Cleaning and Recycling of Residual Mixed Plastic Film

Large quantities of plastics film are still going to landfill which is a waste of resource. This project was set to determine if this film could be economically washed and recycled back in to useful products.

In most recovery operations, multi polymer stream films are discarded as they have low value, or treated as a contaminant (for example where paper is the main product being recycled). This situation is even more common where the films are heavily contaminated, as in residues produced from municipal solid waste (MSW).

The project therefore looked at film residue material procured from 3 different sources:

  • Residual films from the Commercial & Industrial (C&I) stream collected via waste transfer station;
  • Residual post consumer films from a Materials Recycling Facility (MRF) processing dry recyclables; and
  • Residual post consumer films from a MRF handling black bag waste.

In all instances, the format and general polymer composition of the film was photographed and analysed. As an average, the project found that 63% of all films examined were polyethelyne (PE) or polypropylene (PP) based and would be suitable for reprocessing if cleaned of contamination. All of the films identified were available at negative (gate fee based) or negligible (transport only) cost. All of the source materials at the time of the project were destined for landfill if moved within the UK.

The project successfully identified and demonstrated all of the critical elements needed to construct a complete process which included size reduction, cleaning and extrusion techniques capable of utilising film from all three sources. The project subsequently succeeded in producing a commercially acceptable pelletised product with a sales value of £400 to £500 per tonne. The extruded pellet was then successfully evaluated as an input to 3 mm thick moulded products used in the UK at a ratio of 100%. The end use rate would depend on the specific application given the flow behaviour and properties of the recovered material.