Experimental investigation of mechanical properties of hybrid sisal fiber and sheep wool reinforced epoxy composite material

Hybrid two or more fiber-reinforced composites are generally prepared to enhance different properties as compared to single-fiber reinforced composites. Sheep wool and sisal fibers are natural fibers that can be obtained from animal and plant sources respectively. After extracted and treated the fibers, the woven yarn fiber mat was prepared. The woven hybrid composite was fabricated with a 20% weight fraction of fiber by using hand layup fabrication techniques. Composites samples were prepared under five different weight percentage ratios of sheep wool to sisal fiber 0:20, 5:15, 10:10, 15:5, and 20:0. And each weight percentage of a sample was fabricated with two different angles (0°-90° and ±45°) of orientations. From the experimental test results, it was observed that the tensile, compressive, flexural strengths increase directly with increase sisal fiber weight percentage of composite samples in both 0-90° and ±45°angle of orientations. However, between the two angles of orientation, the tensile and flexural strengths of the hybrid sheep wool and sisal fiber epoxy composite samples were highest in 0-90°angle orientations composite samples. On other hand, the compressive and impact strengths were highest in ±45°angle orientation of the composite samples. Overall, the composite sample with a 15:5 sisal fiber-sheep wool ratio (SA4 and SB4) demonstrated the best mechanical performance. The maximum tensile and flexural strengths of 95.73 MPa and 358.80 MPa, respectively, were obtained for the 0°–90° oriented composite, whereas the highest compressive strength of 95.73 MPa and impact strength is 746.77 kJ/m² were observed in the ±45° oriented composite. The experimental test result shows that the hybrid sheep wool and sisal fiber epoxy composite are alternative materials for the interior part of automotive applications like interior roof and door panels.