Direct-printed PET bottles certified rPET recyclable

The global digital printing market for packaging is anticipated to expand at a steady rate, reaching yearly growth close to 11% for 2017-2021, according to research firm Technavio (London).

We’re seeing it used for applications that are largely if not essentially wholly devoted to printing onto flexible material substrates such as labels and rigid to semi-rigid surfaces including for corrugated cases and also paperboard folding cartons.KHS-Bottles with Direct Print

There’s also been a unique method of direct digital print onto rigid containers, the Direct Print Powered by KHS digital printing process, specifically for PET bottles. I’ve covered the no-label process as an editor on sister publication Packaging Digest as a breakthrough, efficient and source-reducing technology for bottling operations. It’s important to point out that labels, particularly shrink film labels, may be problematic for recycling in addition to the source reduction gains of their elimination.

It turns out there’s an angle of interest for PlasticsToday readers, too: the recyclability of these digitally-printed bottles, which was first certified by the European PET Bottle Platform (EPBP) in 2013, has now been reconfirmed in the interim as having no negative impact on rPET, making it officially approved for bottle-to-bottle PET recycling.

Explore packaging, plastics and more in Minneapolis November 8-9 during the 15th anniversary of MinnPack that’s co-located with 5 other exhibitions including PLASTEC. For more information, visit the MinnPack website.

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 (Dortmund, Germany). “The ink must also not deposit itself on the crushed PET bottles.”

KHS developed 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.

Current laboratory tests for the Belgium market, where recycled PET bottles were examined for chemical residues in random checks, confirm the safeness of the process in which printed PET bottles from customer Martens Brouwerij brewery had been fed into the recycling chain. In 2015 the Belgium 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 subsequently been further developed for the customer. These further developments include a higher print quality and new forms of decoration, resulting in a level of flexibility that enables individualized print on separate bottles such as the use of different motifs. 

It seems this proprietary digital printing technique is a win for bottlers, and now for recyclers and ultimately for the environment.

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