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.