (to detect fillers) and impact strength, and run a trial before committing to bulk. Keep different engineering polymers strictly separate in stores, grinders and hoppers, since small amounts of the wrong material can cause brittleness or surface defects.

Trading engineering plastics on PlasticSetu

Buyers can get quotes for ABS, PC, nylon, POM, PMMA and HIPS by specifying polymer, form, colour, filler content and intended application. Suppliers holding sorted regrind or granules can list your materials; the sourcing desk contacts you when a requirement matches.