Application of the NSGA-II Algorithm and Kriging Model to Optimise the Process Parameters for the Improvement of the Quality of Fresnel Lenses

• DOI: 10.3390/polym15163403
• Publication Date: 2023-08-14T14:28:13Z
• Authors: Hanjui Chang; Yue Sun; Rui Wang; Shuzhou Lu
• Keywords: Fresnel lens; Zone plate; Engraving; Fresnel zone

The Fresnel lens is an optical system consisting of a series concentric diamond grooves. One surface the smooth, while other engraved with circles increasing size. Optical interference, diffraction, and sensitivity to angle incidence are used design microstructure on surface. imaging depends its curvature. By reducing thickness lens, light can still be focused at same focal point as thicker lens. Previously, lenses, including were made glass due material limitations. However, traditional grinding polishing methods for making lenses not only time-consuming, but also labour-intensive. As result, costs high. Later, thermal pressing process using metal moulds was invented. high tension caused some detailed parts deformed during process, resulting in unsatisfactory performance. In addition, complex manufacturing unstable processing accuracy hindered mass production. This resulted prices limited applications lenses. These factors prevented widespread use early contrast, polymer materials offer advantages, such low density, weight, strength-to-weight ratios, corrosion resistance. They cost effective available wide range grades. Polymer have gradually replaced manufacture micro-optical miniaturised devices. Therefore, this study focuses investigating parameters injection moulding process. We compare quality products obtained by two-stage moulding, compression IMD (in-mould decoration) techniques. results show that optimal method IMD, which reduces nodal displacement improves transmission To achieve this, we first establish Kriging model correlate optimisation objectives, mapping objectives. Based model, integrate NSGA-II algorithm predictive obtain Pareto solutions. analysing frontier, identify best parameters. Finally, it determined average 0.393 mm, holding pressure 320.35 MPa melt temperature 251.40 °C. Combined technology, product testing shows transmittance 95.43% rate 59.64%.