Many paper cups are coated with a thin layer of plastic to prevent the liquid content to spill out. However, while convenient when the cup is used, these plastic layers are a disaster for recycling companies, as this means the cups cannot easily recycled. Finnish paper and wood products company Koktamills developed a new type of coating for paper disposable food service boards for their ISLA series that is completely recyclable and repulpable.

The new coating is water-based, without using plastics or harmful fluorochemicals. Fluorochemicals are still widely used in fast food packaging, even though studies have shown them to be unhealthy and may cause cancers. The chemicals in the coating change the properties of paperboard so that it becomes naturally resistant to grease and liquids, and is suitable for both hot and cold beverages. The coating can be applied using existing cup- and plate making machinery.

The end product, called ISLA, is completely recyclable after the ink has been removed during the pulping process, without the need for a special recycling route. It can be recycled along other, normal paper waste, rather than being burned as is common with plastic-coated paper cups. The quality is high enough that the recycled pulp can be turned into copy-grade paper, as the paperboard contains a large amount of short fibres.

When tested, cups lined with the new coating were found to be able to hold hot and soft drinks for more than 2 days. The cups could even hold alcoholic beverages for a few hours, similar to 39 per cent of other disposable paper cups on the market.

Photos: Koktamills