PLASTIC PACKAGING RECYCLING USING INTELLIGENT SEPARATION TECHNOLOGIES FOR MATERIALS (PRISM) Edward Kosior 1 , Dr Jon Mitchell 1 , Kelvin Davies 1 , Dr Martin Kay 1 , Dr Rafi Ahmad 1 , Edwin Billiet 1 and Prof. Jack Silver, Nextek Ltd 1 and Brunel University 2 Abstract A new way of rapidly sorting packaging into high purity streams (> 99%) has been developed based on intelligent labels with invisible markers that can be detected and sorted using existing high-speed optical sorting systems used in MRFs with minor modifications. The principles have been proven using a range of commercially available UV responsive fluorescent markers with high emission yields. A full-scale commercial optical sorting trial was conducted at the MRF facilities of Tomra in Germany. Sorting of used plastic packaging for closed loop recycling back into food packaging requires positive identification and sorting of the recycled materials to a higher standard. The operators of commercial food grade recycling processes are required to demonstrate the recycled materials meet relevant European Food Safety Authority (EFSA) criteria; these require at least 95% (PET) and 99% (HDPE) of the feed material must have been used for food contact in their first life. The initiation of closed loop food grade recycling of PP packaging is awaiting a viable technical solution to differentiate the food grade packaging. From previous sorting trials, it can be estimated that of the 143,000 tons of PP food packaging used annually [1], 77,077 tons could be recovered each year in the UK. The objective of this project was to further develop the fluorescent marker technology investigated in earlier projects that has the potential to meet EFSA requirements and to extend the scope to different applications, enabling and facilitating the sorting of different polymers to a high degree of purity. The scope of the project included the optimisation of fluorescent compounds, evaluation of their stability in the supply chain and the ability of the compounds to be effectively removed during the cleaning and decontamination process. The project investigated the viability of the technology and its capacity to be implemented in the UK and elsewhere. Unlike existing NIR sorting systems [2], this technology uses commercial labeling and decoration methods to sort targeted streams potentially including food-contact plastics, bioplastics, chemical packaging, automotive plastics, black plastics and different grades of one plastic. This technique has the potential to create new recycling loops for food grade PP, milk bottle sorting and PET products. The project demonstrated that the use of commercial labels incorporating fluorescent markers can be used to sort plastic bottles and packaging with high yields and purity. Introduction A major challenge in producing recycled plastics from post consumer recycling feedstock is to sort the material into high purity mono-material streams since small quantities, often as little as 0.1%, of a non-compatible plastic can significantly reduce the quality of the final product. In order to keep costs low while processing high volumes, sorting is typically realized with automatic sorting machines using Near Infrared (NIR) detection. The stimulus for this investigation was the need to have an automated method for sorting mixed PP packaging waste into a separate a stream that consists of at least 99% PP previously used for food applications [3,4], from other non- food PP packaging that could be present at levels as high as 50% in the input stream. A previous project [5] evaluated techniques such as polymer additives, surface markings such as diffraction gratings and fluorescent markers. The use of fluorescent markers compounded into plastics was pioneered by Ahmad et al [6,7]. They investigated the feasibility of using single and multiple combinations of fluorescent dyes in a range of polymer materials to identify and sort the packaging at commercial rates. More recently Langhals [8] reported the possibility of identifying polymers based on their auto fluorescence and doping with fluorescent dyes. The article highlighted the possible use of fluorescent dyes to identify special batches of a basic polymeric type. This project investigated the use of machine readable fluorescent markers that can be applied to the surface of packaging or packaging labels so that existing NIR sorting equipment can be utilized with no or minimal modification. The machine readable markers needed to be invisible to the naked eye under normal lighting so not to affect branding and aesthetics, but be detectable at with existing MRF infrastructure at commercial sorting speeds and sorted at high efficiencies. To achieve this, markers were applied as a surface varnish on an existing package or label to provide an adequate means of identification and separation. The labels and markers can then be removed during the normal recycling processes so that the materials can be free of any markers prior to being used in any new applications to prevent false sorting responses in the next cycle of application. PRISM Project PRISM is a new way of rapidly sorting packaging based on intelligent labels with invisible markers that can be detected SPE ANTEC ® Anaheim 2017 / 500
7
Embed
Plastic Packaging Recycling Using Intelligent Separation ...€¦ · PLASTIC PACKAGING RECYCLING USING INTELLIGENT SEPARATION TECHNOLOGIES FOR MATERIALS (PRISM) Edward Kosior 1, Dr
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
PLASTIC PACKAGING RECYCLING USING INTELLIGENT SEPARATION
TECHNOLOGIES FOR MATERIALS (PRISM)
Edward Kosior1, Dr Jon Mitchell1, Kelvin Davies1, Dr Martin Kay1, Dr Rafi Ahmad1, Edwin Billiet1
and Prof. Jack Silver, Nextek Ltd1 and Brunel University2
Abstract
A new way of rapidly sorting packaging into high purity
streams (> 99%) has been developed based on intelligent
labels with invisible markers that can be detected and
sorted using existing high-speed optical sorting systems
used in MRFs with minor modifications.
