Recycled Plastic for Automotive and Appliances: What Buyers Need

Automotive parts and home appliances use a wide range of plastics, and more of their manufacturers are looking at recycled material for suitable components. The opportunity is real, but so are the requirements. Parts in these sectors must meet mechanical, thermal and appearance standards, and a material change usually needs approval from the customer before it goes into production.

This guide covers the polymers most often used, where recycled grades can fit, and what suppliers and buyers need to get right.

Polymers used in these sectors

Polymer	Typical uses	Where recycled grades may fit
PP and PP compounds	Interior trim, battery boxes, housings, washing machine parts	Non-visible parts, brackets, covers
ABS	Appliance housings, panels, consoles	Internal parts, some housings in dark colours
PC and PC blends	Covers, switch parts, light housings	Non-transparent parts with lower demands
PA / Nylon	Under-bonnet parts, clips, gears, connectors	Parts where full virgin properties are not required
HIPS	Refrigerator liners, appliance back covers, trays	Internal trays, covers, non-food-contact parts

For polymer background, see the HIPS page and the pages for each polymer below.

PP compounds

A large share of automotive and appliance PP is not plain PP but a compound: PP with talc, calcium carbonate or glass fibre, often with impact modifiers. Recycled PP can be used as the base for such compounds, and recycled compounds are also available from scrap of filled parts. Buyers should state the filler type and content they need, as this changes stiffness, density and shrinkage. See filled PP compounds.

ABS, PC and nylon

These engineering plastics usually come from post-industrial scrap such as runners, rejected parts and purgings, or from dismantled products. Post-industrial streams from a single grade are the most valuable, because their properties are known. Key points:

• ABS is fairly forgiving to recycle but must be kept apart from PC/ABS blends and HIPS, which look similar. See recycled ABS granules.
• PC absorbs moisture and degrades if processed wet, so drying is essential. See recycled PC granules.
• Nylon also absorbs moisture, and glass-filled and unfilled grades should not be mixed.

More detail is in ABS and engineering plastics recycling.

Consistency matters more than headline values

In these sectors, a recycled grade with slightly lower properties but tight lot-to-lot consistency is often more useful than one with good average values and wide swings. Moulders set their process once and expect the material to behave the same way every time. Suppliers should give ranges for MFI, density, ash and, where tested, impact strength and tensile strength, and should hold those ranges across deliveries.

Trials and approval

Changing material in an automotive or appliance part usually needs the agreement of the customer who owns the part design. The process typically involves:

1. a technical review of the data sheet and test reports;
2. a moulding trial with a sample lot;
3. testing of finished parts against the customer's specification;
4. approval for a defined grade and supplier, sometimes with conditions;
5. regular checks once supply begins.

Approval is tied to a specific grade from a specific source. A supplier who changes the feed or process without telling the buyer can put the approval at risk. Agree in writing how changes will be notified.

Advice for suppliers

Suppliers who want to serve these sectors should focus on traceable, single-source streams, such as runners and rejects from one moulder using one grade. Keep each grade in its own lot, dry hygroscopic materials before pelletising, and test every lot rather than an occasional batch. Keep retained samples and records of feed sources, because approved customers may ask how a lot was made. Be ready to supply the same grade month after month; a customer who has gone through approval will not want to repeat it for a new source.

Advice for buyers

Start with parts that are not visible and not safety critical. Specify the polymer, grade, filler, colour, property ranges and test methods clearly. Ask for samples from more than one lot to judge consistency, not just one good sample. The quality checklist is a useful starting point.

Getting started on PlasticSetu

Buyers can get quotes for recycled engineering plastics and compounds, and the sourcing desk will arrange samples for trials. Suppliers with consistent post-industrial grades can list your materials with test data and lot details.