Colloids Address Black Plastics in the Waste Stream - Colloids
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Colloids Address Black Plastics in the Waste Stream

By December 13, 2019 No Comments
black plastic recycling

Brands are realising that consumers are demanding that they take responsibility for the environmental impact of the packaging they use and one of their subsequent reactions is to turn away from black plastic packaging.

Plastic packaging generally has brought important innovations in keeping food fresh and reducing wastage

It is lightweight, strong and makes a positive contribution to reducing fuel use and emissions by being easier to transport than alternatives.

If food wastage were a country, it would be the third largest greenhouse gas emitting in the world. Food waste in developing countries where packaging is not used effectively can be extremely high, with food loss at production and transport accounting for two thirds of global food waste. Source: The British Plastics Federation.

Historically, black packaging has been considered to indicate quality. Products packaged in black give an aura of premium quality. It has also been popular with brands seeking an aesthetic contrast to fresh foods such as tomatoes, green vegetables, salads and in some instances fresh meat and fish. Black plastic trays have also been favoured for convenience foods. The feeling has been that displayed in this way, the product becomes more attractive to the consumer. This is why black plastic food trays have been so widely used by suppliers to supermarkets and stores.

But black plastic has not just been used in packaging. Due to its low cost, dense colouring and masking properties which allows off cuts of other colours to be mixed together and manufactured into black items, it has also been useful for horticultural products such as flower pots and seed trays which are produced in great volumes.

However, media coverage has made it widely recognised that black plastic packaging is not recyclable. But, this is not the whole story. In fact, black plastics that use the black pigment Carbon Black as a source of their colour are not recycled because the automatic detection systems utilised by the Materials Recycling Facilities are unable to distinguish the types of polymer from which they are made. They are seen as contaminates and generally end up being sent to landfill or for incineration. Estimates suggest that one million tonnes of black plastic is sent to landfill every year.

In order for recycling to operate in an efficient and effective way automation is employed as much as possible. The most widely used technology for the sorting of different types of plastics, used by MRF’s (Material Recovery Facilities) and PRF’s (Plastics Recovery Facilities) is near infrared (NIR) spectroscopy, which provides detection of the different plastics types. NIR sensors are capable of accurately classifying waste made from different plastics such as PET, PP and PS. Materials on a conveyor are fed beneath an infrared beam which identifies the plastic type by its near infrared signature. Once identified compressed air nozzles are triggered, which separate the materials programmed into the machine.

This categorisation of plastics is essential to ensure that the resulting recycled material is commercially viable for processors to use. However, a large amount of these potentially recyclable objects cannot be classified by the NIR systems. The reason being that they contain the colour pigment carbon black that is an excellent infra-red absorber and therefore these items pass undetected by the sorting systems. This is because the infra-red beam does not bounce back to give an identification. So these potentially recyclable waste products are overlooked and end up in landfill.

The use of NIR Detectable masterbatch (black colour pigment) in products not only means that the waste products could be recycled using existing systems. It opens up the possibility to utilise the correctly identified reclaimed material in coloured Jazz streams without causing contamination.

It is clear that a fully identifiable and recyclable alternative to allow black plastics to be used would be highly beneficial for brands and recyclers alike.

The UK Plastics Pact is a collaborative initiative, from WRAP, aimed to create a circular economy for plastics. Members of the Pact using black plastic are requested to use detectable black pigments by the end of 2019 enabling waste management companies to be able sort it for recycling. It has already been announced that consumer goods brand Unilever will be using a detectable black pigment in their HDPE (high density polyethylene) bottles used by two of their brands. Major UK retailers Tesco, Marks and Spencer and Sainsbury’s are collaborating with leading UK waste re-processor Viridor and Faerch UK Ltd, a packaging specialist to provide a circular economy solution for black plastic. Source: WRAP

Addressing the recyclability of black plastic packaging, Colloids expert team have developed two innovative NIR-Detectable black masterbatch pigments suitable for black PET food trays and for black PP or PE food trays. These black pigments are totally identifiable by the NIR classification systems and meet the EC AP (89)1 European Resolution on the use of colourants in plastic materials coming into contact with food. Colloids NIR PP or PE grade has the additional benefit that it is also FDA approved. They are formulated for use with conventional lines and processes for plastic product production.

Our development team are happy to collaborate on individual requirements to meet your Circular Economy goals. You can learn more about Colloids NIR solutions here: https://colloids.com/black-plastic-packaging-recycling-nir