12.1 Introduction

The amount of plastics being recycled continues to increase around the world. As the use of plastics continues to increase as well, plastics recycling rates have declined in some areas. Public pressure for plastics recycling waned in the last half of the 1990s in the U.S.A., although there are some signs that it is increasing in the early 2000s. The early focus of plastics recycling efforts was packaging materials. More recently, recycling of plastics in consumer products such as carpet, automobiles, and appliances is drawing attention.

This chapter deals almost exclusively with recycling of post-consumer plastics. While recycling of process scrap is important for the economic viability of many operations using plastics, recovery and reuse of clean process scrap is regarded, by and large, as a normal part of operations and is not generally classified as recycling. Recovery of contaminated scrap, while more difficult and less routine, is still often regarded as not real recycling. Such materials are sometimes processed along with post-consumer plastics, and some processors and users of recycled plastics depend on the known composition of such materials to help control product properties. Nevertheless, when most people think of plastics recycling, they have in mind the processing for reuse of materials that have served their intended purpose. Post-consumer materials, by this definition, include those generated by business and industry as well as those generated by individuals. The key to the definition is that the...