Paper Title
The Effect of Aging on the Tensile Force of Nets for Covering Plantations in Greenhouses

It is known that the tensile properties of polymer materials exposed to atmospheric influences are significantly reduced. But when it comes to plastic nets, especially when they are used in greenhouses to protect plantations, they must retain certain mechanical properties after a long period of exposure to the sun, water, hail, wind, etc. The purpose of this study was to compare the tensile force of different types of plastic nets before and after their aging (UV rays and humidity). Commercially available nets made of polyethylene (HDPE) were exposed in a laboratory aging chamber according to ISO4892-2 and tested according to ISO 13934-1.After exposure to atmospheric conditions, the tensile force of standard HDPE nets with different mesh size that are used against wind, sun and hail decreased slightly, while the tensile force of net that are exclusively used to protect plantations from wind and the sun decreased by 33% but maximal displacement increased by 63%. This type of test corresponds to approximately 3 years of net application in reality, which confirmed that the nets does not need to be replaced during that period. Keywords - Aging, HDPE Nets, Greenhouse, Plantation, Tensile Force.