Effect of fiber feeding route upon extrusion process on the electromagnetic, mechanical, and thermal properties of nickel-coated carbon fiber/polypropylene composites

Abstract

Extrusion processing and properties of fiber-reinforced polymer matrix composites may be influenced by the fiber feeding route upon extrusion. The purpose of the present study was to investigate the effect of fiber feeding route on the fiber length distribution, electromagnetic interference shielding effectiveness (EMI SE), tensile, and flexural properties and heat deflection temperature of resulting composites with different fiber contents. H-NiCF/polypropylene and S-NiCF/polypropylene pellets were produced through two different feeding routes of nickel-coated carbon fiber (NiCF), hopper feeding (H) and side feeding (S) upon extrusion process, respectively. NiCF-reinforced polypropylene (PP) composites were fabricated by means of compression molding using each pellet, respectively. The effect of fiber feeding route on the electromagnetic, mechanical, and thermal properties of the composites with various NiCF contents was studied. S-NiCF/PP composites exhibited the EMI SE, tensile, and flexural properties and heat deflection temperature higher than H-NiCF/PP composites. The improved properties of S-NiCF/PP composites were ascribed to higher aspect ratio and longer fiber distribution of NiCF remaining in the composite than HNiCF/PP counterparts, due to less shearing and fiber damages during extrusion.