Multi-objective optimization of process parameters for laser cutting polyethylene using fuzzy AHP-based MCDM methods

This experimental study examines how cutting parameters influence surface roughness (Ra), kerf width (KW), heat-affected zone (HAZ), and material removal rate (MRR) during CO₂ laser cutting of polyethylene (PE) material. The aim is to determine the optimal cutting conditions by integrating fuzzy analytic hierarchy process (AHP) and multi-criteria decision-making (MCDM) methods. Control factors (i.e. focal length, power, and cutting speed) were varied in a full factorial experimental design. Criterion weights for the responses were calculated with the help of the AHP method in fuzzy environment, resulting in weights of 0.442 for Ra, 0.102 for KW, 0.287 for HAZ, and 0.169 for MRR. These weights were integrated into MCDM methods (i.e. combined compromise solution [CoCoSo], technique for order preference by similarity to ideal solution [TOPSIS], and Vlsekriterijumska Optimizacija I Kompromisno Resenje [VIKOR]) to rank the experiments and identify the optimal parameters. The optimal cutting condition was found to be a focal length of 8 mm, power of 90 W, and cutting speed of 12 mm/s. Spearman's rank correlation coefficients were applied for analysis of the consistency among the hybrid approaches, with results indicating a very strong positive relationship between them. This comprehensive approach ensures precise and efficient laser cutting of PE, contributing valuable insights to the field of manufacturing and materials processing.