Slime is an Engineering Expo favorite. Here are our tips for running a slime booth for up to 1000 kids. Courtesy of Helen Haskin, Wichita Section, Society of Women Engineers.
Materials list scaled for 1000 children
1000 copies of handout page. I like to use colored paper so it stands out.
5 large trash bags (lawn and leaf size)
8 two-quart bottles of Sta Flo Liquid Starch (available at Walmart or Dillons, for example. Must have sodium tetraborate in it. Check ingredients)
8 gallons of Elmer’s all purpose white glue (Office Depot usually stocks 2 gallons in a store, but can order more. School teacher supply stores often carry this item.)
1000 sandwich sized ziploc-type plastic bags to package up each person’s slime so they can take it with them
Box of 1000 craft sticks for mixing the Elmer’s glue and StaFlo liquid starch together (Walmart has this)
5 rolls of paper towels for people to clean their hands
1000 clear 9-ounce plastic cups (Walmart)
500 3-ounce bathroom plastic cups (you can reuse these during the day so you don’t need as many)
Easel with poster about slime making or some kind of big sign identifying your booth.
Plan on having 3 persons to work the booth at all times.
Request 2 rectangular 6-foot tables placed end-to-end and 3 folding chairs in case you get a chance to sit down during the day.
Cover tables with clear plastic sheeting taped in place. Plastic dropcloths for painting work well for this.
Place 2 large trash barrels at either end of your booth to collect used cups and craft sticks. Someone will need to empty them during the day.
Decide which end of the booth you want the children to start at.
Set up the easel(s) with posters
An hour before the booth is set to open:
At the starting end of the booth set out 300 of the 3-ounce cups and pour about a half-inch of Sta Flow Liquid starch in each.
Downstream from the Sta Flo cups set out 300 of the 9-ounce cups and pour just enough Elmers glue into each to cover the bottom of the cup about one-quarter inch deep.
Place a craft stick in each of the 9 ounce cups after you have added the glue.
Locate a couple of boxes of plastic bags within easy reach for transferring slime to plastic bags.
Place a stack of handouts downstream from the glue cups.
Place a couple of rolls of paper towels near the handouts.
Make a test batch by pouring the Sta Flow liquid starch from a 3-ounce cup into a 9-ounce cup holding glue.
Stir for a couple of minutes. A thick clump of slime should result. If it seems slow, add a little more Sta Flow and stir more. Once the slime has clumped into a glob you can transfer it to a plastic bag by wrapping it around the craft stick.
After the booth opens for business
Stand behind the tables and invite kids to come over and make some slime.
As the kids come to your booth invite them to take a small cup and pour the contents into the big cup. (You can collect the small cup to refill with more Sta Flo for reuse.) Instruct your customer to stir continuously for a few minutes to make the slime.
Sometimes you need to add a little more Sta Flo liquid starch to speed up the polymerization reaction.
Once they have some nice slime or are tired of stirring, help them transfer their slime to a sandwich sized bag so they can take it with them.
Ask them to throw away the 9-ounce cup and craft stick in the big trash cans.
As time permits continue refilling empty 3-ounce cups with Sta Flo and filling new 9-ounce cups with Elmer’s glue and a craft stick. I like to use a 9-ounce cup to pour from rather than pouring from the large bottles.
Today we enjoyed a fun polymer activity – making slime. What is slime? It’s a stretchy,
slimy, cross-linked polymer that is made from white glue and household borax.
The word polymer come from the Greek words poly: “many” and meros: “parts”.
Polymers are composed of many individual units called monomers. These monomers
are linked together with chemical bonds to form long chains. A typical polymer is made
of 1,000 to 10,000 monomers linked together.
Polymers are everywhere! Examples of natural polymers include wool, cotton, wood
(cellulose), silk, protein, starch and rubber. Some synthetic or man-made polymers
include plastics, synthetic rubber, nylon, Styrofoam, polyester, Teflon and fiberglass. It
is a good idea to recycle manmade polymers to conserve our oil resources. Most
plastics are now recyclable. In recycling some polymers are heated and reformed into
new objects like plastic lumber, floor mats and drinking cups, others are degraded to
fuels and burned to make electricity or steam.
The Human Polymer Chain: You and your friends can make a human polymer
chain. Here’s how. First ask four or five of your friends to stand in a straight line. Each
of you represents a monomer. Then link arms. Each link represents a chemical bond.
The chain you have formed has many units and represents a straight chain polymer.
Notice how flexible your chain is. Now ask more friends to form another line. When
some of you hold onto 2 polymer chains at once you have formed a cross-linked human
polymer chain. Now the movement of one chain depends on the movement of the
others. The cross-linked chains are not as free to move around as the single chains
Slime: We mixed equal parts of white glue, which is a water-soluble polymer (polyvinyl
acetate) with StaFlo liquid starch containing borax. Borax is the cross-linker. We stirred until the mixture became a very rubbery material. We played with this in our hands, stretching it, bouncing it and watching it flow. Then we cleaned our hands on wipes and paper towels.
You can take your slime home in a plastic bag to play with as long as you follow the
three rules: (1) Do not eat it or leave it where a younger sibling might eat it. (2) Keep it
off the carpet and furniture. (3) Throw it away in the wastebasket after a few days
before it starts to mold.
Here is a PDF of this activity: WichitaSWEOutreach_Slime