A Century of Plastics

This lesson explores how the development of plastics — and the engineering of plastic components into everyday products — has impacted the world. Students learn about the history of plastics, what plastics engineers do, and how many products have been enhanced through the addition of plastic components. Students work in teams to identify products without plastic, and products they think could not exist in a pre-plastic world. They work as teams of “engineers” to see if they can redesign a product to use 50% less plastic components than in current designs. 

  • Learn about plastics.  
  • Learn about how plastics have been engineered into so many common products.  
  • Learn about teamwork and the engineering problem solving/design process.

 Age Levels: 8-18

Build Materials (For each student)

Required Materials

  • Student Worksheets 
  • Background Topics Section

Design Challenge

You are a team of engineers given the challenge coming up with a list of four machines or products that you think would be impossible without the invention of plastics.  Then, you will decide which plastic parts you will replace in one of those products or machines to make recycling easier. What materials will you use instead and how will it impact performance, price, or aesthetics?

  1. Break class into teams of 3-4.
  2. Hand out the Century of Plastics worksheet and print-out of the Background Concepts Section. 
  3. Discuss the topics in the Background Concepts Section
  4. Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials. 
  5. Instruct students to work as a team to complete the first student worksheet – Plastic Hunt!: 
    • Think about items you can find in your home, classroom, or on the playground. Identify and document any items that have no component parts made of plastic.
  6. As a class, discuss the reflection questions:
    • Was it harder than you thought to find products that contained no plastic?
    • Of the products you found with no plastic, what did they have in common?
    • If you were reengineering one of the products you found, would you change
    •  any of the component parts to plastic? Why? Why not?                                                             
    •  Do you think CDs would be possible without plastics?  Why? Why not?    
    •  Why is recycling important?
  7. Instruct students to work as a team to complete Step One of the second student worksheet – You Be the Engineer:
    • Come up with a list of four machines or products that you think would be impossible without the invention of plastics.  For each, answer these questions:
      • What % of the product is plastic?
      • Why would this be impossible without plastic?
      • How has this machine or product impacted the world?
  8. Instruct students to work as a team to complete Step Two of the second student worksheet – You Be the Engineer:
    • Replace some of the plastic in any of the four products or machines you identified in Part One to make them easier to recycle.  Discuss what materials you will use instead, how it will impact performance, price, or aesthetics.  Then present your ideas to the class: 
      • Describe what your product does, and the percentage of it you think is plastic.
      • Explain which components you will replace with other materials; describe how you selected the replacement materials and how the new materials will impact weight, cost, and functionality of the product.
      • Predict whether this product will be as effective as the current design, whether it might cost more to manufacture, and how it would be easier to recycle.
      • Describe how your team believes that the engineering of plastics into common products has impacted the world.
  9. For more content on the topic, see the “Digging Deeper” section.

Time Modification

The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.

Divide into teams
Review the challenge and criteria constraints
Brainstorm possible solutions (sketch while you brainstorm!)
Choose best solution and build a prototype
Test then redesign until solution is optimized
Reflect as a team and debrief as a class

What are Plastics?  

A Century of Plastics 

The 19th Century saw enormous advances in polymer chemistry. However, it required the insights of chemical engineers during the 20th Century to make mass produced polymers a viable economic reality. When a plastic called Bakelite was introduced in 1908 it launched the “Plastic Age.” Bakelite was engineered into many products from electric plugs, to hairbrushes, to radios, clocks, and even jewelry. The bakelite products from this era are now highly collectible! Today, plastics are found in almost every product. It’s difficult to find many machines that do not incorporate several types of plastic.  

What Are Plastics? 

