Ask any modern materials recovery facility (MRF) operator which material is the bane of their existence and film plastic will likely top their list. Film and automated equipment, such as star screens (found in single-stream MRFs) just don’t mix.
However, with over 40 per cent of the recycling tonnage in the Ontario being managed through single-stream systems, that limitation presents a serious issue. Moreover, the issues with this challenging material aren’t just limited to MRF equipment incompatibility. High labour costs, contamination and low density all make film unattractive to program operators.
However, the reality is that film isn’t going away. Film is, in fact, one of the most rapidly growing segments of the waste stream and already represents over six per cent of the residential printed paper and packaging stream (in Ontario and likely elsewhere) because of the many performance benefits it offers packagers. With harmonization of the blue box “basket of goods” currently top of mind for many stakeholders, film is an issue that needs to be addressed.
In response, the Canadian Plastics Industry Association (plastics.ca) led a partnership including the Continuous Improvement Fund (wdo.ca) and Stewardship Ontario (stewardshipontario.ca) to co-fund a study of residential flexible film management options and their costs. The partnership jointly retained a consulting consortium comprised of Reclay StewardEdge, Resource Recycling Systems and Moore Recycling Asso-ci-ates to complete the study, and invited PacNext to participate in an advisory capacity.
The study found there’s excess reprocessing capacity in North America to handle the volumes of clean commercial and mixed grade PE film currently generated. In marked contrast, however, the opposite was true for curbside-collected PE film and laminated materials. Excess curbside film recovery above North American market capacity is exported to Asia for recycling.
The study examined the feasibility of collecting mixed films by sorting them either at the MRF or at a film reclaimer.
While films such as PE and uncoated PP are marketable if sorted into separate streams, sorters must separate very large volumes of other films that currently lack stable, domestic markets, including metalized PP film (e.g., PP chip bags/candy wrappers).
The study found that the cost of manual separation in MRFs at North American labour rates was prohibitive and no commercial ready MRF sortation technology was identified. Sending mixed film to reclaimers for separation was also not believed to be economically feasible; experience from Europe indicates that PE yields of at least 65 percent or more are needed to be economically feasible. Yields of this level were not considered achievable in Ontario unless the film was initially sorted at the MRFs, followed by further sorting at reclaimer due to current technological limitations.
Even curbside programs targeting PE only, face market capacity issues. Extensive promotion and education can achieve high capture levels but the complexity of film packaging makes it nearly impossible to educate residents to separate out PE for recycling in curbside programs. As a result, curbside PE tends to be heavily contaminated (i.e., over 30 per cent contamination) with paper, organics, multi-laminates and other non-PE films. While producers of low-grade products can make use of this material, the ready availability of clean commercial film makes it relatively unattractive to most re-processors and it’s discounted appropriately (i.e, $440-$529/tonne for clean commercial film vs $25-66/tonne for curbside film).
Long term market stability is, therefore, likely to be found in the development of additional domestic wash line capacity and automated sortation systems such as Ontario-based EFS Plastics which is currently in the process of expanding its operation. (This next phase of its growth plan will allow the company to process 7,500 tonnes of film, which is sufficient to service the entire Ontario residential PE film market. Industry organizations such as Stewardship Ontario are also actively working to identify and develop new processors.)
The study concludes that PE films should be collected separately from other types of films to maximize revenues and ensure market-ability.
Return centre PE based collection proved to be the most cost effective option, although with lower recovery expectations. Return centre costs in a commercial setting, with free backhaul of loose film available, were estimated to be as low as $75/tonne net of revenues. Return centre net costs that do not have free back-haul (requiring baling before transport) were estimated to be approximately $225/tonne for a PE only program.
Alternatively, recovering the same stream of PE film through the average Ontario curbside program was estimated to have a net cost of approximately $360 per tonne.
Incremental processing cost estimates ranged from a low of about $200/tonne in a two-stream MRF to approximately $500/tonne in a single-stream MRF, assuming the vast majority of the material is collected “bag in a bag” when received by the MRF.
Costs to process film were found to be particularly sensitive to the extent to which the material is received loose, escalating to over $1800/tonne if the material is primarily loose (since there’s a direct correlation to the associated pick labour and recovery rate). Resident education and avoidance of equipment that ruptures bags is, therefore, key to avoiding unnecessary processing costs. (This latter situation can be particularly challenging in high-speed single-stream operations.)
Perhaps most surprising is the recovery rate potential of municipal depot vs curbside programs. Intuitively one would conclude that the lack of convenience associated with depot-based systems would severely hamper capture rates. Yet a snapshot of Ontario programs reporting through the 2011 Waste Diversion Ontario datacall suggests depots represent a unique opportunity to potentially capture more materials from residents and local businesses alike.
Whether the combination of burden depth, high belt speeds and automated equipment will ultimately prevent the effective capture of film in larger two-stream and single-stream operations is unclear at this time. This study does, however, provide ample food for thought for municipalities considering the addition of film to their programs.
Mike Birett is Director of the Continuous Improvement Fund in Barrie, Ontario. Contact Mike at email@example.com
Flexible film is particularly challenging because the spectrum of packaging involved is extremely complex and diverse. It encompasses simple monolayer low and high density polyethylenes (PE) such as grocery sacks, bread bags, and vegetable bags through to multi-laminate stand up pouches. Not surprisingly, the study found that the growth of multi-laminate packaging continues to expand at rates ranging from five per cent to 15 per cent depending on the application and market. Multi-laminates such as stand up pouches and films for meats, poultry and fish can consist of a variety of metalized PP, PEs, oxygen and moisture barriers such as ethylene vinyl alcohol (EVA) or polyvinylidene chloride coated nylons, and sealing mediums. Add to that the usual mix of fillers, surface modifiers and stabilizers and one begins to understand the challenges facing re-processors seeking to recycle this material.