Optimization of machining parameters for a novel eco-friendly biocomposite reinforced with date palm fibers: reducing delamination to meet industrial demands

This study focuses on the machinability of a novel eco-friendly biocomposite reinforced with 30 wt. % of treated date palm fibers (DPFs), designed to meet modern environmental requirements. This innovative material, fabricated through a combination of single-screw extrusion and compression molding, holds significant potential for applications in various sectors, including automotive interiors such as dashboards, where precise drilling is essential for component assembly and fixation. The research emphasizes optimizing drilling parameters to minimize delamination, a common issue in machining natural fiber-reinforced composites. It also represents a pioneering effort in analyzing the machining behavior of powdered fibers, underscoring the originality and relevance of the work. Drilling experiments evaluated the effects of three drill diameters (3.5 mm, 5 mm, and 8 mm), feed rates (50 to 200 mm/min), and spindle speeds (500 to 2000 rpm) on critical performance indicators, including delamination factor, circularity, and cylindricity. These parameters were measured using advanced tools such as the Alicona Infinite Focus microscope and a Three-dimensional Measuring Machine (TMM). The study employed the Response Surface Methodology (RSM) and a hybridization of NSGA-II (Non-dominated Sorting Genetic Algorithm II) + SQP (Sequential Quadratic Programming) with a desirability function approach to optimize the drilling process. The RSM results revealed that drill diameter significantly influences delamination, with optimal parameters identified as a 5 mm drill diameter, a 50 mm/min feed rate, and a spindle speed of 500 rpm. These conditions minimized delamination while ensuring excellent circularity and cylindricity. However, the Hybrid RSM-Fuzzy Logic-Multi-Objective Optimization results indicated that the optimal parameters are a 5 mm drill diameter, a 50 mm/min feed rate, and a spindle speed of 500 rpm with a remarkable 100% desirability factor.