“With our Aquantum Alkali Strippable Primer and Sicura UV/LED inks, we developed a solution especially allowing safe and efficient de-inking of crystallisable PET shrink films printed with UV/LED inks following the APR’s deinking and recycling criteria,” said Fabian Köhn, global product manager, narrow web at Siegwerk. “The de-inking of UV/ LED-printed sleeves represents a special challenge for recycling. As standard UV inks form a solid, chemically, and mechanically resistant layer they are not easily and, in most cases, not completely removable from the substrate and therefore minimize the quality of the recycled material.”
Siegwerk’s primer technology works with Sicura UV/LED flexo ink series and offers good block resistance, as well as grease, oil, and heat resistance. It enables recycling of PET sleeves along with the PET bottles without the need of separating bottles and sleeves before. The sleeved bottles are grinded resulting in a mixture of PET bottle material and printed PET shrink sleeve material which is washed in a hot caustic (alkali) washing step. Here, the primer dissolves, the ink washes off and leaves the clear substrate but does not contaminate the wash water nor the PET film meeting requirements of APR testing protocol.
The APR recognition is based on the technical recyclability of Siegwerk’s ink innovation for PET bottle labels. It only recognises the submitted sleeve structure as meeting the most challenging test conditions and strictest guidance criteria and not necessarily the bottles using the sleeves as those bottles would need to be tested to demonstrate their own conformity with the so-called critical guidance protocol for clear PET articles with labels and closures. This protocol is a result of a multi-industry consensus of key issues related to the recycling of postconsumer PET bottles intended to sustainably improve the quality of recycled bottles.
“Meeting APR’s critical guidelines is a truly significant step in demonstrating the overall recyclability of the submitted sleeved product, a crystalised PET shrink sleeve printed with our washable ink technology consisting of Sicura UV/LED flexo ink and Aquantum Alkali Strippable Primer,” added Alina Marm, head of Circular Economy Hub at Siegwerk. “It is a good example for our ‘design for recycling’ approach under which we develop innovative ink technologies to facilitate high-quality recycling, for example, by allowing easy de-inking while keeping full performance during the use phase.”
Siegwerk is constantly working on new sustainable ink technologies and functional formulations to improve packaging recyclability and enable new circular packaging applications.