The principles have been proven using a range of
commercially available UV responsive fluorescent markers
with high emission yields. A full-scale commercial optical
sorting trial was conducted at the MRF facilities of Tomra
in Germany.
Sorting of used plastic packaging for closed loop recycling
back into food packaging requires positive identification
and sorting of the recycled materials to a higher standard.
The operators of commercial food grade recycling
processes are required to demonstrate the recycled
materials meet relevant European Food Safety Authority
(EFSA) criteria; these require at least 95% (PET) and 99%
(HDPE) of the feed material must have been used for food
contact in their first life. The initiation of closed loop food
grade recycling of PP packaging is awaiting a viable
technical solution to differentiate the food grade packaging.
From previous sorting trials, it can be estimated that of the
143,000 tons of PP food packaging used annually [1],
77,077 tons could be recovered each year in the UK. The
objective of this project was to further develop the
fluorescent marker technology investigated in earlier
projects that has the potential to meet EFSA requirements
and to extend the scope to different applications, enabling
and facilitating the sorting of different polymers to a high
degree of purity. The scope of the project included the
optimisation of fluorescent compounds, evaluation of their
stability in the supply chain and the ability of the
compounds to be effectively removed during the cleaning
and decontamination process. The project investigated the
viability of the technology and its capacity to be
implemented in the UK and elsewhere.
Unlike existing NIR sorting systems [2], this technology
uses commercial labeling and decoration methods to sort
targeted streams potentially including food-contact plastics,
bioplastics, chemical packaging, automotive plastics, black
plastics and different grades of one plastic. This technique
has the potential to create new recycling loops for food
grade PP, milk bottle sorting and PET products. The project
demonstrated that the use of commercial labels
incorporating fluorescent markers can be used to sort
plastic bottles and packaging with high yields and purity.
Introduction
A major challenge in producing recycled plastics from post
consumer recycling feedstock is to sort the material into
high purity mono-material streams since small quantities,
often as little as 0.1%, of a non-compatible plastic can
significantly reduce the quality of the final product. In
order to keep costs low while processing high volumes,
sorting is typically realized with automatic sorting
machines using Near Infrared (NIR) detection.
The stimulus for this investigation was the need to have an
automated method for sorting mixed PP packaging waste
into a separate a stream that consists of at least 99% PP
previously used for food applications [3,4], from other non-
food PP packaging that could be present at levels as high as
50% in the input stream.
A previous project [5] evaluated techniques such as
polymer additives, surface markings such as diffraction
gratings and fluorescent markers.
The use of fluorescent markers compounded into plastics
was pioneered by Ahmad et al [6,7]. They investigated the
feasibility of using single and multiple combinations of
fluorescent dyes in a range of polymer materials to identify
and sort the packaging at commercial rates.
More recently Langhals [8] reported the possibility of
identifying polymers based on their auto fluorescence and
doping with fluorescent dyes. The article highlighted the
possible use of fluorescent dyes to identify special batches
of a basic polymeric type.
This project investigated the use of machine readable
fluorescent markers that can be applied to the surface of
packaging or packaging labels so that existing NIR sorting
equipment can be utilized with no or minimal modification.
The machine readable markers needed to be invisible to the
naked eye under normal lighting so not to affect branding
and aesthetics, but be detectable at with existing MRF
infrastructure at commercial sorting speeds and sorted at
high efficiencies. To achieve this, markers were applied as
a surface varnish on an existing package or label to provide
an adequate means of identification and separation. The
labels and markers can then be removed during the normal
recycling processes so that the materials can be free of any
markers prior to being used in any new applications to
prevent false sorting responses in the next cycle of
application.
PRISM Project
PRISM is a new way of rapidly sorting packaging based on
intelligent labels with invisible markers that can be detected
SPE ANTEC® Anaheim 2017 / 500
and sorted using existing high-speed optical sorting
systems used in MRFs with minor modifications. This
technology uses commercial labelling and decoration
methods which are coded with high performing
luminescent compounds to sort targeted streams including
food-contact plastics, bioplastics, chemical packaging,
automotive plastics, black plastics and different grades of
one plastic. Sorting is accomplished using modifications to
existing NIR sorting machinery. The new technology can
boost recycling plant yields with efficient ways of sorting
materials such as PP packaging used for food, HDPE milk
bottles and sleeved PET and increase recovery of food
grade plastics and open up new markets for recovered
plastics.This technology will be compatible with all NIR
sorting equipment. It will help brand owners to ensure that
packaging reaches the recycling loop and boost UK
recycling performance. The partners in the project are :