Theoretical Research And Structure Design Of Cube Corner Retroreflective Film

Retroreflective film are widely used in the production of road traffic signs and personal protective equipments, providing effective security for traffic participants and the dark night operation personnel. According to the difference of retroreflective principle, retroreflective film can be divided into glass beaded type and cube corner prism type. Compared with the former,cube corner prism type has higher retroreflection coefficient, and also it’s production process is environmental friendly and consumes less energy.The retroreflective film made by standard cube corner prism structure will suffer the problems of limited entrance angle and anisotropy of retroreflectance, so it is necessary to improve the standard cube corner prism structure, namely redesign the structure. The traditional process of structure design of retroreflection material is: putting forward design plans, preparing sample, testing, improving, and then finalizing the design. This kind of design method will cost a lot of manpower and material resources, the development cost is very high, and the research period is quite long. Using computer simulation to estimate the retroreflection characteristics of retroreflective film, can reduce the intermediate links such as sample preparation and testing, saving a lot of time and expense. But, error must be strictly controlled during estimation. Adopting the method of ray tracing,cube corner unit retroreflectance calculation model is established based on the basic principle of optics. The model fully considers reflection losses,refraction losses and polarization effect in the transmission process. The retroreflectance in different directions(referred to as entrance angle and azimuth angle) can be calculated out. By directly using the established model,the connection between retroreflection properties and material type as well as structure parameters can be built, thus the blindness of traditional design is solved, and the research period of retroreflective material is greatly shorten.Secondly, we use the model to study the main parameters of cube corner prism which is based on laminae combination technology(including symmetry axis cant, apex decentration, width/thickness ratio), and sums up the optimized parameters to guide the retroreflective film design. Finally, the cube cornertype retroreflective film divergence angle characteristics are analyzed, also an improved structure design sample is put forward.