Flexible film separation analysis of LCD based mask stereolithography

Abstract Mask stereolithography technology uses ultraviolet masks to print curable liquid materials. A key process for layer-by-layer bottom-up mask printing is the separation of cured layer from the vat bottom. For film-assisted separation, most studies focused on the separation process of the inert film that bonded to the vat bottom. The separation characteristics and mechanism of the widely used flexible film has not received much attention. In this investigation, based on liquid crystal display (LCD) mask stereolithography, separation processes of the inert film in both semi-flexible and flexible states were compared and analyzed. The results showed that the average maximum separation force of flexible film was reduced above 48%, and the average separation energy was reduced above 22% compared with the semi-flexible film for both large-area and array supports models. The flexible film can smooth separation process by reducing the stiffness of separation force curve. The reducing effect of separation force of flexible film was achieved by its large deformation and mixed-mode fracture mechanism.