Here is a lesson I picked up at the Fall Knob Noster conference for MAEA. Many have been asking about this one, so here you go!
Comments from MAEA artbytes members:
Megan, your principal is right to be concerned. Many plastics release
toxic gases when heated to melting point. Follow this link to an Ask a
Scientist response to this question:
http://www.newton. dep.anl.gov/ askasci/chem00/ chem00038. htm You might
call up some art suppliers such as Sax and Triarco and ask if they offer
any products that would be safe and do what you want to do.
I have achieved chihulyesque shapes with plastic cups by putting them in the top shelf of the dishwasher and running them through the wash cycle. The water is below boiling point but hot enough to warp the plastic. But stop the dishwasher after the wash cycle. The dry cycle would probably be too hot and might burn the cups. You have no control over the resulting shapes when using the dishwasher method; the form is left to chance. Some come out looking cool but others look like a disaster. You should be able to draw your designs on the cups with Sharpies ahead of time so the design warps with the cup. That’s easier than trying to color them after warping. Bear in mind that this is also an expensive way to go since you are using two appliances: the dishwasher and the hot water heater.
That lesson uses a different plastic-it takes so long for it to work in the hot water and the chance for a child burning himself wasn't worth it. I bought a new toaster oven for $18.99 at Target and melted the plastic at home. Kept the windows open and didn't do them all in one sitting. There are some fumes, stay upwind of the oven. I don't plan on using it for food.
There is also a lesson that uses wire loops that is laminated so you can bend plastic. Actually-there are fewer fumes with the toaster oven than the laminating machine.
I don't know what your lessons plans are but when I did Chihuly Flowers I
used hot water. I used an electric skillet and heated the water. Next I
had the students fold the plastic and clip it together with clothes pens.
I put the folded pieces of plastic in the hot water for a miniate or so.
I then placed the plastic on paper towels to cool. When cooled the
students removed the clothes pens and cut the edges of the plastic to look
like petal and painted the plastic flowers with glass paint. We tied them
together and hung them in the lunch room windows.