6H35.50: Stress Plastics (birefringence)

Description: This demonstrates the stress pattern in diffrent plastic shapes using polarized light (example of birefringence).

Equipment: Setup Procedure:
  1. Tape one polarizer directly onto the overhead projector.
  2. Don't forget to remove the polarizer from the overhead projector when done.
Demonstration Procedure:
  1. Place the polarizer onto the overhead projector. Change the orientation until the desired amount of light is passing through.
  2. Place one stress plastic onto the overhead projector. Note that you can see the stress pattern in the plastic.
  3. Place the stress plastic into the hand clamp.
  4. Place it back over the overhead projector. Gently squeeze the handle and note the stress pattern changes.
  5. This can be repeated for the different shaped stress plastics.
  6. When finished, return everything to the box it came in.