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Posted: Nov 29, 2013
Quality recycled plastics
(Nanowerk News) Industrial painted and laminated plastics currently present a recycling problem. An EU project has produced improved-quality recycled plastics from printed plastic packaging.
Some plastics can be recycled, but transparent film plastics are presently not considered worth reclaiming from landfill. An EU project aimed to change that, promoting flexible painted and laminated plastic film (commonly used for food, toys, cosmetics, and industrial parts) as a valuable recycling resource. The project planned to make a similarly transparent plastic recyclate of equal quality and safety to the non-recycled version. Since the new plastic would be "infinitely" recyclable, that kind of waste could be virtually eliminated, helping EU industry to achieve the packaging-reduction directives set by the EU parliament.
The process relies on stripping ink, adhesives, and contaminants using supercritical carbon dioxide (CO2) as an industrial solvent. Supercritical is an intermediate physical state combining the flow properties of liquid with the expansion properties of gas; supercritical CO2 is an effective and environmentally safe industrial solvent. In conjunction with the CO2 system, the CLIPP process uses systems for micro-particle filtering, which remove impurities, plus a series of innovative extruders. The resulting system allows smooth production of a translucent film.
Full transparency has not yet been achieved with the method tried. However, CLIPP modified its interim goals, aiming instead to make a plastic as transparent as possible, also having low-odour properties.
These efforts successfully produced a translucent material of suitable quality, including low-odour, appropriate for various non-food packaging purposes. An additional translucent recycled material, in conjunction with a barrier layer, proved suitable for sunflower seed packets. Economic analysis indicates that these developed products can be profitably used in value-added manufacturing, and work has begun on full commercial implementation.
Project results have further increased the expertise of EU plastic recycling industries. That may lead to further steps towards the original manufacturing goals. Overall, the outcome will include reduced plastic waste, healthier environments and lower greenhouse gas emissions.