Formation from Recyclable Polymers
Wood splint or glass rod
Aluminum dish or foil
Sample of recyclable plastic (e.g. HDPE, LDPE,
Cut polymer sample (HDPE, LDPE, PET from yogurt
lids, plastic wash bottles, etc.) into @ one square centimeter pieces.
Place two or three pieces of the sample into
an aluminum dish ( this may be fashioned from aluminum foil - try to keep
the bottom as flat as possible for good heat transfer).
Place the aluminum dish on a hot plate and heat
until the sample is molten.
If the plastic starts to brown or discolor,
decrease the temperature of the hot plate. It is best to remove samples
that are discoloring from the heat source to avoid inhaling any decomposition
products. If the sample is very discolored, it may be necessary to repeat
with a new sample.
Insert the tip of a wooden splint or glass rod
into the sample and hold it in the molten polymer for a few seconds.
Slowly pull the splint away at a constant speed.
Try to produce the longest fiber possible. The withdrawal speed may need
to be adjusted depending on the polymer being used.
Try to "cold-draw" the fibers you have formed
by stretching them after they have cooled. How far can they be extended
before they break? What happens to the tensile strength as the fibers are
stretched? Why might the tensile strength change upon stretching?