Polymer and recycling expert Nextek has developed an effective process to recycle polypropylene (PP) waste into recycled polypropylene (rPP) which is suitable for food-grade packaging. 

The recycling of mixed rigid post-consumer PP waste to food-grade quality is tougher in comparison to that of post-consumer HDPE or PET. The challenge lies in the successful decontamination of post-consumer PP to meet food-grade standards and regulations set by the EU. 

The technology has been developed by Nextek under commission by WRAP to work with retailers, brand owners, the UK packaging supply chain, and the recycling industry to obtain food-grade rPP. 

The Nextek's process for decontamination of post-consumer PP is completed in two steps:

• The waste is put through a high-level melt phase (500 F) in an extruder. A specially designed vacuum section is present for the removal of volatile contaminants. 
• Following this, the waste is put through a heated (280 F) high vacuum degassing reactor. 

The resultant rPP is successfully decontaminated, deodorized and suitable for food-grade use. It can be blended with virgin PP in combinations up to 50%. 

The success of the project enables the incorporation of PP post-consumer waste into existing recycling streams. Along with the recycling of HDPE and PET packaging, this promotes a closed-loop system for food packaging. The process has multiple direct benefits like lower carbon footprint, resource efficiency, and diversion of post-consumer waste from landfills. 

Nextek aims to develop an automated sorting process to distinguish food grade PP from previously non-food grade PP in recycling streams and is running large scale trials of food-grade rPP with a number of manufacturers to produce thermoformed pots, tubs, and trays. 

The company is in the process of implementing its process at recycling facilities in Europe.