The photoluminescent film can glow because it is a photoluminescent material. Photoluminescent material is a material that emits or radiates light from its surface after absorbing light energy. The photoluminescent film absorbs ambient light during daytime and glows or shines in darkness by releasing its absorbed light energy.
The photoluminescent film can be charged by any source of light, provided the light intensity is greater than 25LX. Even a standard lamp can charge it. It glows with high light intensity in the first 2-10 hours but gradually reduces after that. The glowing intensity of a photoluminescent film is highest during its first 30 minutes of light emission.
All photoluminescent film products are self-powered. This means when a photoluminescent film product like a safety sign is charged by ambient light, it can emit light or glow on its own. It does not require any external light source or power to shine after it’s been charged.