Food grade recycled Polypropylene (PP) in packaging
WRAP is working in partnership with industry to develop a viable process to recycle post- consumer Polypropylene (PP) packaging waste into recycled PP (rPP) suitable for use in the manufacture of new food packaging. This page and the accompanying reports provide an update on the progress made so far and the remaining challenges to overcome.
Polypropylene (PP) is used in a wide range of food and non-food packaging such as pots, tubs and trays and retailers and brand owners want to be able to use recycled PP (rPP) in new PP food packaging in order to realise the environmental benefits of using r PP, in the same way that they can with rHDPE and rPET.
There have been technical barriers to achieving a food approved rPP material, as well as perceived risks and lack of evidence around the economic and technical viability of recycling PP to food grade quality in the UK.
WRAP is working in partnership with industry to address these barriers and has completed three phases of work so far.
Phase 1 – scoping study
WRAP tested whether a recycling process already used to produce food grade HDPE in the UK could be adapted to recycle PP to meet food grade approval.
The key findings were:
An automated process needs to be developed to sort food contact from non-food contact as hand sorting of food contact is not cost effective
The food grade recycled PP can be both thermoformed and injection moulded and therefore is suitable for use in the common PP conversion processes
Work has proven that better label and ink removal is required in order to develop a successful food grade recycling process
It has been possible to clean the PP in certain applications but an improved cleaning of heavier contaminants is required
To request a copy of the appendices, please email us indicating which appendices you would like.
Phase 2 – development of a food grade recycling process for post-consumer PP
The aim of this phase of work was to develop a food grade recycling process that could decontaminate post-consumer PP packaging waste to the standards required by EU regulations for food contact and cope with the wider range of materials encountered in the post-consumer PP packaging stream.
A range of high performance processing and decontamination techniques were evaluated and a process consisting of two technologies combined was found to produce material that could be suitable for use in a wide range of food packaging applications.
Phase 3 – further development and testing of the recycling process
The work we carried out in phase three had three strands.
A)Polypropylene Packaging market data.
WRAP carried out an assessment of the UK market for PP packaging and estimated the amount of PP packaging waste that could be available for a food grade PP recycling process in the UK. The report provides a breakdown of the PP packaging market by type and discusses key aspects of PP packaging and their impact on food grade recyclability.
B)Decontamination of UK PP packaging waste.
WRAP carried out decontamination trials on the process identified in phase 2, using real PP packaging waste from UK households. Sample packaging was manufactured using rPP from this process and food grade testing was carried out. This work indicated that rPP could be used in a range of food packaging.
C) Sorting plastic that has previously been used with food.
In order for food grade rPP to be produced in the UK a technically and commercially viable automated solution is required to sort packaging that has been used with food from that which has not, because food grade recycled plastics must be made from >99% food contact raw material. This project determined that a marking and detection technique could be developed to identify food contact plastic packaging in recycling plants.
This work included an investigation into whether the use of lasers to identify diffraction gratings in packaging could potentially be used to sort packaging that has been used for food. This technique is also discussed in a 'diffraction grating - proof of concept report'.
WRAP is carrying our further research and development work to enable food grade rPP to be used in new packaging. This includes developing the most promising sorting techniques identified in phase 3 and carrying out additional testing of decontaminated rPP to further assess its suitability to produce a food grade material.