Educator How-To: Recycled Plastic Shrinky Dinks

The beginning of the school year is an exciting time for teachers and students alike. We have a quick science activity here that will engage  new students and make your room too cool appropriately cool for school: Shrinky Dinks.

Educator How-To: Recycled Plastic Shrinky Dinks

There are myriad of ways you can use this activity, so the application is up to you, but I am envisioning name plates or name tags, zipper pulls for pencil bags, cubby or tote markers, key chain fobs … the possibilities are endless!

Materials:

No. 6 plastic
Sharpies, colored pencils, or an inkjet printer
Sandpaper
Scissors
Oven or toaster oven
Parchment paper
Non-insulated baking sheet or flat piece of cardboard
Hole punch

Procedure:

The first thing you need to do for this project is to gather is No. 6 plastic, also known as polystyrene. Polystyrene is hard and clear and often used in protective packaging like deli containers. While it can be tricky to recycle, recycled polystyrene can be used in manufacturing rulers, license plate frames, vents, switch boards, and thermal insulation items. Oddly enough, No. 6 plastic can also be whipped into a foam and made into Styrofoam.

For this example, I saved a bunch of lids from aluminum takeout containers, but you can use just about anything that is rated No. 6.  If you want to make an image that will shrink evenly, you will need a piece of plastic that has been stretched evenly. Corners, cups and edges can be unpredictable because they are stretched and molded in multiple directions.

“Plastics are made of long chain-like molecules called polymers. Because polymer chains are so long, they can be manipulated to create a wide-range of properties — in this case for No. 6 plastic, polystyrene. Polystyrene is a thermoplastic, meaning the long polymer chains are heated and stretched, then cooled to form the plastic sheet. The polystyrene remains in this “stretched out” state unless something causes it to change. The cool thing about thermoplastics is that upon reheating the plastic, it reverts to its original state, in other words, it shrinks. This is the same process used to “shrink wrap” items like food containers or other products that have protective plastic wraps.” Lori Steward, Middle School Science

I decided to try something different this time, so I cut the unpredictable edges off my plastic lid in order to get a flat piece of plastic I could trim and run through the printer.

Educator How-To: Recycled Plastic Shrinky Dinks

(If you decide to use sharpies in your project, you can give your students a piece of plastic and a set of sharpies and let them get to work. The sharpie will adhere to the plastic with no problems. If you want to use colored pencils or an ink jet printer, you will need to scuff up your plastic so that there is a bit of texture for the color to stick.)

Educator How-To: Recycled Plastic Shrinky Dinks

I knew I wanted to cut around the outline of my long-horned beetle, but for students you might want a standard shape like rectangles for name tags or zipper pulls. You might also consider using a die cut to make a particular shape — like circles or the school mascot.

If you want to attach a cord or a ring to your shrink dink, you MUST punch a hole in it BEFORE you bake. The standard sized hole punch shrinks considerably.  I always have the urge to use a smaller hole punch, but then I can’t fit anything through the remaining hole.

Educator How-To: Recycled Plastic Shrinky Dinks

Before baking.The larger hole is a standard sized hole punch. The smaller hole is a mini punch.

SO! After I ran the plastic through the printer, I trimmed around my shapes. The “painted lady” was easy as it was a rectangle, but the beetle was trickier.  Since No. 6 plastic is pretty thin and brittle, corners are delicate. You can see in the picture that I had a bit of a problem around the beetle’s tarsal claws. No worries though; the plastic gets tougher as it shrinks.

Educator How-To: Recycled Plastic Shrinky Dinks

Now get out your baking sheet. I like putting a piece of parchment paper down on the baking sheet to protect the surface that you might otherwise put cookies on, but it isn’t totally necessary. If you do decide to use parchment paper, it has a tendency to curl, so you may need to wad up the paper and flatten it back out before using it.

Place your decorated plastic on the cookie sheet and place the sheet in the oven to bake the plastic for 2- 3 minutes on 325 to 350 degrees. Each oven is different, so watch closely!

Danger Note: You are already working with heat, but you might also be working with a possible human carcinogen. No. 6 plastic has been found to leach styrene, so if you choose to do this craft make sure it is in a well-ventilated area!

You will see the plastic curl up and then flatten back out. Wait about 30 seconds longer than you think you need to. Then wait a few more. It is extremely tempting to take the shrink dinks out before they are totally ready, but waiting longer than necessary doesn’t really hurt anything. So resist!

Occasionally your shrinky will decide to stick in a single spot. Not to worry! When you pull the items out of the oven, immediately use something hard and flat, like the bottom of a pie pan, to press out any uneven spots. If you aren’t quite satisfied, you can actually stick your shrunken piece back in the oven and reheat it until it is soft.

Once you remove the piece from the oven, it cools very quickly, so you can handle it almost instantly. I usually pull the cookie sheet out, flip the piece on the kitchen counter and press it flat for a few seconds. By the time I have done all of this, 30 seconds or so, the piece is ready to hold.

How much shrink can a shrink dink shrink? About this much.

Educator How-To: Recycled Plastic Shrinky Dinks

The image on the left is the starting size and the image on the right is the finished size.

Final product!

