Author: Tess Ewart
View Student Lesson Plan
Participants explore the ties between science and technology as they simulate the plastic manufacturing processes of extrusion, injection molding and blow molding. First participants will examine a variety of simple plastic toys and try to find traits that would lead them to suggest a process by which a given toy was made. Next they will form "manufacturing companies" and actually extrude a product using a common toy - the Play-Doh Fun Factory®. Participants will also make an injection molded product using a hot glue gun, and a blow molded product using plastic tubing and a simple mold. Finally, participants will review their original set of toys and classify them as injected, extruded, or blow molded.
Throughout this lesson, best teaching practices are emphasized. Simulation and hands on/minds on techniques are used in conjunction with the learning cycle to show the ties between science and technology.
The kit of party favor toys for each group in the Engage and Elaboration phases can include one item from each of the following: (Prices are from June, 2006)
Sherman Specialty Co, Inc.: http://www.shermanspecialty.com/ 1-800-645-6513 or fax # 1-800-853-8697
|# E281||1 pack assorted blow molding toys (288/pack)||34.95|
|#S4223||1 pack sea creature blow molding toys (72/pack)||10.95|
|# H47||1 pack dinosaur blow molding toys (72/pack)||9.95|
Oriental Trading Co, Inc.: www.orientaltrading.com 1-800-875-8480
|12/284||Bubble tubes (to use with blow molding)||3.95/dz|
|39/923||plastic jump ropes - extrusion & injection molding||14.95/6dz|
|39/1245||small finger puppets - injection molding||9.95/6doz|
|39/9600||vinyl snakes - injection molding||4.95/4dz|
|9/659||mini insect erasers - extrusion||1 firstname.lastname@example.org|
|39/1561||plastic frog jumpers - injection molding||4.95/4dz|
|24/1204||plastic smile rings - injection molding||3.95/4dz|
|20/45||plastic whistle bracelets - extrusion & injection||2.95/dz|
|39/1572||vinyl dinosaurs - injection||4.95/4dz|
|39/1689||plastic magnifiers - injection molding||4.95/doz|
|57/9017||48" bead laces - extrusion||2.95/dz|
Note: this list does not match the list in the original activity. Toys on the market can change. This is a list of some inexpensive toys that are currently available.
Materials for the Exploration through Explanation phases:
In this phase, the professional development provider will stimulate interest and initiate questions about industrial processes needed to make simple toys.
Give each group of participants a bag of party favor toys to examine. (The list in Materials does not match the list in the original activity. However, the materials list includes toys that are readily available as of summer, 2006.) Let them discuss how they think a particular toy is made and try to classify the toys into groups based on their discussion. Do not give participants any hints or answers at this time. Let participants think and observe and come up with their own questions. Some frustrations may be expressed at this time but this will lead participants into the next phases of this module. Recollect the toys for the final phase of this module.
You may want to suggest to the participants that if they were to do a similar activity with their students, to have students take out only one toy at a time, allow students time to play with the toy, then examine the toy. Students will be more interested in playing with the toys rather than examining them if they take them all out at once.
Assessment: Listen to the participants' observations and methods of classification. There are no wrong answers at this point in time. Share each small group's questions with the entire group. Encourage all members to participate.
In the first part of this phase the participants will simulate the industrial process of extrusion and produce a product that is acceptable to a customer (another group).
Each group should be made up of four participants. Assign each participant a job - factory manager, quality control manager, packaging manager, and factory technician. Job descriptions can be found in the original lesson. Each group is than given a Play-Doh® Fun Factory, customer order form (original lesson) and 2 colors of Play-Doh®. The groups then try to manufacture an extruded product to match the customer's specifications. Products can be massed and the waste (material let behind in the factory) calculated. If a price is assigned to the amount of Play-Doh® given, product cost and waste loss can be calculated. If time permits, the product can be packaged in simple materials (bubble wrap, cardboard, etc.) and "shipped" to the next group for examination and acceptance. More likely, you will not have time to wrap the products, so simply have groups exchange products with the corresponding order form. Each group will then evaluate the product they have received according to the rubric in the original lesson. Encourage groups to discuss the properties of the products they have just produced. Make sure they note the characteristics of an extruded object.
