Recfinmix

At the moment about 1.5 million tonnes of plastic are being recycled annually in the EU, 75% of which is polyethylene, both low density (LDPE) & high density (HDPE). Recycling of plastic film is so far one of the weakest points in all recycling schemes. The reason for this failure is that post-consumer plastic film waste is usually a mixture of diverse plastics, especially polyethylene (LDPE, HDPE) & polypropylene (PP), together comprising 95% of the total film volume. Although cleaning & separation of the polyolefins (LDPE, HDPE & PP) from the rest is easy using flotation or hydrocycloning methods, the effective separation of LDPE, HDPE & PP from each other is difficult, since their densities are very similar, while their variable shapes do not allow the use of automated, sensor-based methods (such as near-infrared detection).

Overall, the market for plastic film in Europe is around 5 million tonnes, of which 4.75 million tonnes are polyolefins, with current projections indicating an annual rise of 2.45% at least up to 2013. From this amount, it is estimated that 3 million tonnes could be collected at municipal separation facilities, corresponding approximately to 2.14 million tonnes of LDPE, 0.53 million tonnes of HDPE & 0.33 million tonnes of PP. The mechanical recycling rate of these materials is about 107 kilotonnes year, 3.5% of the total. These are usually used in mixed form for low added-value applications, since mixed polyolefins cannot be used in high demand, high added-value applications such as film blowing - the most widely-used process for film production - due to the intrinsic inhomogeneity of the material which results in poor behaviour under the high stresses characteristic of this processing method. The current market prices for mixed polyolefin film wastes, suitable only for injection moulding is €180/tonne, which makes it very difficult to find purchasers. By contrast, the market price for recycled LDPE, separated & suitable for film blowing is €481 /tonne, about half the price of virgin material, with market demand far greater than the supply. There exists at the moment no technology which can separate the LDPE component from mixed polyolefin film wastes.

The overall objective of this project is to develop a novel industrial-scale separation technique that is capable of separating a waste stream of mixed polyolefin film into an LDPE fraction (95% pure) & a HDPE/PP fraction (80% pure), with the LDPE being pure enough to manufacture high-quality blown film & the HDPE/PP injection moulded products.

Start date: 1/09/2006
Completion date: 31/08/2008

For more information, please visit - www.recfinmix.com