The materials that I am looking at are a wide variety of types of plastics. They range from almost hard as rock to something I like to drink in. I think that certain types of plastics are used differently then other because they all are different. The way the plastic is being made is much different so naturally the way they are used is a lot different. A milk industry uses high density polyethylene to make it so that it is strong enough to hold the milk but light enough to carry. It is durable and weather resistant making sure the milk does not get ruined by outside things. It is recyclable and reusable, that means it can be reused. We would not use another type of plastic there because it cannot satisfy does needs.