Next, participants can inject hot melt glue into one of the molds on the handle or base of the Fun Factory (or any other small molds you may have available). Vegetable spray placed on the molds in advance serves as a release agent. Once the injected shapes have cooled, they can be removed and examined. Again, encourage groups to discuss the properties of these objects. Both injection molded and extruded objects here are solid but the later is formed in a long continuous stream.
Finally, the process of blow molding can be simulated through a demonstration or hands-on activity if time allows. You will need to have small, 2 sided molds, with an opening in the base for the tubing. Play-Doh® constantly changes the molds available on the market. The Fingles molds mentioned in the original lesson are no longer available. However, look at the Play-Doh® sets currently for sale and you will find molds of various characters or objects. If no molds can be found, a small glass bottle can be used for molding. For bottle use, crimp the heated tubing together at one end and insert the hot tubing into the bottle. Blow gently to inflate the tubing. Once cooled, the blown tubing will have to be twisted and pulled out of the bottle. Follow directions in the original activity if a mold is used. Make sure you practice the molding process yourself. It takes several tries to get a good product.
If heat guns and tubing are unavailable or inappropriate for the grade levels your participants will be teaching, bubble tubes can be purchased from Oriental Trading. A bubble tube set consists of a straw and tube of plastic resin. A small bead of the soft plastic resin is placed on one end of the straw. The participants can blow trough the straw to inflate the plastic into a permanent but very fragile bubble. Once blow molded objects are made or demonstrated, have participants examine their characteristics. The most notable characteristic here is that the objects are hollow. Those made in a mold often have seams.
Assessment: Monitor the groups' discussions. You may want to list the basic characteristics of each manufacturing process on the board. Ask participants to give example of objects other than toys that may be made from the 3 manufacturing processes. Toothpaste, the plastic molding around window screens, and plastic pipes are extruded. Plastic handles of pots, pans, and toothbrushes, as well as the outer casing of their phones or computers may be injected. Bottles are blow molded.
A complete description and diagrams of the 3 manufacturing processes is given in the original activity write-up. Discuss this information with your participants. Ask them to think about the importance of the plastic products they use daily and how all these products are made. Participants can also be encouraged to discuss the properties of different plastics. Some plastics can be heated and easily molded. Others can be drawn into fibers for clothing. Some plastics, such as the handles on pots and pans, can not be easily heated and melted. Different melting ranges of the plastics may affect the products in which they are suitable for use.
Assessment: Encourage the participants to make comments and suggestions that might add to or improve this activity. During the discussion, have participants share examples of how they might incorporate this unit in their own classrooms.
Return the original bag of toys to each group. Have the groups re-evaluate the toys and categorize them again based on possible manufacturing processes. Warn the groups that a few of the toys may have more than one part and be made by more than one process.
Assessment: To assess the learning that has taken place concerning the industrial processes discuss each toy with the group as a whole and compare their answers to the correct answer. (You can find the actual manufacturing process for each toy listed in your materials list.)
Using ideas from the class discussion, have participants write a brief lesson plan template that addresses grade level content and indicators that teaches the ties between science and technology that they can use in their own classrooms. See the Lesson Implementation Plan.
Plastics are man-made or synthetic polymers that play a major role in our society today. Their low cost and superior performance as compared to wood, metals, and fabrics have allowed industry to provide the consumer with improved product performance at reduced cost. The polymer industry currently produces more than 10,000 different polymeric products for diverse uses.
Participants are surrounded by polymeric products. A tremendous amount of research and engineering goes into the formation of these products. As participants work through this module, they will gain a basic understanding of the manufacturing processes that are vital in forming the products we use. The use of toys helps capture the participants' interest and imagination. This module aids in development an understanding of the relationship between science and technology as well as view science as a human endeavor.
