| Abstract [eng] |
Non-recyclable packaging waste from multilayer composites is a major waste management problem. Delamination allows the polymer layers to be recycled individually, increasing their recyclability. Multilayer composite packaging (MCP), which integrates multiple materials in a layered structure, is widely used in various industries because it protects and preserves products in an economical way. The packaging polymer is layered with aluminium foil (Al), cardboard, and other polymers, with each layer serving a different purpose (1-3). In 2020, Europe generated 80 million tonnes of packaging waste, of which plastic accounted for 19.5% (4). Also, 12% of the world's waste is plastic, including plastic packaging (5). For the following study, 24 experiments were conducted for potato chip packaging. Nitric acid (20%, 25%, 30%) was used for delamination, the temperature was 55 0C, 65 0C, 75 0C, and the time ranged from 35 to 1350 minutes. Modde 13.0.1 (Umetrics) was used to create a factorial design of tests. Temperature (T), concentration (C), width (a) (type: quantitative), and ultrasonic (Ult) (type: qualitative) are all elements in the overall experimental design; the response is the duration (t) (type: quantitative). The software has determined the predicted time. Trends can be seen by evaluating the differences between the predicted and observed durations. No ultrasound was used during the experiments, so the predicted values were essentially the same as the observed values and a linear equation was formed with an R2 of 0.9749. The trends of the linear equation are not apparent in the tests with ultrasound, and there is a significant scatter plot of points that deviate from the predicted line. However, in this fourth-degree example, the scatter plot shows a polynomial curve with R2 equal to 0.5544. [...]. |
