Multilevel Modification of High‐Performance UHMWPE Composites: Filler Morphology, Cross‐Link, and Molding Control

High melt viscosity and limited thermal‐mechanical properties restrict ultra‐high molecular weight polyethylene (UHMWPE) applications. This study proposes a multilevel synergistic strategy integrating filler morphology screening, γ‐irradiation cross‐linking, and molding process control. Comparing organic nano montmorillonite, ultrafine white mica, and acicular wollastonite, ultrafine white mica was identified as the optimal filler, reducing the coefficient of friction by 27.2% to 0.19 via its unique “micro‐shovel” slip mechanism. Subsequently, 100 kGy irradiation combined with remelting was established as the optimal processing window. This created a “physical‐chemical dual‐scale confinement network” with mica layers, increasing the Shore hardness of the UPE‐M‐5 composite to 80.1 D and reducing the coefficient of friction to 0.17, while maintaining 334% fracture elongation. Furthermore, single‐screw extrusion with two‐stage cooling was found to effectively utilize shear‐induced crystallization, significantly enhancing the elastic modulus to 555.18 MPa and tensile strength to 37.07 MPa. This work clarifies multiscale structure regulation mechanisms, providing theoretical guidance for the continuous manufacturing of high‐performance UHMWPE composites.