Final answer:
The most common flexible plastic film used in greenhouses is polyethylene, with linear low-density polyethylene (LLDPE) being a prevalent type due to its strength and tear resistance. Polyethylene dominates the plastic market, especially for agricultural uses, including greenhouse films.
Step-by-step explanation:
The most common flexible plastic film used for greenhouses is made from polyethylene, also known as polythene. This material has become immensely popular for agricultural applications, including greenhouse coverings, due to its durability and flexibility. As of 2017, polyethylene resins constituted a significant portion of the plastics market, amounting to over 100 million tonnes of annual production. This accounts for 34% of the total plastics market, making it a dominant player in the industry. Polyethylene's flexible nature allows it to be used in various products including agricultural films, plastic bags, and containers.
Within the category of polyethylene, there are many types which may vary slightly, but most of these polymers share the basic chemical formula (C₂H4)n. Greenhouse films specifically are often made using a type of polyethylene known as linear low-density polyethylene (LLDPE), which provides a strong, tear-resistant film. It's also worth noting that the LLDPE market saw significant growth, with a market volume of US$40 billion as of 2013.