PVC is one of the most widely used polymers in the world and Europe’s third most popular plastic. Today, about 37 million tonnes of PVC are annually produced worldwide, of which 5.5 million tons are made in Europe, as stated in the report published by Vinylplus in 2016. PVC is very versatile: light, strong, fire resistant, excellent insulating properties and low gas permeability. By varying the use of additives in the manufacturing of PVC products, further features such as strength, rigidity, color and transparency can be tuned to meet a wide range of applications, both rigid (e.g. tubes, window frames, bank cards) and soft (wall paper, packaging, cables, floor covering, blood bags). Further, PVC products are durable: they need minimal maintenance and their life-span can range from 30 to even 100 years in the case of cables, pipes and window profiles. This led to the disadvantage that current PVC waste – also called “old PVC” – was made decades ago thus often contains legacy additives, the main ones are lead (compounds) for preventing degradation under influence of heat or UV light and DEHP as phthalate plasticizer for flexibility. Although today they are replaced by alternatives in ”new PVC”, these legacy substances (LS) will be abundant in PVC waste for at least another 30 – 50 years given the long lifetime of PVC and their use until circa 2008 for Pb and circa 2015 for DEHP (for more details, see the RIVM report).
To circularize PVC materials streams that contain LS it is needed to upcycle the “old PVC” with LS into “new PVC” that is fully REACH compliant. The above situation indeed poses a serious challenge for the PVC industry to meet the recommendations published in the European Strategy for Plastics in a Circular Economy. To increase further the PVC recycling rates, also post-consumer ”old PVC” will need to be recycled. This is being hampered, and even threatened, as no methods to remove these LS from PVC are available.
REMADYL therefore steps up to the challenge, to develop a commercially viable technique for the detection and extraction of these legacy additives. The automatic identification of the LS substances under consideration (DEHP and lead) is highly challenging but a mandatory prerequisite for their actual recycling. Based on existing state of the art, we will optimize the hardware and software for the PVC monitoring to identify target LS and allow for presorting of the PVC. This presorted PVC will form the starting material for the further LS extraction steps.
Building further on the available knowledge and expertise the REMADYL consortium will research and develop a continuous extraction technique for the removal of legacy additives out of the PVC matrix and this for both soft and rigid PVC. We will investigate two different systems: (i) metal scavengers in combination with melt filtration and (ii) continuous polymer extraction techniques in combination with processing aids such as scCO2. REMADYL consortium will try to boost the efficiency of both techniques by use of innovative co-solvents. When the LS have been successfully extracted, subsequent procedures for safely handling and processing these LS will be defined. These novel techniques will form the basis for REMADYL demonstration of circular use of post-consumer PVC.
The research executed in REMADYL is supported by industrial and regulatory partners who safeguard the viability and feasibility of the used technologies, to allow further upscaling and industrial implementation.