Testing: Introduction

Testing: a foundation of the updated D4ACE Guidelines

During development of the initial Designing for a Circular Economy (D4ACE) guidelines, a number of knowledge gaps were identified that needed to be filled and supported by robust test data.

The subsequent ‘Phase 2’ sortability and mechanical recyclability testing programme instigated more than two years of continuous collaboration, involving 150 subject matter experts, 15 dedicated material sub-groups and a panel of key advisors.

Testing was conducted across five leading laboratories in Europe under the guidance of three leading universities: Maastricht, Ghent and Queen’s Belfast.

The objective: clear and practical design advice, anchored in robust data on how different materials and packaging structures behave in real recycling conditions.

Phase 2 testing programme

Delivered between 2022 and 2024, this was the most extensive mechanical recyclability and sortability testing programme ever conducted for flexible packaging. With the support of dozens of CEFLEX stakeholders, testing processed more than 600 samples, generating over 1,700 data points across 55 materials and components.

This work filled critical knowledge gaps identified in Phase 1 of the guidelines and provided the foundation for the updated 2025 D4ACE Guidelines. The testing programme covered:

  • Sortability: How flexible packaging performs in near-infrared (NIR) sorting, eddy current separation, metal detection, and size/shape-based sorting.
  • Mechanical recyclability: How different materials and structures behave in recycling processes, and their impact on recyclate quality, yields and processing efficiency.
  • Material-specific insights: Detailed results for adhesives, inks, barriers, metallisation, PET, PVDC, PA, EVOH and more.

In addition to the invaluable support of CEFLEX stakeholders, a major collaboration with UK Research and Innovation enabled a more comprehensive testing programme and addressed essential gaps in knowledge.

UK Research & Innovation
A system performing evaluations of NIR (Near Infra Red) recordings
A system performing evaluations of NIR (Near Infra Red) recordings
CEFLEX Sorting Testing in action
CEFLEX Sorting Testing in action

From testing to guidance

The results were peer-reviewed by leading academics and discussed in over 200 stakeholder sessions to ensure clarity, consensus and transparency. The outcomes now underpin updated thresholds and design recommendations across the guidelines. Examples include:

  • Refined compatibility levels for adhesives, inks and coatings
  • Clearer sortability rules for metallised layers based on ink coverage
  • Defined thresholds for EVOH and PA layers when combined with tie layers
  • Testing evidence confirming PET and PVDC as incompatible with polyolefin-based mechanical recycling

Not perfection – progress

The testing programme has made a major step forward, but it is not the end of the journey. As new materials, technologies and recycling processes emerge, further testing will continue. The D4ACE Guidelines are updated regularly to reflect this – helping the value chain stay ready for what comes next.