Design of Experiment Applied in the Chemical Separation Process of Plastic and Aluminum Present in Aseptic Carton Packages

Objective: This study aimed to investigate the separation of polyethylene and aluminum residue layers from Tetra Pak post-consumer packaging. This was achieved by facilitating a spontaneous reaction between aluminum and water, with the assistance of NaOH as a catalyst. Theoretical Framework: Aseptic carton packaging is widely recognized as safe and high-quality in the food and beverage industry. This type of packaging offers several properties, acting as a barrier against gases, light, loss of flavor, and water vapor while providing shape and flexibility. These characteristics are achieved by combining plastic, paper, and aluminum. Despite the significant advantages of multilayer films, recycling this material presents challenges. Methodology: During the initial planning phase, a 26-2 fractional factorial experiment was conducted to evaluate 6 different process variables: agitation (rpm), pre-treatment, NaCl concentration (g/L), time (minutes), temperature (°C), and NaOH concentration (mol/L). Subsequently, a second experimental design called the Design Central Composite (DCC) was implemented. The results indicated that only temperature and time remained statistically significant. Results and Discussion: Based on the experimental results, were able to identify the most effective conditions for separating polyethylene and aluminum waste from Tetra Pak post-consumer packaging using response surfaces an optimal region can be defined with a minimum temperature of 50°C, a minimum time of 30 minutes, and a minimum NaOH concentration of 3 mol/L. Originality/Value: This study adds to the existing literature by examining the application of experimental planning techniques in the chemical separation process of plastic and aluminum in Tetra Pak® packaging through two consecutive experimental plans.