逆反射材料中玻璃微珠的协同效应

半球镀膜玻璃微珠是逆反射材料的基本反光单元,目前的研究主要局限于单个微珠的属性,很少涉及到逆反射过程中相邻微珠间的协同作用.实际上协同作用的存在使整个膜的反光属性不同于单个微珠的情况.本文全面分析了逆反射光线传输过程,并结合逆反射材料的结构特点设计开发了玻璃微珠阵列结构逆反射材料的数值计算程序,计算了逆反射效率随微珠排布密度、材料折射率、光线入射角等参数的变化.结果表明,微珠阵列的协同作用表现为倾斜效应和遮挡效应.前者严格遵循倾斜因子ε=1/cosθ的定量规律,而后者的作用可通过遮挡因子来定量表示.入射角较小时主要体现为倾斜效应,而入射角较大时倾斜效应和遮挡效应两者共同发挥作用.

Synergistic effect of glass beads in retroreflective materials

Hemispherical coated glass beads are the basic reflective units of retroreflective materials. But, so far, the studies are only limited to the properties of individual glass bead, and have not yet involved synergy between adjacent beads during the retroreflective process. In fact, the presence of synergism makes the reflective properties of the entire film different from that of individual beads. In this paper, the retroreflective ray transmission process was comprehensively analyzed, and a numerical calculation program for glass bead array retroreflective materials was developed taking into account the structural characteristics of retroreflective materials. The variation of retroreflective efficiency with the density of micro beads, the refractive index of the material, and the incident angle of the light were calculated. The results show that the synergistic effect of the bead arrays manifests as inclination effect and shading effect. The former strictly follows this quantitative rule of "the incline factor ", whereas the role of the latter can be quantitatively represented by the shading factor. The inclination effect lonely works at small incident angle, while both inclination effect and shading effect work together when the incident angle is relatively large.