## 2 Materials and Methods
Environmental loads of both the recycled and virgin material types were taken from the Ecoinvent database. As part of this task, a life cycle assessment (LCA) analysis was carried out in accordance with Polish standards PN-EN ISO 14044:2009 [37] and PN-EN ISO 14040:2009 [38]. As part of the study, the boundaries of the system under study weredefined, which limited the process to the five phases of the bulk bottle packaging process (Figure 2). In total, 1000 seals were taken as the functional unit in the analysis. Data about the number of raw materials and energy used in the process under study were adopted for the analysis. The data came from measurements taken in 2023 at an industrial plant that is engaged in, among other things, shrink-wrapping bottles in Poland. Based on data from the operation of packaging machines in 2021-2023, it was determined that defective packages are about 1% of the total annual production. Determination of the impact of the studied process on the environment was carried out using the ReCiPe 2016 method, which is an updated and expanded version of ReCiPe 2008. The method, as a newer version of the methods used in LCA, was transferred from the European to the global category [39]. The activity analyzed the potential magnitude of impacts of all environmental impacts on three categories of damage, i.e., human health, ecosystems, and resource depletion [40; 41]. The use of life cycle assessment analysis is part of global trends in the search for energy-saving and efficient processes and is also the realization of the objectives of a resource-efficient economy of European Union member states [42; 43]. There are a number of products whose impact on the environment at the use stage depends on the user, so it is important to inform users how to properly handle the product in order to minimize its negative impact at the use stage and appropriate post-use management [44; 45; 46]. \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Film Properties**} & \multicolumn{4}{c}{**NRF Film**} & \multicolumn{2}{c}{**RF Film**} \\ \cline{2-6}  & & **LD** & **TD** & **LD** & **TD** \\ \hline Tensile strength [MPa] & 1 & 38.63 & 35.53 & 21.00 (\(-45.42\%\)) & 21.73 (\(-38.90\%\)) \\ SD & 2 & 2.78 & 2.38 & 1.57 (\(-43.51\%\)) & 1.33 (\(-44.14\%\)) \\ Stress at break [MPa] & 1 & 37.62 & 35.10 & 18.48 (\(-50.91\%\)) & 21.50 (\(-48.91\%\)) \\ SD & 2 & 3.78 & 3.23 & 1.96 (\(-48.14\%\)) & 1.45 (\(-55.12\%\)) \\ Yield strength [MPa] & 1 & - & 22.70 & - & 11.96 (\(-47.36\%\)) \\ SD & 2 & - & 0.64 & - & 0.32 (\(-50.01\%\)) \\ Elongation at maximum tensile stress [\%] & 1 & 654.83 & 952.61 & 416.62 (\(-36.47\%\)) & 709.01 (\(-25.63\%\)) \\ SD & 2 & 43.12 & 28.71 & 34.43 (\(-20.21\%\)) & 40.87 (\(+41.21\%\)) \\ Elongation at break [\%] & 1 & 655.15 & 953.32 & 418.31 (\(-36.24\%\)) & 711.35 (\(-25.42\%\)) \\ SD & 2 & 43.02 & 27.95 & 33.02 (\(-23.31\%\)) & 29.82 (\(+6.81\%\)) \\ Elongation at yield point [\%] & 1 & 9.57 & 7.82 & 11.53 (\(+21.13\%\)) & 11.33 (\(+44.83\%\)) \\ SD & 2 & 0.26 & 0.51 & 2.26 & 0.78 (\(+41.81\%\)) \\ \hline \end{tabular}
\end{table} 
Table 1: Statistical tensile test results for the tested heat-shrinkable film samples; 1—average value, 2—standard deviation. Figure 2: A diagram of the mass packaging process included limits of the technical system.