Smart tags and recyclability: Research summary from Smurfit Westrock | 08-10-2024 |

One of the key themes of this year’s AIPIA World Congress is Smart Packaging for Sustainability, and it is clearly one of the major development and innovation routes for Smart Packaging developers. So it is both encouraging and timely that one of our major packaging companies is taking the recycling issue for smart components to the next level with a research project on the issue. Read on! 

AIPIA member and major paper-based packaging supplier Smurfit Westrock worked with Western Michigan University (WMU) to conduct a recyclability study on corrugated boxes with smart labels used for asset tracking. The study evaluated a variety of labels including RFID and BLE (Bluetooth low-energy) technology laminated with both plastic and paper backings

Connectivity with devices, such as smartphones and logistics systems in warehouses and retail stores, is needed for asset tracking. To connect packages with those devices, the primary technology is smart labels, which use small antennas to emit radio waves. With the need for asset tracking and the increasing market shift to sensor-enabled packaging, brands concerned with the sustainability are asking questions about the impact of smart tags on the recyclability of their corrugated packaging within typical recycling systems.

The general results of the pilot work showed that the smart labels did not have a significant impact on the recyclability of corrugated boxes. Based on analysis and observations, re-pulpability and on-machine processing were not impacted by the tags in this study.

NCASI (National Council for Air and Stream Improvement) previously studied the recyclability of RFID tags at the request of the Fibre Box Association (FBA) in 2005. This study was also performed in the recycling pilot plant at WMU, and it included both laminated copper antennas and printed silver antennas. Laminated tags separated during the repulping process with little negative impact. NCASI further evaluated the concentrations of silver, the metal used to print the antenna of the tag, in environmental outputs and found that regulatory limits would not be exceeded. 

Although the industry has previously studied the impact on recycling boxes with RFID tags, there have been significant technological changes in the size and composition of smart labels since that time. This study builds on and evolves the previous work.

Using a pilot plant scale recycling and paper making lab, the study evaluated the impact on technical recycling of a standard-sized box tagged with a single smart label. There was no presumption that the tags themselves would be separated for recycling. The study was designed to cover a range of smart labels and was performed at WMU’s Paper Pilot Plant with analysis at Smurfit Westrock laboratories.

Smurfit Westrock designed the test using a variety of labels commonly used for asset-tracking worldwide, including RFID, BLE, active (battery-enabled) and passive. The four labels selected for this study were meant to represent the various smart labels commonly used in the USA marketplace, but should not be viewed as Smurfit Westrock recommendations.

WMU conducted the study over three days using untagged boxes as a control and the smart tags as the only variable. Each box was labelled with one of four different types of smart labels. The batch size was 135 boxes, with one smart label per box. For processing, the boxes were added to a pulper, which agitated the boxes with water to form a pulp slurry.

At the end of each pulper run, the operator safely entered the pulper and removed any labels that did not pass through extraction plates. The smart labels with plastic backings were separated from the fibre at this pulper extraction plate, while the re-pulpable labels passed completely through the extraction plates and were repulped along with the boxes.

The general results of the pilot work showed that the smart labels did not have a significant impact on the recyclability of corrugated boxes. Further studies, including real-condition environment tests, would be the next logical step to expand the scope and implications of this work, says the company.

AIPIA and AWA Smart Packaging World Congress Amsterdam