Technologies for the Identification, Separation and Recycling Of “Automotive Plastics”

Technologies for the Identification, Separation and Recycling Of “Automotive Plastics”

Abstract: 
 
In this paper, we will discuss
• The role of manual dismantling,
• Mechanical separation technologies,
• Plastic identification technologies,
• Chemical recycling technologies.
Virtually all of the material in today’s automobiles can technically be recycled. The challenge facing engineers is making this recycling process economical. Recycling these components requires the different materials to be separated so that each can be recycled individually. This separation can be accomplished either ‘manually’, where workers disassembly and sort the vehicle components by hand, or ‘mechanically’, where the vehicle is shredded and the materials sorted by properties such as conductivity and density. Mechanical separation includes methods like float sink method using supercritical fluid, air classification, hydrocloning, electrostatic separation, magnetic separation, paint/coating removal, selective solvent extraction, melt characteristics, dielectric characteristics, separation in an oxygen free vacuum oven. In addition to mechanical separation and recycling processes there exists a large body of chemical recycling processes that can be applied which includes pyrolysis, hydrolysis, glycolysis, methanolysis, waste to energy conversion. In this paper, we provide an overview of efforts and technologies, which primarily support automated separation and recycling. Although the paper is focused on automotive applications, many of the technologies are applicable to white goods and consumer electronic products as well. The plastic specimen is illuminated by infrared technique (FT-IR, FT-NIR)(FT= Fourier transform, IR= infrared), YAG laser, or X-ray light and the reflected spectrum is detected and analyzed to determine the type of plastic. This is possible because each type of plastic has its own “fingerprint” in the electromagnetic spectrum. As with FT-IR and similar techniques, “photoacoustics” is only a means of identification after which some action must be taken to separate the material.