SILK FIBER ORIENTATION EFFECT ON FLEXURAL AND TENSILE STRENGTH OF ZEOLITE-REINFORCED HIGH-DENSITY POLYETHYLENE COMPOSITES

The role of silk fibers (SF) orientation is very decisive on the mechanical performance of high-density polyethylene (HDPE) with zeolite (Z) as a reinforcement material. This work aims to analyse the tensile and flexural characteristics of zeolite-filled HDPE (Z/HDPE) composites due to the incorporation of SF in numerous orientations. The SFs with a length of approximately 1 mm is chopped off for incorporation in the powder dry mix of Z and HDPE, which is ready for SF-oriented mold at angles ranging 0 degrees, +/- 22.5 degrees, +/- 45 degrees, +/- 67.5 degrees, and +/- 90 degrees. The compression moulding technology creates composites to fit dumbbell shapes. The flexural test was carried out in compliance with the ASTM D790 standard, whereas tensile properties including elastic modulus, tensile strength, elongation at break as well as yield strength were assessed on dumbbell shape composites. The findings demonstrate that the maximum force, as well as the elastic modulus, drop by changing the orientation of the fiber towards 0 degrees. This propensity also takes place in failure and energybreaking strains. Flexural strength and breaking energy decreased by about 510% of the initial value for each additional 22.5 degrees fiber orientation angle. However, the flexural modulus and other tensile properties are decreased irregularly by the addition of the fiber orientation angle. Furthermore, the theoretical E- modulus value exceeds the experimental value by about 15 to 20%. The flexural and tensile strength of the composite is maximum at the SF orientation angle of 0 degrees.