Siegwerk, one of the leading global providers of printing inks for packaging applications and labels, has developed a proprietary washable ink technology that enables deinking of UV/LED-printed PET shrink sleeves allowing for a recycling of the sleeve along with PET bottles.
The technology has been accredited as the first UV/LED solution of its kind by the Association of Plastic Recyclers (APR), the national trade association of the US plastics recycling industry, that meets its guidelines for the quality improvement of recycled PET bottles.
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 recognizes 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.