Experimental investigation on the large-area fabrication of micro-pyramid arrays by roll-to-roll hot embossing on PVC film

Abstract

Large-area polymeric components with micro-pyramids have been widely applied in the fields of optics, optoelectronics, biology and chemistry, etc. Roll-to-roll (R2R) hot embossing is regarded as a promising approach to fulfil high throughput fabrication of patterned polymeric films. In this study, an R2R hot embossing system has been developed in-house and effective and continuous production of the polymeric component with micro-pyramids is demonstrated by R2R hot embossing. The influence of processing parameters has been firstly investigated by using the one-variable-at-a-time method. Afterwards, a series of experiments based on the central composite design approach have been conducted for the analysis of variance and the establishment of empirical models of the R2R hot embossing process. As a result, a 90 mm × 90 mm PVC sample with a feature height of 65 µm was successfully fabricated and the height consistency reached 94.5%. Additionally, a process window with a mold temperature of 150–160 °C, an applied force of 18–25 kgf and a feeding speed of 0.3–0.5 m min−1, was established to achieve 100% passable micro-pyramid arrays. The processing rules and the concrete ranges of parameter values can guide the process production of large-area micro-pyramids.