First, plastic is collected and taken to a recycling center, where it is "sorted out". When plastic is sorted out by hand, symbols have to be printed on every recyclable plastic product used. Nowadays, machines can sort out the plastic automatically. There are different types of plastic, for example "polyethylene", "polypropylene", "polystyrene", and "polyethylene terephthalate". There are two kinds of polyethylene plastic: "high density polyethylene" (HDPE), and "low density polyethylene" (LDPE). HDPE plastic is usually used to make milk bottles and bottles for shampoo or detergents. LDPE plastic are usually things like toothpaste tubes, plastic bags, and films for packaging. Polypropylene plastic is used to make buckets, plastic boxes, and flower pots. Polyethylene terephthalate is the material from which water and soft drink bottles are made.