Surface Replication and Structural Development in Micromolding for Micro/Nanocomposites

Abstract

Micromolding with micro-scale surface features of hexagonal boron nitride (h-BN) / polypropylene (PP) composites with different h-BN component was performed to improve molded parts’ heat diffusivity and processability. Effects of h-BN content and process parameters on processability, higher-order structure, and microscale surface patterns of molded parts were analyzed using SEM, WAXD, SPM, and confocal laser scanning microscopy. The replication ratio of the microscale surface pattern and flow length of composite molded parts was improved by compounding the h-BN filler. The replication ratio of the microscale surface pattern near the flow end became greater than 1.0 because of deformation of surface patterns during de-molding. The replication ratio and shape of surface patterns of molded parts were improved with the increase of the h-BN component. The h-BN platelet oriented inside surface micro-features; skin-shear-core structures were well observed in the molded parts.

Microinjection molding of thermoplastic polymers: morphological comparison with conventional injection molding

“…They also noted that morphology depends on both the molding conditions and the position of the analysis along the filling length of flow. They show that the relative amount of core is higher near the injection gate, as well as the orientation of crystals [44,45]. The skin is 70 μm thick and presents a high molecular orientation.…”

Microinjection molding of microsystem components: new aspects in improving performance

“…This implies that at this scale level no substantial difference exists between the μIM and CIM in terms of morphology evolution [135]. The main differences associated with μIM parts are basically the increase in relative thickness for skin and shell layers, and thus the decrease for the core [136].…”