National Science Education Standards
Science and Technology: As a result of activities in grades 5-8, all students should develop
Science as Inquiry: as a result of activities, in grades 5-8, all students should develop
Physical Science: as a result of activities, in grades 5-8, all students should develop an understanding of
History and Nature of Science: as a result of activities in grades 5-8, all students should develop an understanding of
Standard A: Professional development for teachers of science requires learning essential science content through the perspectives and methods of inquiry. Science learning experiences for teachers must:
Standard B: Professional development for teachers of science requires integrating knowledge of science, learning, pedagogy, and students; it also requires applying that knowledge to science teaching. Learning experiences for teachers of science must
National Education Technology Standards
Technology productivity tools:
Technology research tools:
Ideally this activity should be conducted in a session at least 2 hours long. However, this can be condensed into a 1 hour session if some of the simulations are done as demonstrations rather than group activities.
A general knowledge of polymers is needed. If participants are unfamiliar with polymers, they can find background information in the Explanation section of the student handout.
A recipe for the homemade dough, Klay-Doh, that works well for eight batches of klay or four factories:
Combine the water and baking soda in a large saucepan and bring to a boil. There will be bubbles when the mixture gets warm and carbon dioxide is given off. Do not let it boil over! Bring to a boil and remove from the heat. Add the cornstarch all at once and stir vigorously until all lumps are gone. Cool and then add 2 teaspoons of oil kneading 3-5 minutes while it is warm. Separate into eight equal sized masses, add a drop of food coloring to each lump, and knead in the coloring. Let these sit overnight with a towel over the container. It is ready for student use the next day.
Note: The hot mixture will be quite soft. Do not put it back on the heat and stir because it will get too stiff. The extruded objects dry in about two days and shrink in length by .5 to .9 cm.
Assemble a bag of party favor toys for each group. Suggested toys are given in the list above but, numerous simple toys can be selected from toy catalogs. Toys should be inexpensive and can often be bought in bulk. Make sure you have some blow molded toys (hollow), injected toys (solid), and extruded toys (long, continuous, solid shapes that can be cut into sections). Note: cookie presses, meat grinders, and toothpaste tubes are all extruders. They produce long, continuous shapes.)
Practice the blow molding process yourself before your session. It takes several tries to make a reasonably shaped object.
Play-Doh® and homemade dough are non-toxic.
Use hot glue guns with caution. Do not touch the injection molded product until it has had several minutes to cool.
A heat gun gets hot enough to blister paint off walls. It should never be aimed directly at a person or any flammable material. It is recommended that the activity supervisor be the only person to hold or move the heat gun. Participants can hold the plastic tubing in the hot air stream. The long length of the tubing prevents heat from reaching the hands as the tubing is rotated in the hot air stream.
Have teachers suggest additional ways to tie the science of everyday objects into today's technology for their own classrooms. For example they might want to investigate how a piece of sports equipment is made, how various types of insulation are made and used, or the role of polymers in modern cars, etc.
See the original lesson write-up - the Explanation section
There are plastics manufacturing processes other than those listed in the module. Have participants research possible processes such as rotational molding, thermoforming, and fiber spinning. Participants could also research the amount of plastic used by each person in the US each year or the total amount of plastic produced.
Have participants list all the plastic products they think they have come in contact with during the day. The list will be quite long! This allows participants to see the importance of plastics in their lives.
Seat everyone so that they can see the demonstrations and make sure every person participates in the discussions and activities. Classroom implementation would also include grouping with diversity in mind.
Hall, Sue; Harris, Mary; Knipp, Rebecca; and Van Natta, Sandra; Industrial Processes of Polymers: How Toys are Made? A Workshop for Elementary and Middle Level Teachers, The Polymer Ambassadors, 2003.