What makes plastic recyclable

But these properties can be recovered by mixing it to additives or virgin plastic. Examples of successful industrial recycling include PET—poly ethylene therephtalate , which is used to make soft drinks bottles, and polystyrene. All of the rest can technically be reprocessed into new materials for different applications. In the final instance, any plastic waste can be shredded and used as filler for asphalt, or be pyrolysed to produce fuel. The Japanese company Blest Corporation already sells a portable machine to convert domestic plastic waste into fuel in a simple, affordable way.

The problem is that recycling much of this plastic waste is currently unfeasible and unprofitable. But the amount of these materials all over the world is frighteningly large and keeps on growing. What if this plastic waste could be used to produce something useful to society? Many universities and entrepreneurs are attempting to do this.

Most solutions target mixed plastic waste and suggest applications different from the original ones. For example, several groups have developed building materials made of plastic waste.

Plastics are strong, durable, waterproof, lightweight, easy to mould, and recyclable—all key properties for construction materials. So what if all of this plastic waste could be converted into building materials for low-income populations? Existing initiatives are promising, but not yet reproducible on an industrial scale. I study plastic waste with the specific aim of finding interesting ways to remove it from the environment.

Since , I have developed a number of building materials made of post-consumer plastics mixed with different waste-stream materials. From agricultural wastes such as sugarcane bagasse —a by-product of the sugar industry in Brazil—and coffee dregs , to concrete waste and construction debris , compounded with recycled plastics, there are many ways to obtain materials to produce bricks, roof tiles, plastic lumber and, other useful elements for building.

Our team is currently trying to develop a viable building block made of recycled plastics. We have prepared a range of prospective materials using a mix of virgin and recycled plastics coloured PET bottles, polypropylene, polyethylene and other local waste-stream materials—hemp, sawdust, concrete waste and red mud. We are currently adjusting the properties of the materials for the rotomoulding process , a plastics moulding technology which is ideal for making large hollow articles. We want to use the maximum amount of recycled plastics in this block.

We are also thinking about the aesthetics of the blocks. Blends of recycled mixed-colour plastics usually end up with a grey or black colour. Bottles and containers used for milk, shampoo, laundry detergent and household cleaners are lightweight and tough — but they usually are made from a different type of plastic than beverage bottles.

What can they become? When they are recycled they can make new bottles and containers, plastic lumber, picnic tables, lawn furniture, playground equipment, recycling bins and more. Plastic Bags and Wraps. We use plastic bags to carry home groceries. They keep our bread and other food fresh. They even let us carry goldfish home from the pet store.

Today there are thousands of grocery and retail stores to collect these bags for recycling, including most Target, Walmart, Lowes, Safeway stores and more. Your bottle is washed, shredded and packed into a bale ready for transportation to the recycling centre — so far, the same as the conventional process.

Then comes the chemical recycling: the plastic that formerly made up your bottle could be taken to a pyrolysis centre where it is melted down. Next it is fed into the pyrolysis reactor where it is heated to extreme temperatures.

This process turns the plastic into a gas which is then cooled to condense into an oil-like liquid , and finally distilled into fractions that can be put to different purposes. Chemical recycling begins the same way as ordinary mechanical recycling, with collecting and crushing plastics and taking them to a plant Credit: Alamy.

Chemical recycling techniques are being trialled across the world. UK-based Recycling Technologies has developed a pyrolysis machine that turns hard-to-recycle plastic such as films, bags and laminated plastics into Plaxx.

This liquid hydrocarbon feedstock can be used to make new virgin quality plastic. The first commercial-scale unit was installed in Perth in Scotland in The firm Plastic Energy has two commercial-scale pyrolysis plants in Spain and plans to expand into France, the Netherlands and the UK.

These plants transform hard-to-recycle plastic waste, such as confectionery wrappers, dry pet food pouches and breakfast cereal bags into substances called "tacoil". This feedstock can be used to make food-grade plastics. In the US, the chemical company Ineos has become the first to use a technique called depolymerisation on a commercial scale to produce recycled polyethylene, which goes into carrier bags and shrink film. Ineos also has plans to build several new pyrolysis recycling plants.

In the UK, Mura Technology has begun construction of the world's first commercial-scale plant able to recycle all kinds of plastic. The plant can handle mixed plastic, coloured plastic, plastic of all composites, all stages of decay, even plastic contaminated with food or other kinds of waste.

Mura's "hydrothermal" technique is a type of feedstock recycling using water inside the reactor chamber to spread heat evenly throughout. Heated to extreme temperatures but pressurised to prevent evaporation, water becomes "supercritical" — not a solid, liquid, nor gas. It is this use of supercritical water, avoiding the need to heat the chambers from the outside, that Mura says makes the technique inherently scalable.

The bigger you go the harder it gets. It's a bit like cooking," explained Mura's chief executive, Steve Mahon. A pilot plant has shown that the use of very hot, supercritical water can help chemical recycling scale-up to useful levels Credit: Licella.

The plastic waste arrives on site in bales — contaminated, multi-layer plastic such as flexible films and rigid trays that would otherwise have gone to incineration or energy-from-waste plants.

The bales are fed into the front-end sorting facility to remove any inorganic contaminants such as glass, metal or grit. It does not necessarily mean the item is recyclable.

They are often recyclable curbside, but not always. Check locally. Clean tubs before placing in the bin. These containers are usually marked with a 5 inside a triangle. Tubs are often made with a mix of plastic types. This can make it a difficult material for recyclers to sell to companies that would rather have a single type of plastic for their manufacturing. Trash collection and disposal company Waste Management says they work with a manufacturer that takes yogurt, sour cream and butter tubs and turns them into paint cans, for example.

Foam polystyrene, like that found in meat packaging or egg cartons, is made of mostly air. A special machine is required to remove the air and condense the material into a patty or block for resale.

These foam products have little value because once the air is removed, very little material remains. Dozens of cities throughout the U. Just this year, Maine and Maryland passed statewide bans of polystyrene food containers. Some communities, however, have drop-off locations for plastic foam recycling, which can be made into crown molding and picture frames.

Take plastic bags back to the grocery store for recycling. Plastic bags — like those used for bread, newspapers and as cereal box liners, as well as sandwich bags, dry cleaning bags and grocery bags — create similar problems for recycling machinery as thin plastic film.

However, bags and wrappers, like those that come around paper towels, can be returned to the grocery store for recycling. Thin plastic film cannot. There are approximately 18, plastic bag drop-off bins at major grocery store chains, including Walmart and Target, around the country.