Retro-reflective Testing
At Viz Reflectives we have the facility to carry out inhouse performance testing of our M-Lite retro-reflective films and temporary road signs to the standard EN 12899-1-2007.
Using a range of reflectivity measuring equipment, allows us to check the measurements of reflectivity over the range of angles, plus measurements X and Y of the retro-reflected night-time colour coordinates.
Laundry Testing
Recently installed in our laboratory, is a Wascator FOM71-CLS and Electrolux TE 1120 Dryer, enabling in house laundry testing of our VizLite and VizLite DT materials to ISO 6330:2012.
This equipment combined with the testing capabilities of our retro-reflective measuring equipment, means that we can offer our customers testing of all sixteen angles of reflectivity before and after washing.
Flame Resistance Testing
Also commissioned and installed is the latest Flexiburn cabinet which facilitates inhouse performance testing to fire standards such EN469:2020, including limited flame spread and edge burn before and after washing.
This piece of equipment will also be used in product development and quality control of the VizLite DT products, manufactured in the UK.
How does VizLite DT Work?
Quantum Physics
On an atomic level when the electrons in an atom of phosphorescent pigment are exposed to photon energy in the form of UV light, they enter an excited state and move into a higher spin state. This Excitation of electrons to a higher state is accompanied with the change of a spin state.
Once in a different spin state, electrons cannot relax into the ground state quickly because the re-emission involves quantum mechanically forbidden energy state transitions. At this point the electrons return to the ground state releasing the stored energy as visible light. As these transitions occur very slowly in VizLite DT, absorbed radiation may be re-emitted at a lower intensity for up to eight hours after the original excitation.
Charging
The Strontium Aluminate phosphorescent crystals that are used to produce VizLite DT are formulated to meet Viz Reflectives requirements of a quick charge time, a bright “afterglow”, extended “afterglow” period and high laundry performance.
The following chart shows the different charging times for VizLite DT depending on the light conditions. The light intensity is measured in Lux which is the number of Lumens per square metre.
| Light Source | ||
|---|---|---|
| Clear Sunlight | >50,000 | 5 Minutes |
| Cloudy | 3,000 - 50,000 | 5 Minutes |
| Dusk | 1,000 | 8 Minutes |
| Fluorescent Office Lights | 500 | 10 Minutes |
