The use of organic polymers as materials in the manufacturing of consumer and industrial products is accelerating during the last 50 years. “Plastics” have surpassed already all other materials in market volume. Plastic comprises a large portion of the packaging materials. Our live today is unthinkable without organic polymers. More and more industrial branches base their activities and products on the use of plastic to reduce the weight of their product, reduce the production costs and increase product added value.

The large volume of plastic packaging that is discarded necessitates the efficient management of this waste. The best way to deal with this problem is to recycle and reuse the polmeric material waste.

The domination of organic polymer in the packaging materials is due to the very wide range of their properties and to the easiness and low cost for their processing. A simple comparison of the energy savings for, e.g., the production and use of a PET bottle vs. a glass bottle of the same content shows that “plastic” is much more “ecological” than glass for the transport of liquids and food. Their excellent properties make organic polymers highly valued materials. Using these advanced materials as single-usage products of packaging and discarding them immediately after use does not make sense in view of their high value. Most commercial polymers have low chemical decomposition rate in the environment, in the order of 10 to 100 years. For these reasons discarding plastics after short usage has doubly negative results. First we discard a material that (still) has high value / usability, for the production of which we have consumed fossil hydrocarbons and energy. Second we charge the environment with synthetic substances that take very long time to decompose without gaining something in return.

The continuously increasing use of materials based on organic polymers in combination with their time stability has resulted in the need of their organised management from their production until the end of their useful life. Simple discarding/landfilling after use should not be acceptable. The simplest solutions to this problem is reusing the product/packaging or recycling the material. Another solution, less favoured than the previous, but better than simple discarding, is incineration with energy recovering, i.e., recycling of the material as fuel. Materials recycling will solve problems concerning also the volume and the costs of municipal non-biodegradable waste management (industrial scrap recycling is already done to some extend). Recycling will also alleviate the poor image that the polymers have as a material class, which, in reality, has many beneficial characteristics and ecological advantages.

Recycling or incineration of plastics is done in many European countries. Many EC directives exist (and are applied) for the reuse or recycling of a large fraction of the materials used in automobiles, home appliances, computers etc. Plastics recycling efforts are still limited in Greece. A major reason is the lack of appropriate education (culture) both among the engineers who manage  municipal waste or use polymers to make consumer products and the society at large that uses the products. Because the limited resources and the waste problems are getting serious very fast, there is a direct need to educate the future Environmental Engineers, the Industrial Designers and the Production Engineers  in the methods of recycling and in the necessity to place recycling in the management system of materials and production.

This course describes the methods of recycling of organic polymers. An effort is done to determine the range of properties of the recycled polymers, the applications that can accept these properties and the methods used to extend/ restitute these properties so that the recycled material will be able to substitute virgin polymer. The course also discusses the costs and the economical sustainability of recycling. Field visits are made in plants in Crete, where either collection / separation or secondary recycling takes place.