When will the paper mill of Quande Company, Dehui City, Jilin Province be officially put into operation?

It will be soon. Unfilled paper is composed of fibers and air. Air exists in the pores between fibers. Since the refractive index of fibers and air are different, when the light beam hits the surface of the paper, part of the light is scattered at the interface between the fibers and the air, giving the paper a certain (lower) opacity. , reflected in printing, mainly showing that it is easy to print through. After adding a filler with a refractive index greater than that of cellulose in the paper, the number of light scattering interfaces inside the paper increases, that is, there are three different interfaces between fibers and air, between fillers and fibers, and between fillers and air. In these three interfaces , the difference in refractive index between the filler and air is large. Light therefore scatters maximally at the filler-air interface, resulting in increased opacity.