Plastics are polymers: long chains of atoms bonded to one another. Plastic is a term that actually covers a very broad range of synthetic or semi-synthetic polymerization products. They are composed of organic condensation or additional polymers and may contain other substances to make them better suited for an application with variances in heat tolerance, how hard it is, color, and flexibility. Plastics can be molded or formed into particular hard shapes, or be developed as films or fibers. At some stage in its manufacture, every plastic is capable of flowing. The word plastic is derived from the fact that many forms are malleable, having the property of plasticity. Engineers often turn to a plastic as component parts in many products because it is lightweight, relatively inexpensive, and durable. It has reduced the cost of many products, and many products would not exist today without plastic.  

Plastics Engineers 

The development of plastics launched a new field of work: Plastics Engineers! They study the properties of polymer materials, and develop machines that can shape plastic parts. They explore ways to mold plastics to meet the needs of other engineers who need parts, such as cell phone covers, soles of shoes, and backpack wheels. They also work to improve the performance of plastics, looking for new materials that react better to high or low temperature or repetitive motion.  

Short Timeline 

  • 1907: the first plastic based on a synthetic polymer — Bakelite — was created by Leo Hendrik Baekeland. Bakelite was the first plastic invented that held its shape after being heated. 
  • 1908: Cellophane was discovered by Swiss chemist Jacques Brandenberger. 
  • 1920’s: Cellulose acetate, acrylics (Lucite & Plexiglas), and polystyrene are produced. 
  • 1957: General Electric develops polycarbonate plastics. 
  • 1968: Consumption of man-made fibers tops natural fibers in U.S. 
  • 1987: Nipon Zeon develops plastic with “memory” so that it can be bent and twisted at low temperatures, but when heated above 37 Celsius it bounces right back to its original shape! 
  • 1990’s: Plastics recycling programs are common, offering new use for old plastics

Pre-Plastic History of Everyday Objects   

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Toothbrush 

The earliest known toothbrush was a “chew stick” made of chewed or mashed twigs. This style of dental hygiene dates back thousands of years. More recently, toothbrushes were manufactured with bone handles with the bristles or hair of pigs wound together using wire. This style was popular from as early as the 1600’s well into the mid 1800’s, though the handle was sometimes made of wood. The next major design change was prompted by the introduction of Nylon. This synthetic material was first applied to the toothbrush around 1938. By 1939 engineers began to develop electric toothbrushes to improve the effectiveness of brushing. The first real electric toothbrush was developed in Switzerland in 1939. In the United States, Squibb introduced an electric toothbrush in 1960, followed by General Electric introducing a rechargeable cordless toothbrush in 1961. Even dental floss, which originally was made of silk thread, wasn’t popularized until the advent of plastics and synthetic materials.  

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Pen 

For the first three thousand years since the invention of paper, the writing instrument most people used was a quill of a bird — usually a goose — which was dipped in a well of ink. Mass produced steel pen points began to appear in the early 1800s, which provided more control over the line. During World War I, pens began to be made of a hard, usually black, rubber substance known as vulcanite. Early colored plastics were introduced in the 1920’s. Sheaffer introduced pens made from celluloid in different colors. These were very expensive, but proved so popular that within a few years most fountain pen manufacturers were offering pens in the new synthetic material, replacing some metal and wood designs. However, it was the widespread use of plastics and the engineering of the non-leaky ball point pen that brought the cost of fine writing instruments down and within reach of most people. By the 1960s, disposable, ball point pens took over, and while fountain pens remain available, they have only a very small share of the market today.  

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Eyeglasses 

Eyeglasses were originally crafted of metal and glass. If someone required a particularly strong prescription, however, the glass would be very heavy resting on the nose. Plastics revolutionized glasses, by replacing the glass lens with lighter weight material, and replacing most of the metal in the frames with lighter, colorful, plastics. There is still metal in the frame however, as most hinges are still made of metal. And, of course, there would be no contact lenses without the development of synthetic materials.

Internet Connections

Recommended Reading

  • American Plastic: A Cultural History by Jeffrey L. Meikle (ISBN: 978-0813522357)  Plastics Engineering by R J Crawford (ISBN: 978-0750637640)

Writing Activity 

  • Write an essay or a paragraph describing whether you think spaceflight would be possible without the introduction of plastics. Give examples to support your point of view.  
  • Write an essay or a paragraph describing how recycling works in your town. Give examples of how engineers incorporate recycled materials into new products.

