Shrink and Be Merry
Originally published in the Santa Cruz Sentinel April 3, 2010
KNOW YOUR RECYCLING SYMBOLS?
Keep your reading glasses on and let’s take a trip to your refrigerator. Open it up and grab the first plastic container you see. Hold it up in the air and squint at the bottom until you can make out the tiny number inside the triangle. Check out a few more containers and you’ll find that there are a whole lot of #1s (soda, juice, salad dressing) and #5s (yogurt, syrup, ketchup), and an occasional #2 (the milk jug) or #7 (“other” like Tupperware). You probably won’t see too many #3s (PVC pipe, outdoor furniture, vinyl siding) or #4s (plastic bags). But there might be a #6 in there, holding a dozen eggs or those leftovers you couldn’t finish at the restaurant the night before.
Polystyrene (also known as #6 PS) comes in a white, foam variety (packing peanuts, Styrofoam cups, meat trays), but also in a clear, rigid form, most commonly used by the food-service industry for to-go clam-shells and disposable drinking cups. Because the foam variety is full of air and the more solid variety is molded into throwaway containers, it’s very lightweight and easily carried away by wind and water currents. For this reason, and because it’s so commonly used away from home, #6 is an abundant form of trash accumulating across the American landscape.
HOW IS POLYSTYRENE UNIQUE?
Stay with me here, as I attempt to explain why polystyrene, unlike many other plastics, is an amazing material for crafts (the clear kind, NOT the foam variety). All the plastics we create from petroleum are formed from chains of polymers linked together in a variety of ways. A thermoplastic is a polymer that turns to a liquid when heated and solidifies to a very glassy state when cooled. Thermoplastic polymers differ from thermosetting polymers (Bakelite) as they can be re-melted and remolded. Polystyrene is a unique thermoplastic, in that, when heated, its chains of polymers will stay in the same conformation as they melt and solidify. So, you don’t just end up with a plastic blob after heating, but a shrunken replica of your original shape. A rectangle will still be a rectangle—it’ll just be smaller and thicker.
FUN FOR KIDS AND ADULTS
Shrinking #6 plastic for crafts (again, not the foam variety) is a really cool thing to watch. As it heats up, a flat piece will roll up, twist this way and that, and finally, resume its original flat formation. What starts out as a flimsy piece of brittle plastic is magically transformed into a shiny, glass-like trinket. Colors can also be added in a number of ways, and become quite concentrated after shrinking.
WHAT YOU NEED
To cut the plastic: Scissors and hole punch
To decorate the plastic: Sharpies, stamp pad ink, acrylic paints, colored pencils, fine-grit sandpaper
To shrink the plastic: Oven and non-corrugated cardboard
To avoid breathing any fumes created in the heating process: Use a toaster oven and do your heating outdoors on a patio table.
To see what’s possible: Go to www.etsy.com/ and search for “shrink plastic jewelry” to see what artists are creating with shrink plastic.
WHAT YOU DO
Start with a clear, clean, flat piece of #6 plastic. Cut into any shape you want. Amount of shrinkage will vary, but count on a 3-inch piece shrinking to about a 1 ¼-inch piece, or to 45% of its original size. Use a hole punch (for stringing as jewelry), decorative scissors or punches as desired.
Color the plastic piece with rubber-stamp designs (heat set and permanent pigment inks hold best on the slippery surface) or Sharpies. To get color pencils, acrylic paints or other inks to adhere better, sand one side of the plastic with fine-grit sandpaper.
Preheat the oven to 300-350 degrees. Put the plastic on a piece of non-corrugated cardboard in the oven. Watch through the oven door and remove the piece (with a potholder) on its cardboard tray once it is done shrinking and is again flat.
A MILLION VARIATIONS
There are a whole lot of ways to vary this basic technique. Here are a few:
To make a bead, roll up a long strip of decorated shrink plastic on a thin, metal knitting needle, wooden dowel or skewer, securing it in place with a twist tie. Using a heat gun (found in craft stores for about $15), heat the rolled plastic on a tile until it shrinks completely. To add texture, wrap the hot beat with an unmounted rubber stamp and press.
To add texture to a flat piece of plastic, layer two or three pieces together and cover top and bottom with a Teflon ironing sheet (found in notions section of fabric store). Iron the plastic with a medium hot iron until it shrinks, waves and then flattens. Remove the top Teflon sheet and immediately press a rubber stamp into the hot plastic.
To make a ring, heat a strip of plastic about 7½-inches long by ¾-inch wide. Use a paper cutter for straight cuts, and round the corners off with scissors. Decorate the plastic. Find an object about the diameter of your finger to mold the ring around, such as the handle of a wooden spoon, market pen, or lip balm tube. Preheat the oven and heat the strip on non-corrugated cardboard until shrunk and flattened. Wearing leather gloves or mittens, take the cardboard tray out of the oven and quickly shape the plastic around your mold. If the plastic hardens before it is correctly shaped, reheat it in the oven.
Shrink plastic is also sold under a variety of brand names, with different opacities, colors and finishes. It also comes in an ink-jet printer variety. Some has a frosted (sanded) finish so that you can decorate your pieces with colored pencils, chalk, fingernail polish, felt tip pens, make up, spray paint, pastels, and other inks. Chalks and pencils or any water-soluble colorant will need to be sealed with varnish or lacquer after baking.
Other plastics that can be heated for amazing effects are Tyvek (ironed between Teflon ironing sheets) and sheet-protectors (beads can be made with yarns, fabric, or thin paper rolled up inside before ironing between Teflon sheets). A great book featuring these plastic crafts and more is Creative Embellishments for Paper, Jewelry, Fabric, and More by Sherrill Kahn.