The design of supported two- and three-site catalysts for ethylene polymerization and tailoring nanophase-separated polyethylene reactor blends represents the key to the development of advanced all-polyethylene nanocomposite materials exhibiting substantially improved performance and high resource-, eco- and energy efficiency. Two or three different single-site catalysts independently produce high density polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMWPE) and PE wax on the same catalyst support. Since this catalyst-mediated nanophase separation prevents UHMWPE entanglement, typical for conventional homogeneous reactor blends, much higher UHMWPE content up to 30 wt % is incorporated in the presence of PE wax without impairing injection molding. During melt processing the shear-induced oriented UHMWPE crystallization affords shish-kebab-fiber-like nano-structures. This accounts for effective PE self-reinforcement paralleled by simultaneous improvement of stiffness, strength and toughness. Hence, this strategy holds great promise for converting commodity PE into high performance plastics and single component PE composites, entering the performance range currently claimed by glass fiber reinforced PE. (C) 2016 Elsevier Ltd. All rights reserved.