The Study On The Mould Designed For A Continuous Injection Direct Rolling Imprint System For Microstructure Thin-Light Guide Plate

With the development of micro-optics,micro-structured polymers have been widely used in many fields of optics due to their variable microstructure characteristics,precise optical properties,and flexible processing methods.However,because of its small microstructure,high precision requirements,and difficult processing,microstructured polymer optical element molding technology has become a key research issue in the field of micro-optics.Continuous injectiondirect rolling is a continuous molding technology that combines injection molding and roll forming.Rolled microstructures are produced on the polymer by rotating rolls to achieve rapid and efficient micro structure replication.In this thesis,the injection-rolling nozzle with a width of 340 mm and a maximum extrusion plate thickness of 1mm was developed.The flow path in the nozzle was a “hanger type and fishtail type” combined flow channel and a rheological constitutive equation of PMMA was established.The finite element simulation software COMSOL was used to numerically analyze the flow state of molten PMMA in the flow channel.Aiming at the optimization problem of uneven exit velocity,a optimization method was proposed.Firstly,the characteristics of the main flow channels affecting the flow are analyzed,32 sets of simulation schemes are designed using the orthogonal flow channel characteristic parameters,and a fast parametric modeling of the injection nozzle is performed through the SolidWorks secondary development technology,and 32 different characteristic size flows are obtained.Through the numerical simulation,the mean flow variance(SDV)at the outlets of the 32 channels was obtained.Using these data,the BP artificial neural network was used to predict the data of another 32 sets of flow channels.The data was then fitted with a regression equation and the genetic algorithm was used to minimize the SDV to get the best channel.In addition to the study of the effect of the characteristic size of the runner on the outlet speed,the influence of the inner wall roughness of the outlet section on the uniformity of the longitudinal velocity of the fluid was also studied.Finally,the continuous injection rolling experiment was conducted to measure thethickness and microstructure of the obtained light guide plate.The data showed that the light guide plate was uniform in general,indicating that the optimized flow path of the injection nozzle was feasible,and the measurement of the light guide plate microstructure was also shown the depth of 20?m microstructure molding quality is better.