How is fleece made? Well,the used plastic bottles are collected from the recycling banks. They aren't all used to make fleece so they are separated into different types of plastic. The PET plastic is sent to a reprocessing plant. Here, the bottles are cut into small pieces and are put in water to clean them. Then they are melted and put in a special machine which creates the synthetic fibres. These fibres are then woven to make the fleece fabric.