AWJ machining of epoxy/crumb rubber/rice-straw powder composite: optimisation of MRR using Taguchi approach

Growing global concern over agricultural and tire waste has spurred research into sustainable recycling solutions. This study examines the abrasive water jet machining (AWJM) of a novel epoxy composite reinforced with rice straw powder and crumb rubber. The material removal rate (MRR) was evaluated using a Taguchi L9 array, varying stand-off distance (SOD), traverse speed (TS), and number of passes across three material compositions. Results showed MRR increased with higher SOD but decreased with faster TS and more passes. A higher rice straw content and lower crumb rubber percentage also reduced MRR. Atomic force microscopy revealed that a low TS produces a smooth surface, even at high SOD and a single pass. A regression model (R² = 90.12%) was developed to accurately predict MRR. This work provides crucial guidelines for manufacturers on machining this sustainable composite, balancing material composition and process parameters for optimal results.