Alignment to Curriculum Frameworks

Note: All Lesson Plans in this series are aligned to the U.S. National Science Education Standards (produced by the National Research Council and endorsed by the National Science Teachers Association), and if applicable, to the International Technology Education Association’s Standards for Technological Literacy and the National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics.

National Science Education Standards Grades K-4 (ages 4-9)

CONTENT STANDARD B: Physical Science

As a result of the activities, all students should develop an understanding of

  • Properties of objects and materials 

CONTENT STANDARD E: Science and Technology 

As a result of activities, all students should develop

  • Abilities of technological design 
  • Abilities to distinguish between natural objects and objects made by humans 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Types of resources 
  • Changes in environments 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • Science as a human endeavor 

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD B: Physical Science

As a result of their activities, all students should develop an understanding of

  • Properties and changes of properties in matter 

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

  • Abilities of technological design 
  • Understandings about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Risks and benefits 
  • Science and technology in society 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • History of science 

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD B: Physical Science 

As a result of their activities, all students should develop understanding of

  • Structure and properties of matter 

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

  • Abilities of technological design 
  • Understandings about science and technology 

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

  • Environmental quality 

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

  • Historical perspectives

Standards for Technological Literacy – All Ages

The Nature of Technology

  • Standard 3: Students will develop an understanding of the relationships among technologies and the connections between technology and other fields of study.

Technology and Society

  • Standard 4: Students will develop an understanding of the cultural, social, economic, and political effects of technology.
  • Standard 5: Students will develop an understanding of the effects of technology on the environment.
  • Standard 7: Students will develop an understanding of the influence of technology on history.

Design

  • Standard 8: Students will develop an understanding of the attributes of design.
  • Standard 9: Students will develop an understanding of engineering design.

Abilities for a Technological World

  • Standard 13: Students will develop abilities to assess the impact of products and systems.

The Designed World

  • Standard 19: Students will develop an understanding of and be able to select and use manufacturing technologies.

Plastic Hunt!

Step One: As a team think about items you can find in your home, classroom, or on the playground.  Can you identify any items that have no component parts made of plastic?

Kitchen Items Bathroom Items Classroom Items   Sports Equipment
 

 

 

 

 

 

 

 

 

 

 

 

Questions:

  1. Was it harder than you thought to find products that contained no plastic?

 

 

 

 

  1. Of the products you found with no plastic, what did they have in common?

 

 

 

 

  1. If you were reengineering one of the products you found, would you change any of the component parts to plastic? Why? Why not?

 

 

 

 

  1. Do you think CDs would be possible without plastics? Why? Why not?

 

 

 

 

  1. Why is recycling important?

 

 

 

 

Step One: As a team, come up with a list of four machines or products that you think would be impossible without the invention of plastics.  For each, answer the questions below:

 

  What % of product is plastic? Why would this be impossible without plastic? How has this machine or product impacted the world?
1-

 

 

 

 

 

2-

 

 

 

 

 

3-

 

 

 

 

 

4-

 

 

 

 

 

 

Step Two: Your challenge is to work as a team of “engineers” to replace some of the plastic in any of the four products or machines you identified in the first part of this worksheet to make them easier to recycle.  Discuss what materials you will use instead, how it will impact performance, price, or aesthetics.  Then present your ideas to the class in three forms:

  • describe what your product does, and the percentage of it you think is plastic.
  • explain which components you will replace with other materials; describe how you selected the replacement materials and how the new materials will impact weight, cost, and functionality of the product.
  • predict whether this product will be as effective as the current design, whether it might cost more to manufacture, and how it would be easier to recycle.
  • describe how your team believes that the engineering of plastics into common products has impacted the world.

Lesson Plan Translation

Additional Translation Resources

Downloadable Student Certificate of Completion