The term “glass” includes many different materials, some you may be familiar with.Soda-lime glass is the most common type of glass and is used to make such things as window panes and glass jars.

Borosilicate glass is another common type of glass that is more heat resistant than other forms of glass. Glass fibers, used to make fiber glass, are made from glass that is similar to windows or drinking glasses.

This experiment will demonstrate how glass fibers are made and how they interact with one another!

The Experiment

Unwrap four of the Jolly Rancher© candies of the same color and put them into a Pyrex© or custard cup. Put the cup in the microwave and heat on high for 8 seconds. If the candy is not yet molten, repeat for up to 8 seconds.

Remove from the microwave and stir with the bamboo rod. This will be a high temperature liquid (140-170°C) capable of burning. Please handle with appropriate insulation. Do not touch the cup bottom with your unprotected hand!

You will form a candy glass ball on the end of the rod. Touch the candy ball to the side of the cup and start to pull the fiber. Notice that the fibers are fairly flexible when they are first pulled, but will harden the longer they are exposed to the air due to the small diameter of the fiber and the temperature difference between the air and the molten candy. Try this several times. How long of fiber were you able to pull?

Demo Delivery Hints




Discussion Questions