In this work, the effects of mold and melt temperatures on microstructures and properties of micropart were systematically investigated. Results showed that the remarkably enhanced flow field generated during microinjection molding process proved to be beneficial in forming, highly oriented self-fibrillating structures. In addition, especially in blends, changing the process temperatures from 200 degrees C to 270 degrees C significantly enhanced the onset crystallization temperature To (Delta t = 4.8 degrees C), peak crystallization temperature (Delta t = 1.5 degrees C), and the crystallization half-time (similar to 18.6 s). Interestingly, because of the orientation maintenance and shear amplification effects of in situ poly(ethylene terephthalate) (PET) microfibrils, the branching of lamella and the formation of hybrid-oriented structures (fan-shaped beta-crystals and trans-crystals) were accelerated. Furthermore, relative content of the beta crystal (increments of similar to 14.1%) and the degree of orientation were also significantly improved as the process temperatures were increased.