Natural protein fiber hybrid composites: Effects of fiber content and fiber orientation on mechanical, thermal conductivity and water absorption properties

The intimately mixed natural protein fiber hybrid composites in three different fiber concentrations (70:30, 50:50 and 30:70) and two different fiber orientations (parallel laid and cross laid) are produced using silk and wool fibers with polypropylene fibers as matrix material. The composites are fabricated using compression molding technique with optimized process conditions. The effects of fiber content and fiber orientation on mechanical, thermal conductivity and water absorption property are studied. Scanning electron microscope is used to examine the fracture morphology of the composites. The study reveals that the fiber content strongly influences the mechanical, thermal conductivity and water absorption property of the resultant composite. But the fiber orientation shows significant effect only on water absorption property of the composites. It does not show any significant difference in mechanical and thermal conductivity properties of intimately mixed silk/wool hybrid fiber composites.