Title : Climatic ageing of low density polyethylene in agricultural greenhouses
Abstract:
Low density polyethylene (LDPE) is a type of plastic that is commonly used to manufacture greenhouse covers due to its desirable properties such as flexibility, durability, and transparency. LDPE is also relatively inexpensive compared to other plastics, making it a popular choice for greenhouse applications. Additionally, LDPE is resistant to UV radiation, which helps to protect plants from harmful rays of the sun. The lifetime of this material, theoretically planned for several years, is often hampered by the ageing process of LDPE is a complex phenomenon that involves several factors such as temperature, humidity, and exposure time. Over time, these factors can cause degradation of the polymer chains, leading to changes in physical and mechanical properties such as reduced strength, brittleness, and cracking.
This study aims to investigate the impact of these factors on the aging process of monolayer and tri-layer PE materials of the virgin (unaged) and aged by observing changes in their mechanical properties and creep behavior.
Over duration of nine months, a genuine greenhouse located in the Tiaret region of northern Algeria was subject to natural ageing as part of this study. The mechanical properties and creep behavior of monolayer polyethylene film are negatively impacted by environmental factors, whereas the tri-layer polyethylene film is more resistant to these effects. This is due to the additional layers providing a barrier against UV radiation and other environmental factors, as well as offering improved strength and stiffness compared to the monolayer film.
