How is polyester made?
High heat applied to specific ingredients creates these long, strong fibers. RecycleMan/Shutterstock
To understand why it lasts so long, it helps to know how it's made. Polyester is made at very high temperatures in a vacuum. Carboxyl acid and alcohol from petroleum are mixed to form a compound known as an ester, which is heated up and stretched into long fibers, according to Plastic Insight. This is chopped into chips or pellets, which are really strong.
To make polyester fiber, the pellets are forced through small holes or spinnerets. When they come through the other side, the fibers solidify, creating a continuous line that resembles fishing line. That line can then be made into just about anything.