In the UK, a conservative estimate indicates that 25,000 tonnes per year of waste black plastic, such as microwaveable meal containers, is disposed into landfill, even if the public sorts black plastic waste into the correct recycling option. The technique for sorting plastic materials by type uses optical (infrared) radiation. This is shone onto the plastic items as they pass along a conveyor belt. The reflected radiation is analysed and from this the particular plastic composition can be determined and the item appropriately sorted. Unfortunately, black plastic cannot be sorted this way because carbon black colourant (which is especially widely used in the food packaging industry in order to maximise the visual appeal of the foodstuff) absorbs infrared radiation and doesn’t reflect a signal, thereby blocking the identification of the plastic.
Colour Tone Masterbatch Limited, a Welsh company specialising in the manufacture and supply of high-quality colourants for plastics, formulated a new black colourant that both achieves a high-quality black appearance in a target plastic and is capable of being sorted using infrared technology. The process of devising a new colourant formulation to achieve the desired black appearance in a target plastic is a complex task. It’s also complicated to protect such a formulation with the maximum scope of patent protection while avoiding known technology.
Our close working relationship with Colour Tone Masterbatch ensured that we truly worked together to achieve valuable patent rights for the devised formulation across key worldwide markets. The patent-protected colourant is predicted to massively reduce the huge quantity of black plastic waste ending up in landfill — waste that the public currently thinks it’s sending for recycling each week…