Plastic is made from hydrocarbons derived from petroleum or natural gas. The hydrocarbons are formed into chains called polymers or plastic resins. Different combinations of hydrocarbon molecules produce different types of plastic. There are seven different types of plastic resins, each with different features. For example, some are resistant to acids and some to caustics. Others may be able to withstand high and/or low temperatures. Some plastics are rigid and some are flexible. There are impact resistant plastics and those that are not. Certain plastics provide a good moisture and/or gas barrier – several are appropriate for contact with food.
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