Educator How-To: Recycled Plastic Shrinky Dinks

Be the Party Smarty: Fuse this time-tested childhood craft with HMNS birthday fun

Creating a fuse bead masterpiece is a different feat at 25 years old than it was at 10. I’d never realized how handy having tiny digits had been until recently, as I fumbled with slippery, miniscule beads to create one of our most popular Party Smarty crafts.

Kiddos who book their birthdays with HMNS get a variety of extra-special extras, but our included craft time is something to be enjoyed by both the young and the young at heart.

I got in touch with my inner child with some good old-fashioned Perler beading. (You can find tubs of these infernal little buggers at Hobby Lobby or Michael’s. These days they even have sparkles.)

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First, carefully place your fuse/Perler beads on your stencil. It pays to work from the center out (for obvious reasons), but if your imagination runs wild and you envision your dinosaur with spots or your butterfly with chevron wings, by all means, don’t let a little thing like common sense get in the way.

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Check out these beauts by our Party Smarty staff and yours truly. Guess which one was by the amateur? (Hint: The answer’s not visible to the naked eye, but it took me twice as long to make the dino at bottom.)

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Next you’ll iron the beads onto the mold with medium heat. Put a piece of parchment paper over your creation and make sure to use a dry iron, keeping the iron parallel to your surface and moving in circular motions. (This craft is recommended for children 7 and up, but Party Smarty staff will assist with this part.)

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We find that it’s best to iron both sides for durability.

Once the beads are fused, as below, gently peel the fused plastic off the mold, cover it once more in parchment paper (which you can reuse, unlike wax paper) and iron again.

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Whether you decide to make your creation into a magnet, a barrette or a creative holiday ornament, you’ll have partied smartly at HMNS.

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Have a chemical Christmas with these chemistry-themed holiday crafts

In our department, you can’t escape science – not even for the holidays.

Have a chemical Christmas at HMNSEvery year during the holiday season, the museum provides pine trees to local non-profits to decorate and spread their organization’s message. Our department is usually given a tree to decorate in a manner that expresses some aspect of the museum.

This year, we have dedicated our tree to chemistry, as we will have a revamped Chemistry Hall in the near future and want to celebrate. And because we know you like science as much as we do, we have compiled all sorts of fun kid- (and adult) friendly chemistry projects that you can do at home. Ours have all been made into ornaments for our tree, but the sky’s the limit!

Check out these links and have your own Chemical Christmas:

Marvelous Marbled Ornaments
Christmas Chromatography
Borax Crystal Ornaments
Amazing Snow Powder
How Does the Periodic Table of Elements Work?

Want to come check out the trees for yourself? Visit the museum from Nov. 30th through the first week of January. Can’t make it? Stay tuned for pictures of all the trees the first week of December!

But in the meantime, enjoy the trees from previous years and this chemist’s version of a holiday classic, “Twas the Night Before Christmas.” John F. Hansen’s version appeared in the St. Louis section of the American Chemical Society in 1978.

‘Twas the night to make crystals, and all through the ‘hood,
Compounds were reacting as I’d hoped that they would.
The hood door I’d closed with the greatest of care,
To keep noxious vapors from fouling the air.

The reflux condenser was hooked to the tap,
And the high vacuum pump had a freshly filled trap.
I patiently waited to finish my task,
While boiling chips merrily danced in the flask.

Then from the pump there arose such a clatter,
That I sprang from my chair to see what was the matter.
Away to the fume hood! Up with the door!
And half of my product foamed out on the floor.

Then what to my watering eyes should appear,
But a viscous black oil which had once been so clear.
I turned the pump off in a terrible rush,
And the oil that sucked back filled the line up with mush.

The ether boiled out of the flask with a splash,
And hitting the mantle, went up with a flash!
My nose turned quite ruddy, my eyebrows went bare,
The blast had singed off nearly half of my hair.

I shut the hood door with a violent wrench,
As acid burned holes in the floor and the bench.
I flushed it with water, and to my dismay,
Found sodium hydride had spilled into the fray.

And then the fire got way out of hand,
I managed to quench it with buckets of sand.
With aqueous base I diluted the crud,
Then shoveled up seven big buckets of mud.

I extracted the slurry again and again
With ether and then with dichloromethane.
Chormatographic techniques were applied
Several times ’til the product was purified.

I finally viewed with a satisfied smile,
One half a gram in a shiny new vial.
I mailed the yield report to my boss,
Ninety percent (allowing for loss).

“Good work,” said the boss in the answering mail,
“Use same condition on a preparative scale.”

Roach races, edible bugs, a mad scientist + more! Join us at HMNS Sugar Land for Spooktacular 2012

Looking for a Halloween celebration that’s more treat and less trick?

Join us at HMNS Sugar Land on Sunday, Oct. 28 for Spooktacular, a costumed celebration for the whole family! This kid-friendly party includes our Spook House, a mad scientist, and a creepy entomologist who will offer a different kind of Halloween treat — this one with a crispy bug.

Sugar Land Spooktacular 2012While you’re there, try your hand at our roach race track, participate in holiday crafts and leave with a treat bag! All Spooktacular activities are included with the price of general admission, so explore our museum halls while you’re here.

For more info on Spooktacular and other HMNS Sugar Land programming, click here.

What: HMNS Sugar Land Spooktacular
When: Sunday, Oct. 28 from 2 to 4 p.m.
How Much: FREE with general admission