The response surface methodology for plastic pallet formulation from flexible multilayer packaging waste

Flexible multilayer packaging (MLP) is a type of packaging that consists of several layers of different polymers and aluminum. MLP recycling is difficult due to the incompatibility of some of its components, resulting in poor recycling product performance and a low market value. Using a compatibilizer in MLP recycling may solve the problem, and thus recycled MLP may find suitable applications. This research blended shredded MLP and HDPE bottle caps with PE-g-GMA as a compatibilizer using a single screw extruder. The barrel temperatures were set at 180 to 260°C for different zones, and the rotation speed was at 100 rpm. The weight ratio of HDPE caps to MLP varied from 0.16 to 1.14, and the weight % of PE-g-GMA varied from 0.3 to 11%. Central composite design (CCD) generates 11 runs with different material formulations. The flexural test specimen was manufactured using injection molding and tested according to ASTM D790. FTIR and DSC were measured to support the investigation. The optimum flexural strength of 16.3 MPa with a 0.65 weight ratio of HDPE caps to MLP and 0.4 wt.% PE-g-GMA was obtained through response surface statistical analysis using Rstudio software. According to optimum flexural strength results, a panel pallet with SNI 8944:2021 dimensions have a 724 kg load.