Novel vat design for liquid crystal display vat photopolymerization: reduction of separation force and pixelated effect

Liquid crystal display (LCD) vat photopolymerization (VPP) is increasingly adopted in additive manufacturing for its precision and affordability. However, challenges such as elastic contact between the resin vat interface and the LCD panel increase the overall separation force, especially at high back force and interface compliance at elevated temperatures. Additionally, the discrete and unconnected pixels in the LCD panels cause pixelation, leading to surface roughness in printed parts. To address the issues, this study introduces a novel resin vat design with a controlled gap (0.5 and 1.0 mm) between the interface (Teflon) and the LCD panel. Tests with commercially available high-viscosity foam resin (4L15) and acrylate-based fast curing (high-speed) resin demonstrate that introducing the gap effectively reduces elastic contact, lowering separation forces by 33.4% and 23.6% respectively. Surface quality improved significantly, with the 1.0 mm gap achieving an 80% reduction in average surface roughness by effectively minimising pixelation. Case studies, such as functional shoe soles with complex lattices and large solid architectural models, highlight the gap design’s effectiveness using foam and fast curing resins. This study offers key insights into improving print quality and reliability in LCD VPP.