Processability Characteristics of Biocomposite from Recycled High‐Density Polyethylene and Brewers’ Spent Grain

Abstract The current awareness of the environmental impact of the massive consumption of fossil fuel‐based resources has prompted the development of biocomposites based on plastic and agro‐industrial waste instead of virgin raw materials, promoting the new circular economy trend. This study uses a torque rheometer to analyze the effect of brewers’ spent grain (BSG) on processing a postconsumer high‐density polyethylene (rHDPE)‐based biocomposite. Processing parameters are measured to contrast the effect of BSG (20 and 40 wt%) and the addition of a coupling agent at low (10 rpm) and high speed (90 rpm). This work allows determining the viability of manufacturing recycled plastic biocomposite with agro‐industrial waste at an industrial scale.