Gloss
Laboratory > Optical
| Gloss | |
Brightness is an optical property that describes how well a surface reflects light in the specular direction. It is of great practical importance for many applications. Reflectance (or reflectance) is defined as the fraction of the intensity of the incident light at the interface (surface effect). Only highly polished metal mirrors have an almost total reflectance of 99.9%. If the reflectance is almost zero, the surface appears completely matt (0%). A material with reflection between these two extremes is called bright, in practically if the reflectance is almost zero, the surface appears completely matte the polished (smooth) surfaces have a high reflectance and appear bright to the eye. The brightness is responsible for the bright appearance of plastic films. The source of the reflection is scattered or scattered by diffraction. The brightness and diffusion light of the surrounding surface, which is often called brightness or contrast brightness. The main cause of opacity in polymers is light scattering and absorption. The more light that is scattered or absorbed, the more opaque the material becomes. The dispersion of light is a purely physical phenomenon: the insulating material that strikes the light induces dipolar oscillations in the material. Each induced dipole acts as a secondary source of light and emits photons in all directions, the so-called scattered light. This, in turn, reduces the intensity of the light transmitted directly. Pure light scattering will not cause loss of radiation energy. In the case of colored or filled plastic, the material absorbs a portion of the light, that is, the radiation is transformed into other forms of energy, such as the movement of the induced molecule (thermal energy). |  |
Mate grade | |
There is a scaling of different levels in the brightness of a finish: this can be extra matte, matt, satin or glossy. In addition there are also intermediate degrees between them. The same color with different levels of brightness may seem very different. The gloss level of a finish is measured with a glossometer or glossimeter and is expressed in GU (Gloss Unit). Matte finishes range from 0-12Gu to 65Gu (60 en angle measurement); serve as a reference that a high gloss finish is above 90-100 Gu. Extra Mate <12 Gu Mate <12 - 35 Gu Satin <50 - 80 Gu Brightness> 90 Gu 20 ° angle - high brightness 45 ° angle - intermediate to low brightness 60 ° angle - intermediate brightness |  |