WRAP has launched a pair of good practice guides aimed at maximising Near InfraRed (NIR) sorting rates for plastic packaging waste.
The sorting technology measures the intensity of NIR light reflected and absorbed by different types of polymer, and compares these against known ‘polymer signals’ in order to identify the types of resin used in each piece of material.
Both guides state that by spending time and effort to optimise NIR sorting operations, purity can be improved by up to around 95%. However, if purer fractions are required, post NIR hand sorting should still be considered and can be recommended as good practice.
The two guides provide information for prospective and current users of NIR technology in MRFs and plastic recycling facilities, as well as best practice advice for maximising purity once the technology is in place.
The guides help on all aspects of NIR sorting, from guidance on the composition of appropriate feed materials before installation begins, the implementation of reliable quality control procedures and maintenance.
Plastics Federation Recycling Council (BPFRC) chairman Mark Burstall said: “The BPFRC strongly recommends that potential plastics recyclers and processors take the time to read, understand and adopt the guidance listed within this document.
“Designing a new plant is a perfect opportunity to ensure good practice is implemented from the beginning. The guide contains helpful advice including the necessary up-stream pre-treatments, ensuring the feed composition is clearly defined and the product specifications are achievable with the designed plant and feed material.”
Both guides are endorsed by the BPRFRC.