# Agrochemical Contamination and Ageing Effects on Greenhouse Plastic Film for Recycling
## 3 Materials and Methods  
Plastic film samples obtained from a PE-LD film commonly available in the market were alternatively contaminated with two agrochemicals. The first one was the anti-aphid insecticide EPIK SL VITHAL (active ingredient: Acetamiprid 50 g/L, producer: Ital-agro srl Salerano sul Lambro, LO, Italy). ), classified as hazardous for the environment--_GHS09, H410, \"very toxic to aquatic life with long-lasting effects\"_[25,26]. The second agrochemical used was the fungicide CUMETA FLOW (active ingredients: Metalaxil-m 1.85%, copper hydroxide sulfate 15.40%, producer: Diachem S.p.A. Caravaggio (BG)--Italy), classified as an irritant--_GHS07, H317 \"May cause an allergic skin reaction + H319 Causes serious eye irritation\"--_and hazardous for the environment--_GHS09, H410, \"very toxic to aquatic life with long-lasting effects\"_[25,27]. These two agrochemicals have been selected, based on information received by agronomists and greenhouse farmers in Southern Italy, since they are among, respectively, the most used anti-aphid insecticide and fungicide. The two agrochemicals were sprayed on one side of the plastic film, simulating the process taking place in real conditions, when droplets are dispersed by the equipment spraying agrochemicals in liquid consistency on cultivated crops. To this aim, a simple sprayer--usually employed for phytosanitary treatment of domestic plants--was employed, spraying the plastic film before extracting specimens for tensile tests at a distance of 30 cm (Figure 1). In this research, only one spraying was applied to plastic film, in order to simulate a simpler application first, corresponding to real conditions. The specimens were then aged for 2 and 4 weeks in an ageing chamber (Figure 1--right). The material was aged keeping a constant temperature of 20 \({}^{\circ}\)C in the ageing chamber. The ageing period was selected so as to simulate a corresponding ageing in open field in southern Italy, at the Municipality of Cellamare. There, a yearly global energy from the sum of 5554 MJ/m\({}^{2}\) = 132.74 kJy was detected in 2018. Since the energy released by the lamp of the ageing chamber has a power of 1000 W/m\({}^{2}\), this value corresponds to approximately 8 weeks of artificial ageing. Therefore, the tested periods of 2 and 4 weeks correspond to three and six months, respectively, in real conditions. The PE-LD plastic film was also analyzed without any contamination, so as to have a reference sample. The tested materials are reported in Table 1.  
After the ageing process, each plastic film was tested through tensile tests and radiometric properties. The mechanical properties were determined by tensile tests in the Laboratory of Material Testing at the SAFE School of the University of Basilicata, Italy. Ten specimens for each PE-LD film typology were cut according to the Italian UNI 8422 Standard [28]. The tensile tests were conducted, using a computerized universal machine Galdabini PMA 10 \begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{3}{c}{**PE-LD Film Typologies**} \\ \hline
**Contamination** & **Number of Weeks** \\
**(1 st Letter)** & **in the Ageing Chamber** \\ \hline
**N** = Not contaminated & 0 = no ageing \\ \hline
**A** = contaminated with anti-**A**phid & 2 = 2 weeks ageing in the ageing chamber \\ \hline
**F** = contaminated with Fungicide & 4 = 4 weeks ageing in the ageing chamber \\ \hline Example: **N2** = PE-LD film Not-contaminated, aged **2** weeks in the ageing chamber \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Nomenclature of the tested PE-LD films. Figure 1: Agrochemicals spraying in the laboratory (**left**) and ageing chamber (**right**). with a load cell of 5 kN (Figure 2), at constant deformation velocity of 200 [mm\(\cdot\)min\({}^{-1}\)]. The results obtained from tensile tests were reported in terms of maximum strength (\(\sigma_{\text{max}}\)) expressed in (MPa), and percentage elongation at break (A) expressed in (%).