Effect of compatibilization agents and rice husk on the energy demand on the extrusion of recycled high-density polyethylene composites

Abstract

The new trend of the circular economy encourages the preservation of the planet’s resources. In this sense, plastic recycling is one of the critical strategies in line with the circular economy. Rice husk is one of the principal agro-industrial waste in Ecuador. Its harnessing also promotes this trend. The energy demand in single screw extrusion has been studied to optimize production cost in extrusion process manufacturing. This study examined rice husk’s effect on the extrusion process’s energy demand using a recycled high-density polyethylene (rHDPE) with a tapered compression screw with dispersive and distributive mixers. Rice husk was reduced to a maximum particle size of 45μm. Two commercial compatibilizers based on Maleic anhydride-grafted polyethylene-octene elastomer (POE-g-MA) and ethylene-glycidyl methacrylate copolymer (E-g-MA) were used to enhance compatibility between the rice husk and the polymer matrix. The energy consumption was measured on the total energy of the extruder machine. The energy consumption (EC) and specific energy consumption (SEC) were measured to contrast the effect of the rice husk (3 wt%) and the addition of the compatibilizers. The SEC of RH/E-g-MA and RH/ POE-g-MA were at about 41.11% and 55.32%, respectively, lower than rHDPE. This work suggests that rHDPE/RH bio-composite processing incurs minor costs when coupling agents, processing conditions, and screws are carefully selected.