Luminous powders are usually divided into two categories: photoluminescent energy storage luminous powders and radioactive luminous powders. After being illuminated by natural light, daylight, ultraviolet light, etc., the photoinduced energy storage luminous powder stores the light energy. After stopping the light irradiation, it is slowly released in the form of night light, so it can still be used at night or in a dark place. Seeing glow, it lasts for hours to a dozen hours.
Noctilucent powder with radioactivity is added to the noctilucent powder, and the luminous powder is excited by the continuous radiation of the radioactive material. This type of noctilucent powder emits light for a long time, but because of its toxic and harmful and environmental pollution, it has a small application range. And he has a life span. When it finishes emitting light, its life is over. This luminous powder is generally used in light sticks.
At present, domestic and international glow in the dark materials mainly use short-acting luminous powder ZnS and rare earth long-acting luminous powder to emit yellow-green, blue-green, and sky-blue light. However, the long-lasting luminous powder material is easy to deliquesce and cannot be widely used. Therefore, it is necessary to pay attention to sealing when using it, but it has a long luminous time, and it can emit light for more than 8 hours after absorbing light for 15-30 minutes, so more and more industries use it for indication and viewing effects: signs, toys, power on, electrical appliances and many other industries.
ZnS currently used on the market is a short-acting noctilucent material. The light absorption time is short, but its afterglow time is only 1-2 hours. This luminous powder is mainly used in the injection molding industry because it has stable performance in injection molding and does not easily turn black, so many plastic industries use it.