## 4 Discussions  
The static tensile test showed that the film had lower tensile strength values by up to 45.4% in the longitudinal direction (38.63 and 21.0 MPa for NRF and RF films, respectively), as well as lower elongation at failure by up to 36.2%. The tear strength test showed that RF film in the longitudinal direction had a strength that was 21.6% lower than that of NRF film (10.79 N for NRF and 8.47 N for RF). In addition, in the impact resistance test, the recycled film had a 14.1% lower strength (0.7 and 0.61 N for NRF and RF, respectively). The abovementioned figures are influenced by the preparation of the polymer blend being processed [6; 47]. Comparing the properties of selected film samples obtained as part of the tests with the data described by [PERSON] [6], we see that the RF film samples are characterized by properties such as those of low-density polyethylene (LDPE), while the NRF film is characterized by linear low-density polyethylene (LLDPE). For example, the determined yield stress for the NRF film was 22.7 MPa and for the RF film was 11.96 MPa. According to data provided by Burelo, yield stress for LDPE is in the range of 8-19 MPa, and for LLDPE is 8-29 MPa. In the case of melting temperature, LDPE is 100-115 \({}^{\circ}\)C and LLDPE is 100-125 \({}^{\circ}\)C. The tests performed showed that the melting temperature of the RF film is in a range that would indicate the presence of a mixture of LDPE and LLDPE in this film, which would confirm the differences in the other determined use values of the tested film samples. Unfortunately, detailed information about this process was not made available by the company from which the tested samples were obtained. In addition, it can be assumed that the performance of the film depends on the batch of recycled material and may vary depending on the contaminants contained and the degree of degradation of the waste, which is the input material throughout the recycling process [48; 49]. The changes in strength shown do not affect packaging efficiency. This was evaluated based on the number of complaints about damaged seals reported by customers. Their number is similar for RF and NRF film seals. The DSC analysis showed that RF film has a 1.85 \({}^{\circ}\)C lower melting point and 1.94 \({}^{\circ}\)C lower glass transition temperature, which affects the process under study at the stage of sealing the film in the heating oven. A lower temperature in the heating oven could be set for RF film than for NRF film packing of bottles, which could consequently reduce the amount of energy consumed in the process. Based on the DSC results, it can also be concluded that the recycled RF film has a higher number of inclusion and contaminants present in its structure, which may be a consequence of the indefinite number of recycling processes (each processing is accompanied by a temperature change, which affects the  
Figure 9: Characterization results within the damage to the ‘resources’ category for the studied variants of the bottle packaging process. changes in film properties). Figure 6 shows that a double peak appeared during the temperature change, for example, in the case of a mixture of LLDPE with another material, such as PP polypropylene. These materials have different melting points [48], and therefore two peaks appeared at their respective temperatures. In our study for FR film, there were also two peaks, one of which was the result of impurities present in the material. For the NRF film (Figure 7), a single peak was visible when the temperature changed, which indicates the higher purity of the granules used in manufacturing. An environmental LCA analysis was carried out based on the ReCiPe2016 method, determining the impact of different variants of the studied technological process on three categories of damage, i.e., \"human health\", \"ecosystems\", and \"resources\".