A plastic doll comes with perfectly coifed hair, often in curls. If the doll gets played with, eventually you end up with hair like My Little Pony Pinkie Pie, shown above. Combing plastic hair is not easy, and even if you get the tangles out, it often only leads to more frizz. Jen Yates tried out some hair setting tips and ended up with Pinkie looking good as new!
Some plastics have a memory of their original shape. Heating and rapid cooling can set it into different shapes, but it returns to the original with time and gentle heat. Think of using a heating iron on straight hair. Put an empty 2 liter bottle in an oven on low. It will not burn, but will return to its original shape.
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