Biology: The Dynamics of Life, California Edition

RECYCLING PLASTICS

Introduction

How many times each day do you use something made out of plastic? From a toothbrush to a soda pop bottle, from a grocery bag to a garden hose, plastics are part of our daily lives. You probably know that plastics are made from petroleum, a nonrenewable resource. When plastics are thrown away, they become part of the solid wastes that end up in sanitary landfills. Today, many solid wastes, including glass, paper, and aluminum, are being recycled rather than thrown away. Some communities are choosing to recycle plastics as well. However, recycling plastics is a bit more complicated than recycling glass, paper, or aluminum.

There are many different types of plastics, and each type requires different handling in the recycling process. The next time you pick up a milk jug or 2-liter plastic soft drink bottle, look at the bottom. Do you see a triangle made out of three arrows? This symbol means that the plastic can be recycled. Inside the triangle you will see a number or perhaps an acronym made up of several capital letters. The numbers and acronyms are part of a coding system that identifies what type of plastic the item is made out of, and how it should be handled in the recycling process. What exactly is a plastic? What are the different kinds of plastics? What is each type of plastic used for? How can each type of plastic be recycled? These are some of the questions you will be able to answer when you have completed this WebQuest on recycling plastics.

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Task

Your job in this WebQuest is to learn about the different types of plastics and how they can be recycled. You will explore the history of plastics and find out what properties make a material a plastic. You will identify the seven different classes of plastics, and discover what each class is normally used for. You will also learn what kinds of items can be made from recycled plastics. Finally, you will fill out a table that lists all of the information you have learned about recycling plastics.

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Resources

Look at the Web sites given here to find the information that will enable you to complete the table on recycling plastics.

• Hands On Plastics: Background Information for Students.
  Visit this site by the American Plastics Council to learn about the history of plastics and polymers and about the chemistry of the polymers that make up plastics. This is an excellent site to begin your exploration of plastics.

• Recycling Plastics – Is the Chemistry Right?[Updated link coming soon.]
  Visit this site to read about the chemistry of plastics and the ways different plastics can be treated in order to be recycled or reused. Scroll down to feedstock recycling to find out how plastics can be turned into a gas.

• Cleaning Up the Waste Stream – Recycling Plastics.
  Visit this site for a brief discussion of the difficulties inherent in recycling plastics. Scroll down to see a chart of the plastic container code system and a description of each type of plastic that can be recycled.

• Recycling Plastics.
  Go to this site by Ecology Action to read about the code numbers used on the bottoms of plastic containers that identify how each container should be handled in the recycling process.

• Buying and Recycling Plastics.
  Visit this Pennsylvania Department of Environmental Protection site to learn more about recycling of PET and HDPE plastics. Scroll down and click on plastics acronyms to see a descriptive list of other plastics and what they are used for.

• Recycling Plastics is as easy as …1, 2, 3 (4, 5, 6, 7)!
  Go to this New York State Department of Environmental Conservation site to see another list of the codes used to identify types of plastic for recycling. The site also describes two methods by which plastic containers are made – blow-molding and injection molding.

• Recycling Plastics.
  At this Colorado School of Mines site you can read a brief discussion of how plastics are made, and about the chemistry of plastics. You can also read about the benefits of using plastic packaging here.

• History of Plastics.
  Visit this site to learn more about the history of the plastics industry. The site discusses the inventions of materials such as celluloid, bakelite, rayon, cellophane, nylon, polyvinyl chloride, saran, teflon, and polyethylene.

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