Fleece can be made from polyethylene terephthalate (PET) bottles. The first step is to wash and then mechanically crush the bottles, shaping the plastic into small chips. The chips can then be heated and forced through tiny holes in a metal plate (called a spinneret), which forms fibers that harden as they cool to room temperature. These fibers are wound onto a spool as they are formed, and they can subsequently be stretched to improve their strength. Machines can then be used to texturize and cut the fibers to their desired length and be used to make fleece cloth for clothing, blankets, etc.