As the UK edges closer to mandatory kerbside collections of flexible plastic packaging by April 2027, the recently published FlexCollect project has delivered timely insights for local authorities preparing for this major shift.
What the Data Says
Across all demographics and collection service types, the most effective method of gathering flexible plastics was the use of dedicated collection bags. Whether used in source-segregated, twin-stream, or co-mingled collections, the presence of a supplied bag consistently increased the quantity and quality of materials collected. Source segregated services achieved the highest average weight of flexible plastic collected per household per week, at 78g. Weekly collections, across all service types, performed even better at 86g, nearly double the average for fortnightly collections, which was just 46g.
This wasn’t just about volume. Composition audits revealed that 82% of the material collected was the target material with the composition being largely presented clean, dry, and free of food residues. Bags helped isolate the flexible plastics from other waste, simplifying sorting and improving MRF compatibility. The consistent use of a 40-micron bag proved optimal for most operations, balancing durability with cost-effectiveness.
Participation Hinges on Supply
One of the most decisive findings from FlexCollect was the importance of supplying the bags directly. Authorities that relied on households to source their own liners saw significantly lower participation and higher contamination. Incorrect bags such as black sacks and untied bundles led to mess, confusion, and material losses.
The solution? Provide a dedicated bag and communicate clearly. Many authorities in the trials used printed, coloured bags (blue or purple) to reinforce purpose, build resident confidence and be clearly identifiable.
Planning Ahead
For councils beginning their flexible plastic journey, the blueprint could include the following:
- Supply durable and identifiable collection bags.
- Avoid assumptions about resident participation with self-supplied bags.
- Coordinate with MRFs early to ensure bag handling is integrated into sorting lines.
- Invest in clear, proactive communications alongside the bag rollout.
Cromwell Polythene are proud to support local authorities as they rise to meet the flexible collection challenge. Their range of printed polythene bags, sacks, and liners and are developed for exactly this purpose, helping to ensure clean capture, secure containment and confident participation; all with minimal disruption and maximum impact.
Cromwell - UK's Leading Suppliers of Waste Sacks & Packaging
