Innovate UK funds research project to “drastically increase” rPET content
22 Feb 2022 --- Scientists from Heriot-Watt University, UK, have received funding from government agency Innovate UK to develop additives and processing methods that will “drastically increase” the recycled content of PET beverage bottles.
The scientists say the outcome will help manufacturers meet the UK and EU requirements that all new PET bottles contain a minimum of 30% recycled PET from 2030.
The team will work with Glasgow-based business EnviroPET and scientists from the University of Strathclyde on the two-year project, which is supported by Interface Scotland.
Douglas Craig, managing director of EnviroPET says: “Our technology will help manufacturers comply with recycling targets and legislation and improve their bottle quality and environmental performance.”
The scientists will be testing how the additive improves the performance of rPET blends in several critical properties that directly affect the PET bottle behavior.Recycled PET content bottle challenges
The researchers explain plastic drink bottles made from PET are difficult to manufacture with recycled PET (rPET) content due to the high degree of variation in the recycled plastic feedstock.
The researchers say this [high degree of recycled plastic variation] makes it difficult to maintain the necessary uniformity in mechanical and optical properties required, leading to potential issues with bottle failures, carbonated fluids going flat and color or clarity variations of the final plastic bottles.
EnviroPET is developing the use of liquid additives, PET-Yield, that can be added during the PET bottle manufacturing process to significantly increase the amount of (rPET) material in new bottles, without the loss of properties compared to virgin PET bottles.
“It could potentially save firms millions by reducing the amount of raw material needed for new bottles, as well as the energy resource required for their manufacture,” says Craig.
“All of the major PET bottle manufacturers have outlets in the UK, which means we have a gateway to a global market,” he adds.
Testing before commercialization
Professor David Bucknall will lead the Heriot-Watt team to understand how the PET-Yield additives affect PET bottles containing recycled material under laboratory conditions before it is put to the test in a production line.
The scientists highlight there are over 800 PET manufacturing plants worldwide.“We want to solve the problems faced by using more rPET content in plastic bottles, which currently results in significantly poorer-quality bottles in terms of their mechanical properties and appearance,” Bucknall says.
The scientists will be testing how the additive improves the performance of rPET blends in several critical properties that directly affect the PET bottle behavior. They will measure gas permeability through the plastic, which has a direct impact on the product shelf-life.
“To have a long shelf-life the plastic must prevent oxygen permeating into the bottle and affecting its content, but also stop CO2 escaping so that carbonated drinks don’t go ‘flat’,” explains Bucknall.
“Our colleagues at the University of Strathclyde will integrate artificial intelligence and deep learning to ensure that the appropriate amount of additives will be included during melt processing of the PET mixtures,” he adds.
“This will help manufacturers to use this system so that the correct blend ratios and processing conditions are automatically maintained to produce consistently predictable products.”
The scientists highlight there are over 800 PET manufacturing plants worldwide, including 140 in the UK and the EU. At the moment, over 580 billion new PET bottles are produced each year, most of which contain little or no post-consumer recycled material.
Last week, Berry M&H launched a 250 ml bottle for syrups that can be produced with up to 100% food-grade recycled PET. According to Berry, the new bottles provide a convenient retail size for a wide variety of syrups, fruit mixes, sauces, frappes, liqueurs, and smoothies and offer easy storage at home.
Edited
By Natalie Schwertheim
