Background The polymerisation of olefins/alkenes is an efficient and low-cost reaction that yields polymers of high industrial value, such as polyethylene and polypropylene. These polyolefins have a variety of uses, such as the manufacture of plastic film, plastic bags, heat-shrink electrical insulation sleeves, and tennis racket strings. Polyolefins are relatively easy to recycle. One of the most common recycling processes used is extrusion blow moulding. This melts the plastic and extrudes it into a hollow tube, which is then closed in a cooled metal mould. Air is then blown into the tube, inflating it into the desired shape before the plastic solidifies on cooling. However, a major obstacle to recycling efforts is the practical difficulty in isolating pure forms of different types of polyolefins. Urban and industrial waste collection always consists of a mixture of three main plastic film components: low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP). These plastic fractions can be processed together for different applications, such as injected or extruded material, but their different physical properties can lead to defects in the final product, thus reducing the possibilities for reuse. Current techniques do not permit the adequate separation of these three types of plastic film at source. Objectives The main objective of the REC-POLYOLEFIN project was to design and develop a demonstration plant for the separation of mixtures of used polyolefin films. Using electrostatic and pneumatic techniques, the new plant would sort plastic that cannot currently be separated after waste collection. The project intends to separate the polyolefins into two fractions. The first would be LDPE with less than 4.5 % impurities, used for the manufacture of essential products such as film. The second would be HDPE and PP with less than 20% impurities, used for the manufacture of continuous shapes of plastic using plastic profile extrusion. The project would treat 15 000 kg of used polyolefin mixtures, targeting a recovery rate of 10 to 55% of waste polyolefins, and a separation capacity of 1 000 kg/hour. It aims to show the technical and economic feasibility of the process and the potential value of the recycled products. The ultimate aim of the project was to increase the recycling of polyolefin film and to reduce the environmental costs associated with producing new film. Results The project carried out a study of the ‘post-consumer’ polyolefin mixes and defined the pre-treatments needed before entering the recycling line. It then designed and constructed a pilot plant composed of two modules or phases: The thermal treatment prototype into which the post-consumer plastics (i.e. LDPE, HDPE and PP) are introduced and treated with heat, so the LDPE shrinks and the HDPE and PP do not; Separation equipment into which the shrunk LDPE and the HDPE and PP are introduced. The equipment is based on a vibrating platform combined with a controlled air flow, which makes the PP and HDPE rise, while the LDPE stays low by the action of gravity. The two phases result in two fractions being obtained. One is 95.5% LDPE, while the other is mostly a mixture of HDPE and PP, with 19% LDPE. Following the successful demonstration of the pilot plant, the project showed that the LDPE fraction is suitable for the production of film, while the mostly HDPE and PP for the manufacture of urban furniture. The long-term benefit for the environment of increased recycling of plastic wastes will be a reduction in the consumption of non-renewable raw materials and a reduction in the amount of plastics ending up in landfills (thus improving soil quality). The recycling of plastic wastes will contribute to reaching the objectives of the European Directive 94/62/EC on packaging and packaging waste and the Waste Framework Directive 2008/98/EC. Moreover, the REC-POLYOLEFIN process is technically suitable and economically viable for implementation on an industrial scale both in Spain and elsewhere in Europe. The beneficiaries calculated the price of the recycled plastic materials and products, and they compare favourably with the current price of raw materials. If the technology is rolled out on an industrial scale, new job opportunities will be created in the plastic waste collection, management, and recycling sectors. The beneficiaries have drawn up a plan for exploiting the results. The next step could be to establish a larger plant, with 5 000 kg/hour capacity and a plastic waste collection plant in the facilities of the associated beneficiary SMSA in Carcar, Navarra. If this initiative succeeds, additional Rec-Polyolefin plants will be created in Tudela and Pamplona (Navarra) in 2018-2020. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).