Until fairly recently it was impossible to imagine that printed bottles could find their way into the recycling process. However, the research carried out by KHS and its partners on development in this field has since paid off: Direct Print Powered by KHS has again been granted interim certification from an official body. The recyclability of the award-winning direct printing process was first certified by the EPBP in 2013 and has now been reconfirmed. This means that an independent organization has clearly attested that PET bottles processed by Direct Print Powered by KHS have no negative impact on the rPET and are thus officially approved for bottle-to-bottle PET recycling.
During development the experts had to overcome one specific challenge before the printed containers could be certified for the recycling process. “The washing water must not be contaminated during the recycling process,” explains Martin Schach, head of the Printing Technology Department at KHS GmbH. “The ink must also not deposit itself on the crushed PET bottles.” KHS has managed to develop a digital printing process with low-migration, LED UV-curing inks for the food-safe decoration of PET bottles where the print reliably flakes off during the recycling process.
More quality, greater performanceCurrent laboratory tests for the Belgian market, where recycled PET bottles were examined for chemical residues in random checks, confirm the safeness of the process. Here, printed PET bottles from Martens Brouwerij had been fed into the recycling chain. In 2015 the Belgian brewery was the first beverage producer to launch PET bottles with Direct Print Powered by KHS to market and make use of the technology which has since been constantly further developed for the customer. These further developments include a higher print quality and new forms of decoration, resulting in a level of flexibility which enables the print on each separate bottle to be individualized through the use of different motifs.
An additionally developed printed image inspection system is also to ensure the standard of quality at an even higher level of industrial performance.