Thursday, July 17, 2014

Are CDs and DVDs Recyclable?

A Compact Disc (CD) is made from a 1.2 mm thick disc of almost pure polycarbonate plastic. The surface of a CD is reflective because the disc is coated with a thin layer of aluminum or sometimes gold. The shiny metal layer reflects the laser that is used to read or write to the device. A layer of lacquer is spin-coated onto the CD to protect the metal.The label print is applied to the top of that surface. 

A Digital Versatile Disc (DVD) is made from essentially the same material but can store up to 6 times the data.

Polycarbonate is a strong, hard, tough, transparent thermoplastic that can maintain its hardness up to 284 degrees Fahrenheit and toughness down to -4 degrees Fahrenheit. Some special grades can withstand temperatures even lower.

A couple of processes exist for recycling polycarbonate, but they are very involved and very different from the process to recycle other plastics, like #1 & #2, for example. The general recycling process of those plastics after they are collected and sorted is as follows:

Chipping - The sorted plastic is cut into small pieces ready to be melted down. 

Washing - This stage removes contaminants such as paper labels, dirt and remnants of                          the product originally contained in the plastic.
Pelleting - The plastic is then melted down and extruded into small pellets ready for reuse.

Considering that the sorting process of plastics is dependent upon the type of plastic and the temperature at which they melt. Since the melting point of polycarbonate is quite a bit different than other plastics, and can vary, and the sheer quantity of polycarbonate collected would be at a minimum, CDs and DVDs remain a trash item as far as our current processes go.

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