Plastic’s black sheep

Whilst many types of plastic come with recyclability problems, there 
is one that harbours its own dark little secret. In the UK, black plastics are commonly used in items such as ready meal trays, yoghurt pots and shampoo bottles. Most British recycling facilities now use near infra-red (NIR) technology to identify and sort different materials, but the black pigment applied to the polymers absorbs infra-red light, thus rendering them undetectable. The result: black plastics invariably end up being unsorted and contaminating the plastic stream.

Many consumers are still largely unaware of the problem and local authorities have often been unclear about whether black plastics should go into the residual waste stream or into recycling. The upshot of this is that an estimated 36,000 tonnes of undetectable black plastic went onto the UK market in 2017.

It’s a problem that the plastics recycling industry is not unaware of. “There has been an increase in political, media and consumer pressure and black plastic was getting a negative name in terms of it being perceived as a problem,” explains Stuart Foster, the CEO of Recoup, the plastics recycling industry body. To this end, Recoup set up the Black Plastics Packaging Forum back in 2017. In July this year the Forum issued a report summarising developments in the field of black plastics, as well as setting out three main options to tackle the central problem of sorting.

The first of these is to simply replace black with alternative colours and indeed this solution has already been put in place by a number of firms. In 2018, for example, Quorn switched its polypropylene trays and CPET (crystalline polyethylene terephthalate) ready meal trays from black to white or clear formats, a
switch that the company estimates has prevented 300 tonnes of black plastic from entering the supply chain annually. Similarly, the Co-op has switched its own brand cookie range from a black to a clear APET (amorphous polyethylene terephthalate) tray, while Lidl announced that black plastic would be removed from a range of
its own-brand vegetable, meat, fish and poultry products by August 2019.

Good news – but Foster highlights one possible downside. “One of the issues is if manufacturers want to recycle a mix of colours from factory waste. When firms do this they have skeletal wastes to which black pigment is often added – then it can be recycled back into black plastic. So in terms of unintended consequences, do we want factories to still reprocess and recycle their own scrap? Removing the darker colours from the waste stream would endanger that.”

One alternative, and Recoup’s second solution, is using a detectable black pigment that can be picked up by NIR sensors. This is what Unilever has put in place for HDPE (high density polyethylene) bottles for its brands TRESemmé and Lynx; The Collective Dairy has done the same for the black lids on its Gourmet Live yoghurt brand.

Edward Kosior has been involved in the TRESemmé initiative through his plastics recycling consultancy Nextek. “The solution that we’ve developed is to create a pigment that absorbs light in the visible spectrum to make it look black, but with no absorption in the NIR region so that it can be readily detected by automatic sorting machinery. All that is involved is to switch the pigment and the package switches to being recyclable from non-recyclable.

“This is the most likely long-term solution as it would involve no changes to the sorting infrastructure. In fact, it’s already being used in a growing number of consumer products such as food packaging, shampoo bottles and home care products. Its use is only going to grow.”

The third solution the Recoup report outlines involves developing an infrastructure of ‘collaborative waste management facilities’ to provide sorting ‘centres
 of excellence’ for coloured, clear and black plastic packaging. One such collaboration has already been launched between waste management company Viridor, the retailers Marks and Spencer, Tesco and Sainsbury’s and the food packaging firm Faerch Plast. Through this partnership, black plastic is taken from household mixed recycling and added to an already-recycled coloured stream; the mixture is then turned into multi colour ‘jazz’ flakes and pellets, which are sent to Faerch Plast to be reshaped and used for food packaging.

“We believe that ensuring that products are designed to be recycled and reprocessed into materials which can be reused in the manufacturing process is the key to creating a more circular UK economy,” explains Viridor’s Head of Recycling Polymers Jez Blake. “In terms of black plastic, we support the use of detectable black plastic but the markets for this material are not fully developed at this stage. This project has proved to be a commercial process which can be extended across the UK.”

There have been other initiatives as well. Faerch itself has announced intentions, within the next three years, to replace all undetectable black plastic CPET trays with a new range that includes an 80 per cent recycled content mixed colour PET. To add to this, Faerch has stated that for every quantity of trays purchased by retailers, it will source the equivalent volume of post-consumer waste to reprocess through its recycling company, 4PET, back into new trays of the same quality as those they manufacture.

Looming over all these developments is the spectre of a plastics tax. Last year the government announced
 it was aiming to introduce a tax on all plastic packaging that includes lower than 30 per cent recycled content by 2022. Of course, with the ongoing political turmoil it’s hard to see further than the next three months, never mind three years. But given the current media focus on plastic waste it would be a brave man that would bet against some sort of governmental move against the material at some point.

This article was taken from Issue 97

Kosior tentatively welcomes the idea. “A plastic tax might work if an exemption was applied to plastics that could be recycled and additionally contained a minimum of 30 per cent or more recycled content. This would drive demand for recycled plastics and create investment in innovative product solutions – including those around black plastics – as well as creating a market for recycled plastics.”

Whilst various solutions 
regarding black plastic are emerging
 just at the right time, Foster argues
 that more work needs to be done in
 creating end markets for the material. He 
highlights a number of issues to consider: “What 
does the legislation look like to make sure we do get the right quality and tonnages through to justify building the plants? How do we absolutely make sure that the end market does exist? For example, if you look at
 past history with closed loop plastics there have been casualties in the plastic reprocessing sector because their model was built on voluntary agreements – and actually it’s still voluntary agreements by and large. If I was going to invest I would want to know that I’m not just going to be outbid by the export market, which makes my recycling system unviable."

Positive moves have been made in the last year or so – Recoup estimates that ‘based on planned developments’ that figure of 36,000 tonnes will be down to 12,000 tonnes by the end of 2019. Certainly, for manufacturers, doing nothing is no longer an option. “It’s in the interests of people putting undetectable packaging into the market place to actually make that change sooner rather than later,” Foster concludes. “Because if they don’t voluntarily do it they might end up being stuck with a much harder policy and mandatory requirements further
 down the line.”