Wednesday, March 15, 2017

Press Play: Oil in CD's

There are plenty of ways to listen to music or even watch your favorite film. One way in particular has been popular for years and comes in the shape of a small circle made out of plastic and aluminum. Its called a CD (Compact Disc) or DVD (Digital Video Disc) only a few millimeters thick, they provide hours of entertainment and hold huge volumes of information. Do you ever stop to think about how CD’s and DVD’s are made, what materials they’re made out of, or what happens to the discs when you don’t want them any more? Making products like CD’s and DVD’s consumes natural resources. produces waste and uses energy. By learning about product life cycles, you can find out how to reduce the environmental impacts and resources used in products you use daily. when you understand these connections, you can make better environmental choices about the products you use and how to dispose them. Follow the  life cycle of a CD or DVD and learn more about how these products are made and what you could do to help reduce waste and save natural resources.

CD’s and DVD’s are made from many different materials, each of which has its own operate life cycle involving energy and waste. They include:

Aluminum- the most abundant metal element of the Earth’s crust. Bauxite ore is the main source of aluminum.

Polycarbonate- a type of plastic, which is made from crude oil and natural gas extracted from Earth.

Lacquer- made of acrylic, another type of plastic.

Gold- a metal that is mined from the Earth.

Dyes- chemicals made in laboratory, partially from petroleum products that come from the Earth.

Other materials such as water, glass, silver and nickel.

When it comes to processing the minerals there is some work that goes into it. For example, Bauxite ore is processed into a substance called alumina by washing, crushing, dissolving, filtering and harvesting the materials, Alumina is then turned into aluminum through a process called “Smelting”. Then the material is shaped rolled and made into a cast.

To make plastics crude oil from the ground is combined with natural gas and chemicals in manufacturing or processing plant.

When it comes to manufacturing, its pretty much the same for both CD’s and DVD’s.  A injection molding machine creates the core of the disc. A 1 millimeter thick piece of polycarbonate (plastic). The plastic is melted and put in a mold. With several tons of pressure, a stamper embeds tiny indendation or pits, with digital information into the plastic mold. A CD’s players laser reads these pits when playing a CD.

The plastic molds then go through the “metallizer” machine, which coats the CD’s with a thin metal reflective layer (usually aluminum) through a process called “Sputtering.” The playback laser reads the information off the reflective aluminum surface.

The CD then receives a small layer of lacquer as protective coating against scratching and corrosion.

Most CD’s are screen printed with one to five different colors for a decorative label. Screen printing involves squeegees and inks, which are also objects made out of petroleum oil.

When it comes to the packaging, CD’s and CD’s are packaged in clear to colored plastic cases (Jewel cases) or cardboard boxes that are then covered with plastic shrink wrap. This packaging can be made from raw materials. For example, the plastic used can be from recycled bottles of from crude oil and natural gas extracted from the Earth combined with chemicals.

Useful Life
CD’s and DVD’s are created with materials that are extremely stable. IF properly stored and handled most discs will last for years, even decades. Certain conditions such as high temperatures, rapid temperature changes or even exposures to certain type of light can damage discs or shorten their useful life. Taking care of your discs by keeping them out of direct sunlight or away from heat will help them last longer.  Not only will you save money but you can also help reduce waste by preventing long term damage.

Reuse, Recycling to Disposal

A good way to keep discs from going in the trash is to reuse them. Minor scratches can be repaired by rubbing a mild abrasive (such as toothpaste) on the non-label side of a disc in circular motion form the center out. Also some commercial refinishers can inexpensively repair your CD’s.  Unwanted CD’s or DVD’s can be sold to stores, traded with friends, or donated to schools or libraries. Buying CD’s or DVD’s or borrowing them from the library can also help reduce the environmental impact associated with manufacturing new products.

CD’s can be recycled for use in new products such as:
Automotive industry parts.
Raw materials to make plastics..
Office Equipment.
Alarm Boxes and panels, street lights and electrical cable insulation.
Jewel cases.

There’s no need to dispose your discs when you could send them to donations or collection centers. Always try to share, donate or trade your discs. If all fails, send them to a recycling center. CD’s and DVD’s that are thrown away waste energy and result in lost valuable resources.

Fun Facts:
In 1983, when CD’s were introduced to the United States, 800,000 discs were sold. By 1990 this number had grew to 1 billion! Every month approximately 100,000 pounds of CD’s become obsolete (outdated, useless or unwanted).

Heres a video on the process in which CD's are made. Very interesting and informative stuff!


Video Source:

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