Design And Analysis Of Polymer Retro-Reflective Films With Micro Structures

Retro-reflective films can make light reflect back mostly along the incident direction to improve their own visibility.Thus,they have been widely used in road transportation.Films performing at optimum levels are very demanding for materials,mould and process including surface roughness and angular precision.With the increasing demand for retro-reflected films with better performance on high-grade highways,it is imperative to improve the structural design,reduce the film processing difficulty,cut down costs and so forth.In this paper,we regard micro cube corner prisms of polymer materials as the object of the research.The retro-reflection mechanism of micro cube corner prism films as well as the influence degree of various structural defects to reflectivity is analyzed and simulated based on the principle of geometrical optics.This study will provide theoretical support and experimental verification for improving self-developed processing technology of retro-reflective films.We establish laboratorial evaluation index system and measuring setup of retro-reflectivity to evaluate the optical performance of homemade films,which will guide the improvement of film processing technology.Meanwhile,we improve the structure design of films based on the principle of retro-reflection of micro cube corner prisms.The optical performance of an improved structure of films(cutting micro cube corner prism hereinafter)are theoretically analyzed and simulated.To achieve the best performance,we optimize the parameters of width-thickness ratio,tilt of symmetry axes,apex offset,etc.The cutting micro cube corner prism films can accomplish retro-reflection completely and have a wide range of effective incident angle in theory.The new type cutting micro cube corner prism films have better optimal performance than the traditional micro cube corner prism films by comparing the experimental results.Finally,we propose creative privacy films based on the optical performance of the micro cube corner prism structures.And the feasibility is analyzed through theory and simulation.