SHORT PINEAPPLE-LEAF-FIBER-REINFORCED LOW-DENSITY POLYETHYLENE COMPOSITES

Short pineapple-leaf-fiber- (PALF)-reinforced low-density polyethylene (LDPE) composites were prepared by melt-mixing and solution-mixing me thods. In the melt-mixing technique, a mixing time of 6 min, rotor spe ed of 60 rpm, and mixing temperature of 130 degrees C were found to be the optimum conditions. Tensile properties of melt-mixed and solution -mixed composites were compared. Solution-mixed composites showed bett er properties than melt-mixed composites. The influence of fiber lengt h, fiber loading, and orientation on the mechanical properties has als o been evaluated. Fiber breakage and damage during processing were ana lyzed from fiber distribution curve and optical and scanning electron micrographs. Considering the overall mechanical properties and process ability characteristics, fiber length of 6 mm was found to be the opti mum length of pineapple leaf fiber for the reinforcement in LDPE. The mechanical properties were found to be enhanced and elongation at brea k reduced with increasing fiber loading. Longitudinally oriented compo sites showed better properties than randomly and transversely oriented composites. Recyclability of the composite was found to be very good. A comparison of the properties of the PALF-reinforced LDPE composites with those of other cellulose-fiber-reinforced LDPE systems indicated superior performance of the PALF-LDPE composites. (C) 1995 John Wiley and Sons, Inc.