More and more printed PET bottles are making their way into the recycling stream, and innovation by KHS and NMP Systems is helping to make this possible.
The first digital Direct Print Powered by KHS printing process for PET bottles has again been certified by the European PET Bottle Platform (EPBP).
This is the second sustainable and environmentally friendly innovation from KHS and NMP Systems to be approved by the initiative within a short time.
The recyclability of the direct printing process was first certified by the EPBP in 2013 and has now been reconfirmed. This means an independent organisation 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.
Cleaning up the process
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,” Martin Schach, head of the printing technology department at KHS GmbH, said.
“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.
Goodbye to high production costs
Current lab tests for the Belgian market, where recycled PET bottles were examined for chemical residues in random checks, confirm the safety 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.
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 individualised through the use of different motifs.
An additionally developed printed image inspection system is also to ensure the standard of quality at a higher level of industrial performance.
Other advantages including falling production costs in the long-term, as there’s no longer any need for labels or adhesive.
Besides Direct Print Powered by KHS, Nature MultiPack by KHS and NMP Systems was also recently granted interim approval.
In this form of packaging, PET bottles no longer require a secondary packing of film as they are joined and held together by dots of adhesive only. This specially developed adhesive has also been certified.
The EPBP is a voluntary, industry-related initiative which provides PET bottle design guidelines for recycling, among other information.