Whitening principle of fluorescent whitening agent
Before understanding the principle of whitening, we must first understand what complementary colors are. Red, blue, and yellow are called the three primary colors, and almost all colors can be tuned out by mixing them. Moreover, when the two colors of light are mixed and the result is white, the two colors are called complementary colors to each other, that is to say, the colors located on the diagonal of the color circle in the figure below are complementary colors to each other. From this picture, we can know that the yellowing of the object is due to the lack of blue light and the loss of balance.
Fluorescent whitening agents absorb ultraviolet light invisible to the naked eye, and then emit it in the form of blue-violet fluorescence. This blue-violet fluorescence is mixed with the yellow light on the object (yellow is the complementary color of blue-violet) to obtain white light, thereby achieving the effect of whitening and brightening.
PS: The yellow light is because the plastic is easy to oxidize during processing, the raw material itself turns yellow, etc.
Brightening principle of fluorescent whitening agent
Ultraviolet UV (ultraviolet) is divided into four types in vacuum: short wave, medium wave, long wave and ultra long wave. Ultraviolet refers to the general term for radiation with wavelengths from 10nm to 400nm in the electromagnetic spectrum, which cannot be seen by people. The short-wave blue light has a wavelength between 400nm and 480nm, which is visible to the naked eye and has relatively high energy.
According to the whitening principle of fluorescent whitening agents, it can be known that the characteristics of fluorescent whitening agents are mainly to absorb invisible ultraviolet rays and emit blue-violet light visible to the naked eye, which increases the total reflection of items, thus making items look brighter and brighter.
PS: The principle of whitening agent anti-ultraviolet
The characteristic of fluorescent whitening agent absorbing ultraviolet rays can also effectively protect items from ultraviolet rays and prolong the service life of items. According to these characteristics of fluorescent whitening agents, you can use your imagination, any products that need brightening and UV protection can use fluorescent whitening agents.