Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE In this study, a self-made double-rotor extruder (DRE) was developed. Glass fiber-reinforced polypropylene composites were successfully fabricated using it. The findings demonstrate that solely increasing the rotational speed of unit II further enhances the mechanical properties. Additionally, the DRE minimizes fiber damage, with all specimens exhibiting an average retained fiber length exceeding 1.9 mm.


ABSTRACT
Glass fiber-reinforced thermoplastic composites, with their high specific strength properties, are a promising material for structural applications. However, due to the brittleness of glass fibers, they are prone to breakage under shear forces, and current processing equipment struggles to balance fiber retention and dispersion efficiency. In this study, the structure and processing principle of the self-made double-rotor extruder (DRE) are described in detail, and experiments on the preparation of glass fiber-reinforced polypropylene (PP/GF, containing 30 wt% glass fiber) composite sheets were conducted by it. The results show that the composites achieved a maximum tensile strength of 72.82 MPa at a rotor speed of 15 rpm. Furthermore, increasing the rotor speed of the second double-rotor unit to 35 rpm significantly enhanced the tensile strength to 86.39 MPa. The study also reveals that the DRE minimized fiber damage, with the average fiber retention length exceeding 1.9 mm across all specimens. SEM images showed a uniform distribution of fibers in the matrix, with no significant agglomerations, indicating effective dispersion. The study successfully addressed the balance between fiber retention and mixing efficiency through optimized equipment design and processing parameters, providing a novel approach for enhancing the performance of fiber-reinforced thermoplastic composites.