Plastics

START

Plastics are useful materials, but the way we currently consume them in a linear economy is wasteful and harmful to the planet. Recycling and reusing them in a circular economy means we can continue to benefit from their usefulness while reducing the harmful impact on the environment.To explore more about the linear and circular plastic economy and about the types of plastics available, how they differ, and if and how they can be recycled, click on START to enter our interactive

Different types of plastics available, what they are used for and how they are recycled

PLASTICS

THE CIRCULAR PLASTIC ECONOMY

THE LINEAR PLASTIC ECONOMY

To understand the types of plastics available, their differences and to figure out what can be recycled, click on each type here.

(Note that this varies in the UK so check local council websites)

Can it be recycled?

What products is it used in?

How is it recycled?

Reuse of individual items often best option. Avoid placing in recycling unless specifically instructed to do so. Bioplastic, biodegradable and compostable polymers best used within an established collection and management system, so they pose no risk of contaminating the mechanical recycling streams or the environment.

Reading glasses, nylons, CDs and DVDs and cases, some electrical connections and wiring, general household plastics, biodegradable and compostable plastics.

Pyrolysis breaks down mixtures of plastics into smaller feedstock chemicals by heating without any oxygen present. Research into recycling bioplastics.

O

Can it be recycled?

What products is it used in?

How is it recycled?

Possible to mechanically recycle, particularly with construction materials but needs separation from other plastics, check your local area. Chemical feedstock recycling is also possible with mixed wastes often after first separation of the PVC components.

PVC-U (unplasticized) construction, pipes, guttering, window frames, toys, piping. Regular PVC wire insulation, medical devices, waterproof membranes, flooring and records.

Mechanically recycled. Gasification or pyrolysis of PVC yields chemical feedstocks and hydrochloric acid which must be separated.

PVC

Can it be recycled?

What products is it used in?

How is it recycled?

Very commonly recycled, remove lids first. Mechanical recycling, technical challenges and regulations mean that the average recycled content in HDPE packaging is often around 20 – 25%.

White milk bottles all sizes, bleach type bottles, washing machine liquids and some bottle caps.

Mechanically recycled which can achieve food grade pellets via a closed-loop process which after melting are moulded into new products.

PET

HDPE

Can it be recycled?

What products is it used in?

How is it recycled?

Can sometimes be recycled - check your local council or supermarket. Ongoing research into wider PP recycling.

Butter and margarine tubs, fresh soup containers, some bottle caps, glass jar caps. In multi-layered films such as crisp packets.

Mechanically recycled. Also possible to purify polypropylene via dissolving in a solvent. Research into PP ongoing, in particular multi-layered films.

PP

Single use plastic means a typical lifecycle for over 90% of plastics is:

• Extraction of fossil fuels for raw materials.
• Processing and manufacture into plastics/polymers.
• Fabrication of plastic products – can contain mixtures of the many types of plastics.
• Discarded at end of life/single use – often back into the ground as landfill.

LINEAR PLASTIC ECONOMY

A circular plastics economy would intervene at end of life to recover, recycle and reuse the plastics. To either feed them back into new products or break them down into raw material. The result keeps the plastics (and the chemical they are made from) in use and out of landfill and the environment. Overall, this aims to keep the plastic/chemicals cycling between the manufacturing and use stages.Mechanical recycling is most common, where plastics are separated by colours and type, cleaned and shredded, before melting and moulding into new products. While chemical recycling is one solution for ‘difficult to recycle plastic’ such as multi-layer components, composites and mixtures. Chemical recycling yields a chemical component of plastic or monomer which can act as the raw material via:

• Chemical depolymerisation – a chemical process breaks the plastic up into the simple molecules it was made from. (Recent work at the OU has been developing plastics that are more susceptible to this process.)

• Pyrolysis – plastic is heated in the absence of oxygen to produce useful chemicals as raw materials.

• Gasification – heating with steam turns the plastic into useful gases as raw materials.

• Hydrothermal treatment – high temperature water is used to break down the plastic.

CIRCULAR PLASTIC ECONOMY

Can it be recycled?

What products is it used in?

How is it recycled?

Reuse of bags with targeted collection in some supermarkets but clean any materials contaminated with food. LDPE recycling is possible by dissolving plastic, purifying and then recovery, the recycled material also exhibits potential in food contact applications. For HDPE in mixtures of plastics, pyrolysis converts it to hydrocarbon feedstock chemicals.

Plastic bags, plastic wrapping, cling film.

Mechanically recycled into new products. Also pilot scale pyrolysis of LDPE, by heating without any oxygen present, yields feedstock chemicals.

LPDE

Can it be recycled?

What products is it used in?

How is it recycled?

Polystyrene packaging not generally recycled, check your local area. Polystyrene can undergo pyrolysis to produce hydrocarbon chemicals. Alternatively polystyrene can be cracked or broken down into the monomer styrene at elevated temperatures over a catalyst.

Yoghurt pots, insulated disposable cups, some trays, parcel packaging, car parts.

High Impact Polystyrene (HIPS) from end-of-life vehicles and expanded PS recycled by specialised mechanical recycling.

PS

Can it be recycled?

What products is it used in?

How is it recycled?

A commonly recycled plastic that food needs to be removed from before recycling . Mechanically recycled by separating colours, cleaning and shredding, before melting and moulding into new products. In textiles which are recycled separately via charity shops or waste recycling centres, this may involve dissolution, cleaning and recovery of PET.

Clear bottles (look for 'bubble' on the bottom of a bottle), food trays (clear, green, black etc.), yogurt pots, clothes, textiles.

Currently clear PET undergoes mechanical recycling. Research ongoing into chemical recycling with improved separation for mixtures, coloured samples and composites.

PET