ND2.2 glass beads are high index refractive glass bead, used for “Enclosed-Lens” type retro-reflective articles, such as engineering grade film, super engineering grade film.
As for glass bead for film ,is used in for billboards, traffic sign boards, vehicle number plates, reflective stick sheets or industrial safe sign boards and so on.
ND2.2 glass bead can not exposed into air directly, otherwise, there is weak reflective brightness. It should has a layer thin film on the beads surface. For printing usage, this retro reflective glass bead is more suitable used in rain day or under water.
ND2.2 glass bead Technical Data
|
Composition |
TiO 2-BaO-ZnO GLASS |
|
Refractive Index |
2.2±0.1Nd |
|
Specific Gravity |
4.5±0.2 g/cm3 |
|
Color |
White to Slight Yellow |
|
Form: |
Fine spheres powder |
|
Size |
60-80um;50-65um; 45-55um;38-45um; 20-30um; (can be provided by specific request) |
|
Roundness |
≥95% |
|
Opacity |
≤3% |
“Enclosed-Lens” type retro-reflective articles: A cover film disposed in front to the glass bead so that said bead do not exposed in air. Engineering Grade and Super Engineering Grade belong to this type. Said glass beads are 2.2